五种出口农产品仓储昆虫群落结构的数量特征

利用群落物种的丰富度、生态优势度、多样性、均匀度等群落特征指数，研究了临沂市5种出口农产品仓储昆虫群落结构的数量特征，并分析了它们的相似性。通过系统聚类分析将5种群落分为4类，脱水蔬菜和中药材仓储昆虫群落同属于一类，其它3种农产品仓储昆虫群落各属一类。除大蒜群落结构合理外，其它群落结构都不合理，粮谷群落结构尤其不合理。结合仓储昆虫群落结构特征指数、害虫及天敌的发生情况，分析了4大类群落的特点，并提出了对应的仓储管理意见。利用群落特征指数，对粮谷昆虫群落时间格局的结构特点进行了研究，根据不同时间害虫及天敌的发生情况，提出了相应的害虫管理措施。     

板栗园蜘蛛群落结构与组成调查

板栗园生态系统中存在着多种多样的生物类群 ,捕食性蜘蛛是其中重要的类群之一 ,种类多、数量大、发生时间长 ,是板栗园捕食性天敌中一个十分重要的组成部分。研究板栗园蜘蛛群落结构及其发生规律对于保护利用天敌资源、制订板栗害虫综合治理策略具有十分重要的意义。笔者于２００１年５月至１０月对重庆合川市板栗园蜘蛛群落进行了系统调查研究 ,并对群落各组成成分的发生规律进行了探讨。１系统调查方法以重庆合川市南津街办事处高歇林场板栗园作为实验基地 ,其生态园内有柑橘、梨树、青冈及各种杂草。栗树３～５年生 ,常年未采取任何施药…     

栽培制度对麦田昆虫群落组成及结构的影响

从群落生态学和害虫综合治理角度出发,1992～1993年连续2年对河南省修武县3种小麦主要栽培制度麦田即单作麦田、麦油菜间作田、麦套棉田的昆虫群落组成及结构进行系统调查研究,并加以分析比较,为组建小麦害虫综合治理技术体系和提高防治策略,提供了参考。     

南宁市十字花科蔬菜植食性昆虫群落分析

南宁市十字花科蔬菜植食性昆虫群落结构，在人为防治干扰下，计有8目32科61种（类），按数量以鳞翅目，按种类以同翅目最多。主要是小菜蛾（Plutella xylostella），黄曲条跳甲（Phullotreta striolata），桃蚜（Myzus persicae），萝卜蚜（Lipaphis erysimi）和斑潜蝇类（Lirimyza）。群落的多样性低，波幅大，均匀度小。文中分析了两种管理菜区群落的特点及其动态。     

广西凤蝶科昆虫的区系组成分析

广西地处亚热带 ,地形多种多样 ,气候温暖 ,雨水丰沛 ,植物繁茂 ,生态环境复杂 ,蝴蝶资源繁多 ,凤蝶资源极为丰富。据李永禧报道 ( 1 988) ,广西有蝴蝶标本 34 1种 ,其中凤蝶 35种 (含亚种 )。张永强等 ( 1 994)在其所著《广西昆虫名录》中记载广西蝴蝶有 30 5种(含亚种 ) ,其中凤蝶科昆虫 39种 (含亚种 )。依据这些已知种 ,探讨了广西凤蝶区系组成特征 ,为进一步研究广西蝴蝶区系的全貌提供参考。1　广西凤蝶的区系组成1 .1　种类组成　　根据周尧 ( 1 994)在《中国蝶类志》中确立的中国蝴蝶分类系统 ,经笔者整理、统计 ,广西已知凤蝶科昆…     

白龙江林区云杉苗圃地下害虫及天敌昆虫群落结构

应用多样性指数、均匀度指数、优势度和群落相似性指数对白龙江林区内不同生境下的云杉苗圃地下害虫及天敌昆虫的群落结构进行了研究。结果表明,3种生境下的云杉苗圃地下害虫优势种群明显,迭部安子沟苗圃以小云斑鳃金电、云杉树叶象、粗绿彩丽金龟为优势种;舟曲沙滩苗圃、白水江中路河苗圃以小云斑鳃金龟、云杉树叶象、蓝边矛丽金龟、大云斑鳃金龟为优势种。主要天敌有中华疱步甲、步甲。休闲1年后的苗圃地多样性指数、均匀度相对较大。     

新香蕉园植食昆虫群落结构及优势种的动态

调查南宁市蕉类（含香蕉类、大蕉类、粉蕉类）植食昆虫种类有８目３８类８６６中,其中新植香蕉园有７目３６科４８种,群落中种群数量最大的是香蕉完网蝽,其次是茶袋蛾和香蕉交脉蚜。新植香蕉园植食性昆虫群落物种重要比值符合正态分布曲线。文中对群落的时、空结构和香蕉冠网蝽的数量消长作了分析,对优势种群的数量控制进行了讨论。     

澳大利亚外来昆虫组成及区系

为明确澳大利亚外来昆虫物种组成及入侵区系,以在线数据库、公开发表文献以及图书等资料为数据源集成澳大利亚外来昆虫数据集,对其物种组成、原产地、空间分布、传入途径进行统计分析。结果显示,收集的澳大利亚外来昆虫数据集共包括382种,隶属于8目78科277属。鞘翅目昆虫的种类最多,有325种,其中象甲科昆虫最多,有74种,其次是隐翅甲科和叶甲科昆虫,分别有27种和20种。澳大利亚外来昆虫主要来源于亚洲,占外来昆虫原产地总记录频次的28.47%,其次是欧洲和非洲,占比分别为19.79%和16.32%。整体上来看,澳大利亚外来昆虫丰富度呈现东高西低的空间分布格局,密度呈现东南密西北疏的格局;从传入途径来看,无意传入的昆虫占91.89%,有意传入的昆虫占8.11%,且主要通过运输污染物和运输偷运物2种途径无意传入。基于澳大利亚外来昆虫现状,考虑我国在全球气候变化背景下面临的跨境生物入侵威胁,建议我国在外来物种入侵防控工作中加大口岸检疫监管力度,规范引种管理,同时加强防范入侵的宣传教育。     

辽宁花生病虫发生危害及种类鉴定

近年来辽宁花生产业迅猛发展,病虫害发生日趋严重.2011年对辽宁花生主产区系统调查发现病虫害共27种,其中病害10种,虫害17种.危害较严重的病虫害分别是花生网斑病、褐斑病、疮痂病、蛴螬、双斑长跗萤叶甲、尺蠖.     

The fate and insecticidal activity of pirimiphos-methyl in stored wheat grain

The degradation of [¹⁴C]pirimiphos-methyl was investigated on a 1-kg bulk of grain stored in the laboratory at 15°C for 28 weeks. Breakdown of pirimiphos-methyl was slow, leaving 77% of the applied dose unchanged at the end of the experiment. The major degradation product was the hydroxypyrimidine (up to 12.5% of the applied dose) with the remainder of the residue (up to 12.1%) remaining within the grain tissues after solvent extraction. The efficacy of the treatment was assessed in a parallel experiment by bioassay of a 5-kg bulk of grain dosed with unlabelled pirimiphos-methyl. 100% Mortality of an organophosphateresistant strain of Oryzaephilus surinamensis L. was maintained throughout the experiment whereas some survival of an organophosphate-resistant strain of Tribolium castanewm (Herbst) occurred after 12 weeks of storage. This increased to give a 20% survival rate at the end of the experiment.     

Toxicity of cyanogen to insects of stored grain

Range-finding studies on the toxicity of cyanogen to all stages of five species of stored product Coleoptera are reported. The species were Rhyzopertha dominica (F), Sitophilus granarius (L), Sitophilus Oryzae (L), Tribolium castaneum (Herbst), Tribolium confusum Jacquelin du Val and Ephestia cautella (Walker). Exposures for 24 h to cyanogen at 1.3 mg litre(-1) controlled all external stages. Control of internal stages of Sitophilus species was achieved by a 5-day exposure to initial concentrations between 13.7 and 27.4 mg litre(-1), whereas R. dominica was controlled at 13.7 mg litre(-1). Cyanogen showed similar toxicity to all tested external stages and, in this respect, was more similar to methyl bromide than to phosphine. Its toxicity to insects increased with both relative humidity and concentration of carbon dioxide. Cyanogen was toxic to insects whether applied as a gas or in an aqueous solution.     

Improving detection probabilities for pests in stored grain

BACKGROUND: The presence of insects in stored grain is a significant problem for grain farmers, bulk grain handlers and distributors worldwide. Inspection of bulk grain commodities is essential to detect pests and thereby to reduce the risk of their presence in exported goods. It has been well documented that insect pests cluster in response to factors such as microclimatic conditions within bulk grain. Statistical sampling methodologies for grain, however, have typically considered pests and pathogens to be homogeneously distributed throughout grain commodities. In this paper, a sampling methodology is demonstrated that accounts for the heterogeneous distribution of insects in bulk grain. RESULTS: It is shown that failure to account for the heterogeneous distribution of pests may lead to overestimates of the capacity for a sampling programme to detect insects in bulk grain. The results indicate the importance of the proportion of grain that is infested in addition to the density of pests within the infested grain. It is also demonstrated that the probability of detecting pests in bulk grain increases as the number of subsamples increases, even when the total volume or mass of grain sampled remains constant. CONCLUSION: This study underlines the importance of considering an appropriate biological model when developing sampling methodologies for insect pests. Accounting for a heterogeneous distribution of pests leads to a considerable improvement in the detection of pests over traditional sampling models. Copyright © 2010 Society of Chemical Industry     

Combinations of pirimiphos-methyl and carbaryl for stored grain protection

In laboratory experiments, whole wheat was treated with pirimiphos-methyl or carbaryl or combinations of these two insecticides; the treated grain was then adjusted to a 12% moisture content and stored at 25°C for bioassay at various intervals over a period of 39 weeks. Pirimiphos-methyl at 5.1 mg kg^?1 effectively controlled Sitophilus granarius (L.) and Tribolium confusum Jacquelin du Val but was ineffective against Rhyzopertha dominica (F.) CRD 118, a strain showing malathion resistance. Conversely, carbaryl at 6.5 mg kg^?1 (but not at 3.1 mg kg^?1) was effective against R. dominica, but ineffective against the other two species. A combination of pirimiphosmethyl + carbaryl, at 1.8 + 5.1 mg kg^?1, controlled S. granarius and R dominica but not T. confusum, whilst a 4.2 + 3.4 mg kg^?1 combination was relatively more effective against T. confusum but less so against R. dominica. In a separate experiment, whole wheat was treated with carbaryl at 2.5, 5.0 and 7.5 mg kg^?1 (nominal rates). Samples were stored and, at various times after the treatments, were bioassayed with R. dominica CRD 2, at 20, 25, 30 and 35°C. The results were comparable with those for the CRD 118 strain, but efficacy was reduced at higher temperatures. The combination of pirimiphos-methyl at 4–5 mg kg^?1 and carbaryl at 5–6 mg kg^?1 is suggested as a potentially useful grain protectant where R. dominica is a problem and long term storage is required. These results are discussed in relation to the protection of stored grain in Australia.     

A biopolymer-based pesticide delivery system for insect suppression in stored grains

Degradation of grain quality during storage is mainly caused by insects and microorganisms. To protect against insects, prevailing practices usually require the application of pesticides and fumigants directly to the stored grain; long-term storage can involve repeated applications. Direct application results in accumulation of chemical residues on the grain, especially from pesticides. A simple delivery system, in which the pesticide (chlorpyrifosmethyl) is incorporated in a biopolymer (xanthan gum), has been formulated with the objective of reducing these residues while increasing the period of effectiveness of a single application. The biopolymer-based formulation was compared to a conventional formulation on the basis of bioassay tests and residue analysis. The biopolymer-pesticide formulation was effective over a longer period of time and produced significantly smaller residues than the conventional emulsifiable concentrate formulation.     

Accumulation of malathion residues in grain stored on malathion-treated wood surfaces

Laboratory studies were conducted to determine whether insecticides applied to storage structures are able to move past a single layer of grain kernels to give adequate control of stored-grain insects. The extent of uptake of insecticides was assessed on three layers of wheat in contact with wood surfaces treated with malathion 836 g litre^?1 e.c. at 1–0 g a.i. m^?2 using chemical and biological methods at predetermined time intervals. There was a progressive uptake of malathion beyond the layer directly in contact with the treated surfaces and the uptake depended on the duration of storage. After 8 weeks a sufficient amount of malathion accumulated on the top layer of grain kernels to cause 100% mortality of adult Tribolium castaneum (Herbst).