As warm-adapted insects of tropical origin, Odonata cope with cold periods by seasonal regulation and diapause. A model for larval-overwintering species is proposed with three response patterns related to the timing of emergence, which can be predicted from seasonal cues during the last few stadia. For emergence during the present season, there is an often time constrained pre-emergence development, accelerated by long days and higher temperatures.
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…
Although a full life cycle approach is optimally needed to make conservation decisions, the egg stage is often neglected for insect species of special conservation interest. Water management and related abiotic factors are relevant factors to consider in aquatic species. Lestes macrostigma is a threatened damselfly restricted to temporary brackish waters. Here we provide detailed…
The hatching phenology of 15 Odonata species was studied under seminatural conditions to find out how the hatching modes of typical species of summer dry temporary waters (vernal ponds) differ from those of species inhabiting both permanent and temporary waters. We attempt to answer the following questions. (1) Do vernal pond species hatch earlier in…
Phenotypic plasticity represents an adaptive tool in organisms including odonates to cope with heterogeneous environmental conditions. However, while some odonate species can occupy various changing habitats, other species are adapted to a narrow range of environmental conditions. Commonly, behavioural modifications are applied to avoid detection and encounters with predators. But reduced behavioural activity results in…
When comparing the phenology of species within the family Lestidae in Numidia, northeastern Algeria, we found that: (1) four of five species—Lestes barbarus, L. numidicus, L. viridis, and Sympecma fusca—feature a prolonged pre-reproductive period approaching five (Lestes spp.) or eight months (S. fusca); (2) adults of L. numidicus, and probably of S. fusca, move to…
Larval growth rate has the same temperature coefficient in three species of coenagrionids, but Argia vivida and Amphiagrion abbreviatum, which frequently live in geothermally heated water, grow fastest at 29.0–30.0°C compared with 23.4°C for Coenagrion resolutum, which lives in cooler water. Survival below 15°C in the laboratory was much better in C. resolutum. These characteristics…
In recent decades, a lack of available knowledge about the magnitude, identity and distribution of biodiversity has given way to a taxonomic impediment where species are not being described as fast as the rate of extinction. Using Machine Learning methods based on seven different algorithms (LR, CART, KNN, GNB, LDA, SVM and RFC) we have created an automatic identification approach for odonate genera, through images of wing contours.
Odonata (dragonflies and damselflies) are efficacious for management and conservation efforts in freshwaters. In recent times, increased effort has gone into enhancing awareness, data and information on dragonflies among scientists and policymakers.
Adaptation of life-history traits is an important factor for the success of insects. Voltinism is a feature that descends from several life-history traits and, given that the latter depend on the specific environment of growth, voltinism can vary between populations across latitudes or habitats. In addition, some insects, like many odonates, have developed different patterns…