Coenagrion mercuriale is a threatened damselfly in most parts of its geographic distribution. It is listed as endangered in North Africa, where no data on its biology or ecology are available. This study aims to illustrate the reproductive behaviour and habitat preferences of adults in a population located in north-east Algeria, representing the southern limit…
The behaviour of Onychogomphus uncatus, including flight and mating activity, was studied at a fast-flowing irrigation canal. During the day, males perched in sections of the canal with a strong current and a turbulent water surface. During short flights, interactions with other con-specific and hetero-specific males occurred, particularly with Orthetrum coerulescens. Under conditions of high…
Amanipodagrion gilliesi was known previously only from four males collected in 1959 and 1962 in the Usambara Mountains, south-east Tanzania. Recently it has been rediscovered at two shady streams in that area. The species is not living in swamps, as previously stated, but is apparently restricted to a small area in the Amani-Sigi Forest. Data…
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…
In high densities males of Calopteryx splendens showed alternative reproductive behaviour at the river Oker in northern Germany. One of several tactics was to pursue females. Pursuing flight was filmed in summer 2006 in slow motion. Frame by frame analysis showed that males fly in irregular flight patterns: they showed different lengths of wing beat…
The status of the Odonata as a model taxon for studying the evolution and diversity of reproductive behaviours is shown here to have declined relative to crickets and Drosophila. Very few available data on ejaculate size, the number of sperm stored by females and the duration of sperm storage reveal poor knowledge of these areas…
The habitat, territorial and reproductive behaviour of the Bornean calopterygid damselfly Vestalis amabilis, are described. Males are territorial and will remain at the same site defending a territory for up to three weeks. Territories take the form of sun flecks whose physical location changes slowly throughout the day as the sun moves across the sky.
Zygonyx torridus inhabits waterfalls, rapids and riffle sections. Males patrol over these sites. After copulation the partners perform an extensive search while flying in tandem over a wide range. Behavioural studies in Mauritius 1997 and 2014 showed that there is considerable plasticity in oviposition behaviour. Three main modes could be distinguished: (A) egg-laying in tandem…
Monitoring methods always recommend gathering data during the maximal activity of adults. Hence monitoring the threatened Lestes macrostigma requires knowledge of its activity pattern. Dragonfly “activity” is ambiguous and its intensity can be assessed in different ways, including by the threshold of response to a predator stimulus, i.e. “awareness”. We studied the daily pattern of…
Predation of aggregated, ovipositing tandems of Sympetrum sanguineum and S. vulgatum by the hornet Vespa crabro was observed in Belarus. The same species of hornet was seen killing territorial males and copulating females of Calopteryx haemorrhoidalis in Italy. Numerous remains of these odonates at the oviposition sites suggest that attacks occur frequently. A short review…