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.
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…
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…
Published records of Mesopodagrion are reviewed and the distributions of M. tibetanum and M. yachowensis are given. Sinocnemis henanese is considered a junior synonym of S. yangbingi. Based on morphological and behavioural characters Sinocnemis is removed from Platycnemididae and placed in Megapodagrionidae. Species of Sinocnemis show a general resemblance to species of Mesopodagrion but it…
We revisit the hypothesis, first advanced in 1962, that, with regard to their means of thermoregulation and overt behaviour, two types of Odonata can be recognised: fliers, when active (during reproductive activity, primarily, or foraging) remain on the wing, whereas perchers, when similarly engaged, spend most of the time on a perch from which they…
Climate change brings with it unprecedented rates of increase in environmental temperature, which will have major consequences for the earth’s flora and fauna. The Odonata represent a taxon that has many strong links to this abiotic factor due to its tropical evolutionary history and adaptations to temperate climates. Temperature is known to affect odonate physiology…
In a recent paper D.R. Paulson (2004; IJO 7: 505-515) presented five hypotheses concerning the way wings are held in the Zygoptera during perching. A critical examination suggests that most of them have substantial flaws that prevent their testing. Based on Bechly’s phylogeny (1998;
Zygoptera show two perching modes, one with wings closed and one with wings open. These perching modes are distributed unequally through the suborder; most Zygoptera perch with closed wings, but species in 43 genera of eight families at least occasionally – in most cases usually – perch with open wings. Alternative hypotheses to explain this…