储粮害虫对磷化氢抗性的研究进展

磷化氢是全世界应用最广泛的高效广谱熏蒸剂。由于储粮害虫对它的抗性日益发展和蔓延，使磷化氢的杀虫效果正大幅度下降，防治工作面临巨大威胁。近二十年来，储粮害虫对磷化氢的抗性一直是国内外有关专家学者普遍关注的一个严重问题。本文对抗性形成原因、机制、抗性遗传、交互抗性、抗性种群治理等问题进行了综述和讨论     

储粮害虫对磷化氢抗性的研究进展

磷化氢是全世界应用最广泛的高效广谱熏蒸剂，由于储粮害虫对它的抗性日益发展和蔓延，使磷化氢的杀虫效果正大幅度下降，防治工作面临巨大威胁，近二十年来，储粮害虫对磷化氢的抗性一直是国内外有关专家学者普遍关注的一个严重问题，本文对抗性形成原因、机制、抗性遗传、交互抗性，抗性种群治理等问题进行了综述和讨论。     

硅藻土对5种储粮害虫和不同磷化氢抗性水平杂拟谷盗防治效果的研究

为初步了解硅藻土对储粮害虫的防治效果以及与害虫磷化氢抗性发生发展的关系, 本研究采用直接拌粮法(设置剂量梯度为0?0.2?0.4?0.6 g/kg和 0.8 g/kg)测定硅藻土对赤拟谷盗?杂拟谷盗?锈赤扁谷盗?谷蠹?玉米象的防治效果, 以及磷化氢抗性杂拟谷盗(抗性倍数为 2.3~144.7)对硅藻土的敏感性差异; 除此之外, 本研究还分析了0.4 g/kg硅藻土在 4 种粮食(小麦?玉米?大豆?稻谷)中对赤拟谷盗的杀虫效果?研究结果表明:一定剂量(0.2~0.8 g/kg)的硅藻土均能够在一定时间内有效杀死上述 5种储粮害虫, 不同储粮害虫对硅藻土的敏感性存在显著差异(P<0.05), 其中杂拟谷盗对硅藻土的耐受性最强, 玉米象对硅藻土最为敏感?除个别品系外, 不同磷化氢抗性品系的杂拟谷盗对硅藻土的敏感性不存在显著差异(P>0.05), 且与磷化氢抗性无关; 硅藻土在不同粮食中对害虫的作用效果存在显著性差异(P<0.05)(处理 7 d后, 死亡率为 13%~98%), 其中在大豆中对赤拟谷盗的杀虫效果最强, 在玉米中对其作用效果不明显?因此本研究得出结论:硅藻土对主要储粮害虫均具有一定的防治作用, 且对抗磷化氢的杂拟谷盗具有良好的致死效果?因此, 硅藻土具备成为储粮害虫防治及其磷化氢抗性治理药剂的潜力?     

害虫对吡虫啉抗性的研究进展

吡虫啉（ｉｍｉｄａｃｌｏｐｒｉｄ）是国内近年发展最快的新型硝基亚甲基类（ｎｉｔｒｏｍｅｔｈｙｌｅｎｅ）杀虫剂,又称为氯化烟碱类（ｃｈｌｏｒｏｎｉｃｏｔｉｎｙｌ）。它是内吸性杀虫剂,但同时具有触杀和胃毒作用,可用于种子和土壤处理,又可进行叶面喷雾。该药...     

不同书虱品系的磷化氢半数击倒时间与抗性相关性研究

参照FAO推荐方法测定了磷化氢对嗜卷书虱(Liposcelis bostrychophila(Badonnel))2个品系、嗜虫书虱(L.entomophila(Enderlein))3个品系和小眼书虱(L.paeta(Pearman))3个品系等共8个不同来源书虱的毒力和抗性系数Rf,测定了磷化氢浓度为2mg/mL条件下供试各书虱品系的半数击倒时间KT50,分析了其LC50值与KT50值的相关性。结果为:3种书虱的8个品系对磷化氢的抗性差异明显,高抗性的嗜虫书虱的磷化氢抗性比敏感的嗜卷书虱高1000倍以上,各品系书虱的KT50值与Rf值呈正相关,相应LC50值之对数与KT50值的对数呈直线相关。结果表明,磷化氢对书虱成虫的半数击倒时间KT50值可以用来判断书虱抗性大小,并可用于快速判断抗性以指导现场熏蒸。     

甲酸乙酯对不同磷化氢抗性水平赤拟谷盗的毒力比较

参考FAO推荐的熏蒸剂毒力测定方法,测定了甲酸乙酯对4种不同磷化氢抗性水平的赤拟谷盗(Tribolium castaneum(Herbst))品系的毒力.主要结果为甲酸乙酯对4个磷化氢抗性系数分别为1、3、170和247倍的赤拟谷盗品系的LD50值相应地为17.354L/m3、18.776L/m3、20.464L/m3和21.470 mL/m3.结果表明,不同磷化氢抗性的赤拟谷盗品系对甲酸乙酯的敏感相似,对磷化氢具有明显抗性的赤拟谷盗对甲酸乙酯未表现出抗性.     

害虫对苏云金杆菌的抗性概述

苏云金杆菌Bacillus thuringiensis作为生物杀虫剂的商品制剂问世已半个多世纪。因其杀虫高效、广谱、对人畜低毒、对天敌和植物安全,已成为害虫生物防治的首选杀虫剂。目前对它的研究主要集中在生产和应用上,在进一步开发利用该制剂的同时,有必要重视害虫对其有可能产生抗性的问题。     

蛇床子素粉剂对主要储粮害虫的生物活性测定

蛇床子素乳油是由武汉绿世纪生物工程有限责任公司研制,天惠生物工程有限公司开发的一种植物性杀虫剂,在农业害虫、蔬菜害虫和储粮害虫的防治上其效果显著,为扩大其应用范围,开发新的粉剂剂型,故研究了蛇床子素粉剂对储粮害虫玉米象、谷蠹及后期性害虫赤拟谷盗的防治效果。现将试验结果报告如下:1材料和方法1·1供试药剂4%蛇床子素粉剂(由2%蛇床子素乳油配制而成),武汉天惠生物工程有限公司提供。1·2供试害虫玉米象(Sitophilus zeamaisMotschulsky);谷蠹(Rhizopertha dom inicaFabricius);赤拟谷盗(Tribo-lium ferrugineumFabricius)。…     

臭氧在农业害虫防治中的双重性

由于具有氧化性强、分解速度快等特点,O_3在农业病虫害防治领域具有高效、无残留等优点。近年来研究发现,生物体对O_3的敏感性,不仅存在种间差异,也存在个体发育阶段的差异。通过O_3或O_3水处理后,虫害可能存在"此伏彼起"的现象。综述并分析了O_3在农业害虫防治领域具有潜在的应用价值,如替代化学农药防治大田害虫和仓储害虫等;也存在一定的负面影响,如改变作物的代谢途径和影响天敌昆虫的种群繁殖等。施用O_3对害虫的防治效果与害虫的龄期、虫态、种类及环境等有关。根据植物光合作用和呼吸作用的特性,建议在夜间施用O_3或O_3水,这样更适合植株的生理活动需求。目前,关于O_3与植物、O_3昆虫、植物与昆虫两两之间的研究较为深入,但是O_3—植物——昆虫三者之间的研究依然缺乏,这将是今后研究的主要方向。     

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.     

Ethyl formate plus methyl isothiocyanate--a potential liquid fumigant for stored grains

BACKGROUND: Methyl bromide is being phased out for use on stored commodities, as it is listed as an ozone‐depleting substance, and phosphine is the fumigant widely used on grains. However, phosphine resistance occurs worldwide, and phosphine fumigation requires a long exposure period and temperatures of > 15 °C. There is an urgent requirement for the development of a fumigant that kills insects quickly and for phosphine resistance management. This paper reports on a new fumigant formulation of 95% ethyl formate plus 5% methyl isothiocyanate as an alternative fumigant for stored grains. RESULTS: The formulation is stable for at least 4 months of storage at 45 °C. A laboratory bioassay with the formulation showed that it controlled all stages of Sitophilus oryzae (L.), Sitophilus granarius (L.), Tribolium castaneum (Herbst), Rhyzopertha dominica (F.), Trogoderma variabile Ballion and Callosobruchus maculatus (Fabricius) in infested wheat, barley, oats and peas at 80 mg L^?1 for 5 days, and in canola at both 40 mg L^?1 for 5 days and 80 mg L^?1 for 2 days at 25 ± 2 °C. After an 8–14 day holding period, residues of ethyl formate and methyl isothiocyanate in wheat, barley, peas and canola were below the experimental permit levels of 1.0 and 0.1 mg kg^?1. However, fumigated oats needed an 18 day holding period. CONCLUSIONS: The findings suggest that the ethyl formate plus methyl isothiocyanate formulation has potential as a fumigant for the control of stored‐grain insect pests in various commodities. Copyright © 2011 Society of Chemical Industry     

Potential of imidacloprid to control four species of psocids (Psocoptera: Liposcelididae) infesting stored grain

The effectiveness of the neonicotinoid insecticide imidacloprid was evaluated against four psocid pests of stored grain. This research was undertaken because of the growing importance of psocids in stored grain and the need to identify methods for their control. The mortality and reproduction of adults of Liposcelis bostrychophila Badonnel, L. entomophila (Enderlein), L. decolor (Pearman) and L. paeta Pearman in wheat treated with imidacloprid were determined. There were five application rates (0.5, 1, 2, 5 and 10 mg AI kg(-1) grain) and an untreated control. There were significant effects of application rate on both adult mortality and reproduction for all four species, but the effect of imidacloprid was sometimes more pronounced on reproduction. Imidacloprid was most effective against L. bostrychophila, with 100% adult mortality after 7 d at 5 mg AI kg(-1), 14 d at 2 mg AI kg(-1) and 28 d at 0.5 and 1 mg AI kg(-1). No live progeny were produced at 2 mg AI kg(-1). For L. decolor, there was 100% adult mortality after 28 d at 10 mg AI kg(-1) and no live progeny were produced at 2 mg AI kg(-1). For L. entomophila, there was 100% adult mortality after 14 d at 10 mg AI kg(-1) and 28 d at 2 and 5 mg AI kg(-1). No live progeny were produced at 10 mg AI kg(-1). At 10 mg AI kg(-1) there was 100% mortality of L. paeta adults after 28 d exposure and no live progeny developed. Because reproduction at some application rates occurred only in the first 14 d of exposure, it is concluded that the application rate leading to population extinction was 1 mg AI kg(-1) for L. bostrychophila, 2 mg AI kg(-1) for L. decolor and L. entomophila and 5 mg AI kg(-1) for L. paeta. This study shows that imidacloprid has potential as a grain protectant to control all four Liposcelis species in stored grain.     

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     

小麦籽粒水分含量变化对小麦品种抗虫性的影响

为探讨小麦含水量对近年新推广种植小麦品种抗虫性的影响,本研究选用河南、山东等省种植较广泛的6个小麦品种‘矮抗58’、‘西农979’、‘良星66’、‘济麦22’、‘泛麦8号’和‘郑麦7698’,检测了水分含量分别为11.50%、12.50%和13.50%时,小麦籽粒中米象子代成虫数量、由卵至成虫的平均发育历期,以及小麦对米象的敏感系数(SI)。结果表明,小麦含水量为13.50%、12.50%和11.50%时,供试小麦中出现子代成虫数量最多的相应为‘郑麦7698’(85.67头)、‘良星66’(45.67头)和‘济麦22’(17.67头)。同一小麦品种中,由米象卵至子代成虫的平均发育历期均在水分含量为11.50%时最长,13.50%时最短。在3种含水量下,米象平均发育历期最长为44.77d(‘泛麦8号’),最短为32.77d(‘郑麦7698’)。含水量为11.50%、12.5%和13.5%时,对米象的敏感系数(SI)最小的分别为‘良星66’(0.54)、‘郑麦7698’(7.76)和‘济麦22’(8.47)。结果表明:小麦籽粒含水量相同时不同品种对米象的抗虫性差异显著。同一品种小麦籽粒含水量从13.50%降低至11.50%时,米象子代成虫数量和SI减小、卵至成虫平均发育历期延长,小麦籽粒含水量对抗虫性的影响大于小麦品种的影响。     

Efficacy of vaporised ethyl formate/carbon dioxide formulation against stored‐grain insects: effect of fumigant concentration,exposure time and two grain temperatures

BACKGROUND: The ethyl formate/carbon dioxide (CO₂) formulation Vapormate? is a rapid‐acting fumigant being developed for the control of stored‐grain insects. The effects have been investigated of concentration, exposure times of 1, 3, 24 and 72 h and two grain temperatures, 15 and 25 °C, on its efficacy against mixed‐stage cultures of Sitophilus oryzae (L.) Tribolium castaneum (Herbst) and strongly phosphine‐resistant Rhyzopertha dominica (F.) strain QRD569. RESULTS: High mortalities (≥92%) of mixed‐stage cultures of all three species were obtained when grain was fumigated with the formulation (193 g m^?3 ethyl formate) for 1 h. Complete control of R. dominica QRD569 and T. castaneum was achieved with 63 and 76 g m^?3 ethyl formate respectively, with exposure for 24 h, whereas mean mortality of S. oryzae was 86% under the same conditions. Mortalities of S. oryzae juvenile stages were significantly lower than adults under the conditions tested, which was due to pronounced tolerance of mid‐stage pupae to the fumigant. Reducing grain temperature from 25 to 15 °C had no effect on insect mortality. CONCLUSION: Ethyl formate/CO₂ formulation is highly effective against stored‐grain insects over a range of concentrations and exposure times. Efficacious fumigations were conducted in as little as 1 h, and a strongly phosphine‐resistant R. dominica strain was readily controlled with the fumigant. Copyright © 2009 CSIRO, Australia. Published by John Wiley & Sons, Ltd     

Improved efficacy of ethyl formate against stored grain insects by combination with carbon dioxide in a 'dynamic' application

Ethyl formate is being evaluated as a fumigant for stored grain as it is a potential alternative to the ozone-depleting fumigant methyl bromide and to phosphine, which is under pressure owing to the development of strong resistance in stored grain insects. However, use of ethyl formate faces significant challenges, such as poor penetration through grain, significant losses to grain sorption, high concentrations of fumigant required to control insects, and flammability risks, which have limited its further development. In this study it was found that the combination of carbon dioxide (5-20%) with ethyl formate significantly enhanced efficacy of the fumigant against external living stages of the rice weevil, Sitophilus oryzae (L.), the lesser grain borer, Rhyzopertha dominica F., and the flour beetle, Tribolium castaneum (Herbst). Dynamic application of ethyl formate and carbon dioxide mixture (100 mg litre-1 ethyl formate, 20% CO2) pumped through a model silo containing wheat (50 kg) for one gas exchange was also investigated. A flow rate of 6 litres min-1 gave a relatively even distribution of fumigant throughout the grain column and similar mortality levels among cultures of S. oryzae and T. castaneum placed at three positions, the top, middle and bottom of the column. Mortality of 99.8% of mixed stage cultures of T. castaneum and 95.1% of S. oryzae was achieved in 3 h exposures to 111 and 185 mg ethyl formate h litre-1 respectively applied by the dynamic method. It is concluded that the combination of carbon dioxide with ethyl formate and dynamic application enhances distribution and efficacy of the fumigant against stored grain insects.     

储藏物害虫生物性防治技术研究现状和展望

有效的杀虫剂和熏蒸剂种类的减少,以及它们对环境的污染和对人畜健康的影响,使得生物性的防治技术在储藏物害虫的控制上显得越来越重要。近年来,有关储藏物害虫生物性防治技术的研究报道越来越多。根据过去20年的文献,特别是根据刚出版的第七届国际储藏物保护会议的有关论文,评述了储藏物害虫生物性防治技术的研究现状,展望了将来的发展。内容涉及到天敌昆虫、昆虫信息素、病原微生物、抗虫品种和遗传防治等领域,着重于它们在实践中的应用。