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…
The larva of Argia percellulata is described and figured. It falls into the group of Argia larvae with a very prominent ligula and one palpal seta, but differs from its closest relatives by having tibiae usually with two well-defined dark rings, posterior margin of sternite 6 smooth, and posterior margin of sternite 7 smooth medially…
Morphometric and genetic differences were analysed for two closely related damselflies, Chalcolestes viridis and C. parvidens. A total of 305 male individuals were collected from six European countries (Austria, Croatia, Germany, Greece, Hungary and Portugal). Measurements from a total of 28 populations of C. viridis and C. parvidens and several intermediate forms were collected to…
It has been hypothesized that sperm removal ability in male Odonata (damselflies and dragonflies) has promoted sexual conflict over the sperm stored in the reproductive tract of the female. Although there is evidence supporting this hypothesis, most studies have been conducted in a small number of species from specific families. We explored sperm removal ability…
Behaviour of dragonflies was observed during the partial solar eclipse in Saitama, Japan, on 22 July 2009. The solar eclipse started at 09:54 h, reached its maximum magnitude of 74.9% at 11:12 h, and ended at 12:29 h. Light intensity at the peak of the eclipse was 1005 lx, a reduction by 28.2% of that…
Interpretations of behavioural visual cues, based on human perception of colour, may mislead because of the difference in our visual range compared to other animals. Investigations into ultraviolet (UV) reflectance have shown that this can be an important mode of communication in many animals. The present study focused on 10 species of British Odonata. Digital
Chlorogomphus manau sp. nov. (holotype ♂: Borneo, Sarawak, Kapit Division, Hose Mountains, 15 April 2011, RMNH) from Malaysia is described from the male and compared with other regional Chlorogomphus species.
In libellulids, mature oocyte size varies within and between individual ovaries. The regulating mechanism is not yet understood. Variations in the contents of the follicle cells, and thereby their ability to secrete material into the oocyte, might explain some of the observed differences in oocyte size. We therefore investigated the follicle cell surface, the interstitial…
The final larval stadium of four species of Cora are described and compared with known species in the genus. Cora skinneri Calvert, 1907, C. semiopaca Selys, 1878 and C. lugubris Navás, 1934 are described and illustrated for the first time using material from Costa Rica for the first two and from Colombia for the latter….
Burmagomphus schneideri sp. nov. (Rung Giong, Kanak commune, K’Bang district, 14° 8′42.05″ N, 108° 36′37.33″ E Gia Lai Province in the southern part of Vietnam, leg. Do, 27 iv 2010, to be deposited in Vietnam National Museum of Nature) is described from the male sex and compared with males of the closely related species B….