Artificial Rearing And Irradiation Sterility Of Bactrocera Tau (Walker)

1. Used the artificial larval diet which was composed of wheat bran 750～850g, sucrose 250～350g, yeast 100-200 g, water 1.5～2L and other components to rear larvae of Bactrocera tau (Walker), used the ratio of sugar:yeast extract=1:1 to rear adult of B.tau (Walker). The effects of artificial larval diet on pupal weight, emergence rate, fly ability, the larval survival rate and F1 egg hatch rate were tested. The results showed that the pupal weight of F1 generation compared with CK had extremely significant difference, but F2, F3 generations had no significant difference. Fly ability, larval survival rate and F1 egg hatch rate had no significant difference compared with CK.2. Pupae were irradiated by 60Co at 1,2 and 3 days (-1,-2,-3d) before emergence with 90,100 and 110Gy respectively. Each dose group of irradiated females were not found any mating behavior with normal males, did not lay eggs. Irradiated males and normal females, the emergence rate of both 90 Gy and 100Gy had no significant difference compared with CK. For 110Gy, pupa emergence rate had no significant difference with CK of -2d, but-Id and -3d had extremely significant difference compared with CK. The results showed that with pupa the emergence rate reduced with the dose increased but increased with the pupal ages increased. The fly ability decreased with the dose increased, but increased slightly with the pupal ages. Sex ratio and survival rate under pressure showed no significant difference compared with CK. Females were more sensitive to radiation than males. The optimum irradiation dose was 100Gy and the optuimum pupal age was -2d.3. The growth of female adults ovary were affected by irradiation. The ovarian area from 1 d-old to 21 d-old remained at around 0.2 mm2 of female adults which emerged from the pupae irradiated by 90,100 and 110Gy at -1,-2,-3 separately, but increased slighly at 26 d-old, and still below 0.4 mm2. The ovarian area of CK grew stability form Id-old to 21 d-old but grew sharaply at 26 d-old. The results showed that irradiation caused ovarian aplasia or hypoplasia of female adults.