Efficacy of some plants as a post-harvest protectant against some major stored pests

The toxicity of vapours of the essential oil of Ferula gummosa, Elettaria cardamomum and Salvia officinalis on the adults and larvae of some stored product pests was investigated. The bioassays were carried out in 70 mL vials containing 10 individuals of each insect. The LC₅₀ values of fumigant bioassay after 24 h were calculated. Results indicated that the effect of the essential oil of F.gummosa was stronger than E. cardamomum, S. officinalis on stored pests. Also fumigant toxicity of S. officinalis on Sitophilus oryzae was similar to that of Sitophilus granarius adults. On the other hand, R. officinalis had a good effect on adults of Tribolium castaneum and larvae of Ephestia kuehniella. According to our results and good effect of these compounds, they will be a safe replace for chemical compounds in the future.     

一种新杀虫剂对储粮害虫和作物害虫的杀虫效果

测定以植物提取物异硫氰酸酯为主要成分而复配的宏劲杀虫剂对玉米象Sitophilus zeamais(Motschulsky)、赤拟谷盗Tribolium castaneum(Herbst)和谷蠹Rhizopertha dominica(Fabricius)3种重要储粮害虫的熏蒸效果及其对菜青虫Pieris rapae(L.)、红蜘蛛Tetranychus cinnabarinus(Boisduval)的杀虫效果。结果表明,宏劲杀虫剂48h对玉米象、赤拟谷盗和谷蠹的LC50分别是0.016,0.009和0.009μL/mL,均明显低于常规熏蒸剂磷化铝的要求处理剂量;对菜青虫和红蜘蛛的LC50分别是0.0159和1.3738mg/mL,其防效均优于对照药剂3%阿菊乳油和3%新型水分散性颗粒剂。     

麦田根际土壤反硝化作用对O_3熏气和太阳辐射减弱的响应

为研究臭氧浓度升高和太阳辐射减弱复合背景下,麦田土壤反硝化作用及N2O排放的变化,采用开顶箱(OTC)法和遮光网技术,设置3个臭氧浓度梯度及3个辐射减弱梯度,连续4a对小麦生长季麦田土壤进行臭氧浓度增加太阳辐射减弱以及它们的复合作用的试验。采用MPN(最大或然数)法测定反硝细菌的数量,用气相色谱法测定反硝化强度。结果显示反硝化细菌数量和反硝化强度受小麦生长发育的影响,在小麦成熟期收割后土壤反硝化细菌数量和反硝化强度增加得特别明显。O3连续作用3个生长季后,以及太阳辐射减弱处理,土壤反硝化菌和反硝化强度显著升高,N2O排放量显著增加。减弱的太阳辐射与增加的O3复合作用,在小麦的每个生育期均显著促进了反硝化菌数量增加和反硝化强度增强,促进率显著高于O3和遮荫的单独作用。结果说明,O3浓度增加以及太阳辐射减弱对土壤反硝化菌和反硝化强度均有一定的促进作用,减弱的太阳辐射与高浓度的O3两因素之间存在协作关系,太阳辐射减弱有利O3的吸收,增加O3伤害,促进反硝化过程。     

Efficacy of ozone fumigation for laboratory animal sanitation]

Ozone resistance of spores of 2 strains of Bacillus isolated from laboratory animals was examined. Each of 0.02 ml of phosphate-buffered saline at pH 7.0 containing 10(6) Bacillus spores was dropped onto sterilized filter strips, wood chip bedding, pellets of diet, cloth pieces and stainless steel plates. After drying at room temperature, the test materials were exposed to ozone gas of different concentrations at 90% RH. Exposure to 200ppm ozone for 6 hours was sufficient to kill spores in filter strips, but a little higher concentration or a little longer period of ozone fumigation was necessary for sterilization of wood chips, cotton cloth pieces and steel plates. The present results indicated that 600ppm ozone fumigation for 6 hours might be effective for routine sterilization of cages, wood bedding, working clothes and other materials used in laboratory animal facilities. However, exposure to ozone gas of 500 or 1,000 ppm for 6 hours or 200 ppm for 24 hours could not kill spores in pellets of diet, suggesting that dietary protein inhibited the bactericidal activity of ozone.     

Voracity of the main stored-product insect pests on wheat grain

The results of an experimental study of voracity of adults and larvae of seven main stored-product insect pests are described. One adult of Sitophilus oryzae, S. granarius, Rhizopertha dominica, Tribolium castaneum, T. confusum, and Oryzaephilus surinamensis consumed 0.38, 0.48, 0.89, 0.15, 0.16, and 0.11 mg of wheat grain per day, respectively. During their development, larvae of these insects consumed 7.60, 13.77, 7.92, 3.32, 3.60, and 2.32 mg of wheat grain, respectively. One larva of Sitotroga cerealella consumed 17.46 mg of wheat grain. The coefficients of harmfulness of these species are calculated, and a method for estimating the “total infestation density” of grain is proposed.     

Bioactivities of extracts from Acorus gramineus on four stored grain pests

1 INTRODUCTIONControl of the stored product insects around theworldis primarily dependent upon insecticides such asorganophosphates and pyrethroids , and gaseousinsecticides such as methyl bromide and phosphine .Although effective ,their repeated use for …     

石菖蒲提取物对四种储粮害虫的生物活性研究

研究了石菖蒲4种溶剂无水乙醇、丙酮、乙酸乙酯、石油醚提取物对玉米象、谷蠹、长角扁谷盗和锯谷盗4种储粮害虫的驱避作用和触杀作用。结果表明：石菖蒲4种溶剂提取物对4种试虫均有明显的驱避作用和触杀作用,处理60 h的平均驱避等级均达到Ⅲ级以上,对4种试虫的触杀死亡率均达到41.11%以上。     

Potential of the neonicotinoid imidacloprid and the oxadiazine indoxacarb for controlling five coleopteran pests of stored grain

Abstract The potential for using imidacloprid (a neonicotinoid) and indoxacarb (an oxadiazine) as grain protectants was investigated in bioassays against resistant strains of five stored grain beetles. The species investigated were Rhyzopertha dominica (F.) (the lesser grain borer), Sitophilus oryzae (L.) (the rice weevil), Tribolium castaneum (Herbst) (the rust‐red flour beetle), Oryzaephilus surinamensis (L.) (the saw tooth flour beetle), and Cryptolestes ferrugineus (Stephens) (the flat grain beetle). Each of these species has developed resistance to one or more protectants, including organophosphorus insecticides, synthetic pyrethroids and the juvenile hormone analogue methoprene. Mortality and reproduction after a 2‐week exposure of adults to treated wheat depended on species, dose and insecticide. Imidacloprid had no effect on S. oryzae at any dose, but none of the other species produced any live progeny at 10 mg/kg. Indoxacarb had no effect on T. castaneum at any dose, but none of the other species produced any live progeny at 5 mg/kg. The results show that although both imidacloprid and indoxacarb can control at least four of the five key pests tested at doses comparable to those used for organophosphorus protectants, more potent neonicotinoid or oxadiazine insecticides would be needed than either of these to provide broad spectrum protection of stored grain.     

Bioactivity of powders and essential oils of three Asteraceae plants as post-harvest grain protectants against three major coleopteran pests

Powders and essential oils were obtained from Achillea biebersteinii, A. fragrantissima and Ageratum conyzoides and tested for their insecticidal activity against Sitophilus oryzae, Rhyzopertha dominica and Tribolium castaneum. Composition of the oils was identified by gas chromatography (GC) and GC/mass spectrometry (MS). The tested plants showed adulticidal activity, where toxicity varied with dosage of the plant product, the insect tested and the exposure period. When mixed with grains as ground powders, a dosage of 20 g/kg grains killed 88.2, 73.6 and 64.4% of S. oryzae after 12 days of exposure with 79.6, 63.3 and 48% reduction in progeny for powders of A. biebersteinii, A. conyzoides and A. fragrantissima, respectively. Under the same assay conditions, A. biebersteinii and A. conyzoides powders killed 100% of R. dominica. T. castaneum was less susceptible to the plant powders. The LC₅₀ values for powders were 22.8, 31.6 and 39.7 mg/g grains for A. biebersteinii, 27.1, 35.4 and 47.8 mg/g grains for A. conyzoides and 36.9, 48.3 and 78.6 mg/g grains for A. fragrantissima against R. dominica, S. oryzae and T. castaneum, respectively. Upon fumigation, a dose of 60 μl/L air of A. biebersteinii and A. conyzoides oils was sufficient to kill 100% of R. dominica after 12 days of adult exposure, while 91.3% adult mortality was recorded in the case of A. fragrantissima oil. S. oryzae and T. castaneum showed a great susceptibility to the plant oils. Powders exhibited a moderate to strong residual activity where A. conyzoides showed the greatest grain protecting activity.     

小麦-油菜邻作对麦田主要害虫和天敌的影响

应用昆虫群落生态学的群落特性分析方法,于2008年和2009年在河北省邯郸市调查了小麦与油菜邻作对麦田蚜虫及主要天敌群落的构成、丰富度和稳定性的影响.结果表明：小麦与油菜田间昆虫群落的组成相似,主要田间害虫为蚜虫,其捕食性天敌包括瓢虫类、草蛉类、蜘蛛类和食蚜蝇,寄生性天敌为蚜茧蜂;两年间田间昆虫群落的组成有一定的变化,但均表现为邻近油菜的麦田蚜虫丰富度最低,捕食性天敌和寄生性天敌的丰富度最高;邻近油菜的麦田昆虫群落、麦蚜亚群落、捕食性天敌亚群落的稳定性高,远离油菜的稳定性低.该模式可以有效保护和利用天敌,增强田间自然天敌对害虫的控制能力.     

A method to quantitative determine the stomach poison on stored grain pests—mixed drug sheet method

本实验制定一种定量测定储粮害虫胃毒作用的方法,命名为混药薄片法.通过试验验证饲料薄片对烟草甲Lasioderma serricorre(Fabricius)的幼虫成活率、发育历期、虫体重量、产卵量等生长发育无影响.在排除烯虫酯对烟草甲的触杀作用的前提下,将混有烯虫酯溶液的混药薄片作为饲料饲养烟草甲3龄幼虫,得到烯虫酯对烟草甲3龄幼虫的准确致死剂量为(0.46±0.03) μg.     

O3浓度升高和太阳辐射减弱对小麦根际土壤微生物功能多样性的影响

采用开顶箱(OTC)法和遮光网技术,设置100 n L/L臭氧熏气与3个辐射减弱梯度结合,模拟臭氧浓度升高和太阳辐射减弱的复合大气背景。用BIOLOG生态测试板,采用孔平均颜色变化率法(AWCD)测定冬小麦根际土壤微生物利用不同碳源的能力,计算微生物群落多样性指数,对不同碳源的利用率进行了主成分分析。两年试验结果显示,臭氧熏气与太阳辐射减弱复合作用,降低了土壤微生物对碳源的利用速度和利用总量;除了聚合物以外其它碳源利用率显著降低;对土壤微生物多样性没有直接的影响;对碳源降解的抑制效应大于增强的O3与减弱的太阳辐射两因素各自的单独作用。太阳辐射减弱20%,一定程度上增加了对聚合物类的分解。O3熏气条件下太阳辐射减弱,糖类、胺类代谢变异度较高,受环境影响较大。     

Efficacy of ethiprole applied alone and in combination with conventional insecticides for protection of stored wheat and stored corn

The insecticidal pyrazole ethiprole, applied at rates of 7.5 and 10.0 ppm either alone or in combination treatments with deltamethrin, piperonyl butoxide, and chlorpyrifos-methyl, was evaluated as a protectant of stored wheat and stored corn. The commodities were treated with six treatment combinations, including an untreated control, and held for 6 mo at 22, 27, or 32 degrees C and 57% RH. Bioassays were conducted monthly by exposing the rice weevil, Sitophilus oryzae (L.), and the red flour beetle, Tribolium castaneum (Herbst), on treated wheat and the maize weevil, Sitophilus zeamais (Motschulsky), and the red flour beetle on treated corn. The storage temperature of wheat did not significantly affect mortality of exposed insects (P > or = 0.05). All rice weevils were dead after 1 wk in all treatments, and no F1 adults were produced. Mortality of red flour beetles was not dependent on either chemical treatment or bioassay month, and no F1 adults were produced. The storage temperature of corn did not significantly affect mortality of exposed insects (P > or = 0.05). Mortality of maize weevils varied from 77.9 to 100% in all chemical treatments, and no F1 adults were produced. Mortality of red flour beetles was also variable among treatments and bioassay month and no F1 adults were produced. This is the first published report of a study in which pyrazoles have been evaluated against stored-grain insects.     

开放式O_3浓度增高对小麦籽粒蛋白的影响

于2006—2009年应用FACE研究平台,设计O3浓度增高50%(E)和自然浓度(CK)两个处理,采用烟农19、扬麦16、扬麦15和扬辐麦2号4个品种,研究了O3浓度增高对不同类型小麦品种籽粒蛋白质组分及其动态的影响.结果表明:随着O3浓度增高,籽粒蛋白质含量上升,3个年度上升幅度分别为7.55%～16.37%(2006—2007年度)、4.93%～22.63%(2007—2008年度)和2.29%～17.65%(2008—2009年度),处理间、品种和年度间差异显著;但籽粒蛋白质产量显著或极显著下降,3个年度降幅分别为1.83%～11.64%(2006—2007年度),-0.41%～24.22%(2007—2008年度)和-1.90%～15.81%(2008—2009年度).籽粒蛋白质4种组分(清蛋白、球蛋白、醇溶蛋白和谷蛋白)含量均表现为O3浓度增高处理高于自然浓度处理,品种间和年度间差异显著,且处理间醇溶蛋白和球蛋白含量差异显著,而清蛋白和谷蛋白含量差异不显著.     

Plant oils as grain protectants against infestations ofCryptolestes pusillus andRhyzopertha dominica in stored grain

Plant oils (cottonseed, soybean, corn, groundnut and palm) at different dosages were evaluated in the laboratory for their ability to suppress the populations ofCryptolestes pusillus andRhyzopertha dominica in maize and sorghum. Exposure of adults of both beetle species to grains treated with 10 ml/kg of the different oils induced 100% mortality within 24 h. A dose of 5 ml/kg of each oil significantly decreased the progeny produced byR. dominica. Complete protection was achieved on grains treated with 10 ml/kg. These oils also repelled the adults of both species. Percentage weight loss caused byR. dominica in grains treated with 5 ml/kg and 10 ml/kg levels were significantly lower than in untreated grains. Oil treatment did not affect the germination of, or water absorption by, maize and sorghum grains compared with untreated grains. The potential use of plant oils in the management of insect pests in traditional grain storage is discussed.     

Imaging techniques for the detection of stored product pests

Stored grains are subject to deterioration and losses through various factors, but mainly insects and fungi. Various techniques are employed to detect stored product pests; however, there is an urgent need for an industrial-scale on-line detection technique. Near-infrared hyperspectroscopic imaging and soft X-rays have shown the potential for real-time application. These techniques are particularly effective for detecting internal infestations of stored grains. The digital images of the scanned objects are analyzed for various spectral and image features using statistical techniques such as complex multivariate tools. Classification accuracies as high as 80–100 % have been achieved for various pest and grain combinations. Dual-energy X-rays have been shown to detect the concealed eggs of stored product insect pests. The main threats to stored cereals come from Aspergillus spp., Penicillium spp., and Fusarium spp., which may produce mycotoxins. These imaging techniques have shown good results in the detection of fungal infections of stored grain.