Ostrinia scapulalis (Lepidoptera: Crambidae) overwinters as a final instar larva. In order to elucidate phenology of the insect, we studied several factors related to its overwintering. Neonate larvae from early August to early October entered overwintering through outdoor rearing. Pupation and adult emergence were observed during the periods from May to June, next year, and from May to July, respectively. Heat addition by 25oC to overwintering larvae induced shorter prepupal periods with progressing season. Supercooling points of overwintering larvae during the period from October to April were below -20oC, and those temperatures were significantly lower than those of a laboratory colony. It was estimated that higher content of glycerol in hemolymph is responsible for cold-hardiness as a cryoprotectant during overwintering.

• I Hyeon Kim(Crop Cultivation and Environment Division, Natl. Institute of Crop Science, RDA)
• Eun Young Kim(Crop Cultivation and Environment Division, Natl. Institute of Crop Science, RDA)
• Bo Yoon Seo(Crop Protection Division, Natl. Institute of Agricultural Sciences, RDA)
• Jin Kyo Jung(Crop Cultivation and Environment Division, Natl. Institute of Crop Science, RDA)