Evaluation of Bacillus thuringiensis to Control Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) under Laboratory Conditions

The tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is among the most destructive pests that attack tomato in many countries. In this study, the efficiency of three suspensions (106;105;104 cell/ml) of Bacillus thuringiensis var. Kurstaki was tested on T. absoluta larvae 1st, 2nd, 3rd and 4th instar was assessed to study the effect of these suspensions on larval mortality. Results showed that the concentration 106 cell/ml resulted in the highest mortality of all instars larvae with an average mortality of 20%, 22.66%, 18.66% and 23.33% was recorded for the first, second, third and fourth instar, respectively. The greatest percentage of mortality occurred in the third day after the larvae fed with leaves treated with suspension B. thuringiensis.

美国的舞毒蛾管理及其启示(Ⅰ)

文章较全面地介绍了美国的舞毒蛾管理及其相关的防控技术,全文分2部分发表。第1部分主要介绍美国联邦政府的舞毒蛾管理机构、防控策略以及州一级舞毒蛾管理的各相关方;以美国威斯康辛州、明尼苏达州和加利福尼亚州为例介绍了州一级舞毒蛾管理的具体内容、步骤和措施。此外,简述了美国有关舞毒蛾的公众教育和宣传。第2部分重点介绍舞毒蛾的种群调查和控制技术。在美国,对舞毒蛾的调查和监测普遍采用性信息素诱捕器;在舞毒蛾常发区内,卵块调查也较为常用。在政府机构执行的舞毒蛾管理项目中,最常采用的种群控制技术是苏云金杆菌(Btk)和除虫脲(商品名为敌灭灵)这2种杀虫剂以及基于舞毒蛾性信息素的交配干扰和大量诱捕技术。在文章第2部分的末尾,讨论了我国舞毒蛾管理中存在的几个问题并提出了相关建议。

苏云金杆菌D—1(血清型H3ab)新菌株的研究

D—1菌株系从自然死亡的灯蛾虫尸分离的一株苏云金杆菌新菌株。经菌种鉴定与Bt.var.kurstaki相同,属血清Ⅲ型。其培养特性表现为:对培养基成分和培养温度适应范围较小,在温度28-30℃,培养基含固量为4.1-6.7％,C/N为5.7-6.2时发酵正常。32℃以上和浓培养基则影响其正常繁殖。这与HD-1菌株相吻合。对菜青虫、棉铃虫、玉米螟和松毛虫等4种昆虫毒力测定结果表明,D—1菌兼有H_5型青虫菌81—6和H_3型HD-1的杀虫特性。它对菜青虫和松毛虫的毒力与81—6相接近而高出HD—12.7—5.1倍。对棉铃虫和玉米螟的毒力则明显高于81—6也比HD—1强。