Reproductive behavior of Acanthagrion truncatum Selys, 1876 (Odonata: Coenagrionidae)

Behavioral data on Neotropical coenagrionids is still scanty, with very few studies on their reproductive behavior. Here we present the first description of the reproductive behavior of A. truncatum in a high density population in the Brazilian Neotropical savanna. The observations were made at a pond in an ecological reserve. Males remain at the water searching for females. Females remain in the surrounding vegetation and only approach the water to mate and oviposit. The mean duration of copulation was 25.6 +/- 3.26 minutes. Copulations are concentrated between 12:00 and 14:00 h (71%). Females oviposit in tandem with males, sometimes submerging to oviposit. Oviposition took 43.08 +/- 22.17 minutes. Female underwater oviposition seems to disrupt male guarding and females emerge from the water by themselves. Malemale interactions usually consist of chases and facing off. This damselfly species is apparently non-territorial, since males did not defend resources and searched for females in the area.