Abstract: 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.

Key words: Homoeosoma nebulellum, sunflower, developmental duration, population dynamics, development progress, life history