We compared the prevalence and intensity of Arrenurus sensu stricto water mite parasites on Enallagma civile Hagen in Selys, 1853 (Zygoptera: Coenagrionidae) from 10 freshwater wetlands (playas) in two different land-cover contexts in western Texas from 2006-2007.
Genetically determined color polymorphisms have a long history in the study of evolutionary change acting on populations. The Odonata exhibit relatively high levels of sex-specific color polymorphisms in mature adults. In Ischnura and Coenagrion, female-specific polymorphisms are known to be controlled by Mendelian genes. Nearly half of Enallagma species have polymorphic females, but the inheritance…
A small inconspicuous spine, first detected at the base of the distal-most seta on each labial palpus of early stadia of two species of Enallagma, is reported to occur in final-stadium (F-0) larvae of Palaearctic and Nearctic E. cyathigerum, in F-0 of 31 other Nearctic species of Enallagma and in F-0 of three other coenagrionid…
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.
In many species of damselflies, sexual conflict in the form of male harassment is thought to explain the widespread existence of female-limited color polymorphisms. With a few exceptions, the majority of investigations into these mating systems have assumed that male damselflies primarily use visual cues to detect and recognize their mates. Recently, laboratory studies have…
The Odonata from the Refúgio Estadual da Vida Silvestre do Rio Pandeiros (RVSP), located in the Cerrado domain, Minas Gerais State, Brazil, were rapidly surveyed. Sampling efforts were undertaken along the Rio Pandeiros margins during four sampling periods between the rainy (spring–summer) and dry seasons (autumn–winter) from July 2014 to April 2015. We sampled 97…
To resolve a prevailing nomenclatorial confusion present in the genus Aciagrion, A. tillyardi Laidlaw, 1919 is placed in synonymy of A. approximans (Selys, 1876). The neotype of “Pseudagrion approximans”, a male specimen from Khasi Hills preserved in Coll. Selys Longchamps at RBINS, is designated to replace the lost holotype, which was an incomplete specimen of…
The odonate fauna of Tuva in Siberia, Russia, is documented, based mainly on data from expeditions in 1990, 2000 and 2004, and examination of collections preserved in Novosibirsk. The checklist of Tuvinian Odonata presently includes 47 species. In the southern Ubsu-Nur depression 29 species were recorded (two just there); in the Central Tuvinian depression 34…
We compiled data on the occurrence and frequency of distinct female variants among Holarctic Odonata and interpreted the data in light of harassment-based hypotheses. The major source of male confusion for male mimicry hypotheses is predicted to be signal similarity between andromorphs and male distractors; for the learned mate recognition hypothesis (LMR), it is predicted…
Co-occurring odonate species often perch at different heights. We studied the effects of interspecific and intraspecific interactions on perch-height selection by Perithemis tenera, Pachydiplax longipennis, and Enallagma spp. by creating artificial perch stations and comparing perch selection when species perched alone or together. We also compared the frequency of perch-height use in the presence or…