【作者】 李兆华； 周翠英； 徐汝梅； 敖贤斌；

【Author】 Li Zhaohua Zhou Cuiying Xu Rumei (Department of Biology,Beijing Normal University) Ao Hsienbine (Changli Fruit-tree Research Institute,Hebei Academy of Agricultural Sciences)

【机构】 北京师范大学生物系； 河北省农科院昌黎果树研究所；

【摘要】 深点食螨瓢虫是果树叶螨的重要天敌,国内外均有报道。1987年作者在河南清丰县一管理粗放的苹果园中,对此种瓢虫自然控制山楂叶螨的作用进行了系统调查.一、深点食螨瓢虫是当地的优势天敌,其高峰期与山楂叶螨的高峰期非常吻合,其他天敌的主要发生期则远在叶螨的高峰期之前或其后,在各种天敌中,深点食螨瓢虫是抑制山楂叶螨种群的主要力量。二、自然观察树组(不予施药)。食螨瓢虫和叶螨均出现1个高峰,高蜂期间二者的比例为1:97.高峰日之后10天叶螨数量急剧下降,一般波动于0～30头/百叶.除有的树在顶部少许落叶外,无明显受害。三、施药树组,当叶螨达到百叶200头成螨时,喷三氯杀螨醇600～800倍药液。各树的叶螨及食螨瓢虫均出现2个高峰。杀螨剂对天敌有明显杀伤作用,但由于后一个高峰叶螨繁殖力降低,其数量变动基本上同观察树组。个别树的顶部亦出现少量落叶.四、室内饲养观察,食蜻瓢虫一龄幼虫平均日食18头幼螨和57粒卵。二、三龄幼虫的食量相似,平均日食23头幼、若螨和77粒卵。三龄幼虫已能日食40头成螨。四龄幼虫平均食18头幼、若螨及115粒卵。成虫平均日食44头成螨或22头幼、若螨及163粒卵。根据调查,初步认为在叶螨发生不重的年份,其高峰期间瓢、螨比在1:50～60时,食螨瓢虫有可能控制叶螨种群而无需施药。更多还原

【Abstract】 Several natural enemies of the hawthorn spider mite was observed in an apple orchard in Honan province.Stethorus punctillum,a coccinellid beetle,is considered the most important predator who effectively contributed to the natural control of the mites in 1987. On 3 unsprayed trees,the population of the mites increased to average 6.24 mites per leave in 24th.July.During the mite population peak,the ratio between S.punctillum (motile stages) and T.viennensis(adults) was 1:97,following this peak,both the populations of the mites and predators fall rapidly,then fluctuated at a quite lower level.With the exception of a few leaves on the top of the trees detached in September,no obvious damage to the trees were observed.This results similar to another 4 trees with 2 applications of acaricide,though the peak population of the mites were much lower and the ratio between the predator and prey was much higher than that on the unsprayed trees. It seems S.punctillum may successfully control the leaf damage caused by T.viennensis without chemical spraying on apple trees when the mite populations are relatively low and the ratio between this predator and mite approximate to 1:50-60 during the mite population peak. The numbers of mites consumed by S.punctillum obtained in laboratory are recorded as well.更多还原