竹卵圆蝽的生物学及其防治

BIOLOGICAL PROPERTY AND ITS CONTROL OF HIPPOTA DORSALIS' (STAL)

竹卵圆蝽Hippota dorsalis(Stal)属半翅目、蝽科。是近年来在浙江西北部竹林中暴发的一种重要害虫。据安吉县1987年调查,受害竹林面积已达8.1万亩。该虫在浙江安吉为一年一代,于11月以4龄若虫在地表落叶层下越冬,翌年4月上中旬开始取食为害,若虫5龄,除越冬外,若虫常年在竹上为害。用黄油、机油、溴氰菊酯混合剂在竹秆基涂环可阻止若虫上竹,在秆基注射50％甲胺磷乳剂,虫口减退率达90％以上。

Hippota dorsalis (Stal) belongs to the family of Pentatbmidae, which is a main pest occured in recent years in the bamboo foresc of the North-west part of Zhejiang Province.According to the observation, there were 5400 hectares of bamboo stands damaged by it in 1987 in Anji County.This insect had one generation per year.98% of them lived through winter by fourinstar nymph, and in the first and middle ten days of April of next year when the mean temperature of day was 10—25℃ and the relative humidity was over 50%, its nymph climed up to the bamboo culms and got food, the quantity of which was increasing while the air temperature was rising and the relative humidity going down.The eclosion of the adults was from the end of May to the beginning of June.After taking supplemental nutrients for 22 days, the adults mated each other and then the female oviposited 30 days later.When the atmospheric temperature reached 27℃ for 3—7 days, the eggs hatched.The nymph had five instars and the first instar nymph did not take food.In Oct.or Nov.when the mean day temperature was below 10℃, the nymph prepared to live on through the winter.It could be cbntroled by making isolating poisonous ring on culms, or spraying 2.5% Decis emulsion of 20 ml per 0.0667ha.on ground, or injecting 50% Methamidophos of 1—2 ml into each bamboo