Evaluation of some insecticides for the control of Aspavia armigera Fabricius on rice (Oryza sativa Linn.)

Abstract

Laboratory and field trials were carried out for two years at the International Institute for Tropical Agriculture (IITA), Ibadan and Olabisi Onabanjo University, Ago-Iwoye, Ogun State, Nigeria to determine the efficacy of deltamethrin, lambda-cyhalothrin and carbaryl against the rice bug Aspavia armigera. In the laboratory, mortality recorded in any of the insecticide-treated plots was significantly higher than mortality recorded for the control plots. Lambda-cyhalothrin reduced A. armigera population density by 39.2% at 6 hours post- treatment with 46% magnitude over other insecticides at 48 hours post-treatment. In field trials at both sites, the three insecticides tested were effective against the bug with the population density of A. armigera in lambda- cyhalothrin plots reduced by 56.8% followed by deltamethrin (50%) in the first year. In the second year, the percentage reduction was 58.4% and 58.3% in lambda-cyhalothrin and deltamethrin plots respectively. Similarly, the lowest number of seeds damaged (P<0.05) was recorded in lambda-cyhalothrin-treated plots in both years and at the two sites thus making the insecticides the best among the tested ones for the control of A. armigera in rice.