Every day, farmers knowingly or unknowingly kill their best friends. This is one of the hidden tragedies of modern agriculture. In our attempt to kill crop pests, we also kill the insects that naturally protect our crops. As a result, nature’s balance is disturbed, pest problems increase, and farming becomes more dependent on pesticides.
A farmer sees a folded leaf, a caterpillar, or a few holes in the crop. The immediate reaction may be: “There is a pest. I must spray an insecticide.”
But wait. Before spraying, observe the plant carefully. There may be another insect nearby—not to damage the crop, but to hunt the pest that is damaging it.
Our farms contain thousands of such relationships. Predatory insects, parasitoids, spiders and other beneficial organisms are constantly working around us. If we spray pesticides without understanding this natural system, we may kill our friends along with our enemies.
A Lesson I Learned from a Folded Hibiscus Leaf:
This idea became very clear to me through a simple observation in my own surroundings.
On a hibiscus plant, I noticed that some leaves were folded and held together with silky threads. There were also holes in the folded leaves. When I carefully opened one of them, I found green caterpillars living inside. They were feeding on the leaf while remaining protected within the fold.
At the same time, I observed wasp-like insects actively visiting and searching around such plants.
This raised an interesting question: Are these wasps searching for the caterpillars hidden inside the folded leaves?
Science gives us good reason to think along these lines. Many solitary wasps are hunters of caterpillars. Potter and mason wasps, for example, search vegetation for caterpillars, paralyse their prey and use it as food for their developing young.
However, we should be scientifically careful about one detail. From observation and photographs alone, we cannot conclude that the wasp itself made the particular holes seen in these hibiscus leaves. Some holes may have been caused by caterpillar feeding. But the association between caterpillars and caterpillar-hunting wasps illustrates an important natural pest-control relationship.
Nature Has Already Created a Pest-Control System:
Remember the food chain we studied in school?
In nature, one organism depends upon another. Insects are eaten by spiders, frogs, lizards and birds. Rats may become food for snakes. Different organisms are interconnected in a complex food web.
Agriculture is no exception.
When the population of a particular crop pest increases, food becomes more plentiful for its natural enemies. Predators and parasitoids may then become more active or numerous. In this way, nature continuously tries to maintain an ecological balance.
The farmer’s aim, therefore, need not be to create a field containing no insects at all. The real objective is to prevent harmful insects from multiplying to a level where they cause unacceptable economic loss.
Meet the Farmer’s Unpaid Workers:
Many beneficial creatures are working in our fields every day.
Spiders catch a wide range of insects. Ladybird beetles and their larvae consume aphids and other soft-bodied pests. Green lacewing larvae are voracious predators of several small insects. Predatory bugs attack eggs, larvae and other pests. Dragonflies and damselflies capture flying insects.
Wasps deserve special attention. Some are predators that capture other insects, while many parasitoid wasps lay their eggs in or on pest insects. Their developing young eventually kill the host.
These creatures do not send the farmer a bill. Nature provides this pest-control service free of cost.
One Spray May Kill Both Enemy and Friend:
This is where unscientific pesticide use becomes dangerous.
A farmer may notice a few caterpillars and immediately spray a broad-spectrum insecticide. The caterpillars may die—but so may spiders, beneficial wasps, ladybird beetles and other natural enemies.
The pest may later return. But its natural enemies may take longer to recover. This can sometimes result in pest resurgence, where pest populations increase again after pesticide treatment.
Therefore:
Seeing an insect is not sufficient reason to spray:
First identify it. Then estimate the extent of damage and observe whether natural enemies are already present. “Talk to Your Plants Every Day” senior farmers sometimes say: “Go to your garden every day and talk to your plants.” Of course, plants do not answer us in words. But there is considerable wisdom hidden in this saying. Walking through the farm every day teaches us what is happening.
Turn over a few leaves. Look inside folded leaves. Observe tender shoots and flowers. Search for eggs, caterpillars, aphids, webs and unusual damage. But equally important, look for spiders, ladybird beetles, wasps and other beneficial organisms.
A problem identified at the beginning is much easier to manage. A few infested leaves may sometimes be removed manually. Depending on the pest, traps, sanitation, biological measures and other Integrated Pest Management practices may be sufficient.
Pesticide Is a Tool—Not the First Answer:
This does not mean that farmers should never use pesticides. When pest populations cross damaging levels and other measures are insufficient, an appropriate pesticide may become necessary.
But chemical control should be need-based, scientifically recommended and preferably selective, using a product legally approved for that particular crop and pest at the recommended dose and time.
This is the principle behind Integrated Pest Management (IPM): observation first, prevention next, encourage natural enemies, use cultural, mechanical and biological measures wherever practical, and use chemical pesticides only when genuinely necessary.
Before You Spray, Look Once More:
The small wasp flying around your crop may appear insignificant. A spider sitting quietly beneath a leaf may appear useless. A ladybird beetle may simply look like another insect. But each may be performing a service for the farmer. So, before pressing the pesticide sprayer, observe the crop once more.
Ask yourself:
“Am I killing only my enemy—or am I also killing the enemy of my enemy?”
If these tiny natural pest controllers could speak to us, perhaps their message would be simple:“Farmer friend, we are protecting your crop. Please don’t kill us.”
