Laboratory evaluation of toxicity of selected insecticides against egg and larval stages of cotton pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae)

Background The cryptic nature of pink bollworm Pectinophora gossypiella(Saunders)larvae enables its reduced vul-nerability to insecticidal control.Further,the development of resistance against Bacillus thuringiensis(Bt)toxins posed a serious threat to transgenic cotton cultivation.This necessitated determining the critical timing of spray applications on the control effectiveness.This study assessed the influence of egg age(freshly laid vs.three-day-old)and the loca-tion of larvae(directly exposed to the insecticide residues on the boll rind vs.burrowed inside the bolls)on insecticide control efficacy.Results The results revealed a significant decrease in the ovicidal activity of tested insecticides with an increase in the age of eggs from one day old to three days old(paired t-test,P<0.05).The larvae directly exposed to the insec-ticide residues on the boll rind were more susceptible(>80%mortality)than the larvae exposed after they had bur-rowed inside the bolls(<49%mortality).The inhibitory effects of tested insecticides on developmental biology were more pronounced in the experiment on pre-larval release insecticide treatment compared with insecticide treatment given post-larval release and entry inside the bolls.Conclusion Egg age influences the insecticide susceptibility,as does the larval location,directly exposed vs bur-rowed inside the bolls.Older eggs and the larvae that had burrowed inside the green bolls of cotton were relatively less susceptible to the insecticide treatments.The toxic effects of insecticides on egg and larval stages were primar-ily ephemeral.These findings are significant for devising a comprehensive strategy for pink bollworm management on a sustainable basis.

Evaluation of the Efficacy of an Aloe barbadensis Based Biological Insecticide against Pests of Abelmochus esculentus for Promoting Ecological Agriculture (Far-North, Cameroon)

Chemical insecticides have been considered as a means to combat crop pests. Although their effectiveness is evident, their impact on the environment is increasingly being discussed. The aim of this study is to determine the agro-ecological potential of a biological insecticide (C25H32O12) based on Aloe barbadensis in a Sahelian context. For this purpose, a completely randomized block experimental design with 3 replications and 4 treatments was set up to experiment with Aloe barbadensis as a bioinsecticide against pests of Abelmoschus esculentus. However, data were collected using an observation and parameter monitoring grid. This includes the cultivation of Abelmoschus esculentus, soil preparation, seeding and watering, plot labeling, preparation of the bioinsecticide (selection and preparation of raw materials, grinding of Aloe barbadensis miller and extraction of the crude bioinsecticide, quantification of treatment doses and dilution, and obtaining the formulated bioinsecticide), plant watering, plant treatment, and finally parameter monitoring. The results obtained reveal that the level of damage is significantly high in the control treatment T0 (63%) compared to the other treatments, with 29% for treatment T1, 7% for T2, and 1% for T3, implying a strong action capability of this insecticide against pests of Abelmoschus esculentus. Therefore, it can be concluded that for a normal growing season of Abelmoschus esculentus, this biological insecticide should be sprayed 12 times. Furthermore, this biological insecticide is unique in that it does not inflict any gastric toxicity on the pests, which gives it the characteristic of being a repellent. It is a biological insecticide whose efficacy period has been tested, with a minimum duration of 21 days. In conclusion, this formulated bioinsecticide based on Aloe barbadensis demonstrates significant efficacy against pests of Abelmoschus esculentus. In the future, we will consider experimenting with its effectiveness against pests of other plants.

The Entomological Efficacy of Piperonyl Butoxide (PBO) Combined with a Pyrethroid in Insecticide-Treated Nets for Malaria Prevention: A Village-Based Cohort Study Prior to Large-Scale Deployment of New Generation Mosquito Nets in Burkina Faso

The efficacy of insecticide-treated nets (ITNs) is increasingly compromised by the prevalence of malaria vectors resistant to pyrethroids. In response to this issue, a new generation of ITNs has been developed that incorporate synergistic components, such as piperonyl butoxide (PBO). The purpose of this study is to provide entomological evidence for the efficacy of a PBO-based ITN brand at the village level, serving as a basis for decision-making before large-scale net deployment. During the high malaria transmission period, ITNs were distributed in each group and vector sampling was conducted biweekly in selected households. Bionomic data were collected to assess the resistance of wild An. gambiae populations to various chemical insecticides. There was a significant disparity in total An. gambiae sl. collected between the ITN arms, the intervention arm (ITN arms), and the control arm (P = 0.003). An. coluzzi was identified as the predominant species in the study area, as confirmed by PCR analysis. Analysis of the blood-feeding inhibition rate revealed that 100% permethrin + PBO ITN exhibited significantly greater inhibition than 66.81% permethrin only ITN. According to the log-time probit regression analysis, permethrin exhibited a knockdown time of 256 min without synergists, while it decreased to 139 min (P = 0.001) when pre-exposed to PBO. The evidence from this trial supports the use of PBO ITNs over standard ITNs for pyrethroids to combat pyrethroid resistance and improve protection against malaria for both individuals and communities, particularly in areas with high pyrethroid resistance.

Insecticide resistance status of Aedes aegypti and Aedes albopictus in Malaysia(2010 to 2022):A review

This review aimed to determine the prevalence of the insecticide resistance status of the field-collected Aedes(Ae.)aegypti and Ae.albopictus in Malaysia from 2010 to 2022 towards carbamates,organochlorines,organophosphates and pyrethroids.Biological and environmental controls were summarized with an emphasis on the mosquito vector control strategies in Malaysia.The information in this review was extracted from several databases such as PubMed(MEDLINE),Science Direct and Scopus by using keywords including“insecticide resistance”,“carbamate resistance”,“organochlorine resistance”,“organophosphate resistance”,“pyrethroid resistance”,“Aedes”and“Malaysia”,between January 2022 and December 2022.Distribution of resistant Ae.aegypti and Ae.albopictus in Malaysia was mapped using QGIS software.Insecticide resistance in both Ae.aegypti and Ae.albopictus is widespread in Malaysia,although the rates vary by states.The most notable was the steep increase in permethrin resistance of Ae.aegypti in Selangor,Malaysia,over the past decade.Ae.albopictus also displayed moderate resistance to permethrin,though not as widespread as Ae.aegypti in Selangor,but showed sign of resistance in Sarawak,East Malaysia.Resistance towards four main classes of insecticides have been widely documented in Malaysia.The extensive resistance towards permethrin in Malaysia which is one of the current insecticides used in Malaysia suggested that policies supporting the widespread use of permethrin fogging needs further evaluation.

Risk of control failure to insecticides malathion,profenophos+cypermethrin mixture,and fipronil in boll weevil(Coleoptera:Curculionidae)populations from Bahia,Brazil

Background To control the boll weevil Anthonomus grandis grandis(Coleoptera:Curculionidae),a key pest of cotton in the Americas,insecticides have been intensively used to manage their populations,increasing selection pressure for resistant populations.Thus,this study aimed to detect insecticide resistance and assess insecticide control failure likelihood of boll weevil populations exposed to malathion,profenophos+cypermethrin,and fipronil insecticides.Results Twelve populations of the boll weevil were collected from commercial cotton fileds of the state of Bahia,northeastern Brazil.These populations were exposed to malathion,profenophos+cypermethrin mixture,and fipronil,at their respective maximum label dose for field applications.Three replicates of 10 adult beetles were exposed to the insecticides and mortality was recorded after 24 h treatment.The control failure likelihood was determined after 48 h.Highest median lethal times(LT_(50))were observed for malathion and the profenophos+cypermethrin mixture.Resistance to at least one insecticide was detected in 11 populations;three populations were resistant to malathion and profenophos+cypermethrin;seven were resistant to all insecticides tested.The resistance levels were low(<10-fold)for the three insecticides.Among 12 populations tested,58%of them exhibited significant risk of control failure for the insecticides malathion and profenophos+cypermethrin.The insecticide fipronil was efficient for the control of the boll weevil in 83%of the populations.Conclusions The results confirm the significant risk of insecticide control failure in the boll weevil populations to the main compounds used in the region.Thus,proper insecticide resistance management plans are necessary for the boll weevil in the region,particularly for malathion and profenophos+cypermethrin insecticides.

Analysis of Changes in Insecticide Consumption at Home and Abroad in Recent 30 Years

The paper analyzes the changes in insecticide consumption and the proportion of insecticides in pesticides in the world and several typical countries in the past 30 years,in order to provide a reference for scientific treatment of pesticide and further implementation of China s"double reduction"policy.

Situational Analysis of Malaria Control Following the 2021 Distribution of Long Lasting Insecticide-Treated Bed Nets in the Tiko Health District, South West Region, Cameroon

Malaria is still a major public health concern in Cameroon as more than 20 million people are at risk of the disease. Despite the government’s effort to scale up the distribution of long lasting insecticide-treated bed nets (LLINs), full ownership and optimal use is still limited. In 2021, over a million LLINs were made available for distribution in the South West Region. However, the current situation of malaria has not yet been ascertained following the 2021 mass distribution campaign (MDC). Therefore, the aim of this study was to determine LLIN ownership, coverage, usage and the prevalence of malaria following the 2021 MDC in the Tiko Health District (THD), South West Region of Cameroon. A cross-sectional study was carried from May 1 to 27, 2022 in which a multi-stage sampling technique was used to enroll eligible participants. Data were collected from household heads using questionnaires and capillary blood samples collected from consented household members were used to test for malaria. Data were analyzed using SPSS version 25 at 0.05 significance level. From the 150 households surveyed, 96 (64.0%) owned a mosquito net before the recent MDC. There was an overall significant increase (p p = 0.644) in LLINs ownership between areas where door-to-door (79.5%) and fixed “Hit and Run” (75.8%) strategies were used in the distribution of LLINs in THD. The prevalence of malaria was 10.2%. The regular use of LLINs was significantly associated (p = 0.007) with low malaria prevalence. The 2021 MDC had an impact on malaria prevalence in those who properly used them.

Improving the Use of Insecticide-Treated Nets among Children under Five Years Old in Benin, West Africa

Background: In Benin, malaria represents the first cause of consultation and hospitalization (48% for children under 5 years old) in health units. It also accounts for 23.1% of deaths recorded in health facilities (MoH, 2019). Between the two main components of vector control adopted by Benin government, the mass distribution campaigns of Insecticide-Treated Nets (ITNs) remained the only proven cost-effective way to rapidly achieve high and equitable coverage (WHO, 2017). After the fourth mass distribution campaign conducted in 2017, the Demographic and Health Survey (DHS) data indicated that the percentage of children who slept under an ITN has increased from 20% in 2006 to 70% in 2011-2012 and to 76% in 2017-2018 while the incidence of malaria (tested positive) is increasing rapidly among children under 5 years old, growing from 36.5% in 2009 to 28.8% in 2012 and then to 51.4% in 2019. This study aims to understand this contrast by identifying the origin of the increase in ITN use over time among children under five years old and the factors which determine this use. Methods: Data from the Demographic and Health Survey (DHS) conducted in Benin respectively in 2006 and in 20018 were used during the analysis, which covered 13,445 children under five years old from 2006 DHS and 12,255 children from 2017-2018 DHS. Firstly, the data were analyzed using decomposition method to highlight the origin of the increase of ITN use over time among children under five years old. Secondly, the chi-square test analysis estimated the association between ITN use and some characteristics (wealth index, maternal or caregiver education level and child age). Finally, the logistic regression model was used to identify the main factors, which influence the net use over the study period. Results: This study shows that the improvement of basic conditions is the main origin of behavior change in the use of ITNs among children under five years old. This improvement of the basic conditions consists of making ITNs available in households and informing household members about the benefits of ITN use. So, the free ITN distribution campaigns, routine distribution, awareness campaigns about the benefits of ITN use are the strategies, which increase the household capacities and knowledge, allowing household members to make their children sleep under net. The analysis also shows that region of residence, wealth index of household, household size, religion, and child age continue to determine the ITN use among children under age 5 years old and MNCP will integrate the factors in malaria prevention strategies in order to achieve universal use of ITNs. Conclusions: Although, sleeping under ITN behavior has indeed spread among children under 5 years old, policymakers and other stakeholders should design strategies to maintain and improve the current level of ITN use to reach the collective protection threshold (80% according to WHO). Therefore, to address the challenges of universal use of ITN, the study recommends expanding the routine distribution system to private sector health centers;discussing issues related to health service utilization (particularly ITN use) within a consultation framework at the communal level. In addition, collecting qualitative and quantitative data in the Oueme region will allow better understanding of all aspects of the ITN use gap among children under 5 years.

基于Bt毒素的杀虫蛋白理性设计与创新应用策略

Bt毒素是源于苏云金芽孢杆菌(Bacillusthuringiensis)的具有特殊杀虫功能的大分子蛋白,其制剂和转基因作物已广泛用于害虫防治,产生了巨大的经济和社会生态效益。围绕Bt毒素挖掘和提升其应用价值是持续研究的热点,特别是随着Bt毒素结构功能和作用机制日趋明晰,为其功能修饰和创新应用创造了条件,相关研究蓬勃发展,成效显著。大量研究表明,采用定点突变、结构域替换或融合以及抗独特型抗体模拟等策略,是理性设计活性更高、稳定性更强、杀虫谱更广、非靶标生物安全性更高甚至是可用于害虫抗药性治理的有别于母体Bt毒素的突变体、结构杂合体乃至功能效应物抗体等新型杀虫蛋白的有效手段;此外,采用催化毒素活化、驱动毒素靶向受体结合、促进毒素表达以及同源或异源杀虫材料复配或共表达的协同促效等创新增效策略,也是助推Bt毒素应用价值的重要手段。本文总结了Bt毒素结构功能和作用机制,梳理了基于Bt毒素功能修饰的突变体、结构杂合体以及功能效应物抗体等新型杀虫蛋白理性设计和基于Bt毒素功能增效的创新应用策略等相关研究进展,并结合作者团队在模拟Bt毒素杀虫功能效应物抗体靶向设计研发方面的最新成果,探讨了基于Bt毒素的杀虫蛋白理性设计与创新应用策略未来发展动向及潜在可行捷径,为相关研究提供较为全面的最新有价值的文献资料和启发思路。

变温条件下小菜蛾对不同温度效应杀虫剂敏感性的变化

为了明确变温环境条件对小菜蛾药剂敏感性的影响,本研究采用食料浸渍法比较了环境温度变化下四氯虫酰胺(正温度效应杀虫剂)和溴虫腈(无温度效应杀虫剂)处理对小菜蛾药剂敏感性的影响;模拟田间变温条件,研究这两种杀虫剂不同施药时间对小菜蛾毒力的影响。结果表明,四氯虫酰胺施药前,15、25、35℃预处理24 h,其35℃下温度系数分别为+28.53、+25.84和+18.77,均表现为显著的正温度效应,但温度系数随预处理温度上升而降低。溴虫腈在15℃预处理24 h,对小菜蛾表现为弱正温度效应,25℃和35℃下预处理均无温度效应。表明药剂处理前温度变化会影响杀虫剂的温度效应。在模拟田间变温的情况下,四氯虫酰胺经过高温预适应后于16:00(30℃)对小菜蛾的毒力最高(0.41 mg/L),显著高于清晨6:00(22℃)持续低温时的毒力(32.33 mg/L),毒力差异倍数高达78.85倍。一天中无温度效应杀虫剂溴虫腈的毒力受温度变化的影响较小。本研究为利用杀虫剂的温度效应指导田间高效防治小菜蛾提供了依据。

安徽庐江褐飞虱的抗药性监测及不同杀虫剂对其田间防效评价

近年来,褐飞虱田间种群已对多种药剂产生了抗性,为筛选可防控褐飞虱的高效药剂,2020年-2022年采用稻茎浸渍法连续测定了安徽省庐江县褐飞虱种群对三氟苯嘧啶、呋虫胺、烯啶虫胺、吡蚜酮、氟啶虫胺腈等5种药剂的抗性水平,并在庐江县开展了不同药剂对褐飞虱田间防效试验。室内抗性监测结果表明,2020年-2022年褐飞虱种群对吡蚜酮始终处于高水平抗性(抗性倍数104.6~154.4倍),对呋虫胺的抗性从中等水平上升至高水平(抗性倍数77.7~157.2倍),对氟啶虫胺腈、烯啶虫胺处于中等水平抗性(氟啶虫胺腈抗性倍数21.3~64.5倍、烯啶虫胺抗性倍数14.6~22.6倍),对三氟苯嘧啶处于敏感状态。庐江单季稻试验田田间试验结果表明,在推荐高剂量下,20%三氟苯嘧啶WG、10%异唑虫嘧啶SC等介离子杀虫剂对褐飞虱速效性和持效性表现较好,除了药后1 d 20%三氟苯嘧啶WG防效为74.72%外,2种药剂3~14 d的防效都在80%以上;50%烯啶虫胺SG、22%氟啶虫胺腈SC防效次之,药后1 d防效在67.63%~71.61%,药后3 d至7 d防效有所提高,为77.16%~84.13%,而药后14 d防效降为71.52%~75.77%;50%吡蚜酮WG药后1~7 d防效均在约70%,而药后14 d下降为62.12%;20%氟啶虫酰胺SC、20%呋虫胺WG、10%醚菊酯SC速效性和持效性都表现较差,药后1~14 d防治效果都在80%以下。结合室内抗药性监测和田间防治效果,说明三氟苯嘧啶等介离子类杀虫药剂作为新型杀虫剂品种,可与新烟碱类、吡蚜酮及其混剂交替轮换使用,用于抗药性褐飞虱的治理。

2022年度宿州市德国小蠊对6种常用杀虫剂的抗药性调查

目的了解宿州市建成区德国小蠊对常用卫生杀虫剂的抗药性情况,为科学开展城区蜚蠊防治提供数据支撑。方法2022年4—6月,在宿州市埇桥区中小餐饮单位、宾馆及农贸集市等环境采捕德国小蠊野生种群,用药膜法对常用6种杀虫剂进行生物学抗药性测定。采用Excel 2024和SPSS 230软件处理和分析检测数据。结果宿州市埇桥区德国小蠊对胺菊酯、高效氯氰菊酯、氯菊酯、顺式氯氰菊酯、溴氰菊酯及敌敌畏6种杀虫剂的24 h死亡率分别为4600%、10000%、9398%、9286%、9495%和9250%,半数击倒时间KT50分别为4492、1821、2485、1941、2051、3205min。依据死亡率抗性判断标准,宿州市德国小蠊对胺菊酯属抗性种群,对氯菊酯、顺式氯氰菊酯、溴氰菊酯及敌敌畏属可能抗性种群,对高效氯氰菊酯属敏感种群。依据击倒抗药性判定标准,宿州市埇桥区德国小蠊野生种群对高效氯氰菊酯产生了低水平抗性(443倍);对顺式氯氰菊酯、氯菊酯、溴氰菊酯和敌敌畏为中等水平抗药性,抗性倍数依次为523倍、538倍、525倍和830倍;对胺菊酯为高水平抗药性(1294倍)。结论宿州市埇桥区德国小蠊野生种群对常用杀虫剂产生了不同程度的抗药性,在防治工作中,应加强抗药性监测,利用监测数据指导杀虫剂的选择和使用,以延缓其抗药性的发展。

杀虫灯诱杀亚洲玉米螟和草地贪夜蛾的距离与性比研究

为明确杀虫灯对亚洲玉米螟Ostrinia furnacalis和草地贪夜蛾Spodoptera frugiperda的杀虫效果,分别对2种害虫人工饲养的成虫进行颜色标记后,在距频振式太阳能杀虫灯不同距离处释放,根据杀虫灯下回收数量确定有效防控距离。同时对高空测报灯和自动虫情测报灯2种不同光源测报灯诱集到的2种害虫的性比进行分析。结果表明,在距杀虫灯15~45 m内,亚洲玉米螟的回收率随着距离的增加呈上升趋势,距灯45 m的回收率最高,为4.95%,在距离增加到60 m时,回收率显著下降。草地贪夜蛾在距灯30 m处的回收率为6.08%,随着离灯距离的增加,雌、雄蛾回收率均呈下降趋势,且回收的雌蛾比例减少。杀虫灯在1.2 m高度时对亚洲玉米螟的回收率高于1.5 m和1.8 m,3个高度雄蛾的回收率均高于雌蛾,随着高度增加,回收率下降,雌蛾的回收比例也呈下降趋势。高空测报灯和自动虫情测报灯捕获的2种害虫雌雄性比均低于0.45∶1,2种害虫的趋光性均存在雄性偏好。

石家庄市家蝇对常用杀虫剂的抗性调查

目的调查石家庄市家蝇对常用杀虫剂的抗药性,为科学使用杀虫剂提供依据。方法采用微量点滴法进行抗药性测定。结果家蝇对甲基吡恶磷、氯菊酯、联苯菊酯、高效氯氟氰菊酯的LD_(50)分别为0.3835、0.3297、0.1786、0.0436μg/♀;家蝇对上述药剂的抗性倍数分别为31.69、38.34、3.78、14.06。结论需要持续开展家蝇抗药性监测,在环境治理的基础上选择低抗性的杀虫剂。

不同温度条件下3种卫生杀虫剂杀灭蚊幼效果研究

目的了解不同温度条件对3种卫生杀虫剂杀灭蚊幼虫效果的影响。方法采用浸渍法,将幼虫置于一定浓度杀虫剂药液中,观察不同温度下蚊幼虫的死亡情况,分析温度对杀虫时间的影响规律。结果温度对3种杀虫剂杀灭蚊幼虫效果影响不同。高效氯氰菊酯在25、30℃时杀灭蚊幼虫所需时间相对较长,约6.5 h,其他温度条件下杀灭蚊幼虫时间缩短,40℃时仅需0.5 h。倍硫磷和残杀威均随着温度的升高,杀灭蚊幼虫所需时间缩短,最短仅需0.5 h。结论不同温度条件对不同杀虫剂杀灭蚊幼虫时间的影响规律不同。这一研究结论可用于蚊媒传染病疫情防控时选择有效杀虫剂的快速筛选研究。

2022年上海市黄浦区蜚蠊密度及德国小蠊抗药性监测分析

目的了解上海市黄浦区不同生境蜚蠊密度和种群构成,以及德国小蠊对3种常用杀虫剂的抗药性情况,为有效防治德国小蠊侵害提供科学依据。方法采用粘捕法开展蜚蠊监测,采用药膜法开展德国小蠊抗药性实验测定。结果黄浦区2022年1—12月共布放粘蟑纸1200张,有效粘蟑纸1139张,阳性49张,粘捕率为4.30%,捕获蜚蠊253只,总密度为0.22只/张夜,其中德国小蠊248只,黑胸大蠊3只,美洲大蠊2只。监测结果显示不同生态环境的蜚蠊密度有明显差异,农贸市场密度最高,其次为中小餐饮机构。抗药性结果显示高效氯氰菊酯、乙酰甲胺磷、残杀威对黄浦区德国小蠊现场品系的半数击倒时间(KT50)分别为213.51、155.36、96.02 min,德国小蠊对3种杀虫剂的抗性倍数分别是90.09、3.84、8.45。结论德国小蠊对常用杀虫剂产生了不同程度的抗性,是黄浦区蜚蠊防治的重点。

杀虫(螨)剂协同抗药性捕食螨对柑橘全爪螨的防治研究

通过研究田间杀虫(螨)剂协同抗药性捕食螨(巴氏新小绥螨,Neoseiulus barkeri Hughes)对柑橘全爪螨(Panonychus citri)的防治效果,为田间捕食螨和化学药剂的使用,达到农药减量、防效增效、时效增长提供理论指导。以高效氯氟氰菊酯、阿维菌素、黎芦碱、螺虫乙酯、联苯肼酯、啶虫脒、吡虫啉和矿物油8种田间常用杀虫(螨)剂为试验药剂,配合抗药性捕食螨的释放,跟踪调查田间抗药性巴氏新小绥螨、柑橘全爪螨的种群数量,并统计分析不同防控措施下柑橘全爪螨的防治效果。结果表明:不同防控措施下,捕食螨种群数量增长较快的为单一使用抗药性捕食螨和矿物油+抗药性捕食螨处理,其次为阿维菌素+抗药性捕食螨、黎芦碱+抗药性捕食螨和联苯肼酯+抗药性捕食螨处理;柑橘全爪螨种群数量较低的为阿维菌素+抗药性捕食螨、黎芦碱+抗药性捕食螨、螺虫乙酯+抗药性捕食螨和联苯肼酯+抗药性捕食螨4个处理。防治效果显示,黎芦碱+抗药性捕食螨、阿维菌素+抗药性捕食螨、联苯肼酯+抗药性捕食螨和螺虫乙酯+抗药性捕食螨4个处理的防治效果较好,其中悬挂捕食螨第35 d和第42 d黎芦碱+抗药性捕食螨处理的防治效果均在90.61%以上,阿维菌素+抗药性捕食螨和联苯肼酯+抗药性捕食螨处理的防治效果均在86.32%以上。调查结果还表明,黎芦碱+抗药性捕食螨和阿维菌素+抗药性捕食螨处理从悬挂捕食螨第14 d开始一直具有较好的防治效果,尤其以黎芦碱+抗药性捕食螨处理防治效果好、防控持效性长。综上,使用阿维菌素、黎芦碱、螺虫乙酯和联苯肼酯等杀虫(螨)剂协同抗药性捕食螨可以有效防控柑橘全爪螨,可以在大田推广应用。

2020—2023年宝鸡市蝇类生态学监测及家蝇抗药性调查

目的调查分析宝鸡市蝇类种群密度、生境分布、季节消长规律及家蝇抗药性现状,为蝇类防控提供依据。方法蝇类监测采用笼诱法,家蝇抗药性测定采用点滴法。结果2020—2023年共捕获3科2属6种7178只成蝇,平均密度为1.43只/笼;全年蝇活动高峰期为6—8月,8月密度最高,为2.62只/笼;宝鸡市优势蝇种为家蝇、麻蝇,占比分别为58.30%、12.13%。农贸市场蝇密度最高(2.03只/笼),其次为餐饮外环境(1.49只/笼)、居民区(1.12只/笼),绿化带密度最低(1.09只/笼);4种生境中家蝇占比较高,且餐饮外环境、居民区家蝇占比均达60%以上。家蝇对残杀威、敌敌畏、溴氰菊酯、高效氯氰菊酯的抗性倍数分别为136.37、54.25、146.03、38.44倍。结论6—8月是宝鸡市成蝇防控重点月份,农贸市场、餐饮外环境和居民区为重点防控区域,应在这些区域采取保持环境卫生、加强孳生地治理、完善防蝇设施等综合防制措施,以便有效控制蝇类密度水平,减少对人类的危害。

5种植物源杀虫剂对美国白蛾的田间药效评价

[目的]明确5种植物源杀虫剂对美国白蛾的田间防效及最适药剂用量。[方法]采用喷雾处理对美国白蛾盛发前期三龄幼虫进行田间防效试验。[结果]1.2%烟碱·苦参碱乳油6、8、12 mg/L对美国白蛾的防治效果最好,药后3 d为87.83%~92.61%,药后14 d防效达到最高,为95.85%~97.99%。1.5%苦参碱可溶液剂、0.5%虫菊·苦参碱可溶液剂药后14 d防效达到最佳,分别为84.62%~95.13%、89.14%~91.93%。[结论]1.2%烟碱·苦参碱乳油推荐有效成分含量6~12 mg/L对美国白蛾盛发前期三龄幼虫的防治效果最好,可大面积推广使用。0.5%虫菊·苦参碱可溶液剂和1.5%苦参碱可溶液剂在防治时也可进行交替使用,对杨树生长、有益天敌种类和数量无不良影响。

药食同源植物杀虫剂制备及其防治效果

以常见药食同源植物辣椒和花椒的果实、大蒜鳞茎和洋葱鳞叶为试验材料,与有效微生物群(Effective microorganisms,EM)菌液混合发酵制作杀虫剂,使用液相色谱分析其杀虫成分含量;结合室内和田间试验,筛选高效生物杀虫剂并评估其杀虫效果。结果表明,花椒125g,辣椒25g,大蒜125g,洋葱250g混合发酵30d,稀释30倍液得到最佳杀虫活性物A;施药后第6天对桃蚜防治效果最佳,虫口减退率为92.38%。田间试验结果表明,杀虫剂A在施药后第5天对桃蚜防治效果最佳,校正防效为78.05%;与市售植物源杀虫剂比较,杀虫剂A持效时间较长,在施药后第6天虫口减退率为70.29%,校正防效为82.95%,杀虫效果显著高于0.3%印楝素乳油和1.3%苦参碱水剂。研究得到一种高效植物源杀虫剂A,为药食同源植物制备杀虫剂研发及其在生产中推广应用提供试验依据和有效方法。