The distribution of an isolated population of adult Calopteryx haemorrhoidalis was studied along a small stream in NE Spain, during two-week or three-week summer periods over five years. Distribution patterns differed consistently between age groups. Reproductive activities took place along the entire stream, whereas the presence of tenerals and older immature individuals was restricted to…
Anisoptera were monitored or sampled regularly at lowland and nearby upland sites in northeastern Algeria during 1992 and 1993. After emerging in lowlands at about sea level in May and June, adults disappeared from lowlands and were then soon encountered in nearby hills at ca 500-1000 m a.s.l. where they aestivated in woodland for about…
Dragonflies are commonly used as indicators of environmental quality and different methods have been employed to monitor odonate assemblages, such as surveys of all adults, evaluations based on breeding adults, sampling of larvae and collection of exuviae. Results obtained with different sampling methods may not be interchangeable, as the different life stages (e.g. larvae, adults)…