After observing the presence of Phylloicus pulchrus (Trichoptera: Calamoceratidae) and tadpoles of Leptodactylus albilabris (Anura: Leptodactylidae) on submerged leaves with recently laid eggs of Telebasis vulnerata (Odonata: Coenagrionidae), we set up an experiment to determine if they were consuming Odonata eggs. We collected leaves from the stream, where consumers were positioned over egg masses, and…
Reciprocal predation involving Odonata, Asilidae and Saltatoria
A singular observation of an adult Tettigonia viridissima (Tettigoniidae) that captured a female Eutolmus rufibarbis (Asilidae) sucking a male Lestes sponsa (Lestidae) is reported. The reciprocal predation of Odonata, Asilidae, and Saltatoria (Ensifera, Caelifera) hitherto recorded in Europe is compiled and augmented by unpublished data on asilids as predators of odonates. Heavy predation by robber-flies…
Repeated predation of Odonata by the hornet Vespa crabro (Hymenoptera: Vespidae)
Predation of aggregated, ovipositing tandems of Sympetrum sanguineum and S. vulgatum by the hornet Vespa crabro was observed in Belarus. The same species of hornet was seen killing territorial males and copulating females of Calopteryx haemorrhoidalis in Italy. Numerous remains of these odonates at the oviposition sites suggest that attacks occur frequently. A short review…
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.
Hiding among traps? Mortality of early instar odonate larvae in the presence of bladderwort plants
We investigated the effects of the presence of bladderwort plants on survival of early instar larvae of one coenagrionid and two libellulids in laboratory experiments. In all three species survival was reduced compared to treatments with a non-carnivorous submerged plant, with effective mortality that could be related to bladderwort being 19–45% dependent on the prey…
First record of Ceriagrion fallax Ris (Odonata: Coenagrionidae) preying on small web-building spiders (Arachnida: Tetragnathidae)
In montane forest of south-western Yunnan, China, a female of Ceriagrion fallax was observed and photographed preying on a small web-building spider of the genus Leucauge. This is the first record of plucking an orb-weaver spider by a representative of the genus Ceriagrion. A brief discussion on the evolution of spider feeding behaviour in odonates…
Differential survival rates of damselfly larvae in the presence of newt and dragonfly predators
The damselfly species Paracercion melanotum has been found to be the most abundant species in damselfly larval communities on Okinawa-zima Island in southwest Japan. To clarify differential susceptibility to predation, a possible factor affecting relative population densities in larval communities, between Paracercion melanotum and a less common damselfly species, Ischnura senegalensis, laboratory experiments were conducted…
Early stadium damselfly larvae (Odonata: Coenagrionidae) as prey of an aquatic plant, Utricularia australis
Two third stadium larvae of Coenagrionidae (probably Coenagrion puella or Ischnura elegans) were recorded in the bladders of U. australis sampled from a garden pond in Karlsruhe, Germany, in June 2010. These are the first records of odonate larvae as prey of carnivorous aquatic macrophytes.
The larva of Tetracanthagyna plagiata, with notes on its biology and comparisons with congeneric species (Odonata: Aeshnidae)
The F stadium larva of both sexes of Tetracanthagyna plagiata is described and figured based on exuviae from which confirmed adult specimens had been reared. Larvae were originally collected in small, slow forest streams in Singapore, and in captivity were fed on local shrimp and small fish species. The known larvae of Tetracanthagyna species, T….
Larval habitats and life history of the Crete Island endemic Boyeria cretensis (Odonata: Aeshnidae)
Boyeria cretensis belongs to the most threatened European dragonfly species. It is restricted to some isolated permanent streams on the island of Crete. The streams have a pronounced gallery vegetation and are situated in a narrow belt of altitude between 50 and 400 m. We understand very little about the biology of this species so…