Protein consumption by mated, unmated, sterile and fertile adults of the Queensland fruit fly, Bactrocera tryoni and its relation to egg production

Abstract. Female adults of Bactrocera tryoni (Froggatt) (Diptera: Tephritidae) at 25 °C require more than 0.1 mg of yeast autolysate per day to mature their oocytes to the vitellogenic stage and mate. Those given 0.2 mg per day from day 2 of adult life mated (when given the opportunity between 11 and 13 days) and each laid approximately 100 eggs (just over one egg per ovariole) by day 56. Females allowed to feed ad libitum from day 2, then 0 or 0.2 mg per day from day 14, laid approximately 75 and 100 eggs, respectively (after mating), whereas those fed ad libitum from day 2 to day 56 laid approximately 540 eggs after mating (averaging just over six eggs per ovariole). The developmental pattern of intake of normal females when on an ad libitum diet showed a rise to a peak at 5–7 days, followed by a decline to sustained low levels if not mated, but rising to a lower peak if mated between days 11–13 followed by a steady decline. Female flies that had been sterilized by 80 Gy gamma irradiation at the puparial stage had a pattern of food consumption similar to that of normal females mated at 7 days but they produced no yolky oocytes and had a darkened fat body. Normal and irradiated males had a feeding pattern similar to that of unmated nonirradiated females but at a lower level. The results are discussed in terms of the control of protein intake and the rate of its conversion to yolk.