Common Mormon Butterfly
Scientific Name: Papilio polytes
Common mormon butterflies are black colored very common butterfly found widely throughout Asia region. Tropical and subtropical regimes are most habitable for common mormon butterflies. Bangladesh, the country I live in, is situated in subtropical region, so these butterflies are found here widely.
Since the pandemic of COVID-19 started, I’ve been spending more time to the garden as I’m staying at home. We have a rooftop garden with lots of plants. So everyday I get this amazing opportunity to learn about the local insects more closely on the garden. There are several plants, some fruiting plants, some flowering plants, some vegetables and some weeds as well who have lovely tiny flowers. And these flowers attract the insects on our garden and lets me to watch them better. There’s is a mandarin orange plant in our rooftop sheltering many bugs and insects. It’s like an entire ecosystem is out there on that one single plant and that’s where I’ve been seeing some caterpillars for a couple of months. At first I had no clue of what could they be but later I got to know that they were caterpillars of "Common Mormon Buttrrfly". It was great to find something so interesting during such uncertain situation. So I got to observe the whole cycle of their life, starting from teeny-tiny eggs to splendid black butterflies hovering on the flowers and this writing is all about the observations I had on them since the month of april to july.
From laying eggs to making chrysalis, all steps have taken place on this one single tree. Common Mormon Butterflies are swallowtail butterflies and have five instars on their life cycle.
Common mormon's whole life is full of mimicking others to protrct themselves from predators.
Life of a common mormon starts from an egg. Adult female butterfly lays eggs on the young leaves, on the petiole or underneath of the leaves. These eggs are lime yellow colored and very similar to the eggs of common lime butterfly eggs. So, it's very difficult to distinguish whether it's a common mormon's egg or lime butterfly's egg from the egg only. They took about 3 days to hatch and the tiny little larvae came out of the eggshell eating that out which is the first source of their nutrition.
Larvae of common mormon took 10-12 days to turn into chrysalis. Light brown coloured larvae is the young stage of mormon's larval stage. Brown and green, larvae of a common mormon comes in two colors. On second and third instar they were brown colored disguising as bird poop and on the third or fourth instar they're green, diffusing themselves on the green branches and leaves on the plant. When they turned to lime greenish color, it looks very cute and beautiful seeing them exploring around the whole tree on their mushy little legs!
Larvae of the caterpillars shed their skin for five times. When their outer skin got tighten for their body to stretch, they shed and leave their previous skin. Like the eggshell, they ate their previous skin too, leaving no trace of shedding and it took only about five to ten minutes to complete each shedding.
When their turned from brown to green it became more difficult to find them because there wasn't much difference left between the larvae and leaves of the mandarin plant for their bright lime color.
Young larva tends to eat the edges of very young leaves only whereas adult larvae ate the whole matured leaves leaving the middle line left only.
When they eat their molted skin, skeleton of head was only left. Maybe it was too hard for them to crush and eat.
When they eat enough to go for next stage to turn into a butterfly, they hang on a branch of the tree. They attached themselves on a branch with silky thread from their bottom and stays there until they turn into butterflies. This was the last molting stage and it's like a complete hibernation period.
As days passed on, the chrysalis turned green to light brown. It took about 13-15 days to turn into a complete butterfly.
Beautiful zet black butterflies came out of the chrysalis. They were so mesmerizing to look at. Though the common mormon caterpillars posses mimic behaviour for their protection, butterflies also follow the same mechanism for their protection. Female butterflies have several polymorphisms resembling other butterflies and it's very difficult to identify them from their polymorphism figures. It's quite common that they mimic common rose butterfly very often and according to my observation, I've seen two different polymorphisms of them flying around the garden. I didn't know about the polymorphism fact earlier so, it's really like a mind blowing fact of them. Though the changes in patterns and colors on wings are quite different and difficult to identify but it becomes easy with experiences from several observations.
Another interesting fact that I observed is, they lift up their head and stays like that while it's raining and doesn't make it down like the other times of their day. The reason could be for saving their head from drenching of the rain.
Citrus plants are on the top of the list of their food plants but some other plants are included on the list as well. They’re also found in fruit orchards, plants such as, wood apple (bael in bengali)(Aegle marmelos), gin berry (aashsheora in bengali) (Glycosmis pentaphylla), curry leaves (Murraya koenigii). I came across the list from different online sources and some other observers as well.
Caterpillar of common mormon looks very squishy, mushy, adorable to touch but they have defence mechanism too. Osmeterium is the name of the organ they use for denfence. It's a fleshy forky tongue like organ that stays hidden inside the body unless there's any need to come out. For a couple of times I noticed, when tiny ants came near to the caterpillars they threw out their osmeterium towards them and the ants went away. First I couldn't understood that it was trying to scare the ant because I didn't knew that ants are threatening for them.
In total I saw about ten to fifteen caterpillars of common mormon growing on the plant and it felt really great to see them so closely. They're very important for the ecosystem and play vital role on pollination. It's true that they are responsible for productivity loss on the citrus plants (because they feed on the tender young leaves) but they're one of the pollinators also helping in the increasement of productivity of fruits. And the most remarkable thing was the opportunity to observe them from such close.