The larva of Erythrodiplax media is described and illustrated based on two exuviae of reared larvae and one final stadium larva collected in Xangri-lá, State of Rio Grande do Sul, Brazil. The larva of E. media can be distinguished from other species of Erythrodiplax by the presence of lateral spines on S8 and S9, the…
Dragonflies and damselflies are important study organisms in many areas of biology. Laboratory experiments with these insects have a great potential for answering evolutionary, ecological and physiological questions. Laboratory studies require insect rearing, because it can provide large sample sizes of specimens that are available throughout the year. These insects are reared under known conditions,…
I investigated whether the level of male harassment affects females’ oviposition behaviour, such that females oviposit unguarded under suboptimal conditions and/or vary oviposition duration, dip number, dip frequency or number of oviposition site changes. The study species were the libellulids Crocothemis erythraea, Ortbetrum chrysostigma, Pantala flavescens, Sympetrum fonscolombii, Trithemis annulata and T. kirbyi ardens. Only…
Large libellulid dragonflies often fly higher than smaller libellulids. We hypothesized that this size-related pattern in flight height might be caused by aggressive displacement. We tested this hypothesis by using a 30 m “dragonfly zip-line” to reel dead dragonfly decoys of four species of different sizes (Erythemis simplicicollis, Libellula incesta, Pachydiplax longipennis, and Perithemis tenera) along…
Oviposition behaviour by Sympetrum frequens, a species endemic to Japan, has been observed throughout its entire breeding season, which extended for about one month after the harvest of rice. Approximately 50% of oviposition events occurred during the first week of the reproduction period. Sunny oviposition sites were preferentially selected by ovipositing pairs. The starting time…
Populations of Ischnura hastata found in the Azores archipelago represent the only known example of parthenogenesis in the order Odonata. In this paper, we present results from fieldwork done on the islands of São Miguel, Pico, Santa Maria, and Graciosa, aimed at characterizing population ecology and habitat preferences of this species. Sampling of several ponds…