Heteragrion makiritare sp. nov with descriptions of hitherto unknown females and larvae of other species from Venezuela (Odonata: Megapodagrionidae, Lestidae)

Heteragrion makiritare sp. nov. is described from two males from the Pantepui region – holotype: Venezuela, Amazonas State, Marahuaka, Sima (3°43′N, 65°31′W), 1,140 m a.s.l., MIZA, no. 17250. It belongs in the species group whose paraprocts are absent in the male sex. The identity of H. macilentum is elucidated by examining its lectotype and a…

Ballistic defaecation by anisopteran larvae (Odonata): a way to increase foraging success?

The article considers the phenomenon of ballistic defaecation by odonate larvae, exhibited by certain Anisoptera but not by any Zygoptera, and explores two possibilities: (1) that ballistic defaecation in Anisoptera may correlate with increased foraging success (the ‘Wudkevich Hypothesis’) by distancing the prey’s alarm pheromone, persisting in the pellet after defaecation, from the larva’s ambush…

Nested-subset structure of larval odonate assemblages in the Enoree River basin, USA

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…

Abundance and vertical distribution of a bromeliad-dwelling zygopteran larva, Mecistogaster modesta, in a Costa Rican rainforest (Odonata: Pseudostigmatidae)

We compared the larval abundance of Mecistogaster modesta between bromeliads at ground level and canopy level in a primary tropical wet forest. Zygopteran abundance correlated strongly with bromeliad diameter at both levels. Although the per-bromeliad zygopteran abundance did not differ between vertical levels, M. modesta showed a strong vertical distribution in abundance owing to the…

Changing distribution patterns along a stream in adults of Calopteryx haemorrhoidalis (Odonata: Calopterygidae): a case of larval-drift compensation?

The distribution of an isolated population of adult Calopteryx haemorrhoidalis was studied along a small stream in NE Spain, during two-week or three-week summer periods over five years. Distribution patterns differed consistently between age groups. Reproductive activities took place along the entire stream, whereas the presence of tenerals and older immature individuals was restricted to…