How Many Eyes Does A Fly Have

It’s springtime which means sunshine, picnics and flies. But this episode might make you think twice about reaching for that fly swatter. Flies are amazing creatures that have the fastest visual systems in the world, use gyroscopes for precision flying, and can see almost 360 degrees.

To understand why a fly is so unique, just look into their eyes. A fly has two large eyes that cover most of their head. Each eye consists of at least 3,000 individual lenses called ommatidia. With all of these “simple eyes” flies can’t focus on a single object like we do. Instead, they see the world as a kind of mosaic.

This makes them really good at spotting quick moving objects like a fly swatter. And their field of view is almost a full 360 degrees. So no use sneaking up from behind. Dr. Michael Dickinson is a bio-engineer and neuroscientist at Cal Tech and a leading expert on American flies.

1. On this episode he shares his love for flies and explains what makes them so special – from their eyes to their lightning fast neurological systems.
2. So next time you might want to reach for that magnifying glass rather than the fly swatter – you’ll be amazed at what you see.
3. Recommended links from Chris Morgan : Dickinson Lab Michael Dickinson: How a fly flies Understanding the neurological code behind how flies fly The Lab: Gwyneth Card + Escape Behavior THE WILD is a production of KUOW in Seattle in partnership with Chris Morgan and Wildlife Media.

It is produced by Matt Martin and edited by Jim Gates, It is hosted, produced and written by Chris Morgan. Fact checking by Apryle Craig, Our theme music is by Michael Parker,

Do flies have 2 eyes or thousands?

They have two prominent compound eyes composed of 3,000 to 6,000 tiny simple eyes (lenses) working together to make one visual masterpiece. A House fly also has three extra simple eyes centrally between the two prominent eyes.

Does a fly have 3 eyes?

Flies have a mobile head with a pair of large compound eyes on the sides of the head, and in most species, three small ocelli on the top.

How many times can a fly see?

Faster vision – Flies have compound eyes. Rather than collecting light through a single lens that makes the whole image – the strategy of human eyes – flies form images built from multiple facets, lots of individual lenses that focus incoming light onto clusters of photoreceptors, the light-sensing cells in their eyes.

1. Essentially, each facet produces an individual pixel of the fly’s vision.
2. A fly’s world is fairly low resolution, because small heads can house only a limited number of facets – usually hundreds to thousands – and there is no easy way to sharpen their blurry vision up to the millions of pixels people effectively see.

But despite this coarse resolution, flies see and process fast movements very quickly. Tiny hexagonal ‘facets’ take in light, and the photoreceptors beneath them process it in quick flashes. Ecole Polytechnique Fédérale de Lausanne, Switzerland, CC BY We can infer how animals perceive fast movement from how quickly their photoreceptors can process light.

1. Humans discern a maximum of about 60 discrete flashes of light per second.
2. Any faster usually appears as steady light.
3. The ability to see discrete flashes depends on the lighting conditions and which part of the retina you use.
4. Some LED lights, for example, emit discrete flashes of light quickly enough that they appear as steady light to humans – unless you turn your head.

In your peripheral vision you may notice a flicker. That’s because your peripheral vision processes light more quickly, but at a lower resolution, like fly vision. Remarkably, some flies can see as many as 250 flashes per second, around four times more flashes per second than people can perceive.

If you took one of these flies to the cineplex, the smooth movie you watched made up of 24 frames per second would, to the fly, appear as a series of static images, like a slide show. But this fast vision allows it to react quickly to prey, obstacles, competitors and your attempts at swatting. Our research shows that flies in dim light lose some ability to see fast movements,

This might sound like a good opportunity to swat them, but humans also lose their ability to see quick, sharp features in the dark. So you may be just as handicapped your target. When they do fly in the dark, flies and mosquitoes fly erratically, with twisty flight paths to escape swats.

Can flies see 360?

Learn more – Flies look at the world in quite a different way than we do. Their eyes are made up of thousands of individual visual receptors called ommatidia, each of which is a functioning eye in itself. Therefore, a fly’s vision is comparable to a mosaic, with thousands of tiny images that converge together to represent one large visual image.

The more ommatidia a compound eye contains, the clearer the image it creates. A fly’s eyes are immobile, but their position and spherical shape give the fly an almost 360-degree view of its surroundings. Fly eyes have no pupils and cannot control how much light enters the eye or focus the images. Flies are also short-sighted — with a visible range of a few yards, and have limited color vision (for example, they don’t discern between yellow and white).

On the other hand, a fly’s vision is especially good at picking up form and movement. Because a fly can easily see motion but not necessarily what the moving object is, they are quick to flee, even if it is harmless. A Q&A with Nikon Small World winner Dr.

1. Razvan Cornel Constantin.
2. What is the subject matter of your winning image and why did you choose this image? It is a closeup of a housefly decaying eye.
3. The image doesn’t just show the structure of a compound eye but also what happens when the eye dries and the individual “cells” start to change color.

It’s always a challenge to shoot at high magnification, and I thought this is a result worth sharing. The pattern is also very photogenic. What are the special techniques and/or challenges faced in creating this photomicrograph? For this picture I used focus stacking, which is challenging at high magnification because of the vibration of the camera and the rest of the equipment.

At 50:1 the working distance is small for reflected light, so getting enough light onto the subject is always a struggle. Also, getting it diffused in such a way that the individual lenses on the eye reflect it in a pleasing way without losing detail was tricky. What is your primary line of work? I make my living as an automotive engineer, but when I get home and pick up my camera, that’s when the job stops and the passion begins.

How long have you been taking photographs through a microscope? What first sparked your interest in photomicrography? I’ve been using microscopes for almost four years, gradually increasing the magnification as I got more experienced. I’ve always had a passion for wildlife, especially insects.

1. As soon as I could afford it, I got a camera and macro lens.
2. While shooting macro you always crave for more magnification and that’s why I got into photomicrography.
3. Do you tend to focus your microscopy toward a specific subject matter or theme? If so, why? I can’t say that I have a specific subject, I find that almost any subject has at least a few interesting poses when put under a microscope at high magnification.

As long as you can’t see it with the naked eye you always get that wow factor. : Housefly compound eye pattern | 2019 Photomicrography Competition

How many hearts do flies have?

The dorsal vessel in a fly is a single tubular structure extending from the head to the abdomen. It consists of two primary regions : the aorta, responsible for transporting hemolymph forward into the head, and the heart, which pumps hemolymph towards the abdomen.

Do flies get blind?

Purdue research illuminates why blue light makes old flies go blind 12/18/2017 | For decades, scientists have known that blue light will make fruit flies go blind, but it wasn’t clear why. Now, a Purdue University study has found how this light kills cells in the flies’ eyes, and that could prove a useful model for understanding human ocular diseases such as macular degeneration.

1. Vikki Weake, assistant professor in Purdue’s Department of Biochemistry, studies aging in the eye and the genetic mechanisms that lead to vision loss as people age.
2. Working with Donald Ready, a professor in Purdue’s Department of Biological Sciences, and Daniel Leon-Salas, an associate professor in the School of Engineering Technology, Weake led a team that compared older fruit flies susceptible to vision loss when exposed to blue light with young flies that are immune to the effects of that light.

“When you put older flies in the presence of really strong blue light, you basically overload the neurons and the photoreceptor cells in their eyes die,” said Weake, whose findings were published in the journal npj Aging and Mechanisms of Disease, a partner journal of Nature. Purdue University assistant professor Vikki Weake led a study on vision loss in flies. The results, which were published in a scientific journal, could prove useful in understanding human ocular diseases. (Purdue University photo/Tom Campbell) Weake’s team found that retinal degeneration in the flies strongly correlated with lipid peroxidation, oxidative damage caused to lipids by reactive oxygen species.

Young flies showed no signs of lipid peroxidation. “Cells in the eye are high in polyunsaturated fatty acids, and that makes those cells highly sensitive to this type of damage,” Weake said. “That makes this a very dangerous environment.” The researchers could reduce the lipid peroxidation by feeding strong antioxidants to the flies.

And they were also able to stop the process entirely by overexpressing a protein called Cytochrome b5, which transports electrons to enzymes within cells. The authors propose that Cytochrome b5 stimulates the activity of enzymes that detoxify reactive oxygen species.

• Cytochrome b5 overexpression rescues the blue light-induced retinal degeneration,” Weake said.
• It strongly suggests that the cause of cell death in this blue light model is the lipid peroxidation.
• Reducing levels of other reactive oxygen species such as hydrogen peroxide, didn’t show such a strong effect.” Weake believes fruit flies offer a model for studying degenerative ocular diseases in humans, including determining how genetic therapies or drugs could slow or stop vision loss.

While blue light affects fly and human eyes differently, lipid peroxidation is believed to play an important contributory role in the development of human retinal diseases such as age-related macular degeneration. Weake’s research will continue to explore how blue light affects gene regulation in photoreceptor cells to identify pathways that might be used to help these cells to survive under stressful light conditions, or under more long-term chronic stress during aging.

Do flies sleep at night?

Fly sleep – Decades of research in circadian rhythms in Drosophila had clearly shown that fruit flies are active and move around during the day, much less so during the night. However, only in 2000 it became clear that the sustained periods of immobility during the night represented a sleep-like state and not just quiet wakefulness, because they were associated with a reversible increase in arousal threshold. Two independent groups of researchers provided the conclusive proof that Drosophila sleep indeed shares all the fundamental features of mammalian sleep ( Hendricks et al.2000 ; Shaw et al.2000 ). Sleep is a complex integrative phenomenon that cannot be defined using one single criterion. Therefore in flies, like in mammals, sleep was defined using multiple criteria, the first of which is behavioral quiescence. Fly sleep behavior was first monitored using 3 methods: visual observation, an ultrasound activity monitoring system, and an automatic infrared system ( Hendricks et al.2000 ; Shaw et al.2000 ). All provided similar results and confirmed that during the night flies show sustained periods of complete immobility that can last several hours. The most critical feature of sleep, however, is not immobility, but the presence of a reduced ability to respond to the external world. This decreased responsiveness is reversible, a feature that allows sleep to be distinguished from coma. Most importantly, an increase in arousal threshold distinguishes sleep from quiet wakefulness. Arousal thresholds in flies have been measured using vibratory, visual, or auditory stimuli ( Shaw et al.2000 ; Nitz et al.2002 ; Huber et al.2004 ). In all cases it was found that flies that had been moving around immediately before the stimulus readily responded to low and medium stimulus intensities. By contrast, flies that had been behaviorally quiescent for 5 min or more rarely showed a motor response, although they quickly responded when the stimulus intensity was increased. Thus, sleep can be operatively defined in flies as any period of behavioral quiescence longer than 5 minutes. Sleep is highly regulated according to 2 processes: the circadian process and the homeostatic process ( Borbely 1982 ). The circadian regulation is responsible for the change in sleep propensity that is tied to the time of day, with obvious adaptive advantages. Flies are diurnal animals and sleep mainly at night, even when kept in constant darkness ( Shaw et al.2000 ). In mammals the circadian and homeostatic regulation of sleep can be dissociated ( Dijk and Lockley 2002 ) ( Cajochen et al.2002 ), at least to some extent. For instance, rats in which the central circadian clock has been destroyed by complete lesions of the suprachiasmatic nucleus no longer sleep in consolidated periods during the day (rats, unlike flies, are nocturnal) but rather show recurring episodes of sleep, lasting 1–3 hours each, across the 24-hour cycle ( Mistlberger et al.1983 ) ( Tobler et al.1983 ). When allowed to sleep after several hours of sleep deprivation, however, these rats still show a sleep rebound. A similar dissociation can be seen in flies in which the central circadian clock has been genetically destroyed by a mutation in one canonical circadian gene, e.g. cycle, period, or Clock ( Shaw et al.2000 ). These mutant flies sleep across the entire 24 hour period rather than just at night. However, after 24 hours of sleep deprivation, they still show a sleep rebound ( Shaw et al.2000 ). The homeostatic process reflects sleep pressure depending on the length of prior waking: the longer one stays awake, the longer and more intensively one sleeps ( Borbely 1982 ). This homeostatic component represents the essential aspect of sleep whose function remains mysterious. In flies, like in rodents and humans, sleep deprivation is followed by a sleep rebound characterized by an increase in the duration and/or in the intensity of sleep ( Huber et al.2004 ). Like in mammals, most of this sleep rebound occurs immediately after the end of the sleep deprivation period, is more pronounced after longer (12–24 hours) than after shorter (6 hours) periods of sleep loss, and the recovered sleep only represents a fraction of what was lost. Importantly, there is no increase in sleep duration when flies are subjected to 12 hours of the same stimulation during the day (when they are normally awake), ruling out non-specific effects. In mammals, sleep after sleep deprivation is also richer in slow-wave activity, a well-characterized EEG marker of sleep intensity and sleep pressure, and is less fragmented, i.e. there are fewer periods of brief awakenings during sleep ( Tobler 2005 ). In mammals, the increase in SWA after sleep deprivation is negatively correlated with the decrease in the number of brief awakenings ( Franken et al.1991 ). Sleep fragmentation as measured by the number of brief awakenings is also reduced in flies after sleep deprivation ( Huber et al.2004 ). Finally, in flies the recovery sleep that follows sleep deprivation is associated with a further increase in arousal threshold relative to baseline sleep, another indication that its intensity is increased ( Huber et al.2004 ). The ability of flies to move away from a noxious stimulus is impaired after 24 hours of sleep deprivation. This occurs despite the fact that sleep deprived flies, during testing, do not show an overall decrease in their spontaneous locomotor activity, ruling out non-specific effects of fatigue ( Huber et al.2004 ). It is still unknown whether sleep deprivation also affects the acquisition and/or the maintenance of memory, although it is clear that at least some short-sleeping mutants have impaired memory (see below). Fly sleep seems to be sensitive to at least some of the same stimulants and hypnotics that modulate behavioral states in mammals. When given caffeine ( Shaw et al.2000 ) ( Hendricks et al.2000 ), modafinil ( Hendricks et al.2003 ), or amphetamines ( Andretic et al.2005 ), flies stay awake longer. By contrast, when fed with antihistamines, they go to sleep earlier ( Shaw et al.2000 ). Other similarities between fly and human sleep are present at the molecular level. Hundreds of transcripts change their expression in the rat, mouse, and sparrow brain between sleep and wakefulness, suggesting that in both birds and mammals sleep and wakefulness differ significantly at the molecular level ( Cirelli et al.2004 ) ( Terao et al.2006 ; Mackiewicz et al.2007 ; Jones et al. in press ). Using transcriptomics approaches such as mRNA differential display and microarray technology, which assess the expression of thousand of genes simultaneously, it was found that this is also the case in fruit flies ( Cirelli et al.2005a ). As in rats, transcripts with higher expression in wakefulness and in sleep belong to different functional categories, and in several cases these groups overlap with those previously identified in rats. Wakefulness-related genes code for transcription factors and for proteins involved in synaptic plasticity, stress response, immune response, glutamatergic transmission, and carbohydrate metabolism. Sleep-related transcripts include glial genes and several genes involved in lipid metabolism. In most mammalian studies, sleep is defined using behavioral as well as electroencephalographic (EEG) criteria: slow waves and spindles characterize non-rapid eye movement (NREM) sleep, while a high-frequency low amplitude EEG pattern with reduced muscle tone is present during REM sleep. Prolonged recordings of local field potentials (LFPs) from the medial part of the fly brain have been obtained in non-anaesthetized flies ( Nitz et al.2002 ). LFPs from awake, moving fruit flies are dominated by spike-like potentials ( Nitz et al.2002 ). These spikes largely disappear during the quiescent state when arousal thresholds are increased. Targeted genetic manipulations demonstrated that LFPs had their origin in brain activity and were not merely an artifact of movement or electromyographic activity ( Nitz et al.2002 ). Thus, like in mammals, wakefulness and sleep in fruit flies are accompanied by different patterns of brain electrical activity. However, the specific EEG features of mammalian sleep depend on the anatomy of the thalamocortical system, which does not exist in flies. It is not surprising, therefore, that sleep-related EEG events such as slow waves and spindles, which dominate the EEG during NREM sleep in birds and mammals, are not seen in flies. Also, electrical activity in neurons undergoes well characterized changes in mammals, including the occurrence, during NREM sleep, of slow (<1 Hz) oscillations in membrane potential. Whether such slow oscillations are also present in flies remains to be determined. In the same fly, daily sleep amount and the timing of the major sleep phase are extremely consistent from one day to another ( Cirelli 2003 ). The same parameters, however, vary significantly within individuals of the same fly population, even when age and housing conditions are kept constant. The response to sleep deprivation also shows a strong interindividual variability, both in terms of sleep rebound as well as in terms of the effects on performance. This is why the characterization of sleep in any wild-type or mutant fly line requires the analysis of several individuals. Also, for the same reason, sleep cannot be measured at a population level, but needs to be quantified in individual flies. Recent studies in humans have also brought new attention to the issue of interindividual variability in sleep amount and in the response to sleep loss ( Van Dongen et al.2005 ). Importantly, in humans both sleep duration and the response to sleep deprivation show high intraindividual consistency, suggesting that they are trait-like ( Tucker et al.2007 ). There are also features that distinguish fly sleep from mammalian sleep. Most animals including humans assume a typical posture when they go to sleep. Flies, however, do not appear to do so, at least not when their behavior is recorded inside the small glass tubes routinely used in sleep studies. Thus, based on the fly posture, it is not possible to distinguish quiet waking from sleep (unless one measures arousal thresholds). Several mammals clearly also change their posture when transitioning from NREM to REM sleep, due to the loss of muscular tone. As mentioned above, no study in flies so far has been able to detect different phases of sleep, similar to the NREM and REM phases in mammalian sleep, but a more accurate behavioral analysis, in more naturalistic conditions, has still to be performed.

Do flies have 50 eyes?

While you might think that the fly has two large eyes, it actually has five eyes. The two that we can see are its compound eyes. Then, there are three smaller eyes on the top of the head. The smaller eyes are called ocelli and while the compound eyes are complex, the ocelli simply process movement.

Do flies have a purpose?

Eat shit and fly – Flies quite literally eat poo but they also clean up other waste too, helping clean-up after us humans. They can eat our household waste and divert it from going into landfill. The black soldier fly, for example, can have up to 600 larvae, with each of these quickly consuming half a gram of organic matter per day.

This small family can eat an entire household green waste bin each year. Flies act as scavengers consuming rotting organic matter so we don’t have to deal with it which is a very important role in the environment. If it wasn’t for flies, there would be rubbish and dead animal carcasses everywhere. A lovely thought to mull over while you’re grilling.

Flies turn poo and rotting carcasses into stock feed, and live bird, frog and lizard food for free. Pretty cool if you think about it.

Can flies feel pain?

Other pain indicators – The framework we used to evaluate evidence for pain in different insects was the one that recently led the UK government to recognise pain in two other major invertebrate groups, decapod crustaceans (including crabs, lobsters, and prawns) and cephalopods (including octopuses and squid), by including them in the Animal Welfare (Sentience) Act 2022.

• The framework has eight criteria, which assess whether an animal’s nervous system can support pain (such as brain-body communication), and whether its behaviour indicates pain (like motivational trade-offs).
• Flies and cockroaches satisfy six of the criteria.
• According to the framework, this amounts to “strong evidence” for pain.

Despite weaker evidence in other insects, many still show “substantial evidence” for pain. Bees, wasps, and ants fulfil four criteria, while butterflies, moths, crickets, and grasshoppers fulfil three. Beetles, the largest group of insects, only satisfy two criteria.

1. But, like other insects that received low scores, there are very few studies on beetles in this context.
2. We found no evidence of any insect failing all the criteria.
3. Our findings matter because the evidence for pain in insects is roughly equivalent to evidence for pain in other animals which are already protected under UK law.

Octopuses, for example, show very strong evidence for pain (seven criteria). In response, the UK government included both octopuses and crabs in the Animal Welfare (Sentience) Act 2022, legally recognising their capacity for pain. The UK government set a precedent: strong evidence of pain warrants legal protection.

1. At least some insects meet this standard, so it is time to shield them.
2. For starters, we recommend including insects under the Animal Welfare (Sentience) Act 2022, which would legally acknowledge their capacity to feel pain.
3. But this law only requires the government to consider their welfare when drafting future legislation.

If we want to regulate practices such as farming and scientific research, the government needs to extend existing laws. For example, the Animal Welfare Act 2006, which makes it an offence to cause “unnecessary suffering” to animals covered by the act.

• This may lead to insect farms, like conventional farms, minimising animal suffering and using humane slaughter methods.
• The Animals (Scientific Procedures) Act 1986 regulates the use of protected animals in any experimental or other scientific procedure that may cause pain, suffering, distress or lasting harm to the animal.

Protecting insects under this act, as octopuses already are, would regulate insect research, reducing the number of insects tested and ensuring that experiments have a strong scientific rationale. Finally, pesticides are a huge welfare concern for wild insects.

Do flies have good memory?

Fruit Flies Can Learn, and Just Like Us, They Forget – Neuroscientists, scientists who study how the brain works, have been very interested in learning how memories are stored in the brain. However, neuroscientists have only very recently begun to study forgetting.

1. To understand how the human brain forgets, we can study how fruit flies forget.
2. Fruit flies are awesome, small insects that are great for scientific research.
3. They grow very fast in the laboratory and we can produce as many flies as we want.
4. Their genetic material, or, is also very easy to change.
5. DNA is a very long, thin chemical that contains the instructions to build any living organism.

DNA contains genes, which are sections of the DNA that tell a cell how to make a, The instructions contained in the DNA of the flies can be changed in the lab. Genes can be removed, making a mutant fly. In this way, we can explore what happens to a fly if a piece of these instructions is removed.

Flies also have small brains that are much easier to explore than a human or mouse brain. Although you will find this surprising, human brains and fruit fly brains have many things in common. Amazingly, fruit flies can learn simple tasks, they can form memories, and they can also forget, just as we do.

Just like human brains, fly brains are made up mainly of cells called neurons. Neurons are the cells that transmit information across the brain. Groups of neurons, like a computer, can form circuits that process and store information. To study how flies forget, we first teach the flies a simple task.

Then we give the flies a test to see how much they remember and how much they have forgotten. What do we teach them and how do we test their memory? Flies have a very powerful sense of smell. For this reason, we give the flies odors (or different smells) to learn. We first allow the flies to smell an odor and at the same time we give them a mild shock of electricity.

This causes the flies to learn that they will feel a bit of pain when they smell the odor. Then we test how much the flies remember by placing the flies in a tiny area with the odor that they smelled when they were shocked. If they remember well, the flies run away from the odor, thinking they will be shocked again—in this case, they score an A+ on this test.

Figure 1 Fruit flies can learn simple tasks, they form memories, and they can also forget. During the learning session, flies are allowed to smell an odor and at the same time they receive a mild shock of electricity. Flies learn that they will feel a bit of pain when they smell the odor. Then, memory is tested to see how much the flies remember by placing the flies in a tiny area with the odor that they smelled during the learning session. If they remember well, the flies run away from the odor and they score an A. If they have forgotten and do not run away from the odor, they score an F.

Using this simple experiment, we and other neuroscientists have found a new group of neurons in the fly brain that form a circuit in charge of making new memories. These neurons work together to learn and store a new memory. Once the memory is stored, these same neurons continue to work and this begins to slowly erase the memory that was just formed.

• If the new memories are not important, they will be gradually eliminated by the activity of this circuit, until they are completely erased,
• However, if the information learned is really important—like the location of a new source of food—or if the memory is recalled an hour or two later, then the memory will be “protected” from forgetting.

The neurons that cause forgetting use a brain molecule called, Interestingly, mutant flies that do not have one of the genes responsible for interpreting the dopamine signal, called dopamine receptor, remember the odor they have learned for a very long time.

• Basically, these flies have a long-lasting memory because they cannot forget.
• Another gene that is very important for forgetting unimportant memories is named Rac,
• The Rac gene makes a protein that speeds up changes to the skeleton of most cells.
• It is thought that changes in the skeleton of neurons are very important to create the structures that hold new memories.

Rac speeds up the chemical reactions that undo these changes in the skeleton and in doing so causes forgetting,

How long can a fly remember?

How fruit flies form orientation memory A small group of ring-shaped neurons (green) in the central brain of the fly (magenta) are the seat of visual orientation memory. Credit: AG Strauss, JGU Insects have a spatial orientation memory that helps them remember the location of their destination if they are briefly deflected from their route.

1. Researchers at Johannes Gutenberg University Mainz (JGU) have examined how this working memory functions on the biochemical level in the case of Drosophila melanogaster.
2. They have identified two gaseous messenger substances that play an important role in signal transmission in the nerve cells, i.e., nitric oxide and hydrogen sulfide.

The short-term working memory is stored with the help of the messenger substances in a small group of ring-shaped neurons in the ellipsoid body in the central brain of Drosophila. Flies form a memory of locations they are heading for. This memory is retained for approximately four seconds.

This means that if a fly, for instance, deviates from its route for about a second, it can still return to its original direction of travel. “This recall function represents the key that enables us to investigate the biochemistry of working memory,” said Professor Roland Strauss of JGU’s Institute of Developmental Biology and Neurobiology.

The researchers are particularly interested in learning how a network in an insect’s brain can build such an orientation memory and how exactly the related biochemical processes function. Working on her doctoral thesis, Dr. Sara Kuntz found to her surprise that there are two gaseous neurotransmitters that are involved in information transmission.

These gaseous messenger substances do not follow the normal route of signal transmission via the synaptic cleft but can diffuse directly across the membrane of neighboring without docking to receptors. It was already known that, for the purposes of memory formation, nitric oxide (NO) is essential for the feedback of information between two nerve cells.

What has now emerged is that NO also acts as a secondary messenger substance in connection with the amplification of the output signals of neurons. A small group of ring-shaped neurons (green) in the ellipsoid body of the fly (magenta in the center of the image) are the seat of visual orientation memory. The scale bar shown at the bottom right of the image is equivalent to 25 micrometers (µm) in length.

Credit: AG Strauss, JGU This function of nitric oxide can apparently also be assumed by (H2S). Although researchers were aware that this gas plays a role in the control of blood pressure, they had no idea that it had another function in the nervous system. “It has long been assumed that hydrogen sulfide was harmful to the nervous system.

But the results of our research show that it is also of importance as a secondary messenger substance,” explained Strauss. “We were absolutely astonished to discover that there are two gaseous neurotransmitters that are important to memory.”

Can flies listen to you?

Abstract – Studying the auditory system of the fruit fly can reveal how hearing works in mammals. Research Organism: D. melanogaster, Human, Mouse Related research article Li T, Giagtzoglou N, Eberl D, Nagarkar-Jaiswal S, Cai T, Godt D, Groves AK, Bellen HJ.2016. The myosin motor proteins play a variety of roles inside cells, such as transporting cargo around the cell and maintaining the structure of the cell’s internal skeleton. Myosins also make important contributions to our sense of hearing, which can be revealed by studying conditions such as Usher syndrome (a severe sensory disorder that causes congenital deafness and late-onset blindness).

• In humans and other mammals, two myosin proteins called myosin VIIa and myosin IIa have been linked to deafness, but we do not understand how these proteins interact.
• Now, in eLife, Andrew Groves, Hugo Bellen and co-workers – including Tongchao Li of Baylor College of Medicine as first author – report evidence of a conserved molecular machinery in the auditory organs of mammals and the fruit fly Drosophila ( Li et al., 2016 ).

Furthermore, the screen identified an enzyme called Ubr3 that regulates the interaction of the two myosins in Drosophila, Auditory organs convert the mechanical energy in sound waves into electrical signals that can be interpreted by the brain. In mammals, this conversion happens in “hair cells” in the inner ear.

1. These cells have thin protrusions called stereocilia on their surface, and the tips of these stereocilia contain ion channels called MET channels (which is short for mechanoelectrical transduction channels).
2. Five proteins associated with the most serious form of Usher syndrome – known as USH1 – are key components of the molecular apparatus that enables the MET channels to open and close in response to mechanical force.

The USH1 proteins are restricted to the tips of the stereocilia, where they form a complex ( Figure 1 ; Prosser et al., 2008 ; Weil et al., 1995 ). Two of the USH1 proteins work together to join the tip of each stereocilium to its next-highest neighbor, forming bundles of stereocilia ( Kazmierczak et al., 2007 ). How sound is detected in mammals and Drosophila, ( A ) Schematic diagram showing a bundle of three stereocilia protruding from a mammalian hair cell. The deflection of the stereocilia by sound waves results in the opening of the MET channels (pale blue cylinders) and the generation of an electrical signal that travels along sensory neurons to the brain.

The motor protein myosin VIIa transports USH1 proteins to maintain the structural integrity of stereocilia. Figure adapted from Figure 1e, Richardson et al. ( Richardson et al., 2011 ). ( B ) Flies use antennae made up of three segments to detect sound. The schematic diagram on the left shows the second segment: there are MET channels for each neuron (outlined in green) and myosin II and myosin VIIa are enriched at the tip of scolopale cells, where USH1 proteins, Ubr3 and Cul1 form a protein complex.

A Pcdh15 protein in the USH1 complex anchors the tip of scolopale cell to the cap cell. When a sound wave hits the antenna, the joint between the second and the third segment is deflected (right panel) and the resultant stretching of the second segment opens the MET channels.

This depolarizes the sensory neurons, causing them to signal to the brain. Figure adapted from Figure 1b, Boekhoff-Falk and Eberl ( Boekhoff-Falk and Eberl, 2014 ). Flies do not have ears as such, but they are still able to detect sounds through their antennae. Despite the auditory organs of flies and mammals having different structures, they work in a similar way.

In Drosophila, structures called scolopidia, which are found suspended in the second segment of the antenna, sense sound vibrations relayed from the third segment ( Figure 1 ). Cells called cap cells and scolopale cells anchor the tip of the scolopidia to the joint between the second and third segments.

The scolopale cells also secrete a protein to form the dendritic cap that connects a sensory neuron with the joint. This structure allows the mechanical forces produced by the sound waves to be transmitted to the neuron, activating the MET channels and causing the sensory neuron to produce an electrical signal.

Inactivating the gene that produces myosin VIIa causes the scolopidia to detach from the joint and causes the protein that forms the dendritic cap to be distributed abnormally ( Todi et al., 2005 ; Todi et al., 2008 ). Now, Li at al. – who are based at Baylor, the Texas Children’s Hospital, the University of Iowa and the University of Toronto – show that inactivating the gene that encodes the enzyme Ubr3 has the same effect.

Ubr3 is a type of E3 ubiquitin ligase. These enzymes regulate a number of cell processes by helping to join small proteins called ubiquitins onto other proteins. Using a forward genetic screen, Li et al. found that Ubr3 is enriched in the tips of scolopidia, particularly at the ends of the sensory neurons and in the scolopale cells closest to the joint between the second and third segments.

Li et al. show that Ubr3 and another E3 ubiquitin ligase called Cul1 negatively regulates the addition of a single ubiquitin to myosin II. This means that the loss of Ubr3 increases the rate of the “mono-ubiquitination” of myosin II, which leads to stronger interactions between myosin II and myosin VIIa.

Importantly, the mono-ubiquitination of myosin II and the interaction between myosin II and myosin VIIa helps to ensure that they (and also the fly equivalents of Usher proteins) localize correctly to the scolopidial tip. Thus, Ubr3 is crucial for maintaining the structure and function of scolopidia.

Overall, the results presented by Li et al. argue that a conserved model underlies hearing in both Drosophila and mammals. In this model, the negative regulation of mono-ubiquitination of myosin IIa (or myosin II in the case of Drosophila ) by Ubr3 promotes the formation of the myosin IIa-myosin VIIa complex (or the myosin II-myosin VIIa complex in Drosophila ).

• The myosin complex then transports the USH1 protein complex to the tips of the stereocilia (or scolopidia) to establish the sound-sensing structure that enables the MET channels to work.
• Using the power of fly genetics, Li et al.
• Have identified new components involved in the development and function of auditory organs, and linked them to genes known to play a role in human deafness.

Undoubtedly, future studies of these deafness-related genes in the Drosophila auditory organ will bring more insights into the interplay among the molecules, including the USH1 proteins, that are important for hearing.

Are flies intelligent?

As they annoyingly buzz around a batch of bananas in our kitchens, fruit flies appear to have little in common with mammals. But as a model species for science, researchers are discovering increasing similarities between us and the miniscule fruit-loving insects.

1. In a new study, researchers at the University of California San Diego’s Kavli Institute for Brain and Mind (KIBM) have found that fruit flies ( Drosophila melanogaster ) have more advanced cognitive abilities than previously believed.
2. Using a custom-built immersive virtual reality environment, neurogenetic manipulations and in vivo real-time brain-activity imaging, the scientists present new evidence Feb.16 in the journal Nature of the remarkable links between the cognitive abilities of flies and mammals.

The multi-tiered approach of their investigations found attention, working memory and conscious awareness-like capabilities in fruit flies, cognitive abilities typically only tested in mammals. The researchers were able to watch the formation, distractibility and eventual fading of a memory trace in their tiny brains.

1. Despite a lack of obvious anatomical similarity, this research speaks to our everyday cognitive functioning – what we pay attention to and how we do it,” said study senior author Ralph Greenspan, a professor in the UC San Diego Division of Biological Sciences and associate director of KIBM.
2. Since all brains evolved from a common ancestor, we can draw correspondences between fly and mammalian brain regions based on molecular characteristics and how we store our memories.” To arrive at the heart of their new findings the researchers created an immersive virtual reality environment to test the fly’s behavior via visual stimulation and coupled the displayed imagery with an infra-red laser as an averse heat stimulus.

The near 360-degree panoramic arena allowed Drosophila to flap their wings freely while remaining tethered, and with the virtual reality constantly updating based on their wing movement (analyzed in real-time using high-speed machine-vision cameras) it gave the flies the illusion of flying freely in the world.

1. This gave researchers the ability to train and test flies for conditioning tasks by allowing the insect to orient away from an image associated with the negative heat stimulus and towards a second image not associated with heat.
2. They tested two variants of conditioning, one in which flies were given visual stimulation overlapping in time with the heat (delay conditioning), both ending together, or a second, trace conditioning, by waiting 5 to 20 seconds to deliver the heat after showing and removing the visual stimulation.

The intervening time is considered the “trace” interval during which the fly retains a “trace” of the visual stimulus in its brain, a feature indicative of attention, working memory and conscious awareness in mammals. The researchers also imaged the brain to track calcium activity in real-time using a fluorescent molecule they genetically engineered into their brain cells.

This allowed the researchers to record the formation and duration of the fly’s living memory since they saw the trace blinking on and off while being held in the fly’s short-term (working) memory. They also found that a distraction introduced during training – a gentle puff of air – made the visual memory fade more quickly, marking the first time researchers have been able to prove such distractedness in flies and implicating an attentional requirement in memory formation in Drosophila,

“This work demonstrates not only that flies are capable of this higher form of trace conditioning, and that the learning is distractible just like in mammals and humans, but the neural activity underlying these attentional and working memory processes in the fly show remarkable similarity to those in mammals,” said Dhruv Grover, a UC San Diego KIBM research faculty member and lead author of the new study.

1. This work demonstrates that fruit flies could serve as a powerful model for the study of higher cognitive functions.
2. Simply put, the fly continues to amaze in how smart it really is.” The scientists also identified the area of the fly’s brain where the memory formed and faded – an area known as the ellipsoid body of the fly’s central complex, a location that corresponds to the cerebral cortex in the human brain.

Further, the research team discovered that the neurochemical dopamine is required for such learning and higher cognitive functions. The data revealed that dopamine reactions increasingly occurred earlier in the learning process, eventually anticipating the coming heat stimulus.

1. The researchers are now investigating details of how attention is physiologically encoded in the brain.
2. Grover believes the lessons learned from this model system are likely to directly inform our understanding of human cognition strategies and neural disorders that disrupt them, but also contribute to new engineering approaches that lead to performance breakthroughs in artificial intelligence designs.

The coauthors of the study include Dhruv Grover, Jen-Yung Chen, Jiayun Xie, Jinfang Li, Jean-Pierre Changeux and Ralph Greenspan (all affiliated with the UC San Diego Kavli Institute for Brain and Mind, and J.-P. Changeux also a member of the Collège de France).

Do flies have feelings?

For decades, the idea that insects have feelings was considered a heretical joke – but as the evidence piles up, scientists are rapidly reconsidering. O One balmy autumn day in 2014, David Reynolds stood up to speak at an important meeting. It was taking place in Chicago City Hall – a venue so grand, it’s embellished with marble stairways, 75ft (23m) classical columns, and vaulted ceilings.

As the person in charge of pest management in the city’s public buildings, among other things, Reynolds was there to discuss his annual budget. But soon after he began, an imposter appeared on one of the walls – a plump cockroach, with her glistening black body contrasting impressively with the white paint.

As she brazenly sauntered along, it was as if she was mocking him. “Commissioner, what is your annual budget for cockroach abatement?” one councillor interrupted, according to a report in The Chicago Tribune, Cue raucous laughter and a mad scramble to eradicate the six-legged prankster.

No one would question the cockroach’s impeccable, though accidental, comic timing. But the incident is partly funny because we think of insects as robotic, with barely more emotional depth than lumps of rock. A cockroach that’s capable of being amused or playful – well, that’s just plain absurd. Or is it? In fact, there’s mounting evidence that insects can experience a remarkable range of feelings.

They can be literally buzzing with delight at pleasant surprises, or sink into depression when bad things happen that are out of their control, They can be optimistic, cynical, or frightened, and respond to pain just like any mammal would. And though no one has yet identified a nostalgic mosquito, mortified ant, or sardonic cockroach, the apparent complexity of their feelings is growing every year.

1. When Scott Waddell, professor of neurobiology at the University of Oxford, first started working on emotions in fruit flies, he had a favourite running joke – “that, you know, I wasn’t intending on studying ambition”, he says.
2. Fast-forward to today, and the concept of go-getting insects is not so outrageous as it once was.

Waddell points out that some research has found that fruit flies do pay attention to what their peers are doing, and are able to learn from them, Meanwhile, the UK government recently recognised that their close evolutionary cousins – crabs and lobsters – as sentient, and proposed legislation that would ban people from boiling them alive. For insects, golden tortoise beetles are unusually good at making their feelings clear (Credit: Alamy) An evolutionary imperative Insects are a jumbled group of six-legged invertebrate creatures with segmented bodies. There are more than a million different types, encompassing dragonflies, moths, weevils, bees, crickets, silverfish, praying mantis, mayflies, butterflies, and even head lice.

• The earliest insects emerged at least 400 million years ago, long before dinosaurs took their first tentative plods.
• It’s thought our last common ancestor with them was a slug-like creature which lived around 200 million years before that, and they’ve been diversifying ever since.
• Initially they ruled over the land as giants – some dragonflies were sparrowhawk-sized, with 2.3ft (70cm) wingspans – before evolving into the extraordinary array of arthropods around today, from flies with fake scorpion tails to fuzzy moths that resemble winged poodles,

As a result, they’re strikingly similar to other animals, and yet vividly different. Insects have many of the same organs as humans – with hearts, brains, intestines and ovaries or testicles – but lack lungs and stomachs. And instead of being hooked up to a network of blood vessels, the contents of their bodies float in a kind of soup, which delivers food and carries away waste.

The whole lot is then encased in a hard shell, the exoskeleton, which is made of chitin, the same material fungi use to build their bodies. The architecture of their brains follows a similar pattern. Insects don’t have the exact same brain regions as vertebrates, but they do have areas that perform similar functions.

For example, most learning and memory in insects relies on “mushroom bodies” – domed brain regions which have been compared to the cortex, the folded outer layer that’s largely responsible for human intelligence, including thought and consciousness.

Tantalisingly, even insect larvae have mushroom bodies, and some of the neurons within them remain for their whole lives – so it’s been suggested that adult insects that went through this stage might be able to remember some things that happened before they metamorphosed.) There’s mounting evidence that our parallel neural setups power a number of shared cognitive abilities, too.

Bees can count up to four, Cockroaches have rich social lives, and form tribes that stick together and communicate. Ants can even pioneer new tools – they can select suitable objects from their environment and apply them to a task they’re trying to complete, like using sponges to carry honey back to their nest,

Do animals suffer from post-traumatic stress? Why so many of us are casual spider-murderers The intelligent monster you should let eat you

However, though insect brains have evolved down an uncannily familiar path to our own, there is one crucial difference: while human ones are so engorged they sap 20% of our energy and drove women to evolve wider hips, insects have compacted their wits into packages several million times smaller – fruit flies have brains the size of a poppy seed, Asian honeybees scream with their bodies, by vibrating them (Credit: Alamy) So, even at first glance, it seems like insects would have the intellectual capacity for emotions. But does it make sense that they would have evolved them? Emotions are mental sensations that are usually linked to an animal’s circumstances – they’re a kind of mental programme that, when it’s set off, can change the way we act.

1. It’s thought that different emotions have emerged at different points in evolutionary history, but broadly they turned up to encourage us to behave in ways that will improve our ability to survive or reproduce, and ultimately, maximise our genetic legacy.
2. Geraldine Wright, a professor of entomology at the University of Oxford, gives the example of hunger, which is a state of mind that helps you to alter your decision-making in a way that’s appropriate, such as prioritising food-seeking behaviours.

Other emotions can be equally motivating – rumblings of anger can focus our efforts on rectifying injustices, and constantly chasing happiness and contentment nudges us towards achievements that keep us alive. All these things could also apply to insects.

An earwig that’s thrilled when it finds a nice damp crevice filled with delectable rotting vegetation will be less likely to starve or dry out, just as one that panics and plays dead when it’s disturbed has a better chance of escaping the jaws of a predator. “Let’s say you’re a bee that ends up in a spider web, and a spider is swiftly coming towards your across the web,” says Lars Chittka, who leads a research group that studies bee cognition at Queen Mary, University of London.

“It’s not impossible that the escape responses are all triggered without any kind of emotions. But on the other hand, I find it hard to believe that this would happen without some form of fear,” he says. A heretical idea When Waddell first started his own research group in 2001, he had a fairly simple goal in mind. It’s difficult to study pain in fruit flies because they don’t respond to morphine. However, they are partial to cocaine (Credit: Alamy) To begin with, Waddell cautiously chose the word “motivation”, rather than “hunger”, to describe the flies’ state of mind – he suggested that they were more motivated to find food if it had been withheld.

And people found it a little problematic,” says Waddell. Some other scientists felt that this was too anthropomorphic and preferred the term “internal states”. “So I often had arguments that I thought were essentially meaningless, because they were just playing with that word,” he says. Then in a matter of years, studying insect intelligence became significantly more fashionable – and all of a sudden the term “motivation” was abandoned, with researchers making the case for insects having “emotional primitives”, says Waddell.

In other words, they experienced what looked suspiciously like emotions. “I had always thought of these physiological changes that occur when animals are in deprivation states – deprived of sex, deprived of food – as subjective feelings of ‘hunger’ and ‘sex drive’,” says Waddell.

1. I’ve never really bothered labelling them as ’emotions’, pretty much because I thought it was going to get me into trouble.
2. But before I knew it, everyone seemed to be more comfortable using that,” Now that the suggestion insects have feelings is slightly less scandalous, the field has exploded in popularity – and this strange group of animals is becoming more relatable by the day.

But proving that an insect can experience an emotion remains tricky. Take the humble bumblebee. In humans, those who have experienced trauma are especially wired to expect the worst – and this has also been demonstrated in a number of other vertebrate animals, including rats, sheep, dogs, cows, cod and starlings. Cockroaches are highly sociable and copy the behaviour of their peers, just like humans do (Credit: Alamy) First, the researchers trained a troupe of bees to associate one kind of smell with a sugary reward, and another with an unpleasant liquid spiked with quinine, the chemical that gives tonic water its bitter taste.

Then the scientists divided their bee participants into two groups. One was vigorously shaken – a sensation bees hate, though it’s not actually harmful – to simulate an attack by a predator. The other bee crowd was just left to enjoy their sugary drink. To find out if these experiences had affected the bees’ mood, next Wright exposed them to brand new, ambiguous smells.

Those who had had a lovely day usually extended their mouthparts in expectation of receiving another snack, suggesting that they were expecting more of the same. But the bees who had been annoyed were less likely to react this way – they had become cynical.

Intriguingly, the experiment also hinted that the bees weren’t experiencing some alien, unrelatable form of pessimism, but a feeling that might not be too dissimilar to our own. Just like humans who are feeling exasperated, their brains had lower levels of dopamine and serotonin. (They also had lower levels of the insect hormone octopamine, which is thought to be involved in reward pathways.) Wright says many of the chemicals in our brains are highly conserved – they were invented hundreds of millions of years ago.

So an insect’s emotional experiences could be more familiar than you would think. “So from that perspective, yes, they may have diverged a little bit in terms of what they signal in which animal lineage, but it’s quite interesting,” she says. For example, Waddell’s research on fruit flies has found that their brains use dopamine just like ours do, to elicit feelings of reward and punishment.

So it’s very, very interesting that those things have, you know, convergently evolved and are sort of similar,” says Wright. “It means that that’s the best way of doing it.” Wright explains that her bee experiment doesn’t necessarily mean that all insects can experience pessimism or optimism, because bees are unusually social – community life at the hive is particularly cognitively demanding, so they’re considered intelligent for insects.

“But other insects probably do too,” she says. A clear message However, it would be surprising if insects could feel emotions but not express them at all. And tantalisingly, there are some hints that insects might be more relatable than you’d think here too. Industrial farming has turned much of the earth’s surface into a hostile environment for insects (Credit: Alamy) The problem is something Charles Darwin first considered in the late 19th Century. When he wasn’t pondering evolution or eating the “strange flesh” of the exotic fauna he discovered, he spent much of his time thinking about how animals communicate their feelings, and wrote up his findings in a little-known book.

1. In The Expression of the Emotions in Man and Animals, Darwin argues that – just like every other characteristic – the ways humans express their feelings would hardly have appeared out of nowhere in our own species.
2. Instead, our facial expressions, actions and noises are likely to have evolved via a gradual process over millennia.

Crucially, this means that there’s probably some continuity among animals, in terms of the ways that we display our emotional state to others. For example, Darwin noted that animals often make loud noises when they’re excited. Among the loud chattering of storks and the threatening rattling of some snakes, he cites the “stridulations”, or loud vibrations, of many insects, which they make when they’re sexually aroused.

Darwin also observed that bees change their hums when they’re cross. This all suggests that you don’t need to have a voice box to express how you’re feeling. Take the golden tortoise beetle, which looks like a miniature tortoise that’s been dipped in molten gold. It’s not actually covered in the element, but instead achieves its glamorous look by reflecting light off fluid-filled grooves embedded in its shell.

However, pick one of these living jewels up – or stress it out in any way – and it will transform before your eyes, flushing ruby-red until it resembles a large iridescent ladybird. Most research on the beetle has focused on the physics of how it achieves the colour switch, but intriguingly, it’s thought that the response is controlled by the insect, which may choose to change depending on what’s going on around it – rather than something that just happens passively. Insects have diversified to fill almost every conceivable niche, but they all share similar brains – so emotions in insects may be universal (Credit: Alamy) Then there’s the Asian honey bee. Around October each year – during what’s ominously referred to as the “slaughter phase” – they run the gauntlet of gangs of bee-decapitating giant hornets, also aptly known as “murder hornets”.

The wasps have a wide native range in Asia, from India to Japan, but scientists suspect they’re slowly invading other areas, with occasional sightings in North America, Their raids on bee hives can last for hours, and wipe out entire colonies – first, they cut up their worker bee victims into pieces, then they go for their offspring.

But the bees don’t go quietly. In work released earlier this year, scientists revealed that they scream – using an amplified, frantic version of their usual buzz. And though no one has conclusively tied the shrieks to an emotional response in the bees, the study’s authors noted in their paper that these “antipredator pipes” share similar acoustic features to the alarm calls of many other animals, from primates to birds to meercats, and might suggest that they’re fearful.

• A n uncomfortable truth However, the most contentious aspect of the inner lives of insects has to be pain.
• There’s lots of evidence in fruit fly larvae that they feel mechanical pain – if we pinch them, they try to escape – and the same is the case for adult flies as well,” says Greg Neely, a professor of functional genomics at the University of Sydney.

As always, proving that these unpleasant experiences are interpreted as emotional pain is another matter. “The issue is really the higher order aspect,” says Neely. However, there’s emerging evidence that they can indeed feel pain as we know it – and not only that, they can experience it chronically, just like humans.

• One basic clue to the former is that, if you train fruit flies to associate a certain smell with something unpleasant, they will simply run away whenever you present them with it.
• They link together the sensory context with the negative stimulus, and they don’t want that – and so they go away from it,” says Neely.

When fruit flies are prevented from escaping, they eventually give up and exhibit helpless behaviour that looks a lot like depression. But perhaps the most surprising results have emerged from Neely’s own research, which has found that injured fruit flies can experience lingering pain, long after their physical wounds have healed. Insect populations are declining accross the whole planet (Credit: Alamy) And though pain hasn’t yet been studied in a wide variety of insects, Neely thinks its likely that it would be similar across the board. “If we look at the overall architecture of how the brain is set up – the receptors, the ion channels and the neurotransmitters are all pretty similar,” says Neely, who points out that you can find examples of insects that are blind to these sensory signals, such as larvae that are in the middle of their transition to adulthood, but this is unusual.

A question of numbers All this research has some unsettling implications. At the moment, insects are among the most persecuted animals on the planet, routinely killed in almost-incomprehensibly large numbers. This includes 3.5 quadrillion – 3,500,000,000,000,000 – poisoned by insecticides on US farmland each year, two trillion squashed or slammed by cars on Dutch roads, and many more that have gone uncounted.

But though there isn’t much data on the full extent of our insecticide, one thing is widely accepted – the numbers we’re despatching are so vast, we’re living through an “insect Armageddon”, an era where insects are vanishing from the wild at an alarming rate. During “slaughter season” gangs of giant Asian hornets launch ferocious attacks on honeybees, decapitating the adults and eating their offspring (Credit: Alamy) The discovery of insect emotions also poses a slightly awkward dilemma for researchers – especially those who have devoted their careers to uncovering them.

Fruit flies are the archetypal research animal, studied so intensively that researchers know more about them than almost any other. At the time of writing, there are around 762,000 scientific papers that mention its Latin name, ” Drosophila melanogaster “, on Google scholar. Equally, studies into bees are growing in popularity, for the insights they can provide into everything from epigenetics – the study of how the environment can influence the way our genes are expressed – to learning and memory,

Both have endured more than their fair share of experimentation. “I like to watch bees and I’ve studied behaviour for a lot of my career, so I empathise quite a lot with them already,” says Wright, who has been a vegetarian for decades. However, the numbers used in research are tiny compared to those sacrificed elsewhere, so she feels that it’s easier to justify.

“It’s this sort of disregard of life in general that we have – you know, people just wantonly take life and destroy it and manipulate it from humans to mammals, insects to plants.” But while using insects for research is still largely uncontroversial, the discovery that they may think and feel raises a number of sticky conundrums for other fields.

There’s already a historical precedent for banning pesticides to protect certain insects – such as the EU-wide embargo on nicotinoids for the sake of bees. Could there be scope for moving away from others? And though insects are increasingly promoted as a noble and environmentally friendly alternative to meat from vertebrates, is this actually an ethical win? After all, you’d have to kill 975,225 grasshoppers to get the same volume of meat as you would from a single cow.

Perhaps one reason we don’t tend to think of insects as emotional is that it would be overwhelming. – Zaria Gorvett is a senior journalist for BBC Future and tweets @ZariaGorvett – Join one million Future fans by liking us on Facebook, or follow us on Twitter or Instagram, If you liked this story, sign up for the weekly bbc.com features newsletter, called “The Essential List”.

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Do flies have 3 second memory?

Insects have a spatial orientation memory that helps them remember the location of their destination if they are briefly deflected from their route. Researchers at Johannes Gutenberg University Mainz (JGU) have examined how this working memory functions on the biochemical level in the case of Drosophila melanogaster,

They have identified two gaseous messenger substances that play an important role in signal transmission in the nerve cells, i.e., nitric oxide and hydrogen sulfide. The short-term working memory is stored with the help of the messenger substances in a small group of ring-shaped neurons in the ellipsoid body in the central brain of Drosophila,

Flies form a memory of locations they are heading for. This memory is retained for approximately four seconds. This means that if a fly, for instance, deviates from its route for about a second, it can still return to its original direction of travel. “This recall function represents the key that enables us to investigate the biochemistry of working memory,” said Professor Roland Strauss of JGU’s Institute of Developmental Biology and Neurobiology.

The researchers are particularly interested in learning how a network in an insect’s brain can build such an orientation memory and how exactly the related biochemical processes function. Working on her doctoral thesis, Dr. Sara Kuntz found to her surprise that there are two gaseous neurotransmitters that are involved in information transmission.

These gaseous messenger substances do not follow the normal route of signal transmission via the synaptic cleft but can diffuse directly across the membrane of neighboring nerve cells without docking to receptors. It was already known that, for the purposes of memory formation, nitric oxide (NO) is essential for the feedback of information between two nerve cells.

1. What has now emerged is that NO also acts as a secondary messenger substance in connection with the amplification of the output signals of neurons.
2. This function of nitric oxide can apparently also be assumed by hydrogen sulfide (H2S).
3. Although researchers were aware that this gas plays a role in the control of blood pressure, they had no idea that it had another function in the nervous system.

“It has long been assumed that hydrogen sulfide was harmful to the nervous system. But the results of our research show that it is also of importance as a secondary messenger substance,” explained Strauss. “We were absolutely astonished to discover that there are two gaseous neurotransmitters that are important to memory.” Biochemical signal transduction pathway for visual working memory Strauss and his colleagues postulate that both neurotransmitters together with cyclic guanosine monophosphate (cGMP) form the perfect storage media for short-term memories.

1. They presume the process functions as follows: The fruit fly sees an orientation point and moves in its direction, at which point nitric oxide is formed.
2. The nitric oxide stimulates an enzyme that then synthesizes cGMP.
3. Either the nitric oxide itself or cGMP accumulate in a segment of the doughnut-shaped ellipsoid body that corresponds to the original direction taken by the fly.

The ellipsoid body is located in the central complex of the insect brain and is divided into 16 segments, rather like slices of cake, each of which represents a particular spatial orientation. Given that a Drosophila fly deviates from its path because it loses sight of its initial orientation point and temporarily becomes aware of another, that fly is then able to get back on its original course because a relatively large quantity of NO or cGMP has accumulated in the corresponding ellipsoid body segment.

• However, all of this only functions under one condition.
• The memory is only called up if the fly does not see anything in the interim, the fly must also lose sight of the second orientation point.
• The recall function only becomes relevant when there is nothing more to see and readily acts as an orientation aid for periods of up to four seconds,” explained Dr.

Sara Kuntz, primary author of the study, adding that this seemingly short time span of four seconds is perfectly adequate to enable a fly to deal with such a problem. “The ellipsoid body retains the backup copy to span any such brief interruptions.” There is no point in having a working memory with a longer duration as objects that have been selected as orientation points are not necessarily anchored in place but may themselves also move.

How long do flies love?

How Long Do Flies Live? – So, is the lifespan of a fly really only 24 hours? Not even close. As it turns out, an adult female house fly typically lives for about 25 days (males live for about 15 days). This can vary quite a bit depending on region, season (temperature), availability of food sources and other factors.

1. In general, insects, such as flies develop faster in warmer temperatures.
2. Hence, cooler weather may extend the life cycle to a certain extent, but this relationship varies depending on biological and environmental factors.
3. In addition, some insects are able to overwinter, which can potentially prolong the lifespans significantly.

Overwintering also means that the insect has minimal to no activity.

Do flies show fear?

A male fruit fly (drosophila melanogaster) may look simple, but its small brain can do complex things, possibly even including feel emotions. Emotions are fundamental to our lives, and yet we know very little about how they arise in the brain. This is mostly because we don’t have the luxury of asking our model organisms, usually monkeys or rodents, how they feel.

1. Instead, researchers studying emotions must rely on signs in the behavior of the animal, such as its facial expression or how much it moves.
2. But who’s to say that we know what to look for to see any particular “emotion,” especially in animals that don’t closely resemble humans? A recent publication in Current Biology uses a new idea, called “emotional primitives,” to explore whether fruit flies can exhibit the hallmarks of an emotional state.

Emotional primitives do not have to resemble the emotional behavior of humans; instead, they follow a set of rules which the authors claim should describe all behaviors arising from emotional states. In the paper, they use this concept to ask whether flies exhibit a fear-like state in response to a visual threat.

1. What they find is that flies will either quickly move or begin hopping rapidly after exposure to the stimulus, and these behaviors increase with the intensity of the threat.
2. Their response also lasts much longer than the threat itself, with the flies continuing to hop or run around for 10 to 20 seconds after the threat is gone.

Most compellingly, starved flies will flee from food when threatened, and are reluctant to return until nearly a minute has passed since the threat. Is this an example of an emotional response? Only a small fraction of flies show the hopping behavior, and the increase in the intensity of movement to a stronger stimulus is relatively small.

However, the behavior’s persistence is clearly not due to a reflex, lending their hypothesis some credibility. Additionally, this study is one of the first attempts at developing a paradigm that allows us to study and talk about emotions in a scientifically rigorous way, and deserves praise for that.

Model organisms are our best chance at understanding the biology behind emotions, and if we don’t have a reliable tool for discussing and evaluating emotions in these animals, we have no hope of making sense of feelings in ourselves. Managing Correspondent: Stephen Thornquist Original paper: Behavioral Responses to a Repetitive Visual Threat Stimulus Express a Persistent State of Defensive Arousal in Drosophila

Do flies know fear?

A fruit fly starts buzzing around food at a picnic, so you wave your hand over the insect and shoo it away. But when the insect flees the scene, is it doing so because it is actually afraid ? Using fruit flies to study the basic components of emotion, a new Caltech study reports that a fly’s response to a shadowy overhead stimulus might be analogous to a negative emotional state such as fear – a finding that could one day help us understand the neural circuitry involved in human emotion.

1. The study, which was done in the laboratory of David Anderson, Seymour Benzer Professor of Biology and an investigator with the Howard Hughes Medical Institute, was published online May 14 in the journal Current Biology,
2. Insects are an important model for the study of emotion; although mice are closer to humans on the evolutionary family tree, the fruit fly has a much simpler neurological system that is easier to study.

However, studying emotions in insects or any other animal can also be tricky. Because researchers know the experience of human emotion, they might anthropomorphize those of an insect – just as you might assume that the shooed-away fly left your plate because it was afraid of your hand.

• But there are several problems with such an assumption, says postdoctoral scholar William T.
• Gibson, first author of the paper.
• There are two difficulties with taking your own experiences and then saying that maybe these are happening in a fly.
• First, a fly’s brain is very different from yours, and second, a fly’s evolutionary history is so different from yours that even if you could prove beyond any doubt that flies have emotions, those emotions probably wouldn’t be the same ones that you have,” he says.

“For these reasons, in our study, we wanted to take an objective approach.” Anderson and Gibson and their colleagues did this by deconstructing the idea of an emotion into basic building blocks – so-called emotion primitives, a concept previously developed by Anderson and Ralph Adolphs, Bren Professor of Psychology and Neuroscience and professor of biology.

“There has been ongoing debate for decades about what ’emotion’ means, and there is no generally accepted definition. In an article that Ralph Adolphs and I recently wrote, we put forth the view that emotions are a type of internal brain state with certain general properties that can exist independently of subjective, conscious feelings, which can only be studied in humans,” Anderson says.

“That means we can study such brain states in animal models like flies or mice without worrying about whether they have ‘feelings’ or not. We use the behaviors that express those states as a readout.” Gibson explains by analogy that emotions can be broken down into these emotion primitives much as a secondary color, such as orange, can be separated into two primary colors, yellow and red.

“And if we can show that fruit flies display all of these separate but necessary primitives, we then may be able to make the argument that they also have an emotion, like fear.” The emotion primitives analyzed in the fly study can be understood in the context of a stimulus associated with human fear: the sound of a gunshot.

If you hear a gun fire, the sound may trigger a negative feeling. This feeling, a primitive called valence, will probably cause you to behave differently for several minutes afterward. This is a primitive called persistence. Repeated exposure to the stimulus should also produce a greater emotional response – a primitive called scalability; for example, the sound of 10 gunshots would make you more afraid than the sound of one shot.

• Gibson says that another primitive of fear is that it is generalized to different contexts, meaning that if you were eating lunch or were otherwise occupied when the gun fired, the fear would take over, distracting you from your lunch.
• Trans-situationality is another primitive that could cause you to produce the same fearful reaction in response to an unrelated stimulus – such as the sound of a car backfiring.

The researchers chose to study these five primitives by observing the insects in the presence of a fear-inducing stimulus. Because defensive behavioral responses to overhead visual threats are common in many animals, the researchers created an apparatus that would pass a dark paddle over the flies’ habitat.

1. The flies’ movements were then tracked using a software program created in collaboration with Pietro Perona, the Allen E.
2. Puckett Professor of Electrical Engineering.
3. The researchers analyzed the flies’ responses to the stimulus and found that the insects displayed all of these emotion primitives.
4. For example, responses were scalable: when the paddle passed overhead, the flies would either freeze, or jump away from the stimulus, or enter a state of elevated arousal, and each response increased with the number of times the stimulus was delivered.

And when hungry flies were gathered around food, the stimulus would cause them to leave the food for several seconds and run around the arena until their state of elevated arousal decayed and they returned to the food – exhibiting the primitives of context generalization and persistence.

• These experiments provide objective evidence that visual stimuli designed to mimic an overhead predator can induce a persistent and scalable internal state of defensive arousal in flies, which can influence their subsequent behavior for minutes after the threat has passed,” Anderson says.
• For us, that’s a big step beyond just casually intuiting that a fly fleeing a visual threat must be ‘afraid,’ based on our anthropomorphic assumptions.

It suggests that the flies’ response to the threat is richer and more complicated than a robotic-like avoidance reflex.” In the future, the researchers say that they plan to combine the new technique with genetically based techniques and imaging of brain activity to identify the neural circuitry that underlies these defensive behaviors.

• Their end goal is to identify specific populations of neurons in the fruit fly brain that are necessary for emotion primitives – and whether these functions are conserved in higher organisms, such as mice or even humans.
• Although the presence of these primitives suggests that the flies might be reacting to the stimulus based on some kind of emotion, the researchers are quick to point out that this new information does not prove – nor did it set out to establish – that flies can experience fear, or happiness, or anger, or any other feelings.

“Our work can get at questions about mechanism and questions about the functional properties of emotion states, but we cannot get at the question of whether or not flies have feelings,” Gibson says. The study, titled “Behavioral Responses to a Repetitive Stimulus Express a Persistent State of Defensive Arousal in Drosophila,” was published in the journal Current Biology,

In addition to Gibson, Anderson, and Perona, Caltech coauthors include graduate student Carlos Gonzalez, undergraduate Rebecca Du, former research assistants Conchi Fernandez and Panna Felsen (BS ’09, MS ’10), and former postdoctoral scholar Michael Maire. Coauthors Lakshminarayanan Ramasamy and Tanya Tabachnik are from the Janelia Research Campus of the Howard Hughes Medical Institute (HHMI).

The work was funded by the National Institutes of Health, HHMI, and the Gordon and Betty Moore Foundation.

Why do flies rub their hands?

Why Do Flies Rub Their Hands Together? (And Other Fly Facts) Spilling the secret about these common household pests Have you ever wondered why flies stop to rub their tiny hands together? While this gesture may look villainous, these pesky pests actually have a good reason for it.

• Flies rub their hands to clean off their taste receptors. These receptors are all over their bodies, including their legs and wings.
• Flies spread disease by landing on feces or trash, picking up bacteria, and then flying around with it.
• To manage flies, throw away garbage outside in a sealed container and keep the inside of your home clean.

1. Flies rub their hands together to clean themselves off. We often think of flies as gross, dirty pests, so it may come as a surprise to learn that they’re actually cleaning themselves. Flies have small sensors all over their bodies that carry taste receptors. When flies walk around, these sensors can get clogged with dirt, dust, and food particles. So when a fly rubs its little hands together, it’s getting ready to taste its next delicious meal.
   • These receptors are on the outside of a fly’s body to tell whether food is good before they eat it. Imagine holding your hand up to a hamburger and tasting it before you put it in your mouth—that’s exactly what flies are doing!
   • Flies have taste receptors all over their bodies, including on their wings and legs.

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1. Flies often land on feces and then track bacteria elsewhere. If flies are constantly cleaning themselves, you might be wondering how they manage to spread diseases to animals and humans. Unfortunately, a fly’s favorite meal is feces. When they land on their food to eat, they often pick up bacteria that they then spread to other areas when they land again.
   • Depending on the area, flies can carry diseases like cholera, salmonella, tuberculosis, typhoid, and more.
   • That’s why it’s always important to get rid of flies and not eat any food that a fly has landed on.

1. Yes, flies spit saliva onto food to digest it. It’s not necessarily “throwing up” as we might vomit, but it is a type of saliva that helps dissolve the food a fly lands on. Since flies don’t have teeth, they use their mouths to suck up the saliva and bits of dissolved food so they can eat it properly.
   • Most of the time, flies don’t suck up all of their saliva-and-dissolved-food combo, leaving bits of it behind wherever they go.

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1. 1 Empty your trash regularly. It’s no surprise that flies love eating garbage. If you notice flies in your home, by taking out the trash and putting it into a sealed dumpster outside. Wipe down countertops, sweep up floors, and clean out sinks to make sure there are no food scraps left behind.
   • House flies tend to congregate around rotted food, but other flies, like fruit flies, like fresh food. Keep fruit flies away by sealing up food in airtight containers.
2. 2 Install screens on doors and windows. Sometimes, flies just wander inside your home by accident. If you love keeping the doors and windows open during the summer, so that bugs and pests can’t get in.
   • Check out other areas of your home that might be letting flies in. Surprisingly, experts note that most flies get in through the attic.
3. 3 Clean up animal waste outside. Besides food and trash, flies are also attracted to animal poop outside. If your animal does their business outside your home, pick up their feces and throw it into a sealed trash bag. That way, the flies won’t have any reason to visit.
   • Plus, picking up animal waste is a great way to keep your yard and grass looking great.
4. 4 Use fly traps to attract and kill flies. If your fly problem just won’t buzz off, use or to solve it. Hang these traps up outside your home where flies tend to congregate, like underneath a covered patio. Clean the traps regularly as dead flies accumulate.
   • Many flies hibernate over the winter, so you’ll probably see more flies in and around your home during the warmer months.

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Ask a Question Advertisement This article was co-authored by wikiHow staff writer,, Hannah Madden is a writer, editor, and artist currently living in Portland, Oregon. In 2018, she graduated from Portland State University with a B.S. in Environmental Studies.

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• Updated: May 30, 2023
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Thanks to all authors for creating a page that has been read 3,198 times. : Why Do Flies Rub Their Hands Together? (And Other Fly Facts)

Do flies have 2 eyes?

It’s springtime which means sunshine, picnics and flies. But this episode might make you think twice about reaching for that fly swatter. Flies are amazing creatures that have the fastest visual systems in the world, use gyroscopes for precision flying, and can see almost 360 degrees.

To understand why a fly is so unique, just look into their eyes. A fly has two large eyes that cover most of their head. Each eye consists of at least 3,000 individual lenses called ommatidia. With all of these “simple eyes” flies can’t focus on a single object like we do. Instead, they see the world as a kind of mosaic.

This makes them really good at spotting quick moving objects like a fly swatter. And their field of view is almost a full 360 degrees. So no use sneaking up from behind. Dr. Michael Dickinson is a bio-engineer and neuroscientist at Cal Tech and a leading expert on American flies.

On this episode he shares his love for flies and explains what makes them so special – from their eyes to their lightning fast neurological systems. So next time you might want to reach for that magnifying glass rather than the fly swatter – you’ll be amazed at what you see. Recommended links from Chris Morgan : Dickinson Lab Michael Dickinson: How a fly flies Understanding the neurological code behind how flies fly The Lab: Gwyneth Card + Escape Behavior THE WILD is a production of KUOW in Seattle in partnership with Chris Morgan and Wildlife Media.

It is produced by Matt Martin and edited by Jim Gates, It is hosted, produced and written by Chris Morgan. Fact checking by Apryle Craig, Our theme music is by Michael Parker,

Do flies have 2 wings or 4?

The true flies belong to the Order Diptera and include many common insects such as mosquitoes, midges, sand flies, blowflies and the House Fly. Most of the insects we see flying around do so with four wings (two pairs). However, dipterans (meaning ‘two wings’) use only one pair. The other pair of wings is reduced to club-like structures known as ‘halteres’ that they use for balance.

Do flies have 50 eyes?

While you might think that the fly has two large eyes, it actually has five eyes. The two that we can see are its compound eyes. Then, there are three smaller eyes on the top of the head. The smaller eyes are called ocelli and while the compound eyes are complex, the ocelli simply process movement.

Do flies only have 2 wings?

Insect Flight | Smithsonian Institution True flight is shared only by insects, bats, and birds. Examples of other animals that are capable of soaring are flying fish, flying squirrels, flying frogs, and flying snakes. The capacity for flight in insects is believed to have developed some 300 million years ago, and initially consisted of simple extensions of the cuticle from the thorax.

• The success of insects during development of flight was due to their small size.
• Of course, not all insects have developed wings, these including such groups as spring-tails and silverfish.
• Some parasitic groups are believed to have lost their wings through evolution.
• When wings are present in insects, they commonly consist of two pairs.

These include grasshoppers, bees, wasps, dragonflies, true bugs, butterflies, moths and others. The outer pair of wings of beetles commonly are quite hard and not functional in flight. The ability to fly is not determined by the number or size of wings.

Some insects with large wings, such as Dobsonflies and Antlions, are relatively poor fliers, while bees and wasps with smaller wings are good fliers. True flies are a large group of insects with only one pair of wings, although they have small balancing organs known as halteres where a second pair of wings might develop.

The halteres vibrate with the wings and sense changes of direction. Flight is one of the primary reasons that insects have been successful in nature. Flight assists insects in the following ways:

• Escaping from danger
• Finding food
• Locating mates
• Exploring for new places to live

Flight in insects varies dramatically, from the clumsy patterns of some beetles and true bugs to the acrobatic maneuvers of dragonflies and many true flies. Flies in the Family Syrphidae (flower flies and hover flies) are capable of astounding feats, including moving forward, backward, sideways, and up and down.

• Migration distance — Painted Lady Butterfly, from North Africa to Iceland, a distance of 4,000 miles.
• Fastest flight in insects — Sphinx Moths, speed of 33 mph.
• Fastest wingbeat — Midge, at 62,760 beats per minute.
• Slowest wingbeat — Swallowtail butterfly – 300 beats/minute.
• Highest altitude — Some butterflies have been observed flying at altitudes up to 20,000 feet.
• Largest wings, modern — Wingspans of some butterflies and moths are the largest of all modern insects.
• Largest wings, extinct — The wingspans of fossil dragonflies, existing millions of years ago, were more than two feet.

A fascinating account of the speed of a Deer Bot fly, Cephanomvia pratti, was made by entomologist C.H.T. Townsend in 1926 by estimating the speed of the fly as it flew between mountaintops. Townsend published his findings, stating that the fly was able to accomplish a speed of 818 miles an hour.

This figure has been repeated for decades, but is now believed to be quite impossible. Another common story involves the flight of bumblebees, which were studied by Antoine Magnan, a French zoologist, in 1934. His conclusions indicated that these insects could not fly at all. Flights for food sometimes encompass distances of hundreds of miles, an example being African grasshoppers.

These insects fly together in large groups, sometimes as many as 100 million individuals. Monarch Butterflies are the best known example of flight for the purpose of migration. In the fall, Monarchs gather in great numbers and migrate across the United States to overwintering localities in Mexico.

Anyone who has seen such accumulations of Monarchs will never forget the experience. Selected References: Armstrong, R.H.1990. “Photographing insects in flight.” American Entomologist, Volume 36, number 3. Pringle, J.W.S.1957. Insect Flight, Cambridge University Press, Cambridge, Massachusetts. Snodgrass, R.E.1930.

How insects fly. Annual Reports of the Smithsonian Institution, 1929.

1. Prepared by the Department of Systematic Biology,, National Museum of Natural History, in cooperation with Public Inquiry Services,
2. Smithsonian Institution
4. Information Sheet Number 96
5. May 1999

: Insect Flight | Smithsonian Institution