Aspectos bionômicos da vespa social Neotropical Polistes canadensis canadensis (Linnaeus) (Hymenoptera, Vespidae) / Bionomics aspects of the Neotropical social wasp Polistes canadensis canadensis (Linnaeus) (Hymenoptera, Vespidae)

Aspectos bionômicos da vespa social Neotropical Polistes canadensis canadensis (Linnaeus) (Hymenoptera, Vespidae). O objetivo deste trabalho foi estudar alguns aspectos bionômicos da vespa social neotropical Polistes canadensis canadensis (Linnaeus, 1758). Vinte e seis colônias foram acompanhadas entre abril de 2004 e julho de 2006, no município de Mundo Novo, estado de Mato Grosso do Sul, região Centro-Oeste do Brasil. Os resultados encontrados nesse estudo sugerem que o padrão fenológico de Polistes canadensis canadensis é assincrônico nessa região, com fundações e abandonos podendo ocorrer o ano todo. A duração média dos estágios imaturos foi diferente entre as estações climáticas fria-seca e úmida-quente. Diferentes substratos foram escolhidos para nidificação, contudo em ambientes que forneceram condições físicas mais homogêneas durante o dia foram encontradas as maiores freqüências de sucesso. Colônias nessa espécie são fundadas por haplometrose ou pleometrose, no entanto, o sucesso tem sido maior para colônias pleometróticas.

Certain aspects of the bionomics of the Neotropical social wasp Polistes canadensis canadensis (Linnaeus, 1758) were studied. Twenty-six colonies were observed from April 2004 through July 2006, in the municipal district of Mundo Novo, state of Mato Grosso do Sul, central-Brazil. The results suggest that the colony phenological pattern of this species is asynchronous, and colonies may be founded or abandoned at any time of the year. The mean duration of the immature stages differed between the cold-dry and warm-rainy seasons. Colonies were founded on several different kinds of substrates, but were more successful in environments that provided more-homogeneous physical conditions during the day. Colonies in this species are founded by haplometrosis or pleometrosis, and pleometrotic colonies were more successful.

Observations on the social wasp Ropalidia montana from peninsular India.

Four colonies of Ropalidia montana collected in August in the Nilgiri Hills of southern India had adult populations of 32,000-61,000. Queens represented 0·46–1·40% of the populations. All colonies contained males, but in widely varying proportions (1·47– 27.00%). The large adult populations and the fact that the nests were largely filled with brood in all stages of development indicate that the colonies were in a stage of active growth in this season. In December, however, colonies have been reported to have smaller adult populations and little brood. Thus brood production appears to be seasonal in southern India. Predation by the hornet Vespa tropica was observed in 4 of 31 active colonies. Ropalidia montana adults were defenseless in the face of these depredations, which appear to continue at a low level for days or weeks on a given nest.