Egg size differences might have an important influence on reproductive success because they may lead to different offspring conditions, hatching date or larval size. We presumed that egg size in odonates positively correlates with egg development time, and larger eggs lead to larger larvae. However, we assumed that the size benefit could only be maintained…
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…
Clutch size is an important fitness component often quantified artificially by inducing oviposition in libellulid females. Female behavior and egg production of the yellow-veined skimmer, Orthetrum nitidinerve, were studied in northeast Algeria during its reproductive season. Data on reproductive behavior and biology of this Mediterranean endemic species has not been published previously. Males guarded territories…
The estimation of lifetime egg production (LEP) is a central question in ecology, since the number of eggs produced determines the potential size of the following generation. In this study, I tried to obtain a rough estimation of the LEPs in libellulids in outdoor cages. The main questions were: (1) does hand feeding influence females’…
Heliocypha perforata (sensu lato) is a common stream-dwelling damselfly widespread in mainland tropical Asia. Recently a report has been published suggesting possible ovo-viviparity in this species, based on the interpretation of evidence from a short video sequence. This video is re-evaluated. The internal and external anatomy of the H. perforata female reproductive system, including mature…
The maintenance of female colour polymorphism in coenagrionids is still an open issue. Here we ask if the three different female morphs of Coenagrion puella represent different reproductive traits in terms of clutch and egg size. Therefore clutch size and egg morphometry of the three female colour morphs were examined. We found that female colour…
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…
Demography and territorial behavior of Hetaerina cruentata was studied along three lowland streams located at Norte de Santander department in the Colombian Andean region. Adult damselflies (N: 278) were individually marked, and using their recapture histories we estimated survival, longevity, sex ratio, age groups and population size at each location.
Habitat loss and fragmentation induce a decline and endangerment of freshwater organisms such as Aeshna viridis, an endangered dragonfly species characterised by a specific insect–plant association to the macrophyte Stratiotes aloides. In order to implement conservation measures, a good level of knowledge about the occurrence, habitat requirements and quality, as well as patch size of…
Larvae were reared at 21.5°C from eggs from southernmost Sweden, and fed ad libitum to emergence in four different photoperiodic treatments, intended to represent increasing levels of time stress: constant LD 16:8, corresponding to late April (or August) conditions, a shift after about two weeks from LD 16:8 to 19.5:4.5, coarsely simulating late spring, constant…