昆虫病原线虫共生细菌嗜线虫致病杆菌All对小菜蛾拒食作用物性质的初步研究

采用叶碟法测定了36个昆虫病原线虫共生细菌菌株对小菜蛾Plutella xylostella二龄幼虫的拒食作用,其中10个菌株对小菜蛾幼虫的选择性和非选择性拒食率高于75%。以嗜线虫致病杆菌Xenorhabdus nematophilus All菌株为代表,研究了对小菜蛾有拒食作用的物质与细菌生长过程、型变、pH值、温度、有机溶剂之间的关系。结果表明：拒食物质产生于细菌的对数增长期和稳定期,在稳定期最高,拒食率达85%左右;次生型菌液未能分泌足够的拒食物质,其拒食率在20%以下。在-80℃-100℃的范围内,其拒食率均在81%以上。pH3-11范围内,对拒食物质稳定性有一定影响,选择性拒食率变化不大,均在96%以上;非选择性拒食率变化明显,pH值为3、5、7、11时,非选择性拒食率下降至23.1%-34.9%。拒食物质可与氯仿、石油醚、乙酸乙酯、正己烷、乙醇相溶,其提取液对小菜蛾拒食率均在80%以上。     

蜜蜂作为病原物载体的研究进展

蜜蜂作为自然界中的一种重要媒介昆虫,除了承担了许多植物的授粉工作外,还可以作为病原微生物的携菌载体,将蜜蜂授粉与病虫害的防治相结合,在农业生产中可以达到双赢效果。本文就目前利用蜜蜂作为病原物的传播载体的应用状况和存在的问题进行探讨。     

膜荚黄芪传粉昆虫的研究(英文)

[目的]研究膜荚黄芪传粉昆虫的种类及其传粉特点,为膜荚黄芪的育种奠定理论基础。[方法]以膜荚黄芪为研究对象,调查膜荚黄芪传粉昆虫的种类及访花行为。日活动规律观测在晴天进行,7:00～18:00每1h绕样地走1圈,约用时间3min,记录每一时间段出现在视野里的不同昆虫种类和数量。盛花期在样地于晴天7:00～18:00对每种传粉昆虫固定1头进行跟踪观测,用秒表记录其在花上停留时间。访花频率采用追踪法,尽可能连续记录其整个访花过程及时间。[结果]膜荚黄芪访花昆虫共有16种,其中红光熊蜂、明亮熊蜂、蜜蜂、狭带贝食蚜蝇和斑缘豆粉蝶为主要传粉昆虫;主要传粉昆虫的日活动规律出现单峰型、双峰型和直线型3种,活动高峰期有一定交错。在正常气候条件下,蜜蜂和食蚜蝇呈双峰活动规律,蜜蜂在7:30～11:00和13:30～15:00有高峰,食蚜蝇在早晨和傍晚有高峰;斑缘豆粉蝶在11:00～13:00出现1个活动高峰,为单峰型;红光熊蜂和明亮熊蜂在1d中的数量比较稳定,除了在1d中最热的一段时间,都可观察到它们的传粉活动,为直线型。红光熊蜂和明亮熊蜂的每小花停留时间相似,分别为(2.05±0.07)s和(2.57±0.05)s,蜜蜂的每小花停留时间为(3.78±0.13)s,食蚜蝇为(5.28±0.16)s,斑缘豆粉蝶的每小花停留时间最长,达(46.72±2.79)s。红光熊蜂访花频率最高,为11.4次/min,明亮熊蜂、蜜蜂、食蚜蝇的访花频率处于中间状态,分别为10.7、7.1、2.7次/min,斑缘豆粉蝶访花频率最低,为0.9次/min。昆虫的传粉频率与停留时间呈负相关关系。[结论]昆虫访花行为对植物与传粉者相互作用等方面产生直接影响,对理解植物多样性与生殖生态过程具有重要意义。     

Anti-Insect Activity of the Methanol Extracts of Fern and Gymnosperm

With environmental and food safety issues becoming one of the greatest concerns of the public, active plant compounds play more and more important roles in pest controlling. Fern to their particular status in plant taxology and co-evolution are of great significance for application as new pesticides due with insects. In this study, methanol extracts were distilled from wild fern and gymnosperm of 54 species of 22 families collected from Shiwandashan Mountain in Guangxi Zhuang Autonomous Region of China. Insecticidal activities of the methanol extracts were assayed on both adult house fly （Musca domestica） and mosquito （Aedes albopictus）. Significant insecticidal activities were exhibited in the methanol extracts of five species, Cupressusfunebris （leaves and stems）, Cycas acuminatissima （roots）, Keteleeria fortunei （leaves and stems）, Onychium japonicum （whole plant）, and Pinus taiwanensis var. Darning shanensis （leaves and stems）. Applications of the extracts of these plants resulted in higher than 50% mortalities in 4th instar larvae of A. albopictus at 24 h after treatment. The methanol extracts from 13 species possessed insecticidal activities against the adult of M. domestica at 48 h after treatment with higher than 90% mortalities. The extensive screening results showed that these fern and gymnosperm were highly potential to be botanical insecticides. The findings provide a feasible and valuable basis for further investigation.     

Cryopreservation of Queen Honeybee （Apis mellifera carnica） Born Worker Eggs by Vitrification

Many species of insect egg can be targeted individually or （and） collectively for cryopreservation by vitrification. However, there has been no report on cryopreservation of honeybee eggs by vitrification. In an attempt to define a preliminary procedure of cryopreservation of honeybee eggs by vitrification, queen honeybee born worker eggs （worker eggs） were stored through vitrification in liquid nitrogen up to 1 h, and then post-vitrification survival of the vitrified worker eggs in vitro and their hatching rates during maturation in vivo were observed using microscopic and close visual inspections. The procedure of cryopreservation by vitrification included dechorionation with sodium hypochlorite and permeabilization with isopropyl alcohol; equilibration by addition of loading solution （i.e., 25% vitrification storage solution） and dehydration by gradual replacement of loading solution with vitrification storage solution; cooling in liquid nitrogen vapor right before droplet vitrification in liquid nitrogen; and recovery in liquid nitrogen vapor right after storage in liquid nitrogen, thawing at temperature of thawing medium （5% sucrose in TC 100-insect medium） and rehydration by gradual replacement of vitrification storage solution with rehydration solution （5% fetal bovine serum in TC 100-insect medium）. It was found that among the worker eggs experiencing cyropreservation by vitrification, 1.25% of them were successfully passed through the four life stages, viz., egg, larva, pupa, and adult. In summary, it can be inferred that although a majority of worker eggs were dead after cyropreservation by vitrification, a few of them were developed into larvae, pupae, and finally emerged as adults.     

蝎昆虫神经毒素BmK IT的基因克隆、表达和生物活性检测

根据Genbank中蝎昆虫神经毒素BmK IT成熟肽编码序列设计引物,从东亚钳蝎蝎尾cDNA pool中克隆获得BmK IT的基因,构建表达载体pSYPU-BmK IT,并在大肠杆菌中实现了非融合可溶性表达。表达产物用金属离子螯合色谱进行分离纯化,纯度在85%以上。重组BmK IT对家蚕表现出神经毒性,而对小鼠无毒。通过同源建模以及与蝎哺乳动物毒素、蝎抑制性昆虫神经毒素的三维结构进行比对,分析了其结构与功能关系。     

气相色谱-质谱法测定饲料样品中三聚氰胺的研究

三聚氰胺为灭蝇胺的降解产物．灭蝇胺是一种选择性昆虫生长调节剂．主要用于防治危害蔬菜以及农作物的潜蝇,因其低毒性、低残留、高防效,具有较好环境相容性．在世界范围内广泛使用。三聚氰胺广泛应用于工业树脂的合成．因此在包装过程中容易进入到食物链中。近年来．三聚氰胺被非法添加到植物蛋白或饲料中．增加非蛋白氮的含量。特别是2007年美国发生了宠物饲料中毒事件．     

原蚕区蚕种生产中防微与防僵的工作体会

近年来,随着养蚕量的增加和多批次养蚕的推广,微粒子病大有发展蔓延之趋势,特别是秦巴山区独特的自然和地理环境,山高树多,野外昆虫较多,空气湿度较大,在原蚕区蚕种生产中,不但给微粒子病的防治增加了难度,同时易发生僵病。通过几年来对石泉蚕种场生产成绩的分析来看,有时僵病带来的损失甚至大于微粒子病的危害。因此,在从事原蚕区蚕种生产工作中,不但要重点抓好防微,也要搞好防僵。     

空心莲子草的天敌昆虫防治研究进展

文章针对我国空心莲子草生物防治中天敌昆虫的应用研究进行综述,并对潜力生防作用物的控制作用进行了简述,针对天敌昆虫防治空心莲子草中存在的问题,提出建议。     

绿色防控“三诱技术”在蔬菜生产上的应用

应用绿色防控技术“三诱技术”（性诱、光诱、色诱）防治蔬菜虫害,即利用昆虫性信息素、昆虫趋光性、昆虫趋色性监控害虫,可以减少化学农药使用量,降低农药残留和防治成本,提高农产品质量,是发展生态农业和无公害生产、促进生态和谐与人类健康的重要措施。