Eeeeekk!! ‘The only good insect is a dead insect’
Bugs in our lives
Most people are scared, or at least wary, of almost all insects (more correctly arthropods) based on reasonable or unreasonable fears. But, insects are integral to all human cultures.
They are part of our language, art, history, philosophy, and religion. They are directly useful to human beings by producing honey, silk, wax, lacquer and other products.
They also play the important roles of pollinators of crops, and scavengers. Some of them are natural enemies of pests, and food for other creatures.
However, as human society has become progressively more urbanised, we have become more distanced from the world of critters. But can we live without them? Not really. So how do we strike a balance?
Morning in an apartment in a city
Mr Mehta: (Rushes in) What is it? What happened?
Rohan: (Scratching himself frantically): Look at these red ants..they are all over the table and all over me now…
Mr Mehta:Hmm…With all these biscuit crumbs strewn around, no wonder these pests are having a feast. Here, let me take care of this. (Takes out a can of insecticides from the bathroom cabinet and briskly sprays it on the table and the floor. Leaving a row of dead ants behind, the family leaves for work).
Afternoon in an apartment in a city
Rohan: (bending over a jam jar near a window in the bed room): Just look at these lady birds (garden beetles). Aren’t they pretty? I am feeding them some green leaves. It’s lunch time for them too.
Amrita: Oh my god, are you keeping those creepy insects in our bed room? Just throw them out, will you?
Rohan: No way! Do I kick up a fuss about that awful gold fish you keep in that bowl? My insects are far prettier than that creature.
Amrita:How can you compare my harmless little fish with your crawlies? And since when have you turned into an insect-lover? Ants are insects too, you know! (Both glare at each other, while Rohan holds the jar protectively)
Morning in a farmland in a village
Sajid: (playing with a stick and stones near the tube well) Yes. School is really boring. Yuck! look at this slithery earthworm over here. It is so ugly.
Meher: Sajid, leave the creature alone at once! Don’t disturb it.
Sajid: (Poking the stick around): Why shouldn’t I?
Meher: (Rushing to stop Sajid): Don’t you remember what Abbu told us the other day? Earthworms eat waste plant material in the soil and convert it to manure. Don’t you see those small balls of soil? That’s the manure.
Afternoon in a farmland in a village
Meher: What will you spray Abbu?
Suleman: (Takes out two plastic cans) This one has kerosene in it, and the other is a chemical insecticide.
Sajid: (Looking worried) Are you going to kill insects?
Suleman: Yes, these pests eat our crops, and they have to be destroyed.
Meher: But won’t these chemicals kill earthworms too? We don’t want them killed, do we?
Suleman: Well, yes, some useful ones will die too. But it is better to have no insects than to be plagued by the rogue critters.
Sajid: (very confused) But…but..
A persistent irrational fear of and compelling desire to avoid insects, mites, spiders, or similar phobic objects.
Entomophobia is acquired in early childhood and is usually a result of traumatic conditioning, i.e. an unpleasant experience, such as a painful sting or, of acquired conditioning. Indeed, the child who sees his parents react violently at the sight of an insect, will automatically associate that insect with the state of fear.
In the scientific literature, the hypothesis is raised that human beings may be more predisposed to entomophobia than any other type of phobia because early man was exposed to a great many dangerous insects and developed a highly effective flight reflex in order to defend himself. This predisposition would therefore be ingrained, programmed in our genes.
World-full of insects
There is no getting away from insects, is there? They are in the soil beneath our feet, in the air above our head, on and inside the bodies of the plants and animals around us, as well as on and inside us! There are well over one million different known species of insects in the world. Some experts estimate that the unknown species may add up to as many as 10 million. All these species are divided up into about 32 orders, of which, the largest is the Beetles, or Coleoptera. With clan of 125 different families and around 500,000 species insects are an incredibly diverse group of animals. In fact, one in every four animal species on this planet is a beetle!
One in every four animal species on our planet is a beetle
Of all the animal species on earth, an astounding 97 per cent are estimated to be invertebrates (with no backbone). Ants form 10 per cent of the animal biomass of the world. Another 10 per cent is composed of termites. In other words, these insects make up an incredible 20 per cent of the total animal biomass of this planet. Exploring the world of insects and their closest relatives — the arthropods — who make up 80 per cent of the species in the animal kingdom, can actually be a fascinating experience.
Want to try? Begin by identifying the distinctive characteristics of insects, arachnids, centipedes, millipedes and crustaceans.
The abundance of insects in nature clearly establishes one fact: the critters, big and small, play a major role in sustaining our ecosystems.
Fight for food
Why are human beings and insects always in conflict? One obvious reason is the sense of disgust that most of the creepy-crawlies seem to stir up. And some insects can actually cause physical harm, so self-defense comes into play, naturally.
But, the most apparent area of conflict is appropriation of food. Insects and human beings put together are the two largest consumers of biomass (both plant and animal ) on our planet. As the human population grows, we need more food and since land is becoming a scarce commodity we need a larger share of the produce. The most effective way to achieve that is by eliminating the second largest consumer of biomass on Earth. So, the battle between insects and us is fought every year at global scale on farmlands and in human settlements.
What do we do to get rid of insects? We poison them. The pesticide industry is one of the largest industries in the world. We began with the use of broad spectrum (general) pesticides and now we manufacture organism specific hormone-based pesticides. We have managed to get rid of insects from our habitat to a very large extent. Without these potent chemical pesticides we would have had ten times the number of insects we now find at our homes.
A better understanding of how insects grow and develop has contributed greatly to their management. For example, knowledge of the hormonal control of insect metamorphosis led to the development of a new class of insecticides called insect growth regulators (IGR). Based on information about growth rates relative to temperature, computer models are used to predict when insects would be most abundant during the growing season and, consequently, when crops are most at risk.
An insect’s environment may be described by physical factors including temperature, wind, humidity, light, and biological factors such as other members of the species, food sources, natural enemies, and competitors (organisms using the same space or food source). An understanding of these factors and how they relate to insect diversity, activity (timing of insect appearance or phenology), and abundance is critical for successful pest management.
Enter the Goliath: pesticide industry
These are chemicals used to destroy insects. Insecticides include ovicides and larvicides that kill eggs and larva. They are used in agriculture, in medicines, in industries and at home.
The use of insecticides is believed to be one of the major factors behind the increase in agricultural productivity in the 20th century. India is a voracious consumer of pesticides. The total demand for insecticides here is over 1,00,000 metric tonnes (MT) for agricultural and 50,000 MT for public health purposes.
Consumption of insecticide in agriculture has grown by more than 100 per cent from 1971 to 1994-95. For instance, insecticide consumption in India, which was to the tune of 22,013 tonnes has increased to 51,755 tonnes by 1994-95
In our frenzy to get rid of ‘pests’, we forget that the chemicals we use are poisons. They kill insects, but also pollute water, soil, and our bodies...
But in recent past, a change has been observed in the trend of pesticides consumption. As a result of adoption of bio intensive Integrated Pest Management Programme in various crops, the consumption of chemical pesticide has come down from 66.36 thousand MT during 1994-95 to 43.59 thousand MT during 2001-02.
But reduction in the volume of pesticides produce is really not significant, because the products manufactured now are more potent, and more toxic.
Are we an entomophobic nation?
Interestingly, consumption pattern of pesticides in India is very different from the rest of the world. In India, insecticides account for 76 per cent of the total domestic market while herbicides and fungicides have a significantly higher share in the global market. We seem to kill insects with extra fervour! Now let’s take a look at what these poisons are made of.
In India, the most commonly used pesticides are monocrotophos, Chlorpyrifos, Quinalphos, Endosulfan, Cypermethrin and Fenvalerate.
There are three classes of pesticides, and they kill the critters in very distinctive ways:
Neurotoxicants: Neuroactive compounds, like DDT and pyrethroids, directly affect the nervous systems of the creatures.
GABA agonists: The avermectins affect invertebrates by disrupting their nerve impulses. Consequently, the insects are paralysed irreversibly and stop feeding.
Nicotinyl Insecticides: Nicotinyl insecticides interact with nicotinic acetylocholine receptors (nAChR) at the central and peripheral nervous systems resulting is paralysis, followed by death.
And their deadening impact …
Nearly all these chemicals have the potential to significantly alter ecosystems. In fact, many are toxic to human beings, and others are concentrated in the food chain. So, are we really being able to balance agricultural needs with environmental and health issues while using them?
Think about it... In our frenzy to get rid of pests we tend to overlook the fact that these poisons have a massive fallout on critical components of our ecosystems.
Pesticides use water, soil and air as carriers and get deposited in bodies of living organisms. Bird species are the worst sufferers. They feed on poisoned insects and the deadly chemicals are concentrated in their internal systems, resulting in infertility and even death. Vultures, that feed on infected cattle carcasses, have virtually disappeared from urban skies.
Fish, birds, and wildlife that live in direct contact with environments subject to pesticide exposure are sentinel species that may be predictive of our own fate. To understand this more clearly let’s find out how a pesticide behaves in soil and in water.
Insect zoos require minimal resources and offers the novel opportunity of observing insects in proximity and inspires everyone to take a closer look at the insect world.
Mini Butterfly Garden
Butterflies are attracted to many different types of flowering plants. You can attract butterflies (and other insects such as bees, flies and beetles) by planting a special flower garden. A butterfly garden need not be big - it could be planted in a terracotta pot, an old wash tub or any other suitable container.
You can also create one in your backyard or terrace at home. Place the garden or garden container in a sunny spot. More butterflies will be attracted if you put out a butterfly table – a platform on which you put pieces of sliced fruit.
Waterscope For Aquatic Insects
You will need a large carton or a fruit drink can, a plastic bag or a piece of plastic big enough to cover the end of the carton or can, scissors or a can opener and two elastic bands. Remove both the top and bottom of the carton or juice can.
Put the plastic over one end of the container and smooth it over the sides. Put the two elastic bands over the plastic, one near the top and one near the end of the plastic, to hold it in place. To use the waterscope, place the end of the container with the plastic in the water. The plastic will act as a lens to help you see beneath the water's surface.
Ant communities are fascinating to watch and you can study them at home with the aid of an ant farm. Ant farms are easy to make and maintain. You will need a large glass jar, a piece of cardboard (bigger than the mouth of the jar), a pan, soil, and ants. Fill the jar with a damp sand/soil mixture and place the jar in the pan. Fill the pan with 1/2 to 1 inch of water.
The water-filled pan acts as a moat to keep the ants from wandering away from the farm. To populate the farm, gather several dozen ants from a local ant nest. Try to include a queen or some other reproductive ants (those with wings) if you can, or the farm won't last too long. Cut a small hole in the centre of the piece of cardboard and set it on top of the jar. Feed the ants honey, pieces of fruit, egg, or peanut butter. Don't overfeed, and periodically remove any excess food.
Know your entomological terms
Insects as Food!
Algeria— The natives of Algeria would collect large numbers of desert locusts to use as food stuff. They were a valuable resource for the poor population. The locusts were cooked in salt water and dried in the sun.
Australia— Australian natives, or Aborigines would come together at the Bogong mountains to feast on Bogong moths. They were harvested, cooked in sand, and stirred in hot ashes. This would burn off the wings and legs. Some of the moths were ground into paste and made into cakes.
Japan— If you were to go to a restaurant in Tokyo, you might have the opportunity to sample some of these insect-based dishes: hachi-no-ko - boiled wasp larvae (left) zaza-mushi - aquatic insect larvae inago - fried ricefield grasshoppers semi - fried cicada sangi - fried silk moth pupae from India where it's known as "Chindi chutney."
India— Ants are collected in leaf cups and put directly into the hot ashes of the fire for a few minutes. The ants then are removed and ground into paste. Salt and ground chilis are added and the mixture is baked.
Venom in water
There are broadly two ways pesticides reach surface and ground watersthrough runoff and leaching. Runoff is when pollutants enter rivers, lakes and other water bodies via the medium of rainwater. Leaching is a process by which pollutants are flushed through the soil by rain or irrigation water as it moves downward. This way they penetrate the surface, and contaminate ground water. In many areas, soils are sandy and permeable and leaching is likely to be a more serious problem than runoff.
Once applied to cropland, a number of things may happen to a pesticide. It may be taken up by plants or ingested by animals, insects, worms, or microorganisms in the soil. Worldwide, extensive studies have shown how the pesticides affect the soil health by killing the vital microbial fauna present in the soil. Each gram of soil may contain millions of microbes, which are important to sustain plant life. Pesticides not only kill these microbes, they persist in the environment and have been observed to accumulate in the food chain. It is due to their tendency to accumulate in the animal fatty tissue, and move up the food chain, that their residues have been found in the mother’s milk.
Now if the water, the soil, as well as the air is contaminated by this poison, how can our bodies remain immune to it? Pesticides that enter the human system through these carriers ravage our metabolism. As per intensive surveys conducted in different parts of the world, they are now known to cause lethal diseases ranging from several forms of cancer, liver damage, and reproductive disfunction to neurological disorders like Parkinson’s and Alzheimers.
But here is some good news. Many farmers, across the world, are turning to biological management of farms. They are supported by agricultural scientists who have studied the preypredator relationship between various species of insects that are major pests and used the same process to control impact of insects on farm yield. They are also experimenting with certain natural substances that also act as insecticides without posing threats to the ecosystem like a chemical product. Today many farmers across the world are practicing organic farming. And their produce fetches a higher price than conventional farm products. Some organic farmers have even proved that there is no drop in the yield due to use of organic substances. However in India, organic farming is still tried out at a miniscule scale. Big farmers who grow cash crops are reluctant to try it out. More help from the government in the form of financial incentives or investment in specific research may do wonders to this practice.
Man, woman and…insects!
Ancient India, in fact, had perfected the art of dealing with pests, without endangering the rest of the planet. And some smart researchers have picked up these tips and are practicing it today… A Karikali-based group in Tamilnadu calls itself a university with multifarious ecological roles — Vazhviyal Multiversity. The herbal pest repellant it produces is based on traditional knowledge listed in the scripture — Vriksha Ayurveda. It is prepared from the leaves of five plant species that are not eaten by cattle. These can vary from place to place, but would ideally include neem, tulsi, and datura. The truth is, neem, tulsi and turmeric powder have been used as insect repellants in Indian homes since ages, and this is still a common custom in scores of rural households.
So it’s a world of fascinating details…some times bordering on the macabre. Try and find out more about insects present at your home and school. What you find will be quite an eye-opener. You will find that all of them perform some function in our ecosystem and if we eliminate them we have to perform their functions to maintain the balance in our ecosystem. It is for you to decide whether we have the right to eliminate such a magnificent order of organisms? Can we change our approach towards insects? Can we change the ways we manage our conflict with the insect world? There are just questions and more questions.