Only late
stage (80% developed) eggs were used in this
study. Late stage medfly eggs were reported to be
most resistant to cold temperatures (Armstrong et
al., 1995) of the three species (Mediterranean fruit
fly, oriental fruit fly, (Bactrocera dorsalis Hendel)
and melon fly, (B. cucurbitae Coquillett)) that
infest avocado in Hawaii. A control consisting of
three groups of 100 eggs were held on moist
blotter paper in covered petri dishes to determine
the hatch rate of the eggs from mass-reared flies.