Population dynamics, seasonality and sex ratio of twig-girdling beetles (Coleoptera: Cerambycidae: Lamiinae: Onciderini) of an Atlantic rain forest in south-eastern Brazil

Abstract

In this study, the population dynamics and sex ratios of 12 species of beetles of the tribe Onciderini (Cerambycidae: Lamiinae) were investigated from 2002 to 2006 in an Atlantic rain forest of south-eastern Brazil located at the Biological Reserve of the Serra do Japi. The period of activity of adult beetles ranged from October to May, with slight differences among the species. From June to September, adults were not found and we considered them absent. Our findings showed that adults of these beetles were strongly seasonal, and abundances were correlated with climatic factors that occurred up to two months in advance. Sex ratios were skewed to females in most of the species. The factors determining the population dynamic and sex ratios of these insects are discussed.

Keywords:

• Cerambycidae
• Onciderini
• seasonality
• sex ratio

Acknowledgements

We thank the Prefeitura Municipal de Jundiaí, SP, Brazil, for the permission to work at the Biological Reserve of the Serra do Japi. The authors also thank Instituto de Estudos dos Himenóptera Parasitóides da Região Sudeste Brasileira (INCTHYMPAR – SUDESTE). We also thank two anonymous reviewers and Iracenir A. dos Santos for helpful comments on the manuscript. Financial support to CMP was provided by a grant from Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, grant No. 4538482008-7). JVN and AA were supported by a research grant from Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Capes), Programa Nacional de Pós Doutorado (PNPD, No. 23038.023315-2009-10).