八斑球腹蛛的生物学特性及其在农田内发生规律

Biological characters of Theridion octomacutatum and its regularity of outbreak in farmland

八斑球腹蛛是农作物害虫的重要天敌。1头雌蛛一生产卵80～135粒,卵的孵化率很高,一般为88.66％～96.52％。一生蜕皮4次。在湖北省南部丘陵山区1年发生6个完整世代,以第6代成蛛、亚成蛛和第7代幼蛛在各种冬播作物上越冬,各虫态发育历期随温度的升高而缩短。农田施药使八斑球腹蛛种群数量减少,作物长势好其种群数量增加。

The living habit and character of Theridion octomacutatum Boes.el str. are bet-ween web- wearing and hunting spiders. It's a natural important fighter against crop's dangerous insects. A female Theridion octomacutatum Boes. et str. can birth about 80 or 135 ovum, 113 on average. There is a high hatching rate,about 88.66% to 96.5% . It casts off skins twice a year and ha:- six periodical life in hills in south part of Hubei province. Sub- adult spiders and 7th young spider spend winter in various kinds of crops. Each period of developing reduces along with the rise of temperature. The major factor which influences the number of the growing Theridion octomacutatum Boes.et str. in larmland is'the amount of agricultural chemical's given and the trend of crops growing.