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…
Oligoclada mortis sp. nov. (holotype male deposited in MZSP: Brazil, Rondônia State, Porto Velho municipality, “T[ransect] 5-21, seg[ment]12” (09°35′19′′S, 65°02′50′′W, 106 m asl, 13 v 2010, leg. Nogueira & Mendes) is described and illustrated based on two males. The new species fits within Borror’s Group III, differing from all other described species in the genus by…
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
Oviposition site selection is crucial in the life history of odonates since females must find a suitable habitat to enhance larval survival and development. Males perch at these sites to get access to females to mate. Here we studied how different types of vegetation influence site selection of the damselfly Oxyagrion microstigma in a Neotropical…
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….
A comparative study of female external genitalia was carried out in representatives of three dragonfly families that lay eggs exophytically, with special emphasis placed on skeletal musculature and sensilla. Female external genitalia are characteristically represented by the vulvar lamina and rudiments on the 9th sternum. In a gomphid, Gomphus vulgatissimus, and a corduliid, Cordulia aenea,…
Detailed descriptions and illustrations are provided of the ultimate instar larvae of Argia medullaris and Argia variegata from Colombia. The principal features are outlined and compared with other species. Argia medullaris differs from other species of the genus by the parallel width of the lateral gills and prominent ligula; the A. variegata larva can be…