Emergence substrate and sunlight penetration inherently trade off in patchy vegetation. Given the importance of solar radiation at emergence, we expected greater sunlight availability in sparse vegetation to advance emergence timing and reduce the average height of emergence fixation. We used outdoor mesocosms stocked with varying cattail (Typha) densities and late-stage Pachydiplax longipennis (Odonata: Libellulidae)…
The larva of Erythrodiplax media is described and illustrated based on two exuviae of reared larvae and one final stadium larva collected in Xangri-lá, State of Rio Grande do Sul, Brazil. The larva of E. media can be distinguished from other species of Erythrodiplax by the presence of lateral spines on S8 and S9, the…
Food intake rate and diet composition have a high impact on all organisms and affect individual fitness, fecundity and mortality. Specimens in enclosures have to be fed in an adequate way and with minimum stress for the specimens. Adult dragonflies are flying hunters. In enclosures, they are usually fed by adding different kinds of adult…
The small African species of Diplacodes have been confused for a long time, in part because the black mature males are difficult to separate. The holotype of D. deminuta belongs to the species commonly known as D. okavangoensis, the former name taking priority, while its paratypes belong to that known erroneously as D. deminuta, which…
Oviposition behaviour by Sympetrum frequens, a species endemic to Japan, has been observed throughout its entire breeding season, which extended for about one month after the harvest of rice. Approximately 50% of oviposition events occurred during the first week of the reproduction period. Sunny oviposition sites were preferentially selected by ovipositing pairs. The starting time…
In the temperate zone, male perch height of co-occurring dragonfly species (Odonata: Libellulidae) often correlates with species body size. I tested for this relationship in a guild of tropical dragonflies at a wetland at La Selva Biological Station, Heredia, Costa Rica. Males of 12 species were observed perching in January–February 2016. Mean male perch height…
How species respond to shifting environmental conditions is a central question in ecology, especially because ecosystems are experiencing rapidly changing climatic conditions. However, predicting the responses of species interactions and community composition to changing conditions is often difficult. We examined the effects of rearing temperature and resource level on larval survival of two ecologically similar…
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…
Large libellulid dragonflies often fly higher than smaller libellulids. We hypothesized that this size-related pattern in flight height might be caused by aggressive displacement. We tested this hypothesis by using a 30 m “dragonfly zip-line” to reel dead dragonfly decoys of four species of different sizes (Erythemis simplicicollis, Libellula incesta, Pachydiplax longipennis, and Perithemis tenera) along…
Risiocnemis corbeti sp. nov. and R. hamaiaineni sp. nov. (for both species: holotype ♂, Dipinantahikan area [16°53′39″N, 122°20′47″E], Dipagsangaan, Palanan, Isabela, Luzon, Philippines, 12-20 ix 2008, in RMNH) are described, illustrated, and diagnosed.