Fifteen to thirty three percent of the adults of Dolycoris baccarum LINNAEUS were parasitized by Cylindromyia brassicaria (FABR.), which were collected at Morioka, Iwate Pref. from June to August, 1983. Only one parasitoid larva emerged from one host insect and the parasitism was found in both sexes of the host. Adults of C. brassicaria emerged from the end of July to August both in the laboratory and in the field. On the other hand, no parasitoid larvae emerged from D. baccarum adults collected in September before the winter.
The handy mill (Freezer-Mill) is useful for a DNA extraction from tissues and organs. In the present experiment, we prepared a high molecular weight DNA (100 to 140kb) from the posterior silk gland of Bombyx mori by use of the mill.