Amanipodagrion gilliesi was known previously only from four males collected in 1959 and 1962 in the Usambara Mountains, south-east Tanzania. Recently it has been rediscovered at two shady streams in that area. The species is not living in swamps, as previously stated, but is apparently restricted to a small area in the Amani-Sigi Forest. Data…
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…
Pseudagrion emarginatum is removed from the synonymy of P. melanicterum. The following synonymies are established: P. coeruleiceps of P. emarginatum and P. angelicum of P. camerunense. The latter, formerly known as Enallagma camerunense, should be removed from the list of threatened African Odonata.
Argia rosseri sp. nov. is described from central Bolivia. Holotype ♂: Santa Cruz Department, Florida Province, seep along Rio Achira, 8.6 km E of Samaipata (18°09′42″S, 63°48′53″W), 1,400 m a.s.l., 25 xi 1999; allotype ♀: same locality, 05 xi 1998; both leg. K.J. Tennessen. The new species appears to be related to the A. gerhardilnigrior…
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…
The European Platycnemis acutipennis and P. latipes and the African Mesocnemis singularis aggregate during oviposition. Choice experiments show that, in all three species, groups develop because tandems preferentially land where conspecifics already show oviposition behaviour. Just a single motionless male in the typical vertical position of a tandem male stimulates aggregation and oviposition behaviour in…
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…