REDUCTION OF ORIENTAL FRUIT-FLY (DIPTERA, TEPHRITIDAE) POPULATIONS IN PAPAYA ORCHARDS BY FIELD SANITATION

The effect of field sanitation in suppressing oriental fruit fly, Dacus dorsalis Hendel, populations in 'Sunrise' papaya (Carica papaya L.) orchards was determined by comparing larval density and percentage infestation in mature green to fully ripe fruits sampled from fields with and without cultural practice of sanitation. In addition, the relative density of adults estimated using methyl eugenol-baited traps was compared between orchards with and without sanitation. Sanitation involved removal of ripe fruits on trees and on the ground twice a week. The orchards without sanitation had an irregular harvesting pattern which resulted in abundant ripe fruits on trees and fallen, rotting fruits on the ground. Mature green fruits had no oriental fruit fly infestation; infestation was observed only in half- and fully-ripe fruits. Oriental fruit fly larval infestation (density and percent infested fruit) was lower in half- and fully-ripe fruits collected from the fields where sanitation was practiced. Likewise, the relative density of oriental fruit fly adults was lower in the orchards with sanitation. Field sanitation should, therefore, be an integral component of pest management methods aimed at suppressing oriental fruit fly population in papaya orchards.