Have you heard of Nature’s eating machines? They are nothing but caterpillars. What are they and why do they eat so much? Come, let’s find out
You may have heard your mother give a small shriek when she is shelling peas and flinging away the offending pod. The culprit is a tiny green worm-like creature with miniature bristles – a caterpillar – the larva of a butterfly or moth!
Caterpillars are the animal kingdom’s most voracious eaters. They range in size from 1 mm to 75 mm. They grow phenomenally, moulting or shedding their skin several times before they spin a cocoon around themselves in the last stage. The tobacco hornworm, for instance, will increase its weight by ten thousand times in less than 20 days!
Hairy horrors
The name derives from the Latin term for hairy cat. That’s because most caterpillars are covered with spiky bristles, fine hairs or spines that are usually connected to venom glands. The secretion from the glands situated at the base of the spines can cause intense irritation and burning. The hairs can also detach and lodge in the skin.
A species of American moth caterpillar carries a sting which can cause temporary paralysis. The Brazilian flannel moth caterpillars sting is so painful, it has been christened ‘bizos de fuero’ or ‘the fire-beast!
The caterpillar of the lasiocampid moth has spiny hairs hidden beneath the folds of skin on its back. When threatened by danger, it arches its back porcupine-like and attacks the predator with its sharp quill-like hairs.
More defences
Besides hair and venom, caterpillars have evolved a variety of tactics to deter predators.
Plants have toxins to defend themselves against herbivores. Some caterpillars have managed to get around this. The caterpillars of the monarch butterfly feed only on the poisonous leaves of the milkweed plant. Not only do they remain unaffected, they are able to store the poison in their bodies unchanged! Even as pretty orange-and-black butterflies, they make a nasty mouthful and predators avoid eating them. Some caterpillars vomit acidic digestive juices on their attackers and some produce bad smells from glands which they can extrude.
A few caterpillars wiggle long, whip-like organs attached to the ends of their bodies to frighten away flies or spin a line of silk and drop off from branches when disturbed. Many species thrash about violently when disturbed to scare away predators. One species called amorpha juglandis lets out a high-pitched whistle that scares away birds.
Clever camouflage
To escape detection, caterpillars can take on the appearance of bird droppings, leaves or twigs. Some lunch in peace within a woven silk gallery, or roll up inside leaves, or mine into the leaf surface.
Do or Diet
A majority of caterpillars feed solely on plants, but there are others that feed on decaying animal matter such as wool and the hooves and horns of dead ungulates. Predatory caterpillars eat the eggs of other insects, aphids, scale insects, or ant larvae or even caterpillars of other species. A few are parasitic on cicadas and leaf hoppers. Hawaiian caterpillars use silk traps to capture snails.
Farmers’ Pe(s)ts
Caterpillars are extremely destructive and can chomp their way through fruits, vegetables and other food crops, mainly feasting on the leaves. However, there are some species of moth caterpillars that are cultivated by man for their ability to spin lustrous silk.
Picture Credit : Google
