竹提取物对玉米象Sitophilus zeamais Motsch.生物活性的初步研究

研究了 10种竹子提取物对玉米象种群形成的抑制作用和驱避作用。结果表明 ,灰水竹和短穗竹提取物对玉米象成虫的驱避效果较好 ,72 h驱避等级达到 级 ,平均驱避率分别为 77.4 4%和6 4.84 %。应用索氏抽提法所得到的灰水竹提取物对玉米象成虫的驱避作用明显强于间歇振荡法所得到的提取物 ,驱避中浓度分别为 0 .9994 g/L。 10 g/L的竹提取物对玉米象种群形成的抑制作用不明显 ,只有白纹短穗竹提取物对玉米象种群的抑制率达到 5 0

Evaluation of the dust and methanol extracts of Garcinia kolae for the control of Callosobruchus maculatus (F.) and Sitophilus zeamais (Mots)

Insecticidal effects of different doses of the dust and methanol extracts of Garcinia kolae on Callosobruchus macu- latus and Sitophilus zeamais were tested. The dust had no significant effect on the two insects; none of them died even at 3 d after treatment. The methanol extracts, however, had rapid lethal effects on both C. maculatus and S. zeamais. The mortality of C. maculatus by the lowest concentration of methanol extracts ranged from 95%~100% whereas in S. zeamais, the mortality ranged from 87.5%~100% and 70%~100% in concentrations of 1 g extract+3 ml methanol and 1 g extract+5 ml methanol, respectively, from 24 to 48 h. The least concentration of 1 g extract+15 ml methanol had no significant lethal effect on Sitophilus zeamais.

Interspecific Competition and Grain-Hosts Selection of Maize Weevil, <i>Sitophilus zeamais</i>(Motsch.) (Coleoptera;Dryophtoridae) and Larger Grain Borer, <i>Prostephanus truncatus</i>(Horn) (Coleoptera;Bostrichidae)

Laboratory interspecific competition and grain-hosts selection experiments involving maize weevil (MW), Sitophilus zeamais (Motsch.) and larger grain borer (LGB), Prostephanus truncatus (Horn) were performed under ambient temperature and relative humidity (25°C - 35°C and 70% - 80% relative humidity) in their major host cereal, maize grains. The species reproductive rate and grain-hosts preference were evaluated by a number of emerged adults. In combined infestation, both species competed intensively by simultaneously increasing their individuals’ emergence, 9-fold or greater than when reared alone. Even though both species simultaneously increased their progeny, S. zeamais was the dominant competitor and had a significant suppressant effect on P. truncatus. The selection result of grain-hosts showed that P. truncatus placed in the environment containing both uninfested maize grains and grains previously infested by S. zeamais, the insect prefers uninfested grains. Indeed, P. truncatus individuals’ emergences were significantly more important to uninfested grains than to infested grains. The weevil-infested grains seemed to have deterrent and detrimental effects on P. truncatus. Conversely, S. zeamais selection of grain-hosts was significantly (P = 0.0001) more attracted by P. truncatus infested grains than to uninfested grains. Sitophilus zeamais individuals’ emergences were significantly (P = 0.0008) more important to infested grains than to uninfested grains. The S. zeamais preference on grains previously infested would be stimulated by P. truncatus larval vibrations in grain.

Comparative Morphometry of the <i>Sitophilus zeamais</i>Motschulsky Populations (Coleoptera: Curculionidae) Infesting Yellow Maize in Four West African Countries

Sitophilus zeamais is a primary pest of stored maize, which can cause quality and quantity losses. Maize is cultivated in several West African countries where different agro-climatic and agro-ecological conditions exist. These conditions could influence the Sitophilus zeamais morphology. Thus, the purpose of this study is to identify the Sitophilus zeamais morphological groups in the four countries. This was carried out through the morphometric study of 30 male Sitophilus zeamais individuals taken from the yellow maize in each country, by measuring with a binocular magnifying glass, 16 variables of the different tagmas belonging to the insect. Subsequently, statistical analyses were firstly carried out with the raw measurements, such as the principal component analysis, in order to extract the contribution of the variables on each factorial axis and to visualise the correlations between the variables. Taking the case of the transformed measurements, in addition to the principal component analysis, a discriminant factorial analysis was carried out to find out the best factor for gathering individuals according to their morphology, a confusion matrix to summarise the individual’s reclassification in order to deduce the good and bad classification rates, and an ascending hierarchical classification which consists of gathering the individuals according to their similarity and separating them according to their dissimilarity using the truncation method. Therefore, five morphological groups were identified. However, the existence of these morphological groups would not be linked to agro-ecological, climatic conditions and to the geographical remoteness between countries.

Insecticidal Activity of the Powders Obtained from the Bauxite Red Mud, Zyzygium aromaticum and Citrus sinensis Peel Extracts on the Conservation of Corn against Sitophilus zeamais: Physicochemical Properties

The remarkable push of technologies increasingly recommends materials for their constructions.Hence the extraction of alumina is for different uses.The exploitation of bauxite pollutes the surrounding areas in this case the discharge of mud wheel.Furthermore,the excessive use of dangerous conventional synthetic insecticides continues to be in circulation in Cameroon despite the known adverse effects.These problems lead us to formulate bio insecticides from rejection of the extraction of alumina and extracts of S.aromaticum and Citrus sinensis which respectively offer us essential oils eugenol and limonene having insecticidal properties against the main insects,pests of corn stocks,Sitophilus zeamais.From the kinetic point of view of the adsorption of the extracts of eugenol,limonene and their association by the red mud,the adsorption curve shows that the Eu/Li mixture(30/70)is better by 0.36 mg/g during the 24 h.The results showed a high toxicity of the Eu-Li binary mixture of ratio 30/70 with respective mortality rates of 95.88%after 8 days of exposure to the concentration of 5 mL/L on the adults of Sitophilus zeamais.The other composites induce an average rate of 80%.The results from the physicochemical analysis of corn before and after treatment with formulated insecticides showed a slight loss in nutritional quality of 14.90%in ash,12.5%in protein,16.14%in lipids and 13.63%in total sugars for 180 days.The powdery formulation from red mud and Eu-Li(30/70)mixture can therefore ensure the protection of corn stocks against Sitophilus zeamais in a farming environment.

米糠油对小麦中玉米象(Sitophihus Zeamais)的防治效果研究

通过米糠油对玉米象生物效应的实验室测定表明米糠油在不拌粮条件下，对玉米象有明显的引诱作用，引诱虫量与米糠油用量成正相关，在拌小麦条件下，对玉米象有明显的驱避作用，驱避率随米糠油用量的增加而上升，用量达１１．８ｍｌ／ｋｇ时，驱避率为９４．４％；当用量≥４ｍｌ／ｋｇ的米糠油拌粮时，对玉米象成虫有致死作用，用１６ｍｌ／ｋｇ拌粮时３－１０天后成虫死亡率达到７１．８－８５％；米糠油能抑制玉米象的繁殖，降低Ｆ１数量，当米糠油用量为４－８ｍｇ／ｋｇ时，玉米象繁殖抑制率为８８．１－９８．６％；米糠油对玉米象成虫无熏杀作用。

小麦粮堆中玉米象和黄曲霉发生与二氧化碳浓度变化关系研究

构建4种模拟小麦粮堆(模拟自然带菌、模拟害虫发生、模拟霉菌发生、模拟虫霉发生),研究了25℃下不同水分(12.5%和15.0%)小麦粮堆CO_(2)浓度变化情况。结果显示,水质量分数为12.5%的自然带菌粮堆二氧化硕(CO_(2))浓度30 d内未出现显著变化(P>0.05);害虫发生粮堆第2天CO_(2)体积分数即超过0.5%,第15~17天后快速增长,于第23天达到4.5%;霉菌发生粮堆第30天时CO_(2)体积分数也未超过0.04%;虫霉共同发生粮堆第2天CO_(2)体积分数即超过0.6%,第13~17天后快速增长,于第26天达到4.5%。水质量分数15.0%的小麦的4种模拟粮堆中霉菌发生粮堆、虫霉共同发生粮堆的CO_(2)浓度增加更快、幅度更大。研究初步明确了虫霉发生与粮堆CO_(2)浓度变化的关系,为利用粮堆CO_(2)浓度变化来监测粮堆虫霉发生提供参考。

复配惰性粉对玉米象致死效果的影响

采用药剂拌粮法,分析了硅藻土、高岭土、沸石粉以及蒙脱石四种惰性粉不同浓度、不同目数对小麦中玉米象在7、14、21 d的致死效果,研究了硅藻土与高岭土两种惰性粉之间复配的杀虫增效作用,评估了惰性粉复配对小麦储藏过程中玉米象害虫防治的应用价值和未来前景。四种惰性粉的杀虫效果均呈现出随着处理浓度的增加而增强的趋势,其中,硅藻土和高岭土的效果较好。随着处理时间的延长,不同惰性粉粒径对玉米象致死效果的差异并不是一成不变的,4种惰性粉在200目的条件下,均获得较好的玉米象致死效果。在1 000 mg/kg浓度条件下,复配200目的硅藻土与高岭土,硅藻土与高岭土在质量比为2/3的复配比例条件下获得较好的杀虫增效作用,得到最佳的玉米象致死效果。

电子束处理对玉米象繁殖力的影响

本研究用电子加速器辐照处理玉米象成虫以及隐藏于小麦籽粒中的玉米象卵、幼虫和蛹 ,研究不同发育阶段玉米象辐照后的繁殖力。结果表明 ,高于 1 80Gy的辐照处理的成虫不能产生后代 ,辐照处理具有明显的当代延迟发育效果 ;高于 1 80Gy剂量辐照处理玉米象的蛹 ,羽化出的成虫不能产生下一代成虫 ;高于 90Gy以上的辐照处理玉米象的幼虫和卵 ,其羽化出的成虫不能产生下一代的成虫。 1 80Gy辐照可以作为阻止不同虫态玉米象的继续繁殖下一代的有效剂量。

植物性杀虫剂防治玉米象的研究进展

本文系统介绍了各种植物性杀虫剂防治玉米象的研究方法,阐述了目前在玉米象防治中已利用的植物性杀虫剂的研究成果和应用价值。

电子束辐照谷物中玉米象不同虫态的生物效应

用ИЛУ 6М2 型电子加速器对玉米象成虫以及隐藏于小麦籽粒中的玉米象卵、幼虫和蛹进行辐照效应试验。结果表明 ,1 80Gy以上的剂量可以完全阻止谷物中幼虫和卵发育为成虫 ;在此剂量下有少量蛹可羽化为成虫 ,但存活力受严重影响 ,30 0Gy以上辐照的蛹即使羽化也在短时间内死亡 ;成虫被 30 0Gy的电子束辐照后寿命大缩短 ,在 1 4d内完全死亡。 30 0Gy电子束辐照剂量可以作为辐照有效防治玉米象的剂量。

石菖蒲根茎提取物β-细辛醚对玉米象成虫的毒力及防治效果

采用药膜法、滤纸药膜法和饲料拌药法分别检测β-细辛醚对玉米象成虫的触杀、驱避及种群抑制等作用。结果表明,β-细辛醚对玉米象成虫具有良好的防治效果。β-细辛醚157.30、78.63μg/cm2浓度处理玉米象成虫96 h后的校正死亡率分别高达100.00%和93.22%,处理96 h后的触杀毒力LC50为28.22μg/cm2;157.30、78.63、39.32μg/cm2浓度处理的β-细辛醚对玉米象成虫的平均驱避率在Ⅴ级以上,较低浓度19.66μg/cm2处理的驱避率也达到了Ⅳ级;0.500 g/kg的浓度处理7 d后,玉米象成虫的校正死亡率达到91.11%,处理45 d后,对子代种群抑制率也高达100.00%。

21种植物提取物对玉米象的生物活性

为了筛选对粮库安全的植物源杀虫剂,研究了21种植物的4种溶剂(无水乙醇、丙酮、乙酸乙酯和石油醚)提取物对玉米象SitophiluszeamaisMotschulsky的驱避和触杀作用。结果表明,高良姜Alpiniaofficinarum石油醚提取物、黄姜Curcumalonga丙酮提取物和山鸡椒Litseacubeba石油醚提取物对玉米象成虫的驱避作用显著,处理60h平均驱避等级均达到Ⅴ级,平均驱避率分别为80.02%、80.60%和81.70%。在21种植物中,石菖蒲Acorusgramineus和巴豆Crotontiglium的4种溶剂提取物均对玉米象成虫的触杀作用明显,7.86mg/cm2的剂量处理4天后的校正死亡率均达到90%以上。

水稻品种在贮藏期间对玉米象抗性的研究

对53份水稻品种进行了抗玉米象的筛选.根据敏感系数的差异,鉴定出抗级品种39份,中抗品种3份和敏感品种11份.并证实了应用自由选择和非自由选择的筛选方法,其趋势基本一致.敏感系数与谷粒的裂颖率呈极显著正相关,与米粒的粗蛋白、总淀粉、支链淀粉和直链淀粉含量及糊化温度无明显的相关性.

大蒜素对储粮害虫熏蒸作用的研究

利用大蒜素对3种储粮害虫米象(Sitophilus oryzae L.)、玉米象(Sitophilus zeamais)和谷蠹(Rhyzopertha dom-inica Fabricius)的不同虫态进行了熏蒸作用的研究.结果表明,大蒜素对储粮害虫有明显的熏蒸作用.室内熏蒸3d大蒜素对米象、玉米象和谷蠹成虫的LC50值分别为6.38,3.02,0.88μL.L-1.室内模拟药效熏蒸3 d,对米象、玉米象和谷蠹成虫的LC50值分别为45.77,13.36,11.37μL.L-1.在对3种成虫进行模拟药效熏蒸时,小麦对大蒜素有一定的吸附作用.大蒜素浓度为40μL.L-1时,对米象、玉米象和谷蠹幼虫的校正死亡率分别为92.00%,93.33%,99.33%;对蛹的校正死亡率分别为76.00%,86.00%,92.91%,说明幼虫比蛹对大蒜素更敏感。

苦杏仁精油的熏蒸杀虫活性研究

采用三角瓶密闭熏蒸法测定了苦杏仁精油对家蝇、白纹伊蚊、粘虫以及玉米象的熏蒸杀虫活性,结果显示:苦杏仁精油对各试虫均有较强的熏蒸杀虫活性,其中含HCN的精油对家蝇、白纹伊蚊、粘虫以及玉米象的LC50分别为3.09、0.63、4.63、12.03μL/L;除去HCN的精油对家蝇、白纹伊蚊、粘虫以及玉米象的LC50分别为3.53、0.52、4.08、23.46μL/L;熏蒸的时间效应试验结果表明,含有HCN的苦杏仁精油和不含HCN的苦杏仁精油对供试试虫的熏杀速度均较快,其中白纹伊蚊的反应最快,其次为家蝇、粘虫、玉米象.除玉米象外苦杏仁精油中所含的微量HCN对试虫的熏蒸活性影响不大,且2种处理的精油对同种试虫的致死中时差别范围不超过10 min.实验结果表明,苦杏仁精油可作为新型的杀虫活性物质,为苦杏仁精油作为植物源杀虫剂提供了依据.

中国10省75地市米象和玉米象的分布调查研究

玉米象和米象为世界性的重要储粮害虫,在中国被列入10种主要储粮害虫之中,掌握其分布对其科学治理具有重要意义。在中国主要储粮生态区的10个省75个地市的粮食储备库、大米加工企业、饲料加工企业、面粉企业和部分储粮农户等536个场所进行现场取样调查。在相关省份及地市调查中均有玉米象被采集到,米象除在原有记录的广东、云南、福建、湖南等省采集到外,还新增加了在浙江、湖北、河南、山东等省的采集记录。分别在浙江省的宁波、湖州、台州、温州、金华和湖北省的恩施、咸宁、武汉、麻城、荆州、荆门等地市采集发现米象,在河南省的17个调查地市中只有南阳、平顶山、洛阳、漯河、周口、商丘6地市新发现米象分布,在山东省的菏泽、日照、青岛、烟台、聊城、济南、临沂等地市的调查中只有青岛采集到米象。

菜油拌粮对玉米象种群增长的抑制作用及保粮效果

玉米象(Sitop hilus zeamais)是最大的毁灭性储藏物害虫之一。它能危害稻谷,小麦,玉米,薯类及其加工品,还能危害莲籽,该仁米,天麻等土特产及中药材。目前在国家粮库等单位主要采用熏蒸剂和化学保护剂防治玉米象,可是在农户及城市居民家中应用化学药剂特别是熏蒸剂很不方便,很不安全。为探讨在农户及城市居民家中防治玉米象的简便、安全的有效措施。

1％蛇床子素粉剂对三种储粮害虫的防效

研究1%蛇床子素粉剂在5种处理浓度下对3种储粮害虫谷蠹Rhizopertha dominica Fabricius、玉米象Sitophilus zeamai Motschulsky和赤拟谷盗Tribolium castaneum Herbst的防治效果。室内毒力测定结果表明,按有效成分0.5mg/kg(蛇床子素:粮食)浓度处理粮食,7d后,粮食中谷蠹、玉米象和赤拟谷盗的校正死亡率分别为97.78%、100%、86.70%,防治效果优于对照药剂防虫磷和谷虫净。将药剂处理4个月后的粮食进行接虫试验,15d后谷蠹和玉米象的防治效果仍可达100%,达到储粮害虫防治要求。