Many insects including odonates thermoregulate using a combination of behavioral and physiological mechanisms. At high ambient temperature (Ta), these mechanisms include decreased heat production and increased heat loss. Heat production can be reduced by decreasing activity. Heat loss can be enhanced by perching in a shaded microhabitat where temperature is cooler than in the surrounding environment.
This short communication reports on the warming ability of the damselfly Sympecma paedisca, which is known for its winter hibernation and tolerance to low temperatures. The data were collected using an infrared camera in late September on two sunny days (air temperature 15–17°C) in the vicinity of Kyiv, Central Ukraine. The obtained data show that…
Regulation of thoracic muscle temperature has been investigated in a number of dragonfly species but is poorly known in the large and diverse family, Gomphidae. Moreover, temperatures of other body regions have been recorded in very few ectothermic insects. In addition, correlations among multiple components of thermoregulatory behavior have rarely been examined quantitatively. Here I…
How species respond to shifting environmental conditions is a central question in ecology, especially because ecosystems are experiencing rapidly changing climatic conditions. However, predicting the responses of species interactions and community composition to changing conditions is often difficult. We examined the effects of rearing temperature and resource level on larval survival of two ecologically similar…
In many cases where two closely related species coexist, ecological interaction or reproductive interference drive species to diversify in their body size and/or other signal traits, often concurrently with microhabitat segregation. However, it is usually unclear how character diversification is associated with microhabitat segregation. We performed laboratory experiments using males of two damselfly species (Mnais…
We review the knowledge about the thermal reaction norms of larval growth in Odonata with a focus on the temperature response function. We re-analyze literature data and present our own results on growth rates of larvae of 14 species of Libellulidae reared at different temperatures. Temperature response curves (TRC) were fitted in order to estimate…
Although the sex ratio of Odonata at emergence has received much attention, we are still far from understanding the exact causes of its variability and imbalance. In this paper we studied the sex ratios at emergence in natural populations of two Gomphus species based on samples of exuviae taken from two European lowland rivers. We
In a heterogeneous environment, males of Somatochlora flavomaculata regularly occupy site-fixed locations away from water, adjacent to vertical landscape elements, and to a lesser extent, also at water, i.e. at oviposition sites. Territories both over land and over water are typically patrolled by continuous site-fixed flights. These places serve as rendezvous sites where copulation is…
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…
Body temperature regulation and behavioral responses to temperature variation in the field were investigated in Sympetrum vicinum, a common North American libellulid that is most abundant as a mature adult in autumn. Because of its late flight season, this species is faced regularly with cooler environmental temperatures than most dragonflies investigated heretofore. By virtue of…