The common lime

Late in the morning I found a nice spot in the hotel in Tadoba from which to do some butterfly photography. Since these flighty creatures are more active at this time, it helps to have a bright day. A common lime (Papilio demoleus) flitted along a straggly row of periwinkles at the edge of the road. In the mornings it prefers to fly low. The butterflies lay their eggs on citrus trees, and the caterpillars are considered to be great pests since they can munch their way through substantial amounts of leaves. Tadoba is close to Nagpur, which is a center of orange trade. So there could have been citrus trees in the neighbourhood. In any case, in there parts of India ber (Ziziphus mauritiana), another host plant for the caterpillars, is also common.

What I find interesting about this butterfly is that it is highly invasive, being found across the world. In the 21st century it managed to reach the Dominican Republic, and is currently spreading fast across the Americas. It has no natural toxins, and is an easy mark for predators. The caterpilar is also parasitized by several wasps, whose larvae eat it from the inside while it is alive. How does it manage to spread in spite of these natural barriers to growth? The answer seems to be that it breeds fast. In the region around Nagpur there are eight or nine generations in a year. In cooler places they may pupate through winter.

Later I found a potter wasp’s nest in the hotel. These wasps belong to the subfamily Eumeninae, and are parasitic. They catch larvae of beetles or spiders, paralyses them, and brings them to their mud nests. There they lay eggs inside the paralysed animal, so that their larvae can feed on them as they grow. I wonder what fraction of wasps have evolved such parasitic lifestyles.