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…
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)…
Description of the final stadium larva of Erythrodiplax media (Odonata: Libellulidae) with preliminary key to known South American larvae in the genus
The larva of Erythrodiplax media is described and illustrated based on two exuviae of reared larvae and one final stadium larva collected in Xangri-lá, State of Rio Grande do Sul, Brazil. The larva of E. media can be distinguished from other species of Erythrodiplax by the presence of lateral spines on S8 and S9, the…
Pre-emergent movements and survival of F-0 larvae of Ophiogomphus rupinsulensis (Odonata: Gomphidae) in a northern Wisconsin river
We marked and released 276 F-0 larvae of Ophiogomphus rupinsulensis in the fall of 2008 in a 99-m riffle (marking riffle) of a small, serially discontinuous, northern Wisconsin river (USA). We then recovered marked exuviae via exhaustive collecting on the banks of a 272-m sampling reach in which the marking riffle was located during spring…
A hotspot for threatened Mediterranean odonates in the Seybouse River (Northeast Algeria): are IUCN population sizes drastically underestimated?
Several odonate species are threatened in the Mediterranean basin and some of them show alarming decreasing trends. The distribution and population estimations provided by the IUCN are based on occasional field sampling or non-rigorous methodologies and could be erroneous and misleading. To obtain reliable estimations of the population size and distribution of three threatened species,…
Aspects of life history of Platycnemis subdilatata (Zygoptera: Platycnemididae) in Northeast Algeria
The determination of seasonal regulation is important to understand how species have adapted to their local environmental conditions. In this study, we investigate the life history of a North African endemic damselfly, Platycnemis subdilatata, in a northeast Algerian population. We combined field and laboratory investigations to assess the embryonic development, larval growth, emergence pattern and…
The Gomphidae of Algeria and the Maghreb: status, ecology and conservation (Insecta: Odonata)
A survey of the Gomphidae of Algeria and the Maghreb was carried out during the period 2013–2014. Sampling of eight main wadis across northern Algeria was undertaken and adults and exuviae were recorded. The survey yielded six species of Gomphidae. Among these, we report on the rediscovery of the Critically Endangered Lindenia tetraphylla in Algeria,…