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

The effect of field sanitation in suppressing oriental fruit fly, Dacu s dorsalis Hendel, populations in 'Sunrise' papaya (Carica papaya L.) orchards was determined by comparing larval density and percentage inf estation in mature green to fully ripe fruits sampled from fields with and without cultural practice of sanitation. In addition, the relativ e density of adults estimated using methyl eugenol-baited traps was co mpared between orchards with and without sanitation. Sanitation involv ed 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 infestati on; infestation was observed only in half- and fully-ripe fruits. Orie ntal fruit fly larval infestation (density and percent infested fruit) was lower in half- and fully-ripe fruits collected from the fields wh ere sanitation was practiced. Likewise, the relative density of orient al fruit fly adults was lower in the orchards with sanitation. Field s anitation should, therefore, be an integral component of pest manageme nt methods aimed at suppressing oriental fruit fly population in papay a orchards.