Dynamics in populations of Cosmopolites sordidus and Metamasius spp. under natural climatic conditions in the banana area of Angra dos Reis, State of Rio de Janeiro, Brazil

Abstract

This paper presents some preliminary results on the dynamics in populations of banana weevil Cosmopolites sordidus Germar, 1824 (Coleptera-Curculionidae) and Metamasius spp. (Coleoptera-Curculionidae) under natural conditions in the banana area of Angra dos Reis, State Rio de Janeiro, Brazil. The banana varieties Prata and Nanicão were investigated in three field experiments rum from March 1972 to February 1973. The variety Prata was cultivated in a lowland and highland area. The variety Nanicão was cultivated on the lowland area only. The largest increase in the banana weevil population occurred in September on the variety Prata, cultivated on the lowland area and in August to September on the same variety growing on the highland area. A similar increase was observed on the variety Nanicão in May. No correlation was found between the dynamics of banana weevil population and weather conditions. The largest banana weevil population throughout the year occurred on the variety Prata cultivated on the lowland area and the smallest population on the variety Nanicão. Evidence of feeding by the genus Metamasius on the banana plant was seen by observing damage.