The effects of odonate species abundance and diversity on parasitism by water mites (Arrenurus spp.): testing the dilution effect

Water mites (Arrenurus spp.) parasitize adult dragonflies. We collected dragonflies weekly at 11 waterbodies in Greenville Co. and Pickens Co., SC, USA, to: (1) compare parasitism prevalence across species, sites, and sampling periods; (2) test the hypothesis that prevalence correlates with host abundance; (3) test the hypothesis that prevalence is inversely related to host diversity…

Shifts in dragonfly community structure across aquatic ecotones

Dragonflies (Odonata: Anisoptera) are often used as indicators of habitat type and quality due to their varied use of aquatic and terrestrial habitats. Species differ in their preferences for lotic and lentic waters, but community changes across ecotones, or transitional zones between distinct habitats (e.g. lotic and lentic), are not well understood. We quantified dragonfly…

Does the damming of streams in the southern Amazon basin affect dragonfly and damselfly assemblages (Odonata: Insecta)? A preliminary study

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…

Odonata of Itatira, a Brazilian semi-arid area in the state of Ceará

The present study provides the first odonate survey for the Brazilian Caatinga, including species habitat information. Specimens were collected during five days in both dry and rainy seasons of 2011 in the municipality of Itatira, state of Ceará, located in the semi-arid region of northeastern Brazil. Adult individuals of 37 species were documented, the highest…

Odonata communities in retrodunal ponds: a comparison of sampling methods

Dragonflies are commonly used as indicators of environmental quality and different methods have been employed to monitor odonate assemblages, such as surveys of all adults, evaluations based on breeding adults, sampling of larvae and collection of exuviae. Results obtained with different sampling methods may not be interchangeable, as the different life stages (e.g. larvae, adults)…

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…

Body temperature regulation in a late-season dragonfly, Sympetrum vicinum (Odonata: Libellulidae)

Body temperature regulation and behavioral responses to temperature variation in the field were investigated in Sympetrum vicinum, a common North American libellulid that is most abundant as a mature adult in autumn. Because of its late flight season, this species is faced regularly with cooler environmental temperatures than most dragonflies investigated heretofore. By virtue of…