In tropical streams, seasonality has a strong influence on heterogeneity, altering available resources and affecting the carrying of organisms, substrate and organic matter. This causes changes in the limnological variables, as well as in the species composition. The aim of our study was to evaluate the response of the congruence of the Odonata community in two seasons in streams of the transition between Cerrado and Caatinga.
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…
Well-adapted flight morphology must allow for efficient behavioral activities. Wing shape has been shown in a variety of species to be influenced by environmental conditions. Analysis of wing shape using geometric morphometrics provides a visualization of wing shape variations. This study examined the effects of varied environments on wing shape and wing size of the…
The determination of seasonal regulation is important to understand how species have adapted to their local environmental conditions. In this study, we investigate the life history of a North African endemic damselfly, Platycnemis subdilatata, in a northeast Algerian population. We combined field and laboratory investigations to assess the embryonic development, larval growth, emergence pattern and…
The effects of photoperiod and temperature on the termination of egg diapause were examined in Sympetrum frequens. Eggs were obtained from adult females collected from three locations in Japan and incubated under short- or long-day photoperiods at a constant temperature of 25, 20, or 15°C. Egg diapause was eventually terminated in all treatments. Because differences…
Anisoptera emergence in the seasonal tropics was monitored at a 35-ha managed wetland site in Hong Kong from February 2004 to November 2007. Exuviae records of 18 species from multiple emergence screens, exuviae traps and transect surveys were combined. The presence of adults during this period was also monitored. The study site comprised a mosaic…
From 12 to 25 August 2009, the odonate fauna of Santo Antão, Cape Verde was surveyed by recording adults and collecting larvae and exuviae at 26 localities, mostly situated in the northwest of the island. Based on the results of this survey and literature data on the Cape Verdes it appears that the resident odonate…
The Palaearctic libellulid Leucorrhinia pectoralis is generally considered to be a species inhabiting fish-free water bodies. Yet, a long-term monitoring study of 38 water bodies in NE Germany resulted in 16 species offish being recorded in reproductive habitats of L. pectoralis, with Rutilus rutilus and Carassius carassius as the most numerous and widespread fish species.
We studied a population of Polythore procera along a stream in the Colombian eastern Andean foothills. Mark and recapture samples were made during January to April 2006, covering both dry and wet seasons. We determined population size, daily survival probability, and longevity during the entire period and compared them with precipitation data. Age and sex…
During a period of nine years, from 2000 to 2008, two consecutive studies—one focusing on observations of adult Odonata, the other on collection of larvae—were carried out in the basin of the Guadiamar River in the southwestern Iberian Peninsula. In addition to monitoring Odonata, several environmental variables were assessed, including an index based on macroinvertebrate…