The sun slowly disappeared behind the hills. The colour of the sky changed hues by the minute. I was at the banks of the Cauvery at Galibore sitting under a gigantic Arjuna tree Terminalia arjuna, soaking in the lovely evening.
Soon it became dark and was now the time for the stars to adorn the sky. A small lantern was brought in and placed on the table. In no time the lantern attracted scores of small insects – some familiar, some too small and some that made a brief appearance, not to be seen again.
Among these visitors was one little insect that decided to move about in the area where the lantern cast its light. It was neither unusual nor colourful. On the contrary, it looked like any other insect and was a dull brown except that it had a flatter appearance.
It had black beady eyes, a pair of antennae. A pair of tail like organs (cerci) that was very noticeable attracted my attention. So, it was photography time! I shot several pictures of this very active little insect until I was satisfied with what I got.
Later, when I was reviewing the pictures I realised that I had seen this insect earlier. The previous occasion was also close to the water and I had then identified it as a Stonefly (Order Plecoptera).
Stoneflies, like you may have guessed, spend their early days in water. The aquatic nymphs are in found in streams, along shores of lakes and often under stones. Now you know where they get their name from! The nymphs live in water until it is time for them to emerge as adults. Some of them have a very long nymphal stage –in some species lasting up to 3 years. Most stone flies do not feed as adults and those that do are known to be herbivorous. As adults they are not good fliers and hence seen in the vicinity of water bodies.
Reproducing is the main responsibility of adult insects. It is not different for stoneflies. To this end, the male stonefly has evolved a very interesting way of attracting the female. He taps on the substrate (often waterside vegetation) with his abdomen! Unmated females respond to this by drumming themselves. And the drumming signals are specific to each species!
I will leave you with another interesting aspect of the stoneflies before I close. These insects generally require unpolluted waters to survive. Hence their presence in a water body is (thought to be) an indicator of very good water quality!