A negative relationship between clutch size and egg size is generally expected. However, no such trade off has been reported in Odonata. In this paper we analyse relationships between egg size and clutch size in the dragonfly subfamily of Sympetrinae using material from Norway, Sweden, Germany and France. Clutch size varied within and among the…
In September and October 1998 adults of Anax junius, (Common Green Darner) were encountered in small numbers at coastal sites in southwestern U.K. Circumstantial evidence supports the inference that they reached there on winds originating from New Brunswick and Quebec Canada in early September, a time when this species regularly migrates southwards along the Atlantic…
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.
We analysed COI and ITS sequences from a total of 69 European Pyrrhosoma nymphula (Sulzer, 1776) and three P. elisabethae Schmidt, 1948 to explore species boundaries and phylogeographic patterns in their Western Palearctic distributions.
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.
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.
Coenagrion castellani Roberts, 1948 was described from Italy as a distinct species almost 75 years ago but has generally not been recognised or was treated as a subspecies of C. mercuriale (Charpentier, 1840). Populations south of the Alps were recently shown to be completely isolated genetically from those in North Africa and elsewhere in Europe.
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.
In species of similar shape and size, biometric analyses make it possible to establish differences. Within one species, biometrics can help researchers to detect differences between populations and analyze their adaptations to environmental conditions. Until now little was known about the biometrics of the Iberian populations of Boyeria irene (Odonata: Aeshnidae), a large species living mainly in southern Europe.
In 2017, we investigated the population dynamics and flying activity of the south-east European endemic dragonfly species Cordulegaster heros Theischinger, 1979. This research was conducted in the southern part of Central Slovakia in the Revúcka vrchovina Upland at a submountainous stream called Drienok. The mark-release-recapture method was applied to study the population. Cordulegaster heros was…