OBSERVATIONS ON THE CITRUS BUD MIDGE DASINEVRA CITRIGEMMINA (DIP:CECIDOMYIIDAE)

The citrus bud gall midge(Dasixeura ctiriyanmina)is a new citrus pest found in South China. Four to five generations each year in Guangdong Province were observed. The larvae led on young buds, which became galls after injury. The larval stage was about 4 - 25 days,but the diapause larvae lived 210-250 days. The pupal period varied from 6 to 28 days. The life - span of the adults was 2 - 7 days. The adults were phototropic and active at daytime. About 20 - 60 eggs were laid in a mass by each female on the young buds. The egg stage lasted 1 - 6 days. There were three larval instars; the larvae lived inside the galls all the time; the matured larvae dropped down into the soil to pupate. In late spring when the matured larvae fell to the soil ,they entered diapause within thin elliptical cocoons, remained there until late November, and then resumed their activity gradually moving to the surface of the soil to pupate. The pupal stage lasted 10 - 20 days and the adults appeared in early December. At the emergence ol 1st generation adults, spraying contact insectcides on the surface of soil and trees could kill the pest with satisfactory result.