Constant and shifting photoperiods as seasonal cues during larval development of the univoltine damselfly Lestes sponsa (Odonata: Lestidae)

Larvae were reared at 21.5°C from eggs from southernmost Sweden, and fed ad libitum to emergence in four different photoperiodic treatments, intended to represent increasing levels of time stress: constant LD 16:8, corresponding to late April (or August) conditions, a shift after about two weeks from LD 16:8 to 19.5:4.5, coarsely simulating late spring, constant…

Aspects of life history of Platycnemis subdilatata (Zygoptera: Platycnemididae) in Northeast Algeria

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…

Voltinism of Calopteryx haemorrhoidalis, (Vander Linden) in the Sierra Morena Mountains, Southern Spain (Zygoptera: Calopterygidae): A preliminary study

Small sweep-net samples of larvae of Calopteryx haemorrhoidalis, obtained during five consecutive years from a permanent stream in the Sierra Morena Mountains, southern Spain, were combined according to month to infer the voltinism during the study period. Detailed records of head width, wing-sheath length and metamorphosis status for individual larvae are consistent with the population…

The Odonata of Tunisia

Between 1987 and 1999 several visits to 69 localities in Tunisia were made. Altogether 46 species of Odonata, including 10 new to Tunisia, were recorded, raising the Tunisian checklist to 52 species. Our observations cover early May to mid June and late September to early November. Using as a basis for inference data from nearby…

The impact of forestry on dragonfly diversity in Central Sweden

A survey of 32 lakes for dragonfly larvae, aquatic plants and forestry regime in the surrounding boreal forests was performed. The highest diversity was found in undisturbed forests. Lakes rich in aquatic plants were shown also to be rich in dragonflies. A rich plant community is proposed to provide a wider range of microhabitats thereby…