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
Odonates of small temporary pools, marshes, large permanent ponds, oxbow lakes, dams, and perennial rivers were sampled in the semiarid Chaco biome of NW Argentina between September 2007 and December 2008. Information from 35 localities yielded 60 species; presence/absence information of species was recorded in a spatial-relational database. Alpha, beta, and gamma diversity and total…
With a total of 75 species the odonate diversity in the Namibian desert is surprisingly high. Based on their distribution characteristics, invasion patterns, and breeding success, there are six well-defined categories of Odonata: widespread species – (1) permanently living in the desert, and desert biased, (2) permanently living in the desert, but not desert-biased; (3)…
The reproductive behaviour of Neurobasis kaupi was studied for the first time in Central and South Sulawesi. The species was recorded in a wide variety of clear and fast flowing creeks, streams and rivers, mostly in forested areas. The males were territorial and defended potential oviposition sites, a limited resource. Territory owners demonstrated their presence…
I sampled odonates in pristine lower montane rainforest in Papua New Guinea over several months, recording habitat characteristics for all encounters with adult odonates. Using ordination techniques such as cluster analysis and canonical correspondence analysis I then classified the odonate fauna into assemblages correlated with environmental factors. Within the 2.5 km2 study area I found…
In this report we review the conservation status of Odonata of southwestern Africa, viz Angola, Botswana, Namibia, Zambia and Zimbabwe. In total, 287 species have been recorded of which three have been previously listed by IUCN. We consider 60 species mainly because of their endemism in the region. The majority of the species have to…
The microdistribution patterns of larval Gomphus graslinii and Oxygastra curtisii in three rivers in southern France were studied. While G. graslinii was caught mainly in sandy reaches covered with leaf litter, O. curtisii was found almost exclusively clinging to alder roots at the river margins. Preferences of habitat structure were determined from habitat selection experiments…
The range of Macromia splendens, a rare anisopteran, includes SE France and some scattered localities on the Iberian Peninsula. During 1996-1998, I made an exhaustive search for the characteristics of the species’ larval and adult habitat, flight period and adult activity in NW Spain. Nine populations were found, greatly increasing its known range. Adults were…