It is often assumed that males do not choose among females because competition for partners is high and male mating costs are low. Nevertheless, this assumption does not always hold. In some species duration of copulation is long, possibly causing a limitation on the lifetime number of matings for males. In this case we expect…
In Norway and throughout the rest of Europe, a continuous decline in the number of small lakes and ponds has taken place. As a consequence, many pond-dwelling organisms have become rare or extinct. Constructed wetlands (CWs) have since the 1990s been used as a remedial action against agricultural runoff. This study has investigated the potential…
Forty-five species of Odonata have been recorded within Numidia, which includes the El Kala and the Guerbes-Senhadja wetlands in northeastern Algeria. Five species are new to the area. Changes occurring in dragonfly diversity over a century and a half are discussed. This paper (Part I) deals with the status and spatial distribution of each recorded…
The final-stadium larva of Leucorrhinia patricia Walker is described from six exuviae with associated teneral adults collected in northern British Columbia. L. patricia belongs to the group of nearctic Leucorrhinia that has larvae with three ventral stripes. The larvae are very similar to those L. hudsonica (Sélys) larvae that are small and lack dorsal spines….
This paper is dedicated to Philip S. Corbet on the occasion of his 70th birthday.
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…