REGULATION OF PHEROMONE PRODUCTION BY FEMALE PINK-BOLLWORM MOTHS PECTINOPHORA-GOSSYPIELLA (SANDERS) (LEPIDOPTERA, GELECHIIDAE)

We present in this study data which indicate that there is a diel peri odicity in the pheromone production of the pink bollworm moth Pectinop hora gossypiella (Sanders) (Lepidoptera: Gelechiidae) but that it is n ot well defined. Moreover the control mechanism of pheromone productio n differs somewhat from that reported for other moths. No pheromonotro pic response was obtained when photophase females were injected with s ynthetic Helicoverpa zea pheromone biosynthesis activating neuropeptid e (Hez-PBAN). After decapitation for 24 h, Hez-PBAN did not induce phe romonotropic activity above control levels, which themselves remained relatively high. No effect on pheromone production was observed after treatment with the non-steroidal ecdysone agonist (RH5999). Decapitati on for 72 h resulted in a significant drop in the control levels of ph eromone titres. After decapitation for 72 h, stimulation by injections of Hez-PBAN and pink bollworm head extracts was observed. In addition , an enhancement of the PBAN stimulation was observed when combined wi th severance of the ventral nerve cord before injection. On the other hand, pink bollworm head extracts did not cross-react with Hez-PBAN an tiserum in a radioimmunoassay, indicating that the pheromonotropic fac tor present is sufficiently different from Hez-PBAN and does not recog nize the antigenic binding sites. In studies using isolated abdomen an d pheromone gland cultures in vitro, no stimulation of de novo pheromo ne biosynthesis was observed but a 3-fold increase in the de novo fatt y acid biosynthesis was detected in pheromone gland cultures.