The previously unknown larva of Argia jujuya Ris, 1913 is described, diagnosed and illustrated. Among other characters, the following combination is important to distinguish it from other species in the genus: antennae with six concolorous segments, ligula projected only slightly, row of small premental setae present, abdominal sternum 8 almost entirely covered with spiniform setae,…
Although the sex ratio of Odonata at emergence has received much attention, we are still far from understanding the exact causes of its variability and imbalance. In this paper we studied the sex ratios at emergence in natural populations of two Gomphus species based on samples of exuviae taken from two European lowland rivers. We
Recent findings suggest that postmating prezygotic isolation (i.e. gametic barriers) could be an important factor preventing hybrid formation. Competitive gametic barriers emerge when a female is inseminated by a conspecific and a heterospecific male. We examined whether sperm proportions after double matings and copulation duration impede hybrid formation. For this, we used females of Ischnura…
The placement and relationships of the red-and-black zygopteran Pyrrhosoma, currently considered to be part of the Teinobasinae, has long been uncertain. DNA fragments (COI and ITS) reveal that Pyrrhosoma s.s. is restricted to the West Palaearctic, with two morphologically distinct name-bearing clades (nymphula, elisabethae), and with a morphologically indistinct third clade in the Middle Atlas,…
Two new species, Cephalaeschna cornifrons sp. nov. and C. ordopapiliones sp. nov. from Yunnan Province, China, are described, illustrated in color and compared with known Chinese Cephalaeschna. All the holotypes are deposited in the Collection of Aquatic Animals, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan City, Hubei Province, China. Brief notes on biology of…
The final instar larva of Heliaeschna idae Brauer is described and figured for the first time based on the exuvia from an advanced female larva collected in Sarawak, Borneo (East Malaysia). It is compared with the known larvae of the genus and is concluded to be most closely allied to Heliaeschna simplicia Karsch, with which…
Three new Cephalaeschna species, C. discolor sp. nov. (holotype male; Shennongjia National Nature Reserve, Shennongjia City, Hubei province, China, 16 August 2012), C. mattii sp. nov. (holotype male; Lujiahe River, Zigui County, Hubei province, China, 18 September 2012) and C. solitaria sp. nov. (holotype male; Dalongtan in Shennongjia National Nature Reserve, Shennongjia City, Hubei province,…
This study showed that the main impact on Odonata species of removal of riparian vegetation for road building was on community composition, since species richness remained unaltered. This result, most evident in damselflies, was probably driven by the entry of generalist species that replaced specialist species after the impact. We collected adult odonates in forested…
Distribution and abundance of sympatric Mnais costalis and M. pruinosa damselflies were studied in a low mountain stream in Shiga, Japan, from 2008 through 2012. The reproductive seasons of the two species overlapped almost entirely: both species emerged in early May and disappeared in late June each year. Males of both species hold territories within…
Rhinocypha taiwana Wang & Chang, sp. nov. is described and illustrated for both sexes. The genetic distance of the cytochrome c oxidase I (COI) gene in R. taiwana and related species ranges from 4.2% to 10.4%. R. taiwana is shown to be a good species based on morphological and genetic criteria. It also is clearly…