竹笋夜蛾生物学观察及药效试验

竹笋夜蛾在陕西竹林区普遍发生,局部成灾,竹笋被害率达60—90％。一年发生一代,以卵在莎草科杂草上越冬。3月中旬孵化,在杂草上取食,幼虫有5龄。5月上旬竹笋出土时,幼虫至3龄转移到笋内蛀食,被害竹笋断落、腐烂,招引江苏泉蝇寄生。幼虫在笋内为害20—25天,脱笋入土化蛹。竹林郁闭度小、林间空地大、经营管理差、杂草多处发生严重。试用40％辛硫磷乳油、40％久效磷乳油1000倍液,防治杂草上初龄幼虫,列亡率可达78—81％,竹笋被害降低率在70％以上。捡拾虫退笋、清除杂草、喷药防治是综合治理的三条主要途径。

OBSERVATION ON BIONOMICS AND EXPERIMENT ON THE CONTROL OF OLIGIA VULGARIS BUTLER

Oligia vulganis Butler generally exists and causes disaster in some areas in the bamboo regions in Shaanxi province. The damaging rate of bamboo shoots is up to 60-90%. It has one generation per year and overwinters in the egg stage on the weeds of Cyperaceae. The overwintered egg incubates in the middle March and the larva starts feeding on the weeds. The larva period includes five instars. When bamboo shoots come up out of the ground in the early May the third instar larva bores into bamboo shoots. The damaged bamboo shoots become broken or decomposed and lute Pegomia kiangsuensis Fan to live. 20-25 days after feeding bamboo shoots. The larva leaves bamboo into soil and pupates. Where the canopy density of bamboo stand is small,the blank in bamboo forest is large, the management is poor and weeds are more, the pest occurs-more seriously. Young larva on weeds may be controled with . 40% Phoxim ( 1 :1000 ) and 40% MonocrotoPhos ( 1:1000 ) to the rate of 78-81% and the damaging rate of bamboo shoots is reduced over 70%. Picking up damaged bambo'o shoots, clearing away weeds and chemical control are the three important ways of integrated management.