Damage and control of larvaf of rice water weevil in Minas Gerais State, Brazil

Abstract

This experiment was carried out in the south region of Minas Gerais State, Brazil, during the 1985/1986 planting season, with the objective of determining the damage caused by the rice water weevil larvae complex Oryzophagus oryzae (Costa Lima, 1936), Lissorhoptrus sp. and Helodytes foveolatus (Duval, 1945) (Coleoptera-Curculionidae), and the efficiency of insecticides in seed treatment and granular formulation applied in water irrigation. The number of larvae of rice water weevil, height and tillering of plants, and also yield, were evaluated. The highest population of larvae was found at the sixtieth day from sowing. The most efficient insecticides were aldrin in seed treatment and carbofuran in granular formulation hand-spread 21 days after irrigation. The rice water weevil caused significant reduction in height of plants but did not affect the tillering. Yield loss, caused by the insect complex was 44%.