Oviposting Bayadera species!

Saturday July 11 I was checking a stream near Nam Bung in Yen Bai Province. Yes, we know that now from the previous posts. But here I want to relate a special spectacle. In the morning I saw a great many Bayadera. Previously I had seen 3 species along this stream: B. hatvan, B. serrata, and B. hyalina. Of these B. hatvan was by far the commonest. This time I did not see B. serrata, but I saw many copula of the other two species. They could be seen ovipositing here and there in floating logs. But in the canyon there was a large tree that had been cut and toppled down into the stream, where it remained standing up. However, it stood in the middle of a water spray from a waterfall, making it soaking wet. There were a great many (several score) tandems ovipositing on it. Interestingly, the tandems formed single species clusters for some reason undoubtedly instinctively clear to them, but not to me.

Three tandems of Bayadera hatvan out of a great many more. It was not easy keeping my camera sort of dry.

A single tandem of B. hatvan. I lined the camera up with the trunk, but in reality they were almost vertical.

Two tandems of B. hyalina, braving the wetness. They were 20cm lower than the Bayadera hatvan tandems.

Adjusted angle of the same tandems of Bayadera hyalina.