杏芽瘿发生规律及其防治

杏芽瘿是甘肃省河西、中部、陇东等地区杏树上发生已久的一种害状。近年来,蔓延很快,为害甚重。其中由梅下毛瘿螨Acalitus phloeocoptes(Nalepa)引起的芽瘿已在武威、张掖发现,受害枝干形成大小不等的瘿瘤。该螨主要以抱卵成虫在活瘿瘤的芽丛内越冬。室内以50ppm激动素保鲜杏鳞片进行单体饲养,及室外群体发育进程观察,结果基本一致。17～20℃,卵期4～6天,若虫期5～6天,成虫期3～4天,完成一代约12～16天。在调查的20个杏树品种中,大偏头受害最重,其次为毛杏。而实生5号、8号尚未发现受害。试验的9种药剂中,50％克螨特、40％乐果防效分别为85～98％及81～93％,而10％天王星为68～91％。

Occurrence and Control of Apricot Bud Gall

The apricot bud gall is a form caused by Acalitus phloeocoptes (Nalepa). In recent years, it is spreading rapidly in the west and centre areas of Gansu province. The mites survived the winter in the form of pregnant imago in the iving gall tumour. The indoor and outdoor experiment were conducted to clarify the development progress of mites. In indoor experiment, the single mite was raised on the bud scale which was kept in 50ppm KT to have it fresh. The result obtained was basically the same as that of the outdoor experimet. At 17～20℃, stage of egg was 4～6 days, nymph was 5～7 days, imago was 3～4 days. A complete generation needed 12～16 days. Resistance of the trees was different. Twenty varieties were investigated in which Dapiantou was most injured, then the wild apricot. But no symtoms were found in True Seed No 5 and No 8. Among the 9 insecticides tested in field, the effectiveness of 1∶30000 progargite (50%) was 98%, 1∶500 Dimethoate(40%) was 93%, 1∶3000 Talstar (10%) was 91%.