The origin of insects is hidden in the mists of time. The sea and the North and South Poles are possibly the only environments that cannot support insect life (though pond skaters have been observed feeding on surface plankton as far as 1,000 miles away from the nearest land mass). The first fully formed and winged specimens appear in the fossil record of the Upper Carboniferous strata (about 300 million years ago). These look very similar to some insects alive on earth today, such as the cockroach! They were obviously so well adapted to earth’s environment that they needed no change in evolutionary design all these many years!
Plants use flowers to lure insects into performing a courier service for them. Scientists call the process pollination. Let me try and simplify a very complicated relationship. Long ago, before insects began to fly, there were no flowers on earth. Plants then used wind and water to transport their seeds. When insects finally learned to fly plants somehow became aware of this new talent and evolved flowers containing nectar (for insects to eat) and colours (to advertise the availability of such food). Fragrances made doubly sure that flying insects could find flowers even in the dark. This was no charity… the plants had ulterior motives.
When the insects came to snatch a sweet mouthful of nectar, the plants sneakily attached their pollen on the visitors. And when the flying creatures departed to visit another plant (hopefully of the same species) the pollen-courier-service was completed. Both plants and insects benefited. This relationship which is millions of years old continues till today and some insects have mouth-parts (a straw- like tongue in the case of moths and butterflies) which coincide exactly with the design of their food plants.
Friends in need
Insects are crucial to the survival of life on earth. Without them many plants would die, because they now have no alternative means to transport their seeds. Humans have learned to use honey bees almost as they do cows! Without honey, several human communities on earth would find themselves short of a crucial food source. Bees are also useful to humans because they help pollinate our fruit in orchards and without bees many of our orchards would almost certainly be ruined. Around 20,000 species of bees now use flowers as their exclusive source of food. If these flowers vanished the bees would follow suit… and vice versa. And that’s not all. Beeswax too is used widely in industry to manufacture candles, sealing wax, polishes and even some kinds of ink! ! Bee venom is used by doctors in the treatment of arthritis.
Thousands of other insects help us in uncounted ways. If there were no ladybirds around, for instance, aphids would destroy vast quantities of our crops. Wasps too eat creatures which would otherwise consume our farm produce. Butterflies do not merely lend quality to our lives because of their gentle, attractive ways; without butterflies thousands of flowering plants upon which millions of humans depend would vanish from the earth. We cannot protect such insects without protecting their wild (host) plants. This often means setting aside vast portions of the earth for sanctuaries and national parks where no human activity is allowed to disturb nature’s balance.
A losing battle
I find it rather silly that humans have chosen to declare war on insects through the use of poisons (insecticides). There is no doubt that caterpillars, beetles and grasshoppers pose a problem to farmers because they eat our food crops. But the Food and Agriculture Organisation (FAO) of the United Nations has more than enough proof on hand to indicate that our crops cannot be protected indefinitely by poisoning the `enemy’. This has not stopped us from waging our absurd chemical war against insects.
Why will we inevitably lose the pesticide-grasshopper-caterpillar- thrip-weevil war? Because the processes of evolution are on the side of the little ones. Pesticides apply selection pressure on species in the same manner as do droughts, floods or climate change.
Evolution has armed insects with the ability to alter their genes so as to: 1. Avoid our poisons. 2. Reduce their toxic impact. 3. Manufacture antidotes fast. If the above defences not work, insects have yet another trick up their sleeves! They can actually move or shrink the vital organs in their bodies that our pesticides target. Though we kill billions of grasshoppers each year their populations continue to rise as does the quantity of crops they consume. The insects are winning the war because they have turned our weapons against us. Pesticides are now a significant cause of kidney damage, blindness, cancer and brain damage in humans. If we did away with pesticides slowly and grew different types of crops organically on our farms, our food security would be enhanced and the cost of food would fall. This would, of course, spell doom for many multinational corporations which profit from pesticides.