Newspapershavewrittenalot about tremendous drops in insect populations and their imminent extinction. With the climate changing before our eyes, mountain ecosystems moving to higher altitudes, the Arctic losing its ice cover, this was very clearly part of a vast and immediate problem. Or so I thought until I saw a headline which said: Insects are declining in India and we don’t even have data. Umm, if we don’t have data, how do we know? It was time to do a web search. The results were not exactly reassuring, but not harbingers of doom either.
Insect populations are definitely declining worldwide, and extremely rapidly in some places. But, as an article in The Atlantic said “The claim that insects will all be annihilated within the century is absurd … Indeed, insects of some sort are likely to be the last ones standing.” Last year the journal Insect Conservation and Diversity put together a special issue on the topic of rapid decline of insects, where many of the articles pointed out that declines have been seen in several insect species, but increase was clear in others. Climate change and direct human intervention upsets all kinds of balances in nature. An article (pay walled, unfortunately) set out a further program for study, opening with the sentences “Many insect species are under threat from the anthropogenic drivers of global change. There have been numerous well‐documented examples of insect population declines and extinctions in the scientific literature, but recent weaker studies making extreme claims of a global crisis have drawn widespread media coverage and brought unprecedented public attention. This spotlight might be a double‐edged sword if the veracity of alarmist insect decline statements do not stand up to close scrutiny.“
So I am reassured that I can continue to worry about the numbers of green jewel bugs (Chrysocorix stolii) as I photograph them.
A bright green spot flew in front of me and landed on a tree which gives a characteristic redolence to this time of transition between sharad and hemant, the night-blooming jasmine (Nyctanthes arbor-tristis, parijat in Hindi and Odia, shiuli in Bengali, xewali in Assamese). When it landed I could see that the shiny green spot was a green jewel bug (Chrysocoris stollii, aka the lychee shield bug). I haven’t identified any of the other 450 jewel bugs, so I can’t be certain. But this had characteristic markings, and the colour, of what I was told was the C. stollii.
Of course one can do better these days, I realized as soon as I wrote that sentence. A little search with the help of google mamu told me quickly that the markings on the back were not of the C. pulchellus or C. patricius. I’m glad I did that check, because I found that in 2017 I’d posted misidentified photos; those smaller bugs were probably C. patricius. I’m also pretty certain now that this is not the C. purpureus, since that should be purple, as its name suggests. Could it be the C. hahn? The pictures I came across are confused, and I can’t figure out whether this is different. But let me go with C. stollii, for now, especially since it is supposed to be the most abundant of jewel bugs in India.
So what do I know about it? It is a bug, not a beetle, although the green shield could mislead you. If you look carefully, you’ll see that there is no mid-line parting on its shield; a beetle will have a divided back. You can also try to distinguish them by counting the number of segments on legs and antennae. Since it drinks sap from plants, it is considered a pest. My fund of knowledge runs out pretty fast. I must look for more bugs, this is a season for insects anyway.
If you are the kind of person who looks closely at leaves and trees now and then, it won’t be long before you start seeing the aptly named green jewel bug everywhere. It is widely spread across continental Asia. I see it in gardens all the time. So I was not going to post the featured photo.
But there is something interesting about these true bugs: apparently they are not found in the islands of Indonesia, Philippines, Sri Lanka and Japan. The photo you see above was taken in South Andaman near the Mount Harriet National Park. I wanted to put on record the fact that there are islands where it can now be seen. Whether it flew or was carried there by winds, or was introduced inadvertently by humans is unclear. Interestingly, the upper parts of its legs are orange, whereas the ones I’ve seen before all had green or black legs. There seems to be quite a bit of variation in form, size, and colour in this species, so I’m not sure how significant this colouration is.
It is fairly easy to photograph these, and other, metallic shield bugs. They are easily seen on upper surfaces of leaves, branches and flowers. They do not hide the moment they spot the huge eye of a camera looking at them. Maybe this has something to do with the fact that they can release bad-smelling chemicals when attacked, and therefore are not good things for predators to eat.
Note added in October 2020: Perhaps I was mistaken in the identification. This looks smaller than C. Stollii, and has somewhat different markings. Could it be the Chrysocoris patricius? I’m not yet sure, and I must read more.