The small African species of Diplacodes have been confused for a long time, in part because the black mature males are difficult to separate. The holotype of D. deminuta belongs to the species commonly known as D. okavangoensis, the former name taking priority, while its paratypes belong to that known erroneously as D. deminuta, which…
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…
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…
Orthemis sibylla is shown to be a junior synonym of O. ambirufa, based on a comparison of the holotype male of O. ambirufa with voucher specimens in the UMMZ identified as O. sibylla by Ris and specimens of this species from French Guiana and Venezuela in the RWG collection. Diagnostic characters of the male holotype…
Of the 86 Odonata species so far recorded for the Levant, four are considered as endangered (Calopteryx hyalina, C. syriaca, Ceriagrion georgifreyi, Pseudagrion torridum hulae), six as vulnerable (Coenagrion vanbrinckae, P. sublacteum mortoni, Gomphus kinzelbacbi, Onychogomphus macrodon, Brachythemis fuscopalliata, Crocotbemis sanguinolenta), and two as extinct (Rhyothemis semihyalina syriaca, Urothemis edwardsi hulae). The history of odonatological…
An overview is given of the present knowledge and current research on the Odonata fauna of Turkey, Iran, and the Caucasus. The occurrence of endemic taxa and of rare and possibly threatened species is discussed. The use of water from various aquatic habitats is reviewed in order to gain insight in existing and potential problems,…
This report summarizes progress that has been made during the past five years toward the understanding of Neotropical Odonata. It also presents a list of critical species and sites, threats to Odonata conservation in the region, and priorities for further research. This region, the richest in the world for Odonata, must be a focus of…
Ten species of Hawaiian Odonata are considered to be currently at risk, all of them zygopterans belonging to the endemic genus Megalagrion. These species and their proposed status are as follows: M. jugorum, endemic to Maui and Lanai [CR, possibly EX]; M. leptodemas, endemic to Oahu [CR]; M. molokaiense, endemic to Molokai [CE, possibly EX];…
This synopsis of adult Triacanthagyna includes the revalidation of two species thought to be synonyms (T. nympha and T. obscuripennis), the description of a new species (T. williamsoni; type locality: Peru, Tingo María), keys to both sexes, illustrations of diagnostic characters, and distribution maps of all species. A phylogenetic assessment of the nine species is…
E.D.V. Prendergast retired from a military career in 1973 and henceforth actively pursued many natural history and field sports interests. Studies of birds were followed in the later years by significant work on Odonata. A systematic study of the species’ distributions of Gambian dragonflies and conservation work involving Coenagrion mercuriale were especially important.