EVIDENCE FOR THE PRESENCE OF A PHEROMONOTROPIC FACTOR IN HEMOLYMPH AND REGULATION OF SEX-PHEROMONE PRODUCTION IN HELICOVERPA-ZEA

In intact animal assays, 2-day-old females of Helicoverpa tea injected with 2 pmol synthetic H. tea-pheromone biosynthesis activating neurop eptide (Hez-PBAN) exhibited significant stimulation of pheromone produ ction, In contrast, octopamine did not stimulate pheromone production when injected 30 min before lights off, Additionally, females injected with PBAN and mianserin (an octopamine antagonist) or reserpine, prod uced significant amounts of pheromone. These results suggest that octo pamine may not be involved in regulation of pheromone production in H. tea. In abdomen incubation assays, synthetic Hez-PBAN stimulated pher omone production at doses as low as 10 fmol. Additionally, one female equivalent of hemolymph or serum from scotophase females exhibited phe romonotropic activity that was comparable to activity elicited by 10 f mol synthetic Hez-PBAN. High pressure liquid chromatographic (HPLC) fr actionation of scotophase H. tea hemolymph serum filtrates, obtained a fter filtration through molecular weight filters, suggested the presen ce of a pheromonotropic fraction with molecular weight that appears to be less than 3000.