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…
Very little is known about the biology of larval odonates from the Neotropical region, and in particular there are no data on behavioral changes during ontogeny and growth ratios, though both are crucial to understanding the dynamics of Odonata communities. Here we study growth ratio, development patterns and behavior of Rhionaeschna marchali larvae. We characterized…
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…
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…
The aim of the study was to determine oviposition site selection in the endangered damselfly Coenagrion mercuriale in its UK stronghold and to determine hatching success of eggs. This was achieved by watching the behaviour of marked pairs from the onset of copulation to the end of oviposition and recording the number and duration of…
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…