S-烯虫酯防治拟谷盗持效性及解毒酶功能影响研究

在当前害虫抗药性强和社会安全健康意识增强的背景下，迫切需要开发生态友好的防治手段。因此，采用小麦入仓全仓拌和S-烯虫酯进行防治。通过分别扦取处理90天和365天后的小麦样品，在实验室内模拟了赤拟谷盗和杂拟谷盗的防治效果，并测定了S-烯虫酯对拟谷盗幼虫三种解毒酶的影响。研究结果表明，施药时间和虫态是影响S-烯虫酯杀虫效果的关键因素。在施用S-烯虫酯90天后的小麦样品中，武汉、成都和齐河3个品系的赤拟谷盗卵孵化率为0%，广东和北京2个品系的杂拟谷盗卵孵化率分别为1.67%±2.04%和0%。此外，施用S-烯虫酯90天后对赤拟谷盗和杂拟谷盗的杀蛹活性较好，羽化成虫无繁殖能力；施用365天后的杀蛹活性大大降低，羽化成虫有繁殖能力，而F1代蛹无法羽化。两处理组对两种成虫直接致死作用也有一定效果，但施用365天后的致死率大大降低，赤拟谷盗F1代仅有幼虫，而杂拟谷盗F1代有部分幼虫可化蛹但不能进一步转化为成虫。说明赤拟谷盗比杂拟谷盗更为敏感。S-烯虫酯胁迫之后，两种拟谷盗科幼虫体内的3种解毒酶活性受到了影响，且随着时间延长而增强。     

人工合成储粮保护剂——β—水芹烯对几种储粮害虫作用的研究

人工合成β－水芹烯对谷蠹、玉米象、米象均有较好的毒杀效果。拌粮法处理剂量为０．３３２％时可全部杀死谷蠹成虫，处理剂量为０．６６４％时可杀死上述３种试虫的成虫。剂量在０．１６６％以上时即可完全抑制谷蠹的繁殖，剂量０．３３２％以上时即可完全抑制玉米象、米象的种群发育。对杂拟谷盗的点滴结果表明，其ＬＤ５０＝１．１８０μｌ／头，对它的种群发育也有一定的抑制作用，并有延缓其发育的作用。     

基于线粒体COI和COII基因的米象与玉米象的分子鉴定

为建立基于线粒体COI和COII基因序列的米象和玉米象的分子鉴定方法。采自全国6个地理种群的米象和2个地理种群的玉米象,PCR扩增试虫线粒体COI和COII基因,将获得的基因序列在GenBank中进行BLAST比对,分析基因序列相似性,分别计算基于COI和COII基因序列的遗传距离,并构建系统发育树。结果表明在本研究所分析的2种象虫样本中,米象COI基因的种内相似度在98.17% 以上,米象和玉米象COI基因的种间相似度为85.84%~86.92%;米象COII基因的种内相似度在98.37% 以上,玉米象COII基因的种内相似度在97.77% 以上,2种象虫COII基因的种间相似度为86.27%~88.31%。米象的种内遗传距离为0.002~0.020(COI)和0.011~0.015(COII),玉米象的种内遗传距离为0.001~0.023(COII)。两种象虫的种间遗传距离为0.145~0.185(COI)和0.128~0.154(COII),基于COI和COII基因的种间遗传距离显著高于种内遗传距离。系统发育树结果显示,在2个基因的系统发育树上,米象、玉米象的基因序列分别位于不同的进化支,同种象虫的基因序列位于相同的进化枝。根据本研究所用的线粒体COI和COII基因序列的差异性可以进行米象和玉米象的分子鉴定。     

赤拟谷盗和玉米象的相互关系研究

在75%RH、30℃条件下通过相互选择性实验、单独饲养和混合饲养实验研究赤拟谷盗和玉米象在小麦中的相互关系。研究结果表明:在相同生态环境中,赤拟谷盗和玉米象间的相互选择行为不明显。在小麦中单独饲养情况下,赤拟谷盗种群中成虫数量随处理时间延长先减少后增加,且增长缓慢,在处理56 d后最大成虫数量增加为起始虫数的11.5倍;而玉米象种群中成虫数量随处理时间延长而显著增加,在处理56 d后最大种群中成虫数量增加为起始虫量的53.9倍。与单独饲养相比,在小麦中混合饲养时,赤拟谷盗和玉米象的繁殖速率和种群中成虫数量都显著增加,在处理56d后最大种群中成虫数量分别增加为起始虫量的20.3倍和93.4倍。因此,赤拟谷盗和玉米象均为小麦储藏过程中重要害虫,玉米象的危害对赤拟谷盗种群增长有促进作用。     

赤拟谷盗和玉米象的相互关系研究（网络首发、推荐阅读）

在75%RH、30 ℃条件下通过相互选择性实验、单独饲养和混合饲养实验研究赤拟谷盗和玉米象在小麦中的相互关系。研究结果表明：在相同生态环境中,赤拟谷盗和玉米象间的相互选择行为不明显。在小麦中单独饲养情况下,赤拟谷盗种群中成虫数量随处理时间延长先减少后增加,且增长缓慢,在处理56 d后最大成虫数量增加为起始虫数的11.5倍;而玉米象种群中成虫数量随处理时间延长而显著增加,在处理56 d后最大种群中成虫数量增加为起始虫量的53.9倍。与单独饲养相比,在小麦中混合饲养时,赤拟谷盗和玉米象的繁殖速率和种群中成虫数量都显著增加,在处理56 d后最大种群中成虫数量分别增加为起始虫量的20.3倍和93.4倍。因此,赤拟谷盗和玉米象均为小麦储藏过程中重要害虫,玉米象的危害对赤拟谷盗种群增长有促进作用。     

温度对高氮气调中米象各虫态致死时间和发育的影响

明确氮气气调中温度对隐蔽性害虫各虫态致死时间的延迟程度及差异,可为气调杀虫时间的科学掌控提供参考。研究了在98%氮气浓度和(75±5)%RH下18、23和28℃时米象Sitophilus oryzae(L.)成虫和隐蔽于粮粒内的卵、幼虫和蛹在不同时间的死亡率、致死时间以及羽化出成虫的时间。18℃温度下达到100%死亡率的时间为25 d,比23℃和28℃时相应延迟了6 d和12 d。18℃下气调致死虫卵、幼虫、蛹和成虫的LT_(50)值(半数致死时间)分别为9、8、11和7 d,LT_(99)值(99%个体致死所需时间)分别为24、21、26和17 d;23℃时相应LT_(50)值为6、5、7和5 d,LT_(99)值为19、16、21和11 d;28℃时LT_(50)值为3、3、4和3 d,LT_(99)值为11、10、12和7 d。98%氮气气调后残存米象隐蔽虫态均可发育,与正常气体环境相比18℃时从卵发育至成虫的历期最大可延迟27 d,温度降低可导致发育历期延长更为明显。米象不同虫态对氮气气调耐力由大到小为:蛹卵幼虫成虫,氮气气调杀除米象时应以完全杀死隐蔽发生的蛹为目标。     

S-烯虫酯的研究进展及应用前景

烯虫酯是首个人工合成的昆虫保幼激素类似物,S-烯虫酯是烯虫酯的纯有效体,S-烯虫酯具有稳定性强、活性高、合成简便等优点.S-烯虫酯不仅对哺乳动物的毒性很低,而且可以在环境、土壤和水中快速降解,对人畜和环境安全,抗性发展风险较低.本文综述了S-烯虫酯的安全性、抗性和国内外的相关应用研究,并对S-烯虫酯的应用及研究前景进行...     

低氧对PH3抗性米象和谷蠹的控制作用研究

针对米象Sitophilus oryzae(Linné)和谷蠹Rhizopertha dominica(Fabricius)等主要储粮害虫对PH_3抗性越来越高,单一使用PH_3防治难度加大等问题,对2%和5%氧浓度环境控制不同PH_3抗性米象和谷蠹成虫及F1代的效果进行了实验室验证。结果表明:氧气浓度为2%时,PH_3抗性的米象和谷蠹成虫在6 d内全部死亡,无F1代出现;氧气浓度为5%时,28 d后PH_3抗性米象和谷蠹成虫的死亡率小于50%,抗性谷蠹和米象均无F1代出现。     

蛇床子素粉剂对5种储粮害虫生物活性研究

蛇床子素粉剂对5种主要储粮害虫的生物活性研究结果表明:蛇床子素粉剂具有很好的防治效果,在最高剂量1.6 mg/kg下,对这5种害虫的校正死亡率达98.00%以上,所需处理时间从2～15 d不等.对玉米象、长角扁谷盗、锯谷盗成虫处理2 d后,校正死亡率分别为98.89%、100.00%、98.84%,致死中量LD50分别为0.19、0.20、0.26 mg/kg;对谷蠹、赤拟谷盗成虫处理15 d后,校正死亡率均为100.00%,致死中量LD50分别为0.03、0.23 mg/kg.蛇床子素粉剂1.6 mg/kg剂量对玉米象、谷蠹、赤拟谷盗和锯谷盗成虫的防治效果好于商业防护剂谷虫净(1 000 mg/kg)和防虫磷(10 mg/kg);对长角扁谷盗成虫的防治效果好于谷虫净,与防虫磷防治效果间没有显著差异性.     

掌叶苹婆种子提取物对三种主要储粮害虫的毒力测定

采用索氏提取法,以丙酮作为有机溶剂制备掌叶苹婆种子提取物,并利用滤纸药膜法研究了掌叶苹婆种子提取物对玉米象、谷蠹和锈赤扁谷盗3种试虫成虫的触杀作用。结果表明,掌叶苹婆种子丙酮提取物对玉米象、谷蠹和锈赤扁谷盗3种试虫成虫具有很强的触杀作用,且触杀作用随着处理时间延长和处理剂量增加而显著增强。在浓度3.923 mg/cm2处理剂量下处理96 h后提取物对3种试虫的触杀作用校正死亡率均达到100%。掌叶苹婆种子丙酮提取物对玉米象、谷蠹和锈赤扁谷盗成虫的触杀毒力LD50值分别为:0.875、0.716和1.389 mg/cm2。3种试虫成虫对提取物的敏感性为谷蠹>玉米象>锈赤扁谷盗。     

The use of modified atmospheres to control Sitophilus zeamais and Sitophilus oryzae on stored rice in Portugal

This study reports the efficacy of using CO₂ against Sitophilus zeamais and Sitophilus oryzae as an alternative treatment to fumigation for rice stored in a rice mill in Portugal. The trials were conducted in a silo containing 40 tonnes of polished rice and in four hermetic big bags of 1 tonne capacity; two with paddy and two with polished rice. The composition of the atmosphere ranged from 90 to 95% CO₂ and 0.7–2.1% O₂. Three trials were carried out at different temperatures and treatment times; stored rice in the silo at 29.6 ± 0.1 °C for 26 days (first trial), at 34.1 ± 0.2 °C for 10 days (second trial), and in big bags at 22 °C for 26 days (third trial).To evaluate the efficacy of each treatment, metal cages with 16 g of infested rice where placed at bottom, middle, top and surface of the polished rice in the silo. Four replications of each type of infested rice containing one-week-old S. zeamais adults, or eggs of S. zeamais or S. oryzae, were incubated in the laboratory, at the same temperature as in the silo, to serve as a control.In all modified atmosphere treatments adults of S. zeamais, and eggs of both S. oryzae and S. zeamais, showed mortality close to 100% and no F1 emergence was recorded in any treatment sample. This was the first time that a Portuguese rice mill used modified atmospheres.     

Efficacy of filter cake and Triplex powders from Ethiopia applied to wheat against Sitophilus zeamais and Sitophilus oryzae

The efficacy of filter cake and Triplex powders applied to wheat was evaluated in the laboratory against the maize weevil, Sitophilus zeamais Motschulsky and rice weevil, Sitophilus oryzae (Linnaeus)—two most common insect pests associated with stored grain in Ethiopia. Efficacy of these powders was determined by exposing 20 adults of each species to 100 g of wheat treated with 0, 100, 500, 700 and 1000 mg/kg of filter cake and Triplex. Adult mortality was determined 7 and 14 d after exposure. In addition, adult progeny production, percentage of insect damaged kernels, and percentage of grain weight loss at each species-powder-concentration-time combinations were determined after 42 d. The 7 and 14 d mortality was 100% for adults of both species exposed to 1000 mg/kg of filter cake; only the 14 d mortality of Sitophilus species was 100% for adults exposed to 700 mg/kg. Mortality of S. oryzae adults was 100% when exposed for 14 d to1000 mg/kg of Triplex. Mortality of S. zeamais never reached 100% in any Triplex treatments. Adult progeny production of S. zeamais was completely suppressed at filter cake concentrations of 700 and 1000 mg/kg, whereas 1000 mg/kg was necessary for complete suppression of S. oryzae adult progeny production. Complete suppression of adult progeny production was not observed in any Triplex treatments. Complete reduction in percentage of insect damaged kernels and percentage of grain weight loss were obtained when S. zeamais and S. oryzae adults were exposed to 1000 mg/kg of filter cake; similar reductions with S. zeamais occurred only at 1000 mg/kg of Triplex. In the case of S. oryzae, complete reduction of insect damaged kernels and grain weight loss were not achieved at any concentration of Triplex. These powders can be used as alternatives to chemical insecticides for management of Sitophilus species.     

食物及挥发物对米象、玉米象及锯谷盗诱集效果的研究

针对为减少粮食损失、减少熏蒸剂的用量,而运用食物引诱剂对仓虫监控和防治这一重要课题,本研究在实验室条件下测试2种食物和4种食物中对害虫有引诱作用的有效化学成分单一或组合时对3种害虫的诱集效果,从而筛选出对每种实验昆虫诱集效果最佳的诱集物配比方案。试验表明,对米象诱集效果最好的组合为香草醛(0.012 g)+二氯甲烷(0.5 m L)+亚油酸(2.5 m L)+二十烷(0.02 g),诱集率最高可以达到65.2%;对玉米象诱集效果最好的为单一米糠,诱集率可达74%;对锯谷盗诱集效果最好的是单一的诱集物香草醛,诱集率最高可以达到64%以上。     

Resistance of packaging against infestation by Sitophilus zeamais

The results of infestation by maize weevil, Sitophilus zeamais (Coleoptera, Curculionidae), in different packaging filled with pasta are presented in this research. Three different types of packaging were used, that is, two paper tubes (one novel, laminated with bio-based polyethylene and one without lamination) and commercial polypropylene, pillow pouch packaging. Material properties such as grammage, thickness, surface analysis, moisture and water resistance, tensile and compressive strength were analysed. Improved compressive strength, moisture and water resistance were detected at the bio-polyethylene laminated tube packaging (approx. 30%), compared to the non-laminated sample. The obtained results demonstrated that adult maize weevils revealed significant preferences to enter the pasta packages through the already existing holes which were in the polypropylene packaging, while no infestation was observed inside the packages at the paper tube packaging. The study revealed that the shape and construction, for example, tube packaging with an innovative bio-polyethylene film, are very effective regarding insect infestation and mechanical overloads.     

Field monitoring Sitophilus zeamais and Sitophilus oryzae (Coleoptera: Curculionidae) using refuge and flight traps baited with synthetic pheromone and cracked wheat

Flight traps with open vertical baffles and refuge traps in the form of rectangular cardboard boxes were used to catch Sitophilus zeamais and S. oryzae in Kenya. Traps baited with the aggregation pheromone (Sitophilure), and for the first time traps baited with pheromone and food bait (cracked wheat), were field tested. Both traps types were effective in capturing Sitophilus spp and gave higher weevil catch when baited with pheromone and cracked wheat combined than with pheromone or cracked wheat alone. The combination of pheromone and cracked wheat had an additive effect on trap catch and not a synergistic effect as reported in earlier laboratory trials. Different pheromone loadings of 0.5, 1 and 2 mg were tested. The catch of S. zeamais in flight traps rose significantly with increasing dosage. For refuge traps, the same effect was observed although the difference between 1 mg and 2 mg was not statistically significant. The trend was for increasing S. oryzae catch with dosage, although total catches were very much lower than those for S. zeamais, and differences did not prove statistically significant. Traps placed on the floor near infested maize cribs captured significantly more Sitophilus spp than those actually placed in the cribs. Adult Sitophilus captured were sexed and in both flight and refuge traps the sex ratio was biased in favour of females even though the sex ratio of weevils from infested maize cobs, which were the source of the captured weevils, was approximately even.     

Radio frequency heating against Sitophilus zeamais Motschulsky in white maize

Radio frequency treatments were evaluated for the control of Sitophilus zeamais Motschulsky in white maize, and their effects on physiological and biochemical properties were evaluated. A 12 kW, 27.12 MHz radio frequency machine was used with an electrode gap of 20 cm; batches of 10 and 20 kg of white maize (11.8% moisture content, w.b.) were treated. Radio frequency heating treatments at 50 °C for 3 min or 60 °C in white maize were effective to achieve 100% mortality of Sitophilus zeamais 4th instar larvae. Significant changes were observed in the moisture content, water activity and color in the corn kernels after the treatments (P < 0.05); however, they were within the range established by the Mexican Standard. As an advantage, the viability and germination of the grain were not affected by the treatments (P > 0.05). Radio frequency has potential to be a postharvest treatment against this pest without damage to white maize.     

Is flint corn naturally resistant to Sitophilus zeamais infestation?

Sitophilus zeamais (maize weevil) is one of the most destructive pests of maize stored in tropical and subtropical regions. This study determined the resistance of flint corn and dent corn to infestation by S. zeamais (Motschulsky), the maize weevil. Improved King Philip hybrid flint corn and Fontanelle 6T-510 hybrid dent corn were used in this experiment. Two temperature conditions (10 °C and 27 °C) and two storage times (15 days and 30 days) were used. Results showed that flint corn was more resistant to insect damage than dent corn at 27 °C and 30 day storage time. After 30 days storage time and 27 °C death rate was significantly higher in flint corn (R² = 0.945) compared to (R² = 0.634) in dent corn. Damaged seed was 10% higher in dent corn then in flint corn at 27 °C and 30 days. However, no significant difference was observed for seed weight loss between flint corn and dent corn at the same storage conditions. Both dent and flint corn were extensively cultivated in developing countries It appears that storage of flint corn may be one promising solution to reducing corn damage infestation problems in the tropics and in developing countries, but more research is needed.     

三大粮种对玉米象成虫易感性研究

在28±1℃和70±5%RH的条件下,研究在培养箱中进行,测定三种储粮(小麦、稻谷和玉米)对玉米象的易感性。实验采用完全随机设计(CRD),设置三次重复。测定F1子代数,成虫存活时间,损失量和产生粉末量。不同的粮种表现出不同程度的对玉米象的易感性。对于F1子代数,稻谷被认为是最具抗性的,玉米是中度抗性的,小麦被认为对玉米象最敏感。然而,玉米象在玉米中的寿命最长,其次是小麦,稻谷中玉米象寿命最短。种子损失量、产粉量和种子含水量与玉米象成虫寿命在三大粮种趋势相似。研究单头玉米象成虫虫态阶段的危害损失模型,对于制定综合治理防治策略,最大限度地减少种子在储藏中的产后损失,特别是对于农户储粮来说具有重要的意义。     

99种植物提取物对玉米象的生物活性测定

为发现新的植物源储粮害虫防控剂,以玉米象(Sitophilus zeamais)为试虫,采用饲料混药法,对50科99种植物样品进行了室内活性筛选.结果表明,在0.013 g DW/g小麦的剂量处理下,百部(Stemona sessilifolia)等24种植物提取物表现出较好的毒杀活性和种群抑制作用,15 d的死亡率或64d的种群抑制率高于80％,其中栓翅卫矛(Euonymus phellomanus)、使君子(Quisqualis indica)、射干(Belamcanda chinensis)和黄芩(Scutellaria baicalensis)的种群抑制率均高达100％;天名精(Carpesium abrotanoides)、百部、狼毒、使君子和栓翅卫矛等5种植物提取物对玉米象还具有一定的触杀作用.测定结果初步表明,天名精、使君子、百部、狼毒、射干、黄芩和栓翅卫矛等7种植物有进一步研究价值.