In a previous study conducted during the dry season at La Selva Biological Station, Costa Rica, mean perch height of libellulid dragonfly species (Odonata: Libellulidae) correlated with male body size, and interactions between species suggested a size-dependent competitive hierarchy. Here, I report on a wet-season study that examined whether seasonal changes in community composition affect…
Ten common libellulid species perch along the shoreline of lakes and ponds in South Carolina, USA. We collected individuals at five ponds throughout summer 2005, weighed them in the field, and calculated wing loading (N·m2) and wing aspect ratios from digital photographs. We measured the perch-height preferences of these species in ‘low perch’ (10, 20,…
A male Libellula depressa was observed to mistake a dark-green passenger coach for a water body thus establishing his territory over the surface of the vehicle and using the radio antenna as perch. A videopolarimetric analysis of the car body showed that the light reflected from the bonnet was highly and horizontally polarized with rather…
A collection of 448 Odonata specimens made on Pohnpei, Caroline Islands, Micronesia, in 2001–2002 allows a reassessment of the fauna of this small, isolated island. There are 15 species, including six species of the zygopteran genus Teinobasis, which apparently speciated in situ, an unusually great diversity for such a small island. One of these species…
Cyanallagma demoiselle sp. nov. (holotype male deposited in DZUP: Brazil, São Paulo State, Cananéia, Ilha do Cardoso State Park), a new small greenish blue and black damselfly, is described, illustrated, and diagnosed based on males and females from the southeastern Atlantic Forest.
Despite a high number of incidental online records of spiders predating upon dragonflies/damselflies, studies on these interactions are scarce. Here, we describe the predatory behavior of Argiope trifasciata on the two most common odonate species in the study area.
In the last decades, studies on sexual selection in odonates have shown a relationship between mating success and costly sexual ornaments, mainly male characters. Here, we conducted a scientometric analysis to assess the state of art of studies on sexual selection in odonates, especially on the role of male ornamentation (pre-copulatory traits) and sperm competition (post-copulatory traits).
The final stadium larva of Anisagrion allopterum is described for the first time for Middle America, based upon specimens reared and emerging in the field, from Cartago, Province, Costa Rica. Detailed illustrations are also provided. The larva of this species is characterized by a slender yellow body, premental setae 4+1, five palpal setae, male cerci…
Very little is known about the biology of larval odonates from the Neotropical region, and in particular there are no data on behavioral changes during ontogeny and growth ratios, though both are crucial to understanding the dynamics of Odonata communities. Here we study growth ratio, development patterns and behavior of Rhionaeschna marchali larvae. We characterized…
Genetically determined color polymorphisms have a long history in the study of evolutionary change acting on populations. The Odonata exhibit relatively high levels of sex-specific color polymorphisms in mature adults. In Ischnura and Coenagrion, female-specific polymorphisms are known to be controlled by Mendelian genes. Nearly half of Enallagma species have polymorphic females, but the inheritance…