A two-variable analysis of male and female Cordulegaster boltonii larvae (head width and hindwing sheath length) in specimens from five Iberian populations was carried out with the objective of ascertaining whether these traits differ between populations.
Within wide geographical areas, Odonata populations can show biometric differences as a consequence of both biotic (e.g., predation, competition) and abiotic factors (mainly temperature). These differences can occur in the larval stage, although reliable characters are needed to detect differences.
The effects of photoperiod and temperature on the termination of egg diapause were examined in Sympetrum frequens. Eggs were obtained from adult females collected from three locations in Japan and incubated under short- or long-day photoperiods at a constant temperature of 25, 20, or 15°C. Egg diapause was eventually terminated in all treatments. Because differences…
Some structural characters, such as wing venation, have been used in odonates to differentiate taxa. In Cordulegaster boltonii, a species widely distributed throughout the western Palaearctic, the main characteristics of its wing venation have not been quantified until now.
Oviposition of Sympecma paedisca was observed in eastern Kazakstan. The main oviposition substrates were living Phragmites leaves. In comparison with European and Japanese populations we propose geographic variation in the proportional use of horizontal versus vertical oviposition substrates. Ovipositing females seemed to avoid the inner parts of Phragmites stands and there was a preference for…
This paper, a companion to Part I which treated status and distribution of Numidian Odonata, summarizes current knowledge of their seasonal ecology and identifies areas where promising research avenues exist. Annual patterns of adult occurrence and reproductive activity are used to infer life cycles, with particular reference to strategies that enable species to bridge the…
Well-adapted flight morphology must allow for efficient behavioral activities. Wing shape has been shown in a variety of species to be influenced by environmental conditions. Analysis of wing shape using geometric morphometrics provides a visualization of wing shape variations. This study examined the effects of varied environments on wing shape and wing size of the…
Aciagrion Selys, 1891 is one of the taxonomically difficult and poorly known genera of Oriental damselflies. Aciargion hisopa race krishna Fraser, 1921 was described from Mahabaleshwar, Maharashtra, India. However, later Fraser (1933) doubted the taxonomic necessity of this taxon. His notion of Aciagrion hisopa (Selys, 1876) was erroneous, as evidenced by syntypes of this species…
Size and mass are often uniformly related within individuals and populations, but the relationship may vary in time or space. I asked whether isolated adult dragonfly populations within the same environmental context (climate, physiography, ecoregion) differ in both size and mature mass, and whether earlier emerging dragonflies are both larger and heavier on average. Differences…
Climate change brings with it unprecedented rates of increase in environmental temperature, which will have major consequences for the earth’s flora and fauna. The Odonata represent a taxon that has many strong links to this abiotic factor due to its tropical evolutionary history and adaptations to temperate climates. Temperature is known to affect odonate physiology…