Study On Mating And Population Dynamics Of Cotton Bollworm And Clover Cutworm (Lepidoptera: Noctuidac)

In order to research larval host use, mating of omnivorous pests Helicoverpa armigera andScotogramma trifolii Rottemberg, migration and population dynamics, moths were collected fromKuerle,Yuli,Kuche,Akesu, Awati,Alaer, Maigaiti and Regiment148in Xinjiang in2013usinglight-traping.female moths were dissected and conduct sample tests of stable isotope analysis to get thatthe local corn field as refuge to affect the Helicoverpa armigera. According to estimated ovariandevelopment in different month to judge migrate dynamics of Helicoverpa armigera and Scotogrammatrifolii Rottemberg. According to dissected of Helicoverpa armigera and Scotogramma trifolii Rottembergin different season to get theirs mating situation and explore the migrate dynamics in different period. Formthe long-term data by those methods to get the population quantity’s changing feature of Scotogrammatrifolii Rottemberg in northern Xinjiang. The results show that:1、 Host use by cotton bollworm: C4-derived Helicoverpa armigera have a higher proportion compared toC3-derived Helicoverpa armigera from May to August in Kuerle; C4-derived Helicoverpa armigeraremained from June to September in Akesu region; C3-derived×C4-derived Helicoverpa armigeraremained below45.8%in early August; C3-derived×C4-derived and C4-derived×C3-derived Helicoverpaarmigera remained below28.8%and20.3%in middle August; C3-derived×C4-derived Helicoverpaarmigera remained below40%, C4-derived×C3-derived Helicoverpa armigera remained below40%inearly September; In Kashi region the Helicoverpa armigera were obtained for C4-derived. Thoseresultes implies that In different month,the different sexual Helicoverpa armigera has parasitise ondifferent plant. The Helicoverpa armigera from C3-derived and C4-derived could randomly mate.2、 Cotton bollworm and Clover cutworm immigration occurred in kuerle in southernXinjiang.Helicoverpa armigera and Scotogramma trifolii Rottemberg are omnivorous pests which iscapable of migration. To explore theirs migratory activity, the ovary and mating frequency had beenmonitored in the Kuerle region of southern Xinjiang. The results showed that mating occurred when theHelicoverpa armigera and Scotogramma trifolii Rottemberg ovaries developed to the second grade. Theindividuals, develop to the third grade, of the all of generations Helicoverpa armigera and Scotogrammatrifolii Rottemberg occupied50%or more,based on the research, Helicoverpa armigera could be concludedthat the initial source from other places. Scotogramma trifolii Rottemberg could be concluded that theinitial source from local source, In the peak mating period, the average mating rate and frequency offemale were95%and1.75.3、 Mating: Helicoverpa armigera and Scotogramma trifolii Rottemberg that there were few femalesunmated. It may relate with that physiological unmaturation period or maturation period butunmated(mating failures).The mating frequency of Helicoverpa armigera is higher during early June,middle and late July, middle August. The mating frequency of Scotogramma trifolii Rottemberg is higherduring middle June and late July. The mating frequency of Helicoverpa armigera is higher than theScotogramma trifolii Rottemberg.4、 There was a periodic fluctuantion of the population of clover cutworm. The results showed that thepopulation of clover cutworm had the characteristic of periodic fluctuation among years and with the cyclesof4～5years. There are3or4generations in one year. The population annual variety regulation of clovercutworm showed that the moths of clover cutworm were generally found in mid-april or late-april. Theoverwintering generation peaked numerically in mid-May, the first generation in mid-and late June, thesecond generation in late July and early August,and of the third generation peaked occasionally in northernXinjiang...