Have you ever gone to pick a handful of curry leaves (Murraya koenigii) in the garden for your sambhar and thrown them away, seeing a caterpillar on them? Or wondered at the odd birds' dropping on certain leaves as you washed them, to put into your potato bhaaji? Fret not, these are the Common Mormon Caterpillar at various stages of their growth and are harmless.
The aromatic curry leaf is used by all of us south Indians copiously in our cooking. Most of us have a little plant in a pot on our terrace, or a fairly large tree in our gardens. But how many of us know that along with us, the Common Mormon Caterpillar voraciously feeds on the curry leaf too?
Go out and check the leaves of your plant or tree. You might be lucky to find the eggs of the Common Mormon which are laid singly on the young stem, or the underside of the leaves of the plant. They are nearly spherical in shape and a miniscule 1.2 mm in diameter. The egg takes about three days to mature. The young caterpillar eats its way out of the mature egg and the newly hatched caterpillar has a rather spiky appearance and is just three mm in length.
Nitin Ravikanth Achari a CBZ student says, “The interesting stage is the bird dropping stage, where the caterpillar looks exactly like the droppings of a bird. If they feel threatened, an osmeterium or two fleshy horns are projected out in defence.” “The large dark black markings are not their eyes, but are patterns meant to scare away predators. The real eyes are located in the lower sides of its head and are called ‘simple eyes',” says N. Arun Kumar a B.Sc student.
Arun goes on to say that after some ‘coaxing' his mother has left the plant alone in their garden for the caterpillars to enjoy and she buys her requirements from the market. “They are the best biological indicators of non-toxic plants such as curry leaves and citrus. Interestingly it is hard to spot them as they are cryptically coloured, to blend with the colour of the leaves, to escape from predators. However they are monophagus, which means they feed on only one host plant and can consume up to ten times their body weight,” explains Professor Ebenezer Wilson, faculty of Environmental Science, St. Joseph's College.
Check out the Common Mormon which might be happily munching all the crisp leaves on your curry leaf tree. It's fun to watch them pupate and after eight days of development, a beautiful, adult Common Mormon Butterfly emerges.
Bangalore has a lot of these little beauties; we just need to be sensitive and look out for them.
