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 final stadium larva of Calicnemia sinensis Lieftinck is described and illustrated in detail. It is characterized by (1) palpal lobe of prementum with two end hooks of unequal size, the inner longer and sharper, and the outer shorter and stouter; (2) inner side of palpal lobe with five long setae above…
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.
The Neotropical genus Forcepsioneura is composed of 11 species that inhabit almost exclusively the Brazilian Atlantic Forest domain, with F. sancta (Hagen in Selys, 1860) being the only species of this genus known to occur in the Cerrado biome. Here we describe a new species of Forcepsioneura from the Cerrado of Minas Gerais State, Brazil….
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,…
Aquatic macroinvertebrates are a primary component of freshwater ecosystems and one of the most threatened by anthropogenic pressures. Among them, dragonflies are a charismatic group of growing scientific and social interest. However, little is known about the natural history of several species. One paradigmatic example is the declining Orthetrum nitidinerve, a Western Mediterranean endemic anisopteran….
Polymorphism has rarely been reported from dragonflies of the Libellulidae (Odonata: Anisoptera) family. Here, we report female-limited polymorphism in females of five species of the Libellulidae and a gynandromorph male of Brachythemis contaminata from South Asia. We describe the morphological variation between andromorph and heteromorph females, and collate records of andromorph females from various sources….