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Notes from Garden and Life

  • Writer's picturesubhashini

The Caterpillars ate my Newsletter!

There is this inconspicuous lemon plant in my backyard. It stands between a coconut tree and a rustic shelf where I store my gardening stuff. It is just a plant with green leaves for most of the year, except when it hosts the caterpillars of the Mormon butterfly.

Though it is not my first time observing these caterpillars, it is refreshing to watch a life cycle unfold and a butterfly being born.

The mormon caterpillars are usually seen twice a year on the lime plant- April/May and October/November. I was quite worried that I did not see these caterpillars in October last. I worry that the butterflies are dwindling.

When I saw them last month, I placed an umbrella on the plant to deter birds. In my honest opinion, I do not think it is wise to collect caterpillars and grow them in bottles or jars. Growing them in captivity and dropping a handful of leaves is sinful. I see a lot of people doing it nowadays thinking they are helping the caterpillars. Allowing them to grow in their natural habitat helps them develop their strength and refine their defense mechanisms. The first week there were twelve caterpillars, but only three made it to a butterfly. I guess some went in search of another place to pupate. That is how nature works. It is a privilege to observe, learn and not disturb them. And this newsletter is about that.

The Common Mormon is a swallowtail butterfly, marked by the characteristic tail like extension on their hindwing. The male has a jet-black wing with white markings at the bottom. The female sports red and orange crescent spots. These markings mimic the Crimson or Common Rose butterflies, which also belong to the swallowtail family.

Why would the Mormon butterfly mimic?

Nature is full of mimics and they do so for many reasons. Here, the butterflies mimic to protect themselves and send a signal to the predators that they too are strong. The Common Mormon butterflies are laidback happy butterflies, drinking nectar and mud puddling. You can spot them in the evenings sleeping on the tip of low branches. After a rainy day, you can see them basking in a sunny spot. They are not territorial and do not drive other butterflies away. The defense mechanisms that they have developed is to mimic the Common/Crimson rose butterflies which are uninviting to the predators. What is it these butterflies do differently? They feed on the toxic leaves of the Aristolochia vine and absorb the toxicity.

There are nearly five hundred species of Aristolochia. The most common being the dutchman’s pipe, pelican flower etc. The vine is made of the poisonous Aristolochic acid. The flowers emit an unpleasant odor to attract flies. They are therefore grown on compound walls and away from the main garden to keep away intruders. Even touching the leaves accidentally can make your hand stink.

The caterpillar of the Common Rose butterflies feeds on this vine absorbing the toxic acid. The butterfly has a bright pink body and flashing red colors sending signals to the predators that they are dangerous and unpalatable. The Mormons have learned that the best way to protect themselves is to look like these butterflies. It is called the Batesian mimicry, where the harmless species imitate the fiery ones.

The host plants of the Common Mormon butterfly are curry leaf and lime. The female mormon lays more than a dozen eggs on the undersides of the leaf or the stem, and it takes three or four days for them to hatch. The young larva eats its way out of the shell and consumes it.

The plant squirms with caterpillars for thirty to forty days. There are a total of five instars that the caterpillars go through. They move up and down the plant, across branches, and choose the leaves. Until the fourth instar, the caterpillars look like bird droppings. The fifth instar is when they undergo a dramatic change into a mini caterpillar. The pictures below were taken in a gap of an hour. Look at the two caterpillars on top and bottom. I missed watching them molting but look at the transformation!

A fully grown caterpillar is nearly five to six centimeters long and bulky. When it is ready for pupation, it seeks the tip of a branch or a stem, shrinks its body to enter the pre-pupation stage.

It takes twenty-four hours for it to spin the pupa. The pupa is green or brown with diamond markings on the underside and held by a silk girdle.

(It also happens that they venture out of the plant to build a chrysalis. I noticed one on the wall behind the mopping cloth and another on a pipe.)

Six days later, the pupa starts changing color. It turns black on the eighth day, and then transparent on the day it emerges.

The newborn butterfly dries its wings for a few hours after eclosion. Watch how it winds and unwinds its proboscis to smoothen it.

Butterflies are vulnerable from the moment they are born. I had to drive away a gecko, waiting to pounce on it. For people who ask whether the plant will bounce back with new leaves? Yes.

If you want to watch the life cycle of these caterpillars,

Check the lime or curry leaf plants in April and October. The caterpillars appear as small bird droppings on leaves. If the plant is in a pot, move it to a safe place away from birds. While taking photographs, avoid using the flash. Do not touch the caterpillars or shake the plant. Do not try feeding them with leaves or your newsletter.

Another notable thing that happened was the realization that I need to wear glasses. I found the photos in my camera roll blurry. I blamed the smudged camera lens at first but it later dawned that my eyesight was poor. I am bespectacled now.

See you next time with a fresh gossip from the garden.

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