What does the insect world look like? – A Question of Science – Sanjay Sane Lab, NCBS


Invisible irritant, disease spreading pest, destroyer of crops factories churning out products is that all insects are? Train your lenses on these creatures and you will find an astounding other world a world where events unfold in a fraction of a second where razor-sharp decisions are made in record time where secret languages convey information without words and superhuman mechanics reach unimaginable speeds. What happens in the unique world of insects that’s a question of science. 400 million years ago nearly 350 million years before any vertebrate animal walked the earth the first insects emerged onto dry land through the ravages of time and massive upheavals in climate and geology they endured but they didn’t just survived they thrived today insects are the most populous on the planet with more numbers of individuals and species than any other animal added together their biomass outweighs all other animals on earth combined what makes insects one of nature’s most successful life forms that’s the question being asked by scientist and insect enthusiasts from jasani at bangalore’s National Center for Biological Sciences I’m crazy about insects I can’t get enough of them you know the simple little creatures you might think they’re helpless are actually extraordinarily smart so how exactly are insects smart in a way that’s different from humans insects specifically flying insects were the first animals to fly in the natural world this along with their tiny sizes gave them powers that bigger species just didn’t have for example they could crawl into cramped in accessible spaces to seek out food and be safe from predators but the biggest edge came from flight flight allowed them to reach areas that no one else could access flight also gave them a unique perspective a high-speed turbulent word that whizzes past so quickly that humans can barely see or sense it you and I are extremely slow and sluggish compared to a standard insect or flying insect and just how slow away compared to insects to you and I a standard light bulb in our hose appears quite stable in its beam but here’s how it looks to an insect a regular lightbulb flickers 50 to 60 times a second a phenomenon so quick that it doesn’t even register to the human eye it’s a whole other story for the insect a typical flying insect will flap its wings hundred to two hundred times a second it can’t afford to have human-like sluggish vision and so it captures every flicker of the light bulb along with every high-speed event that you and I wouldn’t even notice this begs the question what sort of biological system allows insects to react and respond so quickly the system has to be something that sense is very fast it is open to process very fast it is able to respond very fast and in all these matters insects are way ahead of us flying insects like common houseflies have an intricate biology one that is tailor-made for this high speed world flies have wings to help them move aerodynamically through the air they have a compound I made up of thousands of individual units to detect split-second movements they have muscular legs that give them lift for takeoffs and position them for perfect landings there are antenna to detect any mechanical sensations like wind turbulence or vibrations and they have unique organs called Hall tears which act like stabilizing gyroscopes to ensure a balanced flight all in all a housefly that you and I try so hard to get rid of is a sophisticated system it does everything a military or commercial aircraft can but much much faster you are fascinating animals they flap about 200 to 250 times a second so it’s faster than an eye blink notice that it’s true legs are stretched because the fly knows it’s going to land it pitches up very slowly note how perfect this one over is it’s you know the fly is completely in control of it and all of this is happening in a matter of literally 60 milliseconds now how is a fly able to do this in such a short amount of time this is just one of the questions that Sanjay Sunny’s lab is experimenting to answer researchers here delve into the complex mechanisms that go into insect flight they’re asking how do insects use their powers of vision or smell in flight how do they use mechanosensory organs like antenna or whole tears to these different types of sensory organs act independently or do they collaborate and how does an insect generate high speed responses and make rapid fire decisions the lab looks at all these questions from every possible angle sensory muscular neurological and behavioral one of the experiments revolves around honey beads and how they control their flights using eyes for vision and antenna for mechanosensory perception the bee is immobilized and mounted on a rig then it is placed inside a black box which allows no light to enter when the bee emerges from the dark it is exposed to computer screens with running striped patterns the bee is now at the center of attention with multiple high speed cameras trained exclusively on it they capture how the bee reacts to the visual stimuli of stripes they also capture how this effects its antennae movement this gives researchers invaluable insight into how vision and mechanosensory responses are connected the bee has to get information from two different channels process them integrate them and then react to them what makes it interesting is if these two information gives you conflict in information which one do you react to due process they figure out balance out something and then give it a net result or do you rely on one more than the other these are questions that you looking at not too far from here another experiment gives the same question a different twist this time researchers are studying the relationship between an insects vision and powers of smell the housefly is given a serious challenge to locate its food source by following a tempting smell all while navigating a visual landmark presented by a black sphere how the fly you know moving and then the trace follows it if you put the red mark around your response then only it causes like to pass costs extra the experiment asks what will the fly depend on more to control its flight vision odor or both this basic setup allows you to get into the mind of the instant you can say okay so what was the insect trying to do is it tracking the visual object or the order source in the experiment and odor source typically a food item like fruit juice is positioned inside a wind tunnel as a distraction a black landmark is placed some distance away from it the insect pursues the food order but then it encounters the black landmark so what is surprising is that fly is keeping track of landmarks but the landmarks are actually making research slower researchers observe how this affects the Flies original search they track it using high-speed cameras and collect the data digitally in retracing the Flies flight path a lot can be learned oh yeah we go visit if you turn it like this the other way oh so this is you know the search thing allergy below but when then it goes in front of the object we have quantified is that flight and to search more before making that same decision of landing on the other source so the final outcome is same but the approach it’s before that is completely modified because of the surroundings these behavioral experiments show that insects are capable of making complex decisions extremely quickly so the next logical inquiry is how is this decision making happening at a neural level researchers want to understand how insect neurons process two types of information visual and mechanical to ensure smooth flight control neurosurgery is tough enough in us humans imagine carrying out the same in small insects the insect chosen for this operation is the only under hawk moth its size enable scientists to reach into its ventral nerve cord and record its activity with an electrode I’ll be recording from within one particular neuron using a very fine electrode and trying to see how these two informations are encoded by the neuron such neurological tests are conducted to discover which neuron corresponds to which sensory perception biet vision mechanical stability or motor control the results once more reinforce just how intelligent insects are and do you find any neurons yes we found several neurons which respond just to mechanical stimulus just to visual stimulus and few which respond to both of them mapping the nervous system of insects can give us precious Clues into what enables insects to fly for India these types of inquiries have been long overdue in the early days post-independence a lot of attention was paid to entomology or insect studies as part of agricultural research but for a nation grappling with food shortages insects were only interesting as crop destroying fest unfortunately these entomologists were taught how to kill insects not how to study them from the perspective of studying the other aspects of its eclectic Emma kill ecology or all of these different things there is unfortunately not much of a tradition now there’s a fresh swarm of Indian entomologists dedicated to unearthing the fascinating world of insects they’re coming from disciplines like neuroscience physiology physics and even aerospace engineering to understand how these complex creatures behave from training insects to fly directly into lab setups to breeding insect and operating high-end digital rigs this group of scientists is venturing into a niche of the wild reserved only for insects the idea is to see how a female moth contract its host plant in wild that is the reason we are doing this experiment in a cage outside the lab so that we can provide it a semi environment to a female moth when it is in the you know in a forest there are tons of plants around and it is extremely difficult to to identify its host plant and lay eggs only on on the host plant so this behavior is what we are very interested in closely linked to flight behaviors of insects is one of the most fascinating questions in entomology how do insects communicate the answer is different for different insects in 1973 Austrian scientists call one fish won the Nobel Prize for cracking the secret language of bees he revealed that honeybees communicated using a dance called the waggle dance this dance told otherwise about the location of food the speed of the waggle of the beasts posterior showed how far the food was the axis of orientation of this waggle movement indicated which direction the food source was in relative to the Sun but you might start thinking that there are problems here why because the Sun is not in the same place all the time so the bees need to be able to compensate for the fact that the Sun moves in the sky and they can but it’s not just bees that have remarkable languages mots crickets cicadas and other species have unique meeting communication from chemical to auditory these are astonishingly accurate strategies where a female can localize her mate in a crowd of males even ants have an extremely sophisticated communication system ads will communicate to each other using chemical means it will lay a chemical on the ground and that chemical can have many different connotations it may be a repulsive chemical it could be a attractive chemical the world of insects is indeed very different from the one humans inhabit but that doesn’t mean we can’t get along bugs like mosquitoes flies or cockroaches aren’t just disease spreading pests and insects like bees aren’t only valuable for the products they make in fact some cutting-edge technologists are finding a whole new reason for studying insects robotics aerospace chemistry defense engineering hardly areas one would associate with buzzing crawling flying or creeping insects but new-age engineers are swarming to study them in a bid to artificially replicate them imagine robotic bees that can reach inhospitable heights to carry out scientific research a cockroach like machines that can crawl into tight spaces to detect oil coal or even unexploded landmines imagine sensors that mimic the sophisticated vision of insects or rescue robots that can travel in harsh or disaster-hit terrains but there’s a bigger or rather tinier reason why insect-like robots are ideal take the example of a mega science endeavor like Mars exploration conventional wisdom would suggest a single large robot that’s packed with all kinds of sensors to collect different information and samples the problem with that is that a robot like that if it goes out and fails because these are all inhospitable environments you get nothing back for all the effort that you put in a different paradigm of looking at it is to do it the way in six to it which is you send hundreds of probes out or thousands of probes out and even if half of them fail you still get something back I’m so engineers around the world are looking closely at the intricate biology of insects to build futuristic machines the lab at NCBS is no different we are trying to understand how flies move about in the real world so what we want to do is understand how motion of the wing relates to these body moments the fly is remarkably gifted in 3d choreography it’s a lesson in aerodynamic aerobics with the ability to pitch up or tail down roll sideways or display yoing movement how do its wings execute these maneuvers in a split second to find out experimentalists build a maze through which a fly makes its way in negotiating the maze its wings and body work together seamlessly each of these moves is recorded by high-speed cameras we are trying to find out by filming them how they do what they do we are not trying to mimic it but we are trying to get close to it so that we can build vehicles called micro air vehicles which are the small vehicles which can fly into confined spaces all engineering that we do is indirectly learned from nature because nature is our best teacher in studying insects we return to nature and it’s astonishing secrets like the mathematical dance by which bees talk to each other or the Chemical trails that ants leave behind to communicate with fellow ants or the zen-like praying mantis that exploits the imperfections of others to catch its prey at any given time there are a million dramas playing out in the insect world ones that are as thrilling as anything we create in the human world so the next time you encounter an insect look closer don’t blink or you just might miss it if you’d like to share your feedback on today’s program please send your suggestions and comments to began Prasad c24 kutub institutional area New Delhi 110016 or you can mail us at info at vigyan Prasad da govt dot in you you