REGULATION OF VITELLOGENIN SYNTHESIS AND UPTAKE IN THE BOLL-WEEVIL, ANTHONOMUS-GRANDIS

Hormonal factors influencing reproductive development were examined in adult boil weevils, Anthonomus grandis (Boheman) (Coleoptera: Curculi onidae). Long-day, high-temperature rearing conditions promote reprodu ction whereas short-day, low-temperature conditions do not. implants o f corpora allata (CA), brains, or brains plus retrocerebral complexes taken from long-day donors, or hormone analogue treatments were used t o examine onset of vitellogenin synthesis and uptake in decapitated bo dies of adult weevils reared in short-day, low-temperature conditions. Weevils decapitated within 2 days after eclosion and reared in short- day, low-temperature conditions never initiated vitellogenin productio n or ovarian development. Females and males decapitated on day 2 showe d haemolymph vitellogenin within 5 days following treatment with Juven ile Hormone (JH) analogue or implantation of CA, but not after implant ation of brain alone or implantation of muscle (sham). Uptake of vitel logenin into the oocytes did not occur unless both JH analogue and bra in were given as replacement therapy. These experiments indicated that JH is necessary and sufficient to stimulate vitellogenin synthesis in this species but that a brain factor must be present for vitellogenin uptake.