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…
The functional morphology of the male caudal clasping apparatus of Zygoptera is compared to that of Epiophlebia superstes (Anisozygoptera) and Anisoptera. Hypotheses concerning the mechanics and muscle functions have been advanced by parallel construction of mechanical working models. The evolution of the clasping apparatus and the tandem linkage shifting – from the female pronotum to…
Site attachment and displacement of adult Somatochlora alpestris were studied by means of mark-release-resighting during two years at two clusters of ponds (A, B) ca 8 km distant from each other on opposite slopes of Prättigau Valley in the Swiss Alps. Data on 127 marked tenerals in 1998 and 92 in 2000 at (A) were…
We compared the larval abundance of Mecistogaster modesta between bromeliads at ground level and canopy level in a primary tropical wet forest. Zygopteran abundance correlated strongly with bromeliad diameter at both levels. Although the per-bromeliad zygopteran abundance did not differ between vertical levels, M. modesta showed a strong vertical distribution in abundance owing to the…
A terminology is presented for structures and events in larval development of Odonata with the aim of bringing terms into conformity with those used for other insect orders in the light of accepted views of homology. The terms ‘exuvia’, ‘larva’, ‘prolarva’ and ‘stadium’ receive special mention. Records of the number of stadia required to complete…
The morphology of the last stadium larvae of the African Coryphagrion grandis is described for the first time, based on one exuvia and three last instar larvae from Kenya. Taxonomically important morphological characters are illustrated and discussed. Important characters are the shape of the larval caudal appendages, the labial palpi and the branched setae on…
Oviposition in water-filled tree holes and mating behaviour of Hadrothemis scabrifrons was observed in a lowland coastal forest in Kenya. Conforming with the predominant mode of oviposition in the Libellulidae, females of H. scabrifrons touch the water with their ovipositor while hovering above tree holes. Male behaviour is opportunistic: usually males perch and patrol in…
The distribution of an isolated population of adult Calopteryx haemorrhoidalis was studied along a small stream in NE Spain, during two-week or three-week summer periods over five years. Distribution patterns differed consistently between age groups. Reproductive activities took place along the entire stream, whereas the presence of tenerals and older immature individuals was restricted to…
Boyeria vinosa is a common anisopteran in the southeastern United States. Here we describe relationships between the abundance of B. vinosa larvae and the chemical, physical and biological properties of the Enoree River of South Carolina and nine of its tributary stream systems. Chemical profiles were conducted weekly for seven weeks at 63 sites in…
This revision of the subgenus Marmaraeschna includes the description of three new species: Aeshna (M.) fissifrons, A. (M.) obscura and A. (M.) brevicercia, as well as redescriptions of the previously known species, including the first description of the male of A. (M.) pallipes, a key for males and females and an updated distribution for each…