Reproductive behaviour of Sympetrum striolatum (Charp.) at an artificial pond in northern Italy (Anisoptera: Libellulidae)

Observations were carried out at an artifical pond, where the larvae cannot survive but imagines exhibit reproductive behaviour (inch oviposition). The males attempt to perch at the pond, but only the "pond owner” does so, excluding the others which perch around the pond according to a hierarchy; those most successful in contest remaining closer to the water. Receptive females are usually present only above water. For this reason the pond owner has the greatest probability of finding a mate. After copulation he remains in tandem during oviposition. Meanwhile the second most aggressively successful male takes his place, and after oviposition the dominant male is usually excluded by the former, which becomes the new owner. Copulatory behaviour is described, and the factors inducing and limiting oviposition are discussed.