The fluid dynamics of aerodynamic force control in insects depends on how oscillating wings interact with the surrounding air. The resulting flow structures are shaped by the flow induced by the wing’s instantaneous motion but also on flow components resulting from force production in previous wing strokes and the motion of other wings flapping in…
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…
Territorial behaviour and mate guarding are important components of mating systems in various insect groups, including the Odonata. This paper reports observations of male territorial behaviour associated with potential ovipositing sites, and postcopulatory, non-contact mate guarding in Petalura gigantea. This is the first unambiguous and detailed report of mate guarding in the Petaluridae. Additional observations…
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…
For eleven species of sympatric libellulids, male mean mass was positively correlated with wing aspect ratio, wing loading, and mean perch height. We tested the hypotheses that perch height selection was governed by interspecific competition or biomechanical responses to increased wind speed at higher perches. Although larger odonates might prefer higher perches to offset their…
Ten common libellulid species perch along the shoreline of lakes and ponds in South Carolina, USA. We collected individuals at five ponds throughout summer 2005, weighed them in the field, and calculated wing loading (N·m2) and wing aspect ratios from digital photographs. We measured the perch-height preferences of these species in ‘low perch’ (10, 20,…
Odonata flight performance capabilities and behaviour and their body and wing form diversity are explored, and their interrelationships discussed theoretically and from observational evidence. Overall size and particularly wing loading appear predictably to be related to speed range. In Anisoptera at least, relatively short bodies and long wings should favour high speed manoeuvrability, though further…
Dragonflies and damselflies (the Odonata) are among the most efficient flying insects. However, fragmentation of the landscape can increase distance between habitats and affect costs of dispersal, thus shaping phenotypic patterns of flight-related traits, such as wing shape, wing loading and wing size. Urban landscapes are highly fragmented, which limits dispersal among aquatic habitats. Hence,
Sympetrum striolatum (Charpentier, 1840) and S. vulgatum (Linnaeus, 1758) are two closely related Libellulidae that are widespread and common in Central Europe. The idea for this research originates from normally using saltwater shrimps for rearing young larvae, the observations of Sympetrum species laying eggs in seawater and the suggested ability of S. striolatum to colonize brackish water habitats.
Although the endemic damselfly, Platycnemis subdilatata Selys, 1849, is widespread in the Maghreb, many aspects of its reproductive behaviour, biology and ecology are still unstudied. One particular feature of this species is that its coloration pattern continues to change during maturation and afterwards, which makes it a good model for assessing age effects on behavioural…