桑飞象生物学特性及防治的初步研究

在江苏省丰县首次发现桑飞象为害桑树,并酿成严重灾害.此虫一年一代,以幼虫在土中越冬;翌年3月下旬至4月上旬在3—10厘米土层内化蛹,蛹期12—17天;4月中、下旬成虫出土上树取食桑芽和叶片,交尾后2—7天产卵在枝顶及春季剪梢口下段等处,每头雌成虫产卵44—205粒,卵期15—19天;初孵幼虫入土取食植物.用50%辛硫磷1000倍液每亩喷雾150—200斤防治效果良好.

A preliminary study on the biological characters and control of Scythropus yatsumatsui Kono et Morimoto

The mulberry fly weevil Scythropus yotsumatsui Kono et Morimoto was recorded for the first time to damage the mulberry trees seriously in Feng county, Jiangsu province. This pest has one generation per year. The larva overwintered in the soil, and pupated at the last ten days of March to the first ten days of April in the soil layer of 3-10cm under the ground. The pupal period ranged from 12 to 17 days.In about the medium or late of April, the abnlt broke through the soil surface and encroached on the leaves and buds of mulberry tree. 2-7 days after mating, the adult laid eggs on the lower part of the branch below the tip-pruning wound in spring. A female laid 44-205 eggs, and the incubation period was 16-19 days. Early hatched arva fed on the plant in the soil. For chemical control, sprays of 76-100kg per mu of 50% phoxim in 1:1000 dilution can give satisfactory effects.