Structure and dynamics of the Taxocenoses of Pimplinae, Poemeniinae, Rhyssinae, Anomaloninae and Metopiinae in an urban secondary semideciduous montane forest

Abstract

Ichneumonidae (Hymenoptera) is one of the largest families of Insecta, but information on family diversity and distribution in Brazil is limited. The aim of the study was to assess the abundance, richness and seasonal distribution of Ichneumonidae in an urban secondary semideciduous montane forest. Insect specimens were captured in a Malaise trap placed within a restored sub-evergreen forest and sampling was performed every week during three non-consecutive 12-month periods. Of the 507 specimens collected, 338 were captured between May 1991 and May 1992, 95 between May 2000 and May 2001, and 74 between May 2007 and May 2008. Specimens were distributed among the subfamilies Pimplinae (n = 444), Anomaloninae (n = 42), Metopiinae (n = 16), Poemeniinae (n = 3) and Rhyssinae (n = 2). Species richness was highest in 1991–1992 with 33 rare and eight common species captured, followed by 2000–2001 with 31 rare and one common species captured, and 2007–2008 with 24 rare and one common species captured. The Shannon-Wiener diversity index (H’) and Jackknife 1 species richness (S) values for the respective periods were 2.75/59.6, 3.15/35.8 and 2.83/35.8. In the 1991–1992 and 2000–2001 periods, parasitoid abundance was higher during the rainy season, while in 2007–2008 abundance was higher during the dry season. Colpotrochia mexicana (Cresson), Colpotrochia neblina Gauld & Sithole and Exochus izbus Gauld & Sithole were recorded for the first time in Brazil.