内蒙古巴彦淖尔地区向日葵螟的种群动态与生活史

为了制定科学、有效的向日葵螟Homoeosoma nebulellum Denis et Schiffermüller（鳞翅目：螟蛾科）测报和防治对策，通过野外调查和室内饲养观察对内蒙古巴彦淖尔地区向日葵螟的发生为害规律及生活史进行了研究。结果表明：当地向日葵螟的寄主有菊科的向日葵Helianthus annuus L.、茼蒿Chrysanthemum coronarium Mill.、刺儿菜Cephalanoplos segetum（Beg.） Kitam和苣荬菜Sonchus brachyotus DC.，其中苣荬菜作为向日葵螟的寄主在我国是首次报道。应用性信息素监测结合田间调查的结果表明，当地向日葵螟一年发生2代，其中越冬幼虫4月下旬开始化蛹，5月中旬开始羽化，但此时羽化的成虫由于缺乏开花寄主而无法产卵为害。第1代幼虫在6月末为害茼蒿、7月下旬开始为害开花的向日葵。第1代幼虫于7月下旬开始羽化产卵形成第2代，其中有9.2%的老熟幼虫直接滞育越冬。第2代幼虫自8月中旬起为害晚开花的向日葵，9月中旬老熟后陆续入土越冬，至10月上旬收获时仍有30.0%的幼虫未老熟而随收获的葵花盘转至筛选出的杂质中越冬。在24℃，RH 70%和L16∶D8光照条件下测定第2代向日葵螟卵、幼虫和蛹的发育历期分别为4.2、15.9和11.1 d，雌、雄蛾寿命分别为14.9 d和15.1 d.综合观察结果，绘制了巴彦淖尔地区向日葵螟的生活史表。

Population dynamics and life history of the European sunflower moth, Homoeosoma nebulellum(Lepidoptera:Pyralidae)in Bayannur,Inner Mongolia

The population dynamics and life history of European sunflower moth, Homoeosoma nebulellum Denis et Schiffermüller (Lepidoptera: Pyralidae), a serious pest of cultivated sunflower in China were investigated in Bayannur (41.06°N, 107.24°E), Inner Mongolia from 2008 to 2009 to develop a sound forecast and management program. The results indicated that the sunflower, Helianthus annuus L.，Garland chrysanthemum, Chrysanthemum coronarium Mill.，common cephalanoplos, Cephalanoplos segetum (Bge.) Kitam.， and common sowthistle, Sonchus brachyotus DC. in the family Asteraceae are host plants for H. nebulellum in this district. S. brachyotus is a newly recorded host plant species for this pest in China. Two generations occurred annually in the field of this district as investigated by sex pheromone traps and filed surveys. The overwintering larvae began pupating in late April, then emerged in mid-May, but at this time they are still not able to oviposit due to the absence of blossoming host plants. Larvae in the first generation damaged sunflower blossoming in late July although they could also attack C. coronarium blossomed in late June. Majority of the matured larvae in the first generation pupated and emerged after late July, but 9.2% of them enter diapause for hibernation. Larvae in the second generation damaged sunflower blossoming after mid-August. Most larvae began burrowing into soil for hibernation after mid-September, but there were still 30% of larvae that could not mature when sunflowers were harvested. The immature larvae were transferred into impurities of sunflower seeds for overwintering. Under temperature of 24℃, RH 70% and photoperiod of L16∶D8, the mean developmental duration of egg, larva, and pupa was 4.2, 15.9 and 11.1 d, respectively, and longevity of male and female adults was 14.9 and 15.1 d, respectively. An annual life history table for the H. nebulellum in Bayannur was drawn based on the observed data.