The determination of seasonal regulation is important to understand how species have adapted to their local environmental conditions. In this study, we investigate the life history of a North African endemic damselfly, Platycnemis subdilatata, in a northeast Algerian population. We combined field and laboratory investigations to assess the embryonic development, larval growth, emergence pattern and…
Female limited polymorphism consists in the coexistence of two or more female morphs in the same population and is widespread among odonates. Generally, one female morph, the andromorph, resembles males in colour or, sometimes, also in morphology and behaviour, while one or more other morphs, gynomorphs, differ from males. This phenomenon is probably promoted by…
Polythorid damselflies are Neotropical stream dwellers, whose behavior has rarely been recorded. Here we describe the territorial and courtship behavior of Chalcopteryx scintillans McLachlan, an Amazonian damselfly with shiny copper-colored hind wings. Territorial behavior consists of aerial contests, when males engage in threat displays and mutual pursuits in ascending and rocking flights. During courtship, males…
By means of slow-motion film analysis we found new female refusal behaviour patterns against male harassment in a variety of Odonata species. Often, females could escape simply by flying faster than males. Due to the morphological preconditions, there were differences in the two suborders. In Anisoptera, several behavioural specialities were analysed: (a) females of Aeshna…
Little is known about the ability of adult dragonfly individuals to survive into or over the winter in the Cape Floristic Region (CFR), a significant biodiversity hotspot in South Africa. Dragonfly species richness and abundance were recorded throughout winter and into spring in Jonkershoek Nature Reserve. Several environmental variables were also measured. Individuals of eight…
Slow motion films of fight behaviour of five different species of Odonata were analysed. In all cases biting played a major role. The biting duration depended on the duration of a stable connection between the two opponents. Sitting odonates showed much longer biting than those that were flying. In fights of Anax junius and Calopteryx…
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…