Zygonyx torridus inhabits waterfalls, rapids and riffle sections. Males patrol over these sites. After copulation the partners perform an extensive search while flying in tandem over a wide range. Behavioural studies in Mauritius 1997 and 2014 showed that there is considerable plasticity in oviposition behaviour. Three main modes could be distinguished: (A) egg-laying in tandem…
Second and third stadium larvae of Gomphus flavipes have dorsolateral cuticular outgrowths in the form of small basal tubercles bearing fan-shaped setae. These sensilla are aligned in two rows on each side of the thorax and abdomen. European species of Gomphus, Onychogomphus and Ophiogomphus that we examined lack these structures, having instead, at most, short…
Phenotypic plasticity represents an adaptive tool in organisms including odonates to cope with heterogeneous environmental conditions. However, while some odonate species can occupy various changing habitats, other species are adapted to a narrow range of environmental conditions. Commonly, behavioural modifications are applied to avoid detection and encounters with predators. But reduced behavioural activity results in…
The reproductive behaviour of the damselfly Chlorocypha cancellata (Chlorocyphidae) was filmed at 600 frames per second. Different flight styles including straight, forward flight, threat and courtship display were analysed with respect to changes in wing beat frequency and phase relationships of fore and hind wings. The analysis revealed significant differences in the flight style between…
A three-year field study (January 2011–December 2013) of the Odonata of Curaçao, supported by photos and exuvial collections, recorded a total of 21 species from the island, almost doubling its previously known fauna. The lists of Odonata known from Aruba and Bonaire were also updated by specimen and photo records, and 24 species are now…
Territorial behaviour and mate guarding are important components of mating systems in various insect groups, including the Odonata. This paper reports observations of male territorial behaviour associated with potential ovipositing sites, and postcopulatory, non-contact mate guarding in Petalura gigantea. This is the first unambiguous and detailed report of mate guarding in the Petaluridae. Additional observations…
Our goal was to investigate whether the loss of riparian forests alters the structure of assemblages and populations of dragonflies and damselflies. We tested the hypothesis that the composition of the odonate assemblages found upstream from dams are significantly different from those found downstream of these barriers. To test the hypothesis, we investigated stream sectors…
In this paper we record a likely instance of ovo-viviparity in a chlorocyphid damselfly from south-western China. If confirmed, this will be the first record of live birthing in the Odonata: indeed in any member of the Palaeoptera. The widespread Asian damselfly Heliocypha perforata (Percheron, 1835) is proposed to be, at least facultatively, viviparous. A
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…
A new species of the endemic New Guinean genus Lanthanusa is described from the Trauna River Valley in Western Highlands Province, Papua New Guinea. Characters of the male are illustrated and affinities of the new species are discussed. Some characters of the type species of Lanthanusa, L. cyclopica, are reassessed and a revised key to…