Rearing of fruit flies for assays. Approximately 1000 B. dorsalis eggs (18 to 24 h old), obtained from insectary-colonized fruit flies (Tanaka et al., 1969, Vargas, 1989), were inoculated in half-ripe whole C. papaya L. var. 'Solo' (weight range 430-488 g per fruit) or seeded on 235 g wheat diet.