Bio-ecology and management of the mango weevil, Sternochetus mangiferae (Fabricius) (Coleoptera: Curculionidae).
Shukla R. P., Tandon P. L.
Author Affiliation: Indian Institute of Horticultural Research, Hassaraghatta, Bangalore 560?080, India.
International Journal of Tropical Agriculture 3 : 293-303
Abstract : Studies on the biology, ecology and management of the mango pest Sternochetus mangiferae were conducted in the laboratory and in the field in Bangalore, India, from 1980 to 1983. The immature stages of the weevil are described. In studies using mango cv. Alphonso, females oviposited in the fruit epicarp during March and April, starting 3-4 days after mating. The mean developmental periods at 27°C and 75% RH were 6.6 days for eggs, 29.6 days for the 5 larval instars and 7.5 days for pupae. The mean lifespan of adult females was 302 days and of adult males was 287 days. The larvae developed in fruits in the field between March and May and pupated in late May and early June. Adults emerged from the fruits during June-July and went into diapause between July and February in cracks and crevices of the tree trunk, mostly at a height below 2 m above the ground. Four field experiments were conducted on cultivars Alphonso and Raspuri to evaluate the efficacy of insecticides as foliar sprays during the oviposition period and as spot application treatments on tree trunks just before the adults emerged from diapause. The results of 3 years work indicated that deltamethrin (0.003%) was the most effective foliar spray followed by fenthion (0.1%) and, less consistently, carbaryl and fenvalerate. Diazinon (0.05%) was effective as a trunk spray; this insecticide and method of application is recommended for weevil management for economic and environmental reasons. Treatment of harvested fruit with hot water at 48-70°C for different durations, and with gamma irradiation at 1-50 krad, proved to be ineffective.