黄地老虎耐寒机理初探

黄地老虎个体发育期间各虫态的过冷却点,以卵期和蛹期最低,分别为-21.79和-19.2℃;成虫期最高为-5.75℃;幼虫期1～4龄随虫龄增大,其过冷却点升高,分别为-17.45,-16.29,-8.41和-6.51℃;5～6龄时又下降,分别为-12.72和-8.82℃.6龄幼虫在25,15,5和0℃4级降温锻炼下,抗寒力提高。主要表现为:①虫体过冷却点下降(从-7.58℃降到-17.41℃);②体内多种生化含量明显积累,0℃下处理的幼虫,其血糖、血脂、丙氨酸、丝氨酸、脯氨酸和蛋白质分别北25℃下处理时增加3.28,1.67,5.72,1.27,0.6和0.8倍。没有发现甘油和多元醇积累。     

广东省茶秆竹竹笋夜蛾种类及侵入规律研究

林间抽样调查表明怀集县境内共发现危害茶秆竹的竹笋夜蛾4种,经鉴定为：淡竹笋夜蛾KumasiakumasoSugi、笋秀夜蛾Apamea．apameoidesDraudt、笋连秀夜蛾SapporiarepetitaButler和竹笋禾夜蛾OligiavulgarisButer。茶秆竹竹笋夜蛾危害率为10％～86．67％,其中淡竹笋夜蛾最早侵入,竹笋禾夜蛾和笋秀夜蛾次之,笋连秀夜蛾侵入时间最晚。由于竹笋夜蛾种类多,危害大,制约了茶秆竹产业的健康发展,对竹笋夜蛾的防治提出了建议。     

基于三种抗性机制评价大豆对抗斜纹夜蛾的抗性

通过室内养虫鉴定,农艺性状考查和收获后单株考种,对194份栽培大豆进行了抗斜纹夜蛾的鉴定和评价.结果表明:在抗生性和抗选性上对斜纹夜蛾表现为高抗或抗的材料分别有77份和107份.194份品种在株高、主茎分枝数、单株粒数和单株粒重性状上表现出不同程度的耐害和补偿能力.大豆对斜纹夜蛾的抗生性与抗选性的相关性表现相对一致,而...     

紫茎泽兰对烟草小地老虎的室内毒力及田间防效试验

为探索新型植物杀虫药源,以外来入侵生物紫茎泽兰为试验材料,对烟草小地老虎进行了室内毒力测定和田间防效试验。结果表明,紫茎泽兰提取物对小地老虎具有较强的生物活性,其毒杀作用随提取液浓度的增大和处理时间的延长而增强,浓度8g/L处理48h后,小地老虎校正死亡率可达53.59%;田间施用紫茎泽兰粉渣8kg/100m2,其防效与喷施2.5%溴氰菊酯乳油3000倍液的防效接近,达74.9%。     

性诱剂对花生田棉铃虫和小地老虎防治效果研究初探

2011～2012连续两年利用性诱剂开展花生田棉铃虫和地老虎的防治试验,并比较不同诱捕高度及诱捕器类型对诱捕效果的影响。结果表明:使用棉铃虫性诱剂悬挂在花生上方60 cm,使用小地老虎性诱剂悬挂在花生上方20～60cm,诱捕效果最佳;对两种靶标害虫,三角型诱捕器的日均诱蛾量均显著高于桶型诱捕器;从防治效果看,第一年小地老虎和棉铃虫幼虫虫口减退率分别为41.7%、40.0%,花生植株受害率分别降低44.4%、36.3%;连续诱捕两年后防治效果得到明显提高,幼虫虫口减退率分别为63.6%和69.6%,植株受害率分别降低60.0%和73.7%。     

不同温度对小地老虎实验种群的影响

研究了不同温度对小地老虎发育、存活、生殖、种群参数、种群趋势指数等的影响 .结果表明 :在 17- 35℃恒温内 ,小地老虎的发育速率随温度上升呈逻辑斯蒂曲线趋势 .该虫卵的孵化率 (SE)、幼虫的存活率 (SL)、蛹的存活率 (SP)、成虫产卵量 (E)和种群趋势指数 (I)与温度 (X)变化的回归关系分别为 SE=- 118.94 17+19.0 12 X - 0 .4 2 14X2 ;SL =- 10 7.2 795+18.0 815X - 0 .4 0 4 3X2 ;SP=- 10 6 .0 318+17.7372 X - 0 .384 5X2 ;E =- 4 5.10 2 7+455.50 0 3X - 9.350 4 X2 和 I =- 1757.318+176 .76 59X - 3.6 6 56 X2 .通过不同温度下实验种群参数的比较得出 :2 5℃时内禀增长力最大 (rm=0 .1353) ,2 1℃次之 (rm=0 .130 6 ) ,确定最适温度为 2 1- 2 5℃ .高温不利于种群的生长发育 ,在 35℃时 ,各虫态存活率及成虫产卵量急剧下降 .     

青海巴滩草地小地老虎虫害发生的气象预测模型建立

为了预防小地老虎(Agrotis ypsilon)的危害,采用相关分析、多元线性回归方法,利用2000-2013年青海省同德县巴滩放牧草地取得的小地老虎虫口密度数据和同时期气象观测资料,研究了气候因子对草原小地老虎虫害发生的影响。结果表明,近14年同德巴滩草原小地老虎虫害以每年6.81头·m-2的速率上升,虫口密度的平均绝对变率为66.07头·m-2,最多年虫口密度比最少年多93.95%。小地老虎虫口密度与气温、降水、地温、光照和平均风速之间的相关性较好。多元回归分析显示,影响小地老虎虫口密度的主导气候因子有上一年9月降水量、12月平均气温、上年年日照时数和12月10 cm平均地温,共同决定了小地老虎虫口密度的95.02%。回代检验表明,模型预测的准确率达96.3%,模拟效果较好。     

作物景观结构对旋幽夜蛾种群动态的影响

农业景观复杂性对昆虫种群的影响是目前昆虫生态学研究的热点。新疆兵团和地方在土地利用模式及作物景观上存在着明显的差异,这可能影响昆虫种群动态及其管理策略。在兵团和地方的不同试验点,应用智能测报灯、杀虫灯诱集监测在地区尺度和区域尺度旋幽夜蛾Scotogramma trifolii种群动态,结合各样点作物种类及面积调查,分析旋幽夜蛾种群动态与景观复杂性之间的关系,研究结果表明:(1)在地区尺度上,简单景观条件下旋幽夜蛾诱集量小于复杂景观,不同调查半径下旋幽夜蛾诱集量与景观多样性指数(Shannon-Wiener)呈显著正相关(P0.05);(2)在区域尺度上,兵团作物体系内,南疆的旋幽夜蛾诱集量小于北疆,并且存在显著性差异;地方作物体系内南疆的旋幽夜蛾诱集量大于北疆,同样存在显著性差异;在南疆地区,兵团和对应地方的诱蛾量均呈现显著性差异(P0.05),在北疆地区,兵团与对应的地方之间无显著性差异(P0.05),这可能与北疆地区兵团和地方在土地利用模式及其作物布局趋于一致有关。     

Entomopathogenic nematodes for the management of Agrotis ipsilon: effect of instar, nematode species and nematode production method

BACKGROUND: Previous laboratory studies have indicated the potential of some entomopathogenic nematode (EPN) species for the control of larvae of the black cutworm (BCW). To determine the most promising EPN species and the most susceptible BCW stages, a more in‐depth evaluation of seven EPN species against different BCW instars was carried out, the efficacies of in vitro‐ and in vivo‐produced EPNs were compared and the suitability of BCW instars for EPN reproduction was examined. RESULTS: Heterorhabditis megidis was the most virulent species, irrespective of larval stage in small arenas, followed most often by H. bacteriophora. In pots with grass, Steinernema carpocapsae tended to be the most virulent species, followed by H. bacteriophora, H. megidis and S. riobrave. Fourth and/or fifth instars were the most susceptible stages to most EPN species, and pupae the least susceptible. Furthermore, H. bacteriophora, H. megidis and S. carpocapsae successfully reproduced in fifth and sixth instars and pupae. In vivo‐produced H. megidis and S. carpocapsae controlled fifth instars better than the corresponding in vitro‐produced products; production method did not affect H. bacteriophora and S. riobrave efficacy. CONCLUSIONS: Several in vitro‐produced commercial EPN strains were highly virulent to BCW and warrant further testing under field conditions, along with some in vivo‐produced strains. Copyright © 2011 Society of Chemical Industry     

Synthesis and insecticidal activity of benzoheterocyclic analogues of N'-benzoyl-N-(tert-butyl)benzohydrazide: Part 1. Design of benzoheterocyclic analogues

The N'-benzoyl group of N-tert-butyl-N'-benzoyl-3,5-dimethylbenzohydrazide (1) was converted to a series of benzoheterocyclecarbonyl groups in order to investigate the potential usefulness of superimposing a hydrazine insecticide on 20-hydroxyecdysone. A series of analogues with benzodioxole, benzodioxane, benzodioxapine, indole, benzoxazole, benzoxazine or benzothiazole instead of the phenyl group of (1) were synthesized and tested for their insecticidal activity against the common cutworm (Spodoptera litura F). N-tert-Butyl-N'-(3,5-dimethylbenzoyl)-1,3-benzodioxole-5-carbohydrazide and N-tert-butyl-N'-(3,5-dimethylbenzoyl)-2,3-dihydro-1,4-benzodioxine-6-carbohydrazide showed high insecticidal activities, superior to that of (1) and equal to that of the commercial insecticide tebufenozide (RH-5992).