First report of underwater oviposition by the island bluetail damselfly, <em>Ischnura genei</em> (Zygoptera, Coenagrionidae)

Among odonates that exhibit endophytic oviposition, a few, mostly damselflies, are known to be able to perform underwater oviposition. Among them, just a few species do so very frequently. Here I report the first observation of underwater oviposition for the damselfly Ischnura genei, which becomes the eighth species of its genus known to adopt this strategy after I. asiatica, I. aurora, I. elegans, I. graellsii, I. hastata, I. nursei, and I. verticalis. The reasons why these species or other odonates choose this particular mode of oviposition on rare occasions are not yet known, although a number of possible costs and benefits have been proposed.