JH III levels in larvae and pharate pupae of Anastrepha suspensa (Diptera: Tephritidae) and in larvae of the parasitic wasp Biosteres longicaudatus (Hymenoptera: Braconidae).

This is the first report of a juvenile hormone (JH) in the Caribbean fruit fly, Anastrepha suspensa (Diptera: Tephritidae). JH III was identified in whole body extracts of L3 (final instar) larvae and pharate pupae (PhP) by using a physicochemical method. JH III was also found in PhP superparasitized (up to 11.3 ± 3.5 S.D. parasites/host) by the solitary wasp Biosteres longicaudatus (Hymenoptera: Braconidae) and in first instars of the parasite. The levels of JH III in hosts were up to 15 × higher than those of the controls. The JH esterase (JHE) levels in the hemolymph of 1-day-old PhP controls were significantly (P < 0.05) higher than those of superparasitized individuals. These results suggest that the elevated JH III levels induced by superparasitism may arise from JH buildup due either to decreased JHE activity to continued synthesis of JH by the ring gland or to secretion of JH III by the parasites into the host's hemocoel.