Habitat requirements of Orthetrum coerulescens and management of a secondary habitat in a highly man-modified landscape (Odonata: Libellulidae)

Due to the destruction of its primary habitats, the West Palaearctic libellulid Orthetrum coerulescens has suffered much decline in central Europe. However, at the regional scale it has survived in a variety of secondary habitat, such as draining ditches. In order to find adequate measures for its conservation and promotion, habitat use and habitat recognition…

The Orthetrum coerulescens complex in Bulgaria (Odonata: Libellulidae)

Although there are many records of Orthetrum coerulescens in Bulgaria, the presence of the nominotypical subspecies is doubtful. A critical analysis of all specimens available revealed that they belong either to O. c. anceps or to intermediate forms, but not to O. c. coerulescens. The latter taxon is therefore omitted from the Bulgarian species list,…

Diel pattern of activity, mating, and flight behaviour in Onychogomphus uncatus (Odonata: Gomphidae)

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…

Lifetime egg production of captive libellulids (Odonata)

The estimation of lifetime egg production (LEP) is a central question in ecology, since the number of eggs produced determines the potential size of the following generation. In this study, I tried to obtain a rough estimation of the LEPs in libellulids in outdoor cages. The main questions were: (1) does hand feeding influence females’…