The effect of accessory gland and ejaculatory duct fluid in modulating female remating behaviour in the female Queensland fruit fly, Bactrocera Tryoni

Molecules within the accessory gland and ejaculatory duct fluid (AGF and EDF) play a wide range of roles in affecting female reproductive activity in insects. following insemination, the female Queensland fruit fly, Bactrocera tryoni, enters a refractory period. During this period, there is a 60-7-% decrease in female re-mating frequency. It has already been determined that number of sperm stored in the spermathecae does not directly drive female re-mating inhibition. The other obvious candidates, AFG and EDF, and their role in inhibiting re-mating in females are explored in this study. Injections of AGF and EDF into virgin females show that the response is dose dependent. Seminal fluid molecules, which carry sperm-related functions seem likely to act mainly within the female reproductive tract, whereas those molecules that influence female behaviour and physiology typically appear to pass through the wall of the tract into the haemocoel. With the help of radioactive labelling, (using [L - 35 S] methionine and cysteine) we determine the fate of these seminal fluid molecules in the female reproductive tract of B. tryoni. The study of these seminal fluid molecules is of importance, as their manipulation may provide novel methods of insect control, especially in Bactrocera tryoni, which is Australia's most costly horticultural pest.