In species of similar shape and size, biometric analyses make it possible to establish differences. Within one species, biometrics can help researchers to detect differences between populations and analyze their adaptations to environmental conditions. Until now little was known about the biometrics of the Iberian populations of Boyeria irene (Odonata: Aeshnidae), a large species living mainly in southern Europe.
Detection probabilities and sampling rates for Anisoptera exuviae along river banks: influences of bank vegetation type, prior precipitation, and exuviae size
Exuviae collections have considerable value in population studies of Odonata, but methods for standardizing collections or estimating densities and detection probabilities have been little studied. I measured sampling rates for Anisoptera exuviae and used a maximum likelihood, four-pass, depletion population estimator to standardize collections and to estimate exuvial densities and detection probabilities along 10 riverbank…
Geographical variation of prementum size in Iberian Cordulegaster boltonii (Odonata: Cordulegastridae) populations
Within wide geographical areas, Odonata populations can show biometric differences as a consequence of both biotic (e.g., predation, competition) and abiotic factors (mainly temperature). These differences can occur in the larval stage, although reliable characters are needed to detect differences.
Description of last instar larvae of Ceratogomphus triceraticus Balinsky, 1963 and C. pictus Hagen in Selys, 1854 (Odonata: Gomphidae)
The final instar larvae of the two species of the southern African gomphid genus Ceratogomphus, the South African endemic C. triceraticus and the more widespread C. pictus, are compared based on exuviae. Main differences are the shapes of the prementum and of the last abdominal segments, giving C. pictus a more slender and pointed appearance.
Odonata species diversity, distributions, and status in a rare sand prairie-savanna wetscape
Inland sand areas scattered across the North American eastern deciduous forest and western tallgrass prairie ecotone are known for supporting pyrogenic early-successional vegetation and specially adapted terrestrial faunas. Many of these globally and regionally rare systems contain functionally connected wetland networks (“wetscapes”) potentially important for aquatic insects.
Description of the larva of Vestalis gracilis (Rambur, 1842) (Zygoptera: Calopterygidae) from Thailand
Vestalis gracilis (Rambur, 1842) is a forest stream damselfly belonging to the family Calopterygidae. Its last-stadium larvae and exuviae are described and illustrated based on laboratory-raised specimens from Thailand, and observations of agonistic behavior are provided. The taxonomical characters of V. gracilis larvae are similar to those of V. amoena.
Descriptions of the last instar larvae of two species of Megalestes Selys from Yunnan, China (Odonata: Zygoptera: Synlestidae)
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,…
First description of the larva of Psaironeura, based on specimens of P. angeloi from Costa Rica (Odonata: Coenagrionidae: Protoneurinae), with a key to the genera of Central American Protoneurinae
The larva of Psaironeura is formally described for the first time, based upon reared specimens of Psaironeura angeloi from the Tirimbina Biological Reserve, Sarapiquí, Heredia Province, Costa Rica. Detailed illustrations are also provided. The larva is characterized by a slender dark brown body, premental setae 2+1, six palpal setae, male cerci globose, and caudal lamellae…
Occurrence of Aeshna viridis in marsh ditches in relation to habitat conditions (Odonata: Aeshnidae)
Habitat loss and fragmentation induce a decline and endangerment of freshwater organisms such as Aeshna viridis, an endangered dragonfly species characterised by a specific insect–plant association to the macrophyte Stratiotes aloides. In order to implement conservation measures, a good level of knowledge about the occurrence, habitat requirements and quality, as well as patch size of…
Emergence timing and fixation height in Pachydiplax longipennis (Odonata: Libellulidae) at varying substrate density and sunlight exposure
Emergence substrate and sunlight penetration inherently trade off in patchy vegetation. Given the importance of solar radiation at emergence, we expected greater sunlight availability in sparse vegetation to advance emergence timing and reduce the average height of emergence fixation. We used outdoor mesocosms stocked with varying cattail (Typha) densities and late-stage Pachydiplax longipennis (Odonata: Libellulidae)…