Diapause Characteristics And Cold Resistance Correlation In Different Geographic Population Of Xinjiang Helicoverpa Armigera

The thesis had studied the Xinjiang bollworm larvae and pupae diapause as materials, analysis the influence of diapause induction factors for different geographical regions bollworm populations; populations of different geographical areas and Cold Resistance Determination of the mechanism of cotton bollworm, and compare different geographic regional population diapause characteristics and cold resistance. The main findings are as follows:1. According to the measurement of the diapause induction factors in different geographical population of Xinjiang bollworm, photoperiod and temperature has ascertein effect on the cotton bollworm larvae, and the difference between the two are significant. Bollworm populations in diapause pupae at 20 ?, light cycle LD10: 14 h, such as Kashi,Aksu, Turpan, Hami, Shanshan and other populations, as well as photoperiod LD11: 13 h Changji, Bole, Yili, etc, the diapause rate reached to 95%. Under the circumstances of LD14: 10 h and above, the diapause rate of geographical population in Xinjiang region is very low. In short day LD8: 16 h, in addition to the 97.6% diapause rate in Kashi, other areas have reached 100% rate of diapause. Xinjiang bollworm populations in different geographic regions diapause induction critical photoperiod respectively shows three different diapause induction characteristics. The critical photoperiod for Kashi and Aksu population is LD11: 13 h; the critical photoperiod for Turpan, Hami, Shanshan population is LD12: 12 h; Changji, Bole, Yili and other areas critical photoperiod for bollworm is LD13: 11 h.2. Use Logger 220 measured the super cooling point of Xinjiang bollworm population, the results showed no significant differences between different populations of the area; the diapause pupae in three northern regions of different geographical populations, provided ambient conditions between-15 and ?-20 ?, 50% of the individuals required lethal time(LT50) respectively 13 days, 0.4 days; in addition, according to the measurement to the sugar content in the population Xinjiang diapause pupae, Kashi, Aksu, Shanshan Turpan, Hami, Changji, Bole, Yili and other population and pupal hemolymph of females reached between 2.72 mg / 100 mg ~ 3.1 mg / 100 mg, sugar males reached between 3.12 mg / 100 mg ~ 3.56 mg / 100 mg.3. According to the analysis to the the factors inducing diapause and cold resistance of Xinjiang bollworm populations. On the whole, two factors. photoperiod and temperature, has significant influence on cotton bollworm diapause induction and ground duration and diapause pupae in different geographical populations, and the difference between the two could reached to a significant level. But according to the cold resistance measurement, different geographical populations has little difference in terms of low viability bollworm three northern regions, as well as diapause pupae in sugar content measurement results. Thus there are some differences in Xinjiang bollworm on different diapause characteristics of the geographical population, but almost no difference in cold resistance.