Abstract As a result of environmental change by anthropic action, animal species that inhabit these areas may suffer the effects of it on their phenotypes as a consequence of adapting to these conditions. In the case of social wasps, cuticular chemical compounds may be influenced, since these vary depending on genetic and environmental factors. However, few studies have investigated the synanthropic effects over the cuticular surface of social wasps. Therefore, the aim of this study was to investigate how cuticular compounds vary according to the different degrees of human activity and test the hypothesis that cuticular compounds of social wasps are affected by the level of anthropic activity in which their nests are found. Data on the cuticular chemical compounds composition of colonies of 3 species of social wasps were used along with the level of anthropization of their nesting sites in four municipalities in the state of Mato Grosso do Sul, Brazil. From the geographical coordinates of the sampling sites, the percentages of urban construction areas, agriculture, water body, vegetation and exposed land were calculated, and the nesting sites of the colonies were classified as more or less anthropized areas. The chemical profile was determined by extraction of cuticular compounds and analyzed by Gas Chromatography coupled to Mass Spectrometer (GC-MS). The results show that the cuticular chemical composition of the individuals of these species is affected by the level of anthropization in their nesting sites, with a qualitative and quantitative variation that must be tied not only to genetic differences, but, above all, to the local environmental conditions to which their colonies are subjected.

Para descrever alguns aspectos da ecologia populacional de Phallotorynus pankalos em um riacho de primeira ordem da bacia do rio Iguatemi foram realizadas amostragens de março/2007 a fevereiro/2008. Um total de 2680 indivíduos, distribuídos em 948 machos e 1732 fêmeas, foi coletado. Fêmeas adultas foram maiores que os machos e sua fecundidade média foi estimada em 6,5 embriões/fêmea. Foi observada forte correlação entre o comprimento padrão e o peso dos ovários, peso relativo dos ovários e número de embriões. O tamanho da primeira maturação de 50% da população de fêmeas foi estimado em 18,24 mm de comprimento padrão. Observamos elevada mortalidade de fêmeas após a primeira reprodução e variação sazonal na proporção sexual, com maior proporção de fêmeas no inverno.

Some aspects of the population ecology of Phallotorynus pankalos in a first-order stream of the Iguatemi River Basin are described based on samples taken from March/2007 to February/2008. A total of 2680 individuals, including 948 males and 1732 females was collected. Adult females are larger than males; theirs mean fecundity was estimated as 6.5 embryos/female. There was a strong correlation between standard length and ovary weight, relative ovary weight, and number of embryos. The size of the first maturation of 50% of female population was estimated as 18.24 mm of standard lenght. High female mortality was observed after the first reproduction and sex ratio presents seasonal variation with higher female proportion in the winter.