In sexual conflict, males are often thought to gain fitness benefits from harassing females over mating. Yet when harassment itself incurs costs to males and if alternative, receptive females are available in a local population, theory predicts that when confronted with a female refusal, a male’s choice of persisting or retreating is determined in part by the likelihood of achieving a mating.
By means of slow-motion film analysis we found new female refusal behaviour patterns against male harassment in a variety of Odonata species. Often, females could escape simply by flying faster than males. Due to the morphological preconditions, there were differences in the two suborders. In Anisoptera, several behavioural specialities were analysed: (a) females of Aeshna…
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…
Assessment of conservation status is a necessary step before management plans can be formulated. Historically such assessments have a strong bias toward vertebrates, particularly endothermic terrestrial vertebrates (i.e. birds and mammals). Invertebrates, by contrast, tend to be ignored, and many insect groups, despite being species rich and reasonably well studied, such as the Odonata (damselflies…
Lanthanusa bilineata, a new libellulid from the mountains of central New Guinea (holotype: Mekil Research Station (04°48′ S, 141°39′ E), leg. 1 September 2004, dep. at RMNH, Leiden), is described. The new species combines characteristics previously used to distinguish between Huonia and Lanthanusa with wing venation characteristic of the genus Huonia and accessory genitalia characteristic…
Size and mass are often uniformly related within individuals and populations, but the relationship may vary in time or space. I asked whether isolated adult dragonfly populations within the same environmental context (climate, physiography, ecoregion) differ in both size and mature mass, and whether earlier emerging dragonflies are both larger and heavier on average. Differences…
Communities have a nested-subset structure if the species found in species-poor assemblages are also found in progressively more species-rich assemblages. This nested-subset structure can be caused by differential colonization rates among species, differential extinction rates among species, or nested niche space. In this study, the assemblages of larval odonates in the Enoree River of South…
Boyeria vinosa is a common anisopteran in the southeastern United States. Here we describe relationships between the abundance of B. vinosa larvae and the chemical, physical and biological properties of the Enoree River of South Carolina and nine of its tributary stream systems. Chemical profiles were conducted weekly for seven weeks at 63 sites in…
Globally, freshwater ecosystems and the organisms that depend on them are at risk. Dragonflies and damselflies (collectively, “odonates”) have a history of being used as bioindicators of freshwater habitat quality due to their wide range in environmental sensitivities across species and because they are relatively accessible.
Disjunct biogeographic patterns of similar species remain enigmatic within evolutionary biology. Disparate distributions typically reflect species responses to major historical events including past climate change, tectonics, dispersal, and local extinction.