Gamma radiation sensitivity of larvae and adults of the red flour beetle, Tribolium castaneum Herbst

In this study, the susceptibility of larvae and adults of Tribolium castaneum (Herbst) to gamma radiation was investigated in the laboratory in Turkey. Gamma radiation was applied at 6 dose levels between 20 and 200Gy to 13–15day-old adults and at 5 dose levels between 20 and 180Gy to 18–20day-old larvae of T. castaneum. All experiments were performed in growth chambers maintained at 27±1°C and 70±5% r.h. The larvae proved to be the more susceptible stage, survival to the adult stage being prevented by exposure of the eggs to 100Gy; the adult stage was less susceptible. LD₅₀ and LD₉₉ values were determined as 19,75 and 42,97Gy for larvae and 33,21 and 64,50Gy for adult stage, respectively. It was concluded that 100Gy is the effective dose for both larval and adult stages.     

Treatment of rice with diatomaceous earth and effects on the mortality of the Red flour beetle Tribolium castaneum (Herbst)

Diatomaceous earth has been demonstrated in Australia, Germany, and the USA to protect stored products from infestation by insect pests. However, application of diatomaceous earth has rarely been used in Asian countries for the protection of stored grain from insect damage. These facts and the paucity of existing data from the tropics prompted the present study of storage with diatomaceous earth. We exposed rice treated with the diatomaceous earth product Fossil Shield® to infestation by Tribolium castaneum Herbst. During the dry season, when tests were conducted, the mean temperature was 29±2°C and relative humidity was 80±3%. The population of T. castaneum in rice was significantly reduced after treatment with Fossil Shield®. Diatomaceous earth at 1g and 2g per kilogram rice reduced population growth of T. castaneum to a coefficient of 0.27, and 0.02 respectively after 42 days. Fossil Shield® at 0.5g per kilogram rice increased the mortality of T. castaneum, but did not stop population growth.     

气调及温度对杂拟谷盗发育和繁殖的影响

杂拟谷盗Tribolium confusum Jacquelin du Val是重要储藏物害虫之一,主要危害面粉。笔者研究了气调及温度对杂拟谷盗生长发育和繁殖的影响,旨在弄清杂拟谷盗在低氧、低药(双低)环境中的生物学及生态学特性,为有效地控制该虫提供理论依据。 1 材料与方法采用两种气调环境5％O_2、12％CO__2(CA_1)和9％O_2、16％CO_2(CA_2)以及非气调环境     

Effects of temperature and yeast supplementation on the development ofTribolium castaneum (Herbst) in wholemeal and polished flour derived from four cereals in Maiduguri, Nigeria

The effects of temperature, yeast and polishing (removal of bran) on the development ofTribolium castaneurn (Herbst) in flour derived from millet, sorghum, maize and wheat were investigated for one generation in Maiduguri, Nigeria. Significantly moreT. castaneurn adults and larvae developed in flour stored at 35 °C than in flour stored at 30 °C or 40 °C; mortality of adult beetles in flour stored at 40 °C was 95 % in sorghum and maize and 100 % in millet and wheat. Addition of three levels (2.5, 5.0 and 10.0 %, w/w) of yeast to cereal flour, on average, significantly increased the population of adult and larval progenies relative to the population in yeast-free flour. Considerably higher number of adult beetles developed in wholemeal than in polished flour derived from millet.     

Effects of temperature and yeast supplementation on the development ofTribolium castaneum (Herbst) in wholemeal and polished flour derived from four cereals in Maiduguri, Nigeria

The effects of temperature, yeast and polishing (removal of bran) on the development ofTribolium castaneurn (Herbst) in flour derived from millet, sorghum, maize and wheat were investigated for one generation in Maiduguri, Nigeria. Significantly moreT. castaneurn adults and larvae developed in flour stored at 35 °C than in flour stored at 30 °C or 40 °C; mortality of adult beetles in flour stored at 40 °C was 95 % in sorghum and maize and 100 % in millet and wheat. Addition of three levels (2.5, 5.0 and 10.0 %, w/w) of yeast to cereal flour, on average, significantly increased the population of adult and larval progenies relative to the population in yeast-free flour. Considerably higher number of adult beetles developed in wholemeal than in polished flour derived from millet.     

Laboratory selection of resistance by the red flour beetle,tribolium castaneum (Herbst), to an atmosphere of low oxygen concentration

Adult populations of the red flour beetle,Tribolium castaneum (Herbst), were exposed for 40 generations to an atmosphere containing 99.5% N₂ and 0.5% O₂ at 95% RH, in order to select a strain resistant to the low oxygen concentration (LOC) atmosphere. Selection pressure was maintained at between 50% and 70% mortality. At the 40th generation comparison of sensitivity between the selected strain and the original non-selected strain indicated a resistance factor at the 50% mortality level (LT50) of x 5.2. However, throughout the selections, log-time against probit-mortality curves remained roughly parallel from generation to generation and the slope remained low. These findings indicate a multiplicity of genetic factors that at a high level of selection contribute together towards an adaptation of the insects to survival in the LOC atmosphere. Removal of selection pressure from a sub-population of the selected strain from the 13th to 21st generation revealed that resistance was partially retained with a decrease in resistance factor of 23%. Although the study revealed that the insects were able to develop a strain resistant to hypoxia, exposures were at 95% RH to minimize the desiccation effect. This does not reflect field situations, where ambient relative humidities are generally below 70%.     

Potential of zimtaldehyde, 4-allyl-anisol, linalool, terpineol and other phytochemicals for the control of the confused flour beetle (Tribolium confusum J. d. V.) (Col., Tenebrionidae)

Toxicity and repellency effects of several pure compounds (of plant origin) against the confused flour beetle (Tribolium confusum) were investigated in a filter paper test. The compounds were α-pinen, β-pinen, 4-allyl-anisol, camphor, 1,8-cineol, eugenol, linalool, menthol, piperin, terpineol, thymol and zimtaldehyde. Five compounds (4-allyl-anisol, linalood, terpineol, thymol and zimtaldehyde) caused enough mortality of this insect to allow the determination of LD₅₀ and LD₉₅ values. Zimtaldehyde and 4-allyl-anisol showed the strongest toxicity effects with LD₅₀ values of 0.04–0.05 μl/cm² within an exposure period of 24 h. When the isolated fumigant effects were tested by separating the insects from the filter paper, the toxicity of zimtaldehyde (LD₅₀=0.29 μl/cm²) was much lower than that of 4-allyl-anisol (LD₅₀=0.10μl/cm²).     

Potential of zimtaldehyde, 4-allyl-anisol, linalool, terpineol and other phytochemicals for the control of the confused flour beetle (Tribolium confusum J. d. V.) (Col., Tenebrionidae)

Toxicity and repellency effects of several pure compounds (of plant origin) against the confused flour beetle (Tribolium confusum) were investigated in a filter paper test. The compounds were α-pinen, β-pinen, 4-allyl-anisol, camphor, 1,8-cineol, eugenol, linalool, menthol, piperin, terpineol, thymol and zimtaldehyde. Five compounds (4-allyl-anisol, linalood, terpineol, thymol and zimtaldehyde) caused enough mortality of this insect to allow the determination of LD₅₀ and LD₉₅ values. Zimtaldehyde and 4-allyl-anisol showed the strongest toxicity effects with LD₅₀ values of 0.04–0.05 μl/cm² within an exposure period of 24 h. When the isolated fumigant effects were tested by separating the insects from the filter paper, the toxicity of zimtaldehyde (LD₅₀=0.29 μl/cm²) was much lower than that of 4-allyl-anisol (LD₅₀=0.10μl/cm²).     

The activity of some compounds extracts byAllium on stored-product insectsOryzaephilus surinamensis (L.),Sitophilus oryzae (L.) andTribolium castaneum (Herbst)

The bioactive metabolites of someAllium plants, all exhibiting interesting pharmacological activities, were tested for their attractive/repellent activity against saw-toothed grain beetle,Oryzaephilus surinamensis (L.), rice weevil,Sitophilus oryzae (L.), and rust-red flour beetle,Tribolium castaneum (Herbst), insects infesting the stored-products. The data obtained showed significant repellent effect of the thiosulfinates againstS. oryzae.     

The activity of some compounds extracts byAllium on stored-product insectsOryzaephilus surinamensis (L.),Sitophilus oryzae (L.) andTribolium castaneum (Herbst)

The bioactive metabolites of someAllium plants, all exhibiting interesting pharmacological activities, were tested for their attractive/repellent activity against saw-toothed grain beetle,Oryzaephilus surinamensis (L.), rice weevil,Sitophilus oryzae (L.), and rust-red flour beetle,Tribolium castaneum (Herbst), insects infesting the stored-products. The data obtained showed significant repellent effect of the thiosulfinates againstS. oryzae. Part 6 in the series “Chemistry of the genus Allium”.     

Gamma radiation susceptibility of strains of Tribolium castaneum (Herbst) resistant and susceptible to fenvalerate

Gamma radiation susceptibility of adults of the fenvalerateresistant strain of Tribolium castaneum (Herbst) (Coleoptera : Tenebrionidae) was studied under laboratory conditions. Selection for resistance to fenvalerate in adult beetles was carried out up to the sixth generation. In each generation of selection, adults of the fenvalerateresistant strain were evaluated for susceptibility to gamma radiation and compared with their fenvalerate-susceptible counterparts. Susceptibility to 60Co gamma radiation was evaluated on the basis of dosage-mortality (LD) and time-mortality (LT) responses. We found the LD values 50 50 50 for the fenvalerate-resistant and-susceptible strains to be 89.16 and 97.46 Gy respectively, showing no significant difference in susceptibility to gamma radiation. LT values were 7.58 and 17.20 days for the 50 fenvalerate-resistant and-susceptible strains respectively, showing that mortality in the resistant strain occurred markedly earlier than in the susceptible strain.     

转Bt基因水稻稻谷对赤拟谷盗生长发育的影响

鞘翅目、啮虫目昆虫是储粮昆虫群落中的优势类群[1],在适宜环境下繁殖速度较快,是评价转Bt稻谷对非靶标节肢动物长期效应和非预期效应的理想对象[2]。已有研究表明,Bt稻对稻田生境中的节肢动物无明显影响[3];小鼠毒理试验显示Bt稻米无毒[4]。但是,转Bt稻谷对储粮昆虫群落影响的     

高效氯氰菊酯对龟纹瓢虫幼虫-棉蚜的综合作用效应

进行了杀虫剂高效氯氰菊酯对龟纹瓢虫幼虫-棉蚜综合作用效应的研究,在高效氯氰菊酯对棉蚜、龟纹瓢虫幼虫毒力测定的基础上,进一步研究了药剂直接处理后的龟纹瓢虫幼虫、取食不同药剂处理棉蚜的龟纹瓢虫及药剂综合作用后龟纹瓢虫幼虫的死亡率、捕食量及残虫化蛹率变化.结果表明,高效氯氰菊酯对棉蚜和龟纹瓢虫幼虫的毒杀作用强,LC50分别为7.369mg/L和0.912mg/L.药剂处理后的龟纹瓢虫幼虫3天捕食量下降15.6%～25.0%,而饲食带药棉蚜的龟纹瓢虫幼虫3天捕食量下降28.7%～51.6%,捕食量与药剂浓度呈反相关.同时,随着药剂浓度的升高,龟纹瓢虫残虫化蛹率逐渐下降.     

双斑青步甲的生物学特性及其成虫对草地贪夜蛾的捕食能力

为更好地利用捕食性天敌双斑青步甲Chlaenius bioculatus来防治草地贪夜蛾Spodoptera frugiperda,在全期喂养体型相当的草地贪夜蛾3龄幼虫的条件下,记录双斑青步甲的生活史,并通过捕食功能反应试验评估其成虫对草地贪夜蛾的捕食作用。结果表明,在全期喂养草地贪夜蛾的情况下双斑青步甲可以完成完整的生活史,其卵、 1龄、 2龄、 3龄幼虫和蛹的发育历期分别为5.85、1.65、 2.75、 11.15和4.30 d;雌成虫的产卵总量平均为45.6粒。双斑青步甲成虫对草地贪夜蛾的捕食功能反应属于Holling Ⅱ型,其雄成虫和雌成虫对草地贪夜蛾3龄、 5龄幼虫的瞬时攻击率分别为1.038、 0.818和1.070、 1.378,处理时间分别为0.015、 0.225 d和0.016、 0.337 d。表明双斑青步甲成虫对草地贪夜蛾幼虫有很好的捕食能力,具有作为草地贪夜蛾生防天敌进一步开发的潜力。     

光谱对二点委夜蛾成虫趋光行为的影响

为明确二点委夜蛾趋光反应特性,利用光行为学方法研究了14种不同波长单色光对其成虫趋光行为的影响。结果表明:在340~605 nm波谱范围内,成虫的趋光率较高,均在56.0%以上;雌成虫对360 nm紫外光、440 nm蓝光、524、562 nm绿光及605 nm橙红光的趋光性较强,趋光率分别为75.0%、72.5%、72.5%、72.0%和71.5%;雄成虫对360、380 nm紫外光、440 nm蓝光、498 nm绿光及605 nm橙红光的趋光性较强,趋光率分别为73.0%、71.0%、71.5%、70.0%和69.0%;性别对二点委夜蛾趋光行为略有影响,除雄成虫对483 nm蓝光的趋光率显著高于雌成虫外,雌、雄成虫对其它单色光的趋光率、避光率均无显著差异;二点委夜蛾雌、雄成虫的避光率较低,均在4.0%以下。表明二点委夜蛾成虫具有很强的趋光性,且对360 nm紫外光趋光性最强。     

光肩星天牛和星天牛的分子快速鉴定

正光肩星天牛Anoplophora glabripennis和星天牛A. chinensis同属鞘翅目天牛科星天牛属,均为世界性林业蛀干害虫。前者主要为害杨树、柳树、榆树等阔叶树,后者主要为害柑橘、苦楝、木麻黄、柳树等林果植物。2种天牛常以卵或幼虫虫态在港口被截获,从形态上难以区分。在分子标记技术上,随机扩增多态性DNA标记(random amplified polymorphic     

四种Bt毒素蛋白对二点委夜蛾幼虫毒力测定及中肠组织病理学变化

为更好地了解苏云金芽胞杆菌Bacillus thuringiensis毒素蛋白对二点委夜蛾Athetis lepigone的毒力以及作用机理,通过饲喂含有Cry1Ac、Cry1Ab、Cry2Ab和Vip3Aa四种不同Bt毒素蛋白饲料,测定Bt毒素蛋白对二点委夜蛾幼虫的毒力,并观察取食4种毒素蛋白后幼虫中肠组织的病理学变化。结果显示,二点委夜蛾幼虫取食毒素蛋白后72 h,Cry1Ab和Cry1Ac毒素蛋白对二点委夜蛾幼虫的杀虫活性较高,校正死亡率为84.7%和76.4%;Vip3Aa和Cry2Ab毒素蛋白的毒力较弱。二点委夜蛾幼虫取食4种Bt毒素蛋白后,中肠柱状细胞微绒毛脱落,杂乱地分散在肠腔内,杯状细胞变形和腔内微绒毛脱落,线粒体和内质网等变形破裂,细胞核的核膜消失、核质凝聚和形状发生变化,经Cry1Ab和Cry1Ac毒素蛋白处理后中肠细胞的病变症状和速度明显高于Cry2Ab和Vip3Aa毒素蛋白处理。表明Cry1Ab和Cry1Ac毒素蛋白对二点委夜蛾幼虫杀虫活性较高,显著高于Cry2Ab和Vip3Aa毒素蛋白,且对其中肠细胞的破坏作用也较强。