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1.
West Nile virus (WNV) invaded New York in 1999 and rapidly swept across the North American continent to the West Coast, north into southern Canada and south into Latin America, with minimal genetic change. Regional epidemics in equines and humans typically have included a year of viral introduction with minimal activity, successful overwintering, explosive amplification to epidemic levels the following year and then rapid subsidence. Overwintering possibly included long-term mosquito or avian infections, continued low-level transmission at southern latitudes and dispersal by south-north migrants. Explosive amplification has been associated with infections in several corvid species and other urban birds that produce elevated viremias capable of efficiently infecting even moderately susceptible mosquito species. Intervention has included mass vaccination of equines, and proactive and reactive mosquito control. Proactive mosquito control in areas with established infrastructure has been successful in reducing case incidence.  相似文献   

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蚊虫是登革热、疟疾等疾病病原的重要传播媒介,因其防控的艰巨性给全球人类健康造成巨大威胁。传统蚊虫防控主要采用化学防控策略,化学药剂造成的环境污染以及蚊虫对化学药剂抗性的产生,亟需探索新的蚊虫防控策略。微生物和基因编辑是很有前景的2种蚊虫防控新策略,两者都可以通过抑制或者修饰蚊虫种群来达到蚊媒病原防控的目的。本文将详细阐述上述2种蚊媒病原防控策略,并基于现有的研究进展阐述其作用机理。  相似文献   

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Abstract

During recent years, blister beetles have gained importance in species diversity and as pests of food crops in West Africa. Among the 97 species reported, Psalydolytta fusca Oliv, and P. vestita Duf. are economically important beetle species. Beetle abundance is generally associated with the flowering of crops in a region. Regular intensive weeding and early crop establishment are recommended for pest management in food crops. Global pest control strategies are discussed in the context of subsistence agriculture.  相似文献   

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8种杀虫剂对花生蛴螬的田间防效及安全性评价   总被引:4,自引:0,他引:4  
为科学有效控制花生田蛴螬为害,通过田间小区试验比较了吡虫啉十辛硫磷颗粒剂、3%辛硫磷颗粒剂、30%毒死蜱微囊悬浮剂、60%吡虫啉悬浮种衣剂、60%吡虫啉悬浮种衣剂+5%氯虫苯甲酰胺悬浮剂、6%毒·辛颗粒剂、5%二嗪磷颗粒剂、苏云金杆菌(Bt)制剂8种杀虫剂对花生蛴螬的防治效果及对花生的安全性.结果表明:播种期施用的吡虫啉十辛硫磷颗粒剂(沟施)、3%辛硫磷颗粒剂(拌种)、30%毒死蜱微囊悬浮剂(拌种)、60%吡虫啉悬浮种衣剂、60%吡虫啉悬浮种衣剂+5%氯虫苯甲酰胺悬浮剂机械包衣对花生出苗率没有影响,以上5种药剂对蛴螬的防治效果与保果效果分别为62.5%~85.4%和45.4%~60.7%,显著高于开花下针期施用的6%毒·辛颗粒剂和5%二嗪磷颗粒剂;首次使用苏云金杆菌工程菌株3A-SU4灌根防治暗黑齿爪鳃金龟幼虫,防虫效果和保果效果分别为53.9%和31.2%,与6%毒·辛颗粒剂和5%二嗪磷颗粒剂药效相当.各处理对花生均有不同程度的增产效果,为2.4%~21%,其中30%毒死蜱微囊悬浮剂拌种增产效果最高.收获后采用气相色谱或高效液相色谱方法对土壤和花生中的农药残留进行检测,结果表明各药剂在花生荚果中的残留量均低于日本肯定列表和中国限量要求,可以在花生上安全使用.  相似文献   

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草地贪夜蛾Spodoptera frugiperda (J.E.Smith)是世界性重大农业迁飞害虫, 在我国已呈严重暴发态势, 对我国玉米等农作物生产安全构成严重威胁?农药防治是草地贪夜蛾应急防控中最有效的手段之一, 但是不合理的使用农药会对环境安全和施药人员带来潜在的风险?本文结合我国田间化学农药防治草地贪夜蛾的实践和效果, 评估了8种田间常用防治药剂的环境风险及其对施药人员的健康风险?推荐甲氨基阿维菌素苯甲酸盐?乙基多杀菌素?氯虫苯甲酰胺?虱螨脲作为草地贪夜蛾应急防控的首推农药, 甘蓝夜蛾核型多角体病毒作为首推生物药剂, 高效氯氟氰菊酯和乙酰甲胺磷须谨慎使用?本研究从农药应用风险角度提出了具体的草地贪夜蛾合理用药建议, 以期为草地贪夜蛾的有效安全防控提供科学依据?  相似文献   

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对西部农业开发与生态建设的关系、发展的生态平衡观、生态农业与农业现代化的关系、生态重建必须符合自然生态规律等几个科学问题,结合西部实际,从系统生态学、生态经济学等学科理论和思维出发,进行了论述。  相似文献   

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BACKGROUND

With no effective drugs or widely available vaccines, dengue control in Bangladesh is dependent on targeting the primary vector Aedes aegypti with insecticides and larval source management. Despite these interventions, the dengue burden is increasing in Bangladesh, and the country experienced its worst outbreak in 2019 with 101 354 hospitalized cases. This may be partially facilitated by the presence of intense insecticide resistance in vector populations. Here, we describe the intensity and mechanisms of resistance to insecticides commonly deployed against Ae. aegypti in Dhaka, Bangladesh.

RESULTS

Dhaka Ae. aegypti colonies exhibited high-intensity resistance to pyrethroids. Using CDC bottle assays, we recorded 2–24% mortality (recorded at 24 h) to permethrin and 48–94% mortality to deltamethrin, at 10× the diagnostic dose. Bioassays conducted using insecticide–synergist combinations suggested that metabolic mechanisms were contributing to pyrethroid resistance, specifically multi-function oxidases, esterases, and glutathione S-transferases. In addition, kdr alleles were detected, with a high frequency (78–98%) of homozygotes for the V1016G mutation. A large proportion (≤ 74%) of free-flying and resting mosquitoes from Dhaka colonies survived exposure to standard applications of pyrethroid aerosols in an experimental free-flight room. Although that exposure affected the immediate host-seeking behavior of Ae. aegypti, the effect was transient in surviving mosquitoes.

CONCLUSION

The intense resistance characterized in this study is likely compromising the operational effectiveness of pyrethroids against Ae. aegypti in Dhaka. Switching to alternative chemical classes may offer a medium-term solution, but ultimately a more sustainable and effective approach to controlling dengue vectors is required. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.  相似文献   

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BACKGROUND: Soil application of systemic neonicotinoid insecticides can provide opportunities for long‐term control of insect pests in vineyards, with minimal risk of pesticide drift or worker exposure. This study compared the effectiveness of neonicotinoid insecticides applied via irrigation injection on key early‐season and mid‐season insect pests of vineyards in the eastern United States. RESULTS: On vines trained to grow on drip irrigation, early‐season application of imidacloprid, clothianidin, thiamethoxam and dinotefuran provided high levels of control against the potato leafhopper, Empoasca fabae. Protection of vines against Japanese beetle, Popillia japonica, and grape berry moth, Paralobesia viteana, was also observed after mid‐season applications. Efficacy was poor in commercial vineyards when treatments were applied to the soil before irrigation or rain, indicating that vines must be grown with an irrigation system for efficient uptake of the insecticide. CONCLUSIONS: In drip‐irrigated vineyards, soil‐applied neonicotinoids can be used to provide long residual control of either early‐season or mid‐ to late‐season foliage pests of vineyards. This approach can reduce the dependence on foliar‐applied insecticides, with associated benefits for non‐target exposure to workers and natural enemies. Copyright © 2012 Society of Chemical Industry  相似文献   

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对目前中国主要蜜源作物上登记的农药品种进行了梳理,并采用现有的风险评估标准方法,对其中毒死蜱、吡虫啉等共61种杀虫剂对蜜蜂的风险进行了初级评估。结果表明:在58种喷雾施用的杀虫剂中,35种对蜜蜂的风险商值均大于1,风险为不可接受;其余23种的风险商值小于1,风险为可接受;所评估的6种土壤或种子处理内吸性杀虫剂中,5种对蜜蜂的风险商值大于1,风险为不可接受,仅氯虫苯甲酰胺的风险商值小于1,风险为可接受。但由于文中是以药剂在所登记作物上的单次最高施药剂量为暴露量进行的初级评估,并未考虑农药在花粉、花蜜中的降解及降雨引起的淋洗损耗,以及施药时间与作物花期之间的关系等影响因素,因而使得评估结果具有较大的保守性。研究结果一方面可为这些农药的合理使用和管理提供参考,另一方面提示了目前中国关于农药对蜜蜂的初级风险评估程序需进一步优化。  相似文献   

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在GIS技术的基础上,提出了一种空间模糊综合评价的方法来解决模糊数学在生态环境质量评价中所遇到的空间表达问题,并以吉林省西部为例,对区域生态环境质量评价中遇到的隶属度的空间化、权向量的确定等问题进行了深入研究。  相似文献   

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本研究通过室内外试验评估了12种苗前除草剂对红花的安全性和除草效果。盆栽试验表明,50%乙草胺EC有效剂量675~1 350 g/hm~2,33%二甲戊灵EC 495~990 g/hm~2,960 g/L精异丙甲草胺EC 675~1 350 g/hm~2,24%乙氧氟草醚EC 60~180 g/hm~2,30%吡氟酰草胺SC 54~162 g/hm~2,250 g/L噁草酮EC 270~540 g/hm~2,50%丙炔氟草胺WP 45~90 g/hm~2,对红花生长抑制相对较小,鲜重抑制率基本上低于20%。田间对上述除草剂及其混用的安全性进行了测定,结果表明,960 g/L精异丙甲草胺EC 900 g/hm~2+250 g/L噁草酮EC 450 g/hm~2对红花生长抑制较小,与对照差异不显著,其他除草剂单独使用或混配使用对红花苗前期生长均有一定的抑制作用,但对叶色、株型等无明显影响,整体药害程度较轻。调查表明,除草剂混配使用较除草剂单用对杂草控制作用更好。  相似文献   

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兰溪杨梅是农业农村部农产品地理标志产品, 随着大棚设施的普及, 以柏牡蛎蚧为主的介壳虫呈日益加重趋势。本研究在浙江兰溪大棚杨梅主产区调查了大棚和露天杨梅柏牡蛎蚧的发生规律, 并开展了化学防治试验。结果表明, 大棚与露天杨梅柏牡蛎蚧一年发生2代, 种群数量动态呈现双峰型。大棚杨梅柏牡蛎蚧发生高峰期为3月中旬至下旬, 相比于露天柏牡蛎蚧早一个半月左右。不同乡镇和不同栽培方式条件下杨梅柏牡蛎蚧虫口发生量均有显著差异, 4个乡镇街道大棚杨梅柏牡蛎蚧平均每叶虫量是露天的5倍之多, 其中马涧镇杨梅受害最为严重。药效试验结果表明, 20%螺虫·呋虫胺悬浮剂(SC) 2 000倍液药后15 d和30 d平均药效分别为90.5%和94.4%, 防治效果最好, 20%螺虫·呋虫胺SC 2 500倍液及3 000倍液、95%矿物油乳油(EC) 50倍液和20%松脂酸钠可溶性粉剂(SP) 200倍液30 d药效均在85%上, 显著优于65%噻嗪酮可湿性粉剂(WP) 2 500倍液。建议果农在杨梅柏牡蛎蚧卵孵化高峰期选择矿物油或松脂酸钠进行防治, 目前螺虫·呋虫胺还未在杨梅上登记, 待进一步测试并登记后, 可在实际生产上推广应用。  相似文献   

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杨小龙  杨俊  杨石有  张蕊  杨申 《植物保护》2024,50(4):356-361
为了筛选对石榴蓟马有效的防治药剂, 同时评价添加喷雾助剂对药剂的减量增效作用,本研究开展了12种杀虫剂对石榴蓟马的田间防效试验, 同时将450 g/L吡虫啉微乳剂常规用量减量10%、20% 后添加0.05%的有机硅Silwet 408、矿物油、芦荟精油助剂, 测定其对药液物理性能的影响及对石榴蓟马的田间防效, 评价喷雾助剂的减量增效作用。结果表明:12种杀虫剂对石榴蓟马具有较好的田间防效, 按照667 m2用量, 450 g/L吡虫啉微乳剂10 mL、60 g/L乙基多杀菌素悬浮剂30 mL、10%多杀霉素悬浮剂20 mL、240 g/L虫螨腈悬浮剂40 mL、25%噻虫嗪水分散粒剂30 mL对石榴蓟马防效较高, 可作为防治石榴蓟马的临时推荐药剂。添加3种喷雾助剂均能显著降低药液的表面张力、增大扩展直径并提高药液持留量, 提高药剂对石榴蓟马的防效。相对常规用量, 通过添加有机硅Silwet 408、矿物油助剂可使450 g/L吡虫啉微乳剂用量减量20%, 添加芦荟精油可使药剂减量10%。生产上可通过向450 g/L吡虫啉微乳剂中添加3种喷雾助剂来达到对石榴蓟马减量增效的作用。  相似文献   

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