In sexual conflict, males are often thought to gain fitness benefits from harassing females over mating. Yet when harassment itself incurs costs to males and if alternative, receptive females are available in a local population, theory predicts that when confronted with a female refusal, a male’s choice of persisting or retreating is determined in part by the likelihood of achieving a mating.
The Indian Elattoneura are a difficult group to identify due to their extreme morphological similarity and sparse information in identification keys and on geographical distribution. The ambiguity is prominent among two Peninsular Indian Elattoneura species, E. nigerrima (Laidlaw, 1917) and E. tetrica (Laidlaw, 1917), described a hundred years ago.
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.
The matrix, an environment in the landscape that individuals move through but do not reside in, can affect species dispersal and the arrival of individuals at habitat patches. Elements around this matrix that provide refuge or resources may shape the arrival of animals at habitat patches, even when those patches are equivalent in quality. Adult dragonflies (Odonata: Anisoptera) frequently use open terrestrial environments during movement and dispersal in north-temperate regions…
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.
More than 400 scientific journal articles and gray literature reports that addressed macroinvertebrate drift were reviewed and 63 articles were found that reported on the natural drift of Odonata at some taxonomic level. Forty-three species and 44 genera within 15 families (nine Zygoptera; six Anisoptera) were documented in the drift. Drift of another 13 species…
Dragonflies (Insecta: Odonata) use both aquatic and terrestrial ecosystems, and the abundance and diversity of odonates should be good indicators of habitat integrity. To determine which environmental variables affect odonates, we sampled adult dragonflies three times at 12 sites in Pickens and Greenville Counties, SC, USA, in different habitats, at different spatial scales, across a…
The final stadium larvae of Megalestes micans Needham, 1930 and M. kurahashii Asahina, 1985 are described and illustrated from Yunnan Province, China, and a key to the known larvae of seven species of the genus Megalestes is provided. All exuviae will be stored at the Invertebrate Collection of the College of Agriculture and Life Sciences,…
Odonates have been recognized as an important group for evaluating ecosystems since they are used as bioindicators of the conservation status of the habitat they occupy, in addition to being generalist predators feeding on invertebrates and small vertebrates. In this work, the biodiversity of adult odonates from a locality near the San Marcos River, in…
Tropical America is currently experiencing the establishment of a new apex insect predator, the Paleotropical dragonfly Hemianax ephippiger (Odonata: Aeshnidae). H. ephippiger is migratory and is suggested to have colonised the eastern Neotropics by chance Trans-Atlantic displacement. We report the discovery of H. ephippiger at three new locations in the Caribbean, the islands of Bonaire,…