Susceptibility breakpoint for cefquinome against Escherichia coli and Staphylococcus aureus from pigs

Cefquinome is the only fourth-generation cephalosporin used solely for veterinary applications.In this study,we established the wild-type cut-off (CO_(WT)) and pharmacokinetic/pharmacodynamic cut-off (CO_(PD)) of cefquinome against Escherichia coli and Staphylococcus aureus.A total of 210 E.coli and 160 S.aureus isolates were collected from pigs in Guangdong Province between 2014 and 2018.The minimum inhibitory concentrations (MICs) were determined using a microdilution broth method.MIC_(50) and MIC_(90) were 0.06 and 0.25μg m L~(–1) for E.coli and 0.5 and 1μg m L~(–1) for S.aureus,respectively.Statistical analysis and the ECOFFinder Program showed that the CO_(WT )for cefquinome against E.coli and S.aureus were0.125 and 2μg m L~(–1),respectively.The resistance rates were 11.9%for E.coli and 6.25%for S.aureus.Based on a5 000-subject Monte Carlo simulation,the CO_(PD) value for cefquinome against E.coil and S.aureus was 0.25μg m L~(–1) under the recommended dose (2 mg kg~(–1),twice a day for 3 days),confirming that infections caused by strains with MIC≤0.25μg m L~(–1) could be effectively treated.Following adjustment of the dosing regimen to 4.5 mg kg~(–1),effective treatment (90)was achieved for S.aureus infections with MIC_(90) 1μg m L~(–1).This susceptibility breakpoint determination is significant for resistant surveillance and cefquinome dosage guidance against E.coli and S.aureus in pigs.     

Insecticide resistance of the field populations of oriental armyworm,Mythimna separata (Walker) in Shaanxi and Shanxi provinces of China

Resistance of five field populations of Mythimna separata(Walker) collected from Shaanxi and Shanxi provinces of China to six different insecticides was evaluated by leaf dip method in the laboratory. The results showed that all populations were relatively sensitive to emamectin benzoate with a resistance ratio(RR) of 0.583–1.583 folds. All populations showed susceptible or low level resistance to chlorantraniliprole and beta-cypermethrin. Compared with a relatively susceptible strain of M. separata, the resistance level of the whole populations ranged from susceptible to moderate to chlorpyrifos and lambda-cyhalothrin, moderate to high to phoxim(RR=19.367–70.100) except for population from Sanyuan County(RR=2.567). Pair-wise correlation analysis among different insecticides indicated that chlorpyrifos has a significantly positive and significant correlation with emamectin benzoate. Chlorantraniliprole didn't have significant correlation with emamectin benzoate, chlorpyrifos and phoxim. Therefore, emamectin benzoate, chlorantraniliprole and beta-cypermethrin are recommended to control oriental armyworm. Meanwhile, to postpone the occurrence and development of insecticide resistance in Shaanxi and Shanxi provinces, alternative and rotational application of insecticides between chlorantraniliprole and emamectin benzoate or chlorpyrifos is necessary.     

3种杀虫剂对樱桃果蝇的田间防治效果

明确乙基多杀菌素悬浮剂、短稳杆菌悬浮剂和甲维盐水分散粒剂3种新型杀虫剂对樱桃果蝇的最佳使用剂量和防治效果,为生产应用提高科学依据.采用常规喷雾法进行试验.结果 表明,24、30和40 mg/L的60 g/L乙基多杀菌素悬浮剂,5.00、6.25和8.33 mg/L的5％甲维盐水分散粒剂,以及1.00×107、1.11×...     

化学防控玉米蛀穗害虫对减轻拟轮枝镰孢穗腐病及伏马毒素的作用

【背景】拟轮枝镰孢（Fusarium verticillioides）引起的穗腐病严重影响玉米产量和品质,其产生的伏马毒素威胁食品安全。亚洲玉米螟（Ostrinia furnacalis）和桃蛀螟（Conogethes punctiferalis）等穗期害虫危害可导致玉米严重减产,并加重玉米穗腐病的发生。【目的】评估2种杀虫剂（甲维盐和氯虫苯甲酰胺）、3种杀菌剂（氰烯菌酯、戊唑醇和苯醚甲环唑）对玉米穗期病虫害的防治效果以及对玉米产量和籽粒中伏马毒素含量的影响;明确施用杀虫剂后接菌对穗腐病发病的影响,探究防治玉米穗期病虫害的有效方案,为玉米安全生产提供技术支撑。【方法】以郑单958为供试玉米,在2019年春、夏两季于河北廊坊进行田间试验。玉米大量吐丝后5 d和20 d两次施药,接菌处理于吐丝后7 d进行。在玉米完熟期调查虫害级别、穗腐病发病率和病情指数、果穗穗长、行粒数、穗重和百粒重,计算防治效果和增产情况,并用高效液相色谱-串联质谱法分析籽粒中伏马毒素B1、B2的含量。【结果】与对照相比,施用甲维盐和氯虫苯甲酰胺均可显著降低平均虫害级别、穗腐病发病率、病情指数、伏马毒素含量。与单独施用杀虫剂相比,施用杀虫剂与杀菌剂的混剂未显著降低平均虫害级别、穗腐病发病率、病情指数、伏马毒素含量,也未显著提高产量和对上述病虫害的防治效果。与仅接菌的处理相比,施用氯虫苯甲酰胺后接菌处理在穗腐病发病率、病情指数和伏马毒素含量方面均显著下降。在春玉米和夏玉米试验中,25 g·hm^-2氯虫苯甲酰胺及其与杀菌剂的混剂对穗部螟虫的防治效果分别达82.1%—92.7%、94.2%—95.0%,而30 g·hm^-2甲维盐及其与杀菌剂的混剂对穗部螟虫的防治效果显著低于25 g·hm^-2氯虫苯甲酰胺,仅为57.8%—78.0%、83.1%—89.9%。2种杀虫剂对穗腐病的防治效果无显著差异,春玉米防治效果均>60%,夏玉米防治效果均>88%。对于产量而言,各处理均对果穗穗长和行粒数无显著影响,药剂处理后的果穗穗重均显著高于对照,且各处理间无显著差异。施用杀虫剂后接菌对产量无显著影响。分别施用2种杀虫剂单剂或其与杀菌剂的混剂后,春玉米可增产5.49%—13.49%,夏玉米可增产9.20%—13.95%,玉米籽粒中伏马毒素含量均低于500 μg·kg^-1,而对照玉米中伏马毒素含量达2 817 μg·kg ^-1。喷雾接菌处理的玉米中伏马毒素含量高达8 710 μg·kg ^-1,而接菌前施用杀虫剂可将伏马毒素含量降至1 500 μg·kg ^-1以下。【结论】施用25 g·hm^-2氯虫苯甲酰胺和30 g·hm^-2甲维盐均可通过显著降低玉米蛀穗害虫的危害,从而减轻穗腐病的发生并降低籽粒中伏马毒素含量,提高玉米产量和品质,而杀虫剂/杀菌剂混用与杀虫剂单用对虫害防控效果差异不显著;穗期害虫对果穗的伤害在穗腐病的发生过程中起决定性作用。综合各方面因素,25 g·hm^-2的氯虫苯甲酰胺是防治穗期玉米害虫、减轻穗腐病较为理想的药剂。     

Laboratory-based flight performance of the fall armyworm,Spodoptera frugiperda

In late 2018, the fall armyworm(FAW) Spodoptera frugiperda Smith(Lepidoptera: Noctuidae) made its arrival in China and its populations have since proliferated across most of eastern Asia. While S. frugiperda exhibits a considerable dispersal capacity and engages in long-distance migration, there's only scant information on the species' flight capability. Here, we empirically assessed S. frugiperda flight activity under varying climatic conditions using a flight mill. More specifically, under laboratory conditions, FAW exhibited superior flight performance at 20–25°C and 60–90% relative humidity(RH). When quantifying flight performance over five consecutive nights(i.e., 10 h/night), all flight parameters initially increased and then gradually dropped and FAW adults attained a total flight distance, duration and velocity equal to 63.73 km(48.42–94.12 km)(median, quartile range), 24.12 h(20.87–27.73 h) and 2.73 km h~(–1)(2.13–3.33 km h~(–1)), respectively. Our work constitutes a first comprehensive assessment of S. frugiperda flight performance and provides baseline information for future efforts to forecast spatiotemporal changes in its geographical distribution, movement patterns and invasion trajectories. Such can ultimately permit a timely and targeted deployment of area-wide pest management measures against this newly-invasive pest in China and across eastern Asia.     

14种杀虫剂对栎黄枯叶蛾4龄幼虫的室内生物活性

为筛选防治栎黄枯叶蛾幼虫的高效药剂,采用浸虫法测定14种杀虫剂对其4龄幼虫的室内杀虫活性。结果表明,4种拟除虫菊酯类杀虫剂对栎黄枯叶蛾4龄幼虫均具有高致死能力,半致死质量浓度LC₅₀值介于0.199～2.046 mg/L;乙基多杀菌素、阿维菌素和甲维盐也有较高的杀虫活性,LC₅₀值在2.733～6.470 mg/L;苦参碱对幼虫的毒力水平最低,在测试的质量浓度梯度内试虫校正死亡率均小于45%。除苦参碱外,其他13种杀虫剂的杀虫活性大小依次为:高效氯氰菊酯、溴氰菊酯、高效氯氟氰菊酯、联苯菊酯、乙基多杀菌素、阿维菌素、甲维盐、辛硫磷、氯虫苯甲酰胺、四氯虫酰胺、杀虫双、甲维虫酰肼、马拉硫磷。综合考虑药剂残留及沙棘作为果叶兼用的生态经济型树种,拟除虫菊酯类杀虫剂可用于栎黄枯叶蛾幼虫大发生时的应急药剂,乙基多杀菌素、阿维菌素和甲维盐等生物源农药可作为常用药剂,在高效防治栎黄枯叶蛾幼虫的同时兼顾环境及生态效益。     

应用浸叶法评价14 种杀虫剂对棉花粉蚧的毒力

棉花粉蚧（Phenacoccus solenopsis Tinsely）是一种近年来在世界范围内发生危害的入侵性害虫,已给巴基斯坦、印度等多国的棉花生产造成严重损失。2008 年中国大陆发现其发生,目前已在局部地区入侵棉田、造成危害,对中国棉花产业潜在威胁巨大。为了寻找合适的防治药剂,采用浸叶法测定了14 种杀虫剂对棉花粉蚧三龄若虫的毒力。结果表明,高效氯氟氰菊酯、丙溴磷、毒死蜱和阿维菌素相对毒力较高;随着处理时间延长,阿维菌素、甲维盐、多杀霉素和溴虫腈4 种杀虫剂对棉花粉蚧三龄若虫毒力上升明显。药后24 h,14 种药剂的相对毒力由高到低依次为高效氯氟氰菊酯、丙溴磷、毒死蜱、阿维菌素、辛硫磷、丁硫克百威、多杀霉素、溴虫腈、高效氯氰菊酯、灭多威、甲维盐、三唑磷、矿物油、鱼藤酮;药后48 h,14 种药剂的相对毒力由高到低依次为高效氯氟氰菊酯、丙溴磷、阿维菌素、毒死蜱、甲维盐、溴虫腈、多杀霉素、丁硫克百威、辛硫磷、高效氯氰菊酯、灭多威、三唑磷、矿物油、鱼藤酮,与药后24 h的相对毒力顺序略有变化。     

8种药剂对斯密二鬃蓟马成虫的室内毒力

[目的]筛选防治斯密二鬃蓟马的有效药剂。[方法]在室内采用浸叶法测定8种药剂对斯密二鬃蓟马成虫的毒力。[结果]药剂处理24 h后,阿立卡、联苯菊酯、烯啶虫胺、吡虫啉、氰氟虫腙对斯密二鬃蓟马成虫的LC50分别为5.505 3、7.945 4、42.747 1、69.593 3、578.344 1 mg/L;药剂处理12 h后,甲维盐、虫螨腈·甲氨基阿维菌素苯甲酸盐、毒死蜱对斯密二鬃蓟马成虫的LC50分别为0.019 0、0.071 6、0.256 5 mg/L。[结论]8种杀虫剂中甲维盐、毒死蜱、虫螨腈·甲氨基阿维菌素苯甲酸盐对斯密二鬃蓟马成虫有较好的毒杀效果。甲维盐、虫螨腈·甲氨基阿维菌素苯甲酸盐属于生物源农药,且毒性较高,是高级花卉、无公害花卉生产中防治斯密二鬃蓟马的较理想药剂。     

10种杀虫剂对蓝莓重要害虫黑腹果蝇生物活性的测定

黑腹果蝇Drosophila melanogaster为皖南山区危害蓝莓的一种重要害虫。采用药膜接触法测定了10种杀虫剂对黑腹果蝇成虫的生物活性。供试药剂以乙基多杀菌素的杀虫活性最高,溴氰虫酰胺和核型多角体病毒的生物活性次之。乙基多杀菌素以15 mg·L~(-1)处理后24 h和48 h试虫的校正死亡率分别为91.8%和100.0%,处理后24和48 h的LC50分别为6.90和1.74 mg·L~(-1)。溴氰虫酰胺以40 mg·L~(-1)处理后72 h试虫的校正死亡率为93.7%。核型多角体病毒、甲氨基阿维菌素和苏云金杆菌按厂家推荐剂量处理后72 h对黑腹果蝇也表现出较好的生物活性。乙基多杀菌素和溴氰虫酰胺可作为防治蓝莓园黑腹果蝇的理想杀虫剂加以交替轮换施用。     

5种常用杀虫剂对尖喙库蠓的毒性测定

以野外采集的尖喙库蠓成虫为试验对象,通过滤纸接触法,测定了毒死蜱、敌敌畏、溴氰菊酯、高效氯氰菊酯和高氯·甲维盐等5种常用杀虫剂对尖喙库蠓的毒杀效果.结果表明:5种杀虫剂对蠓的毒性差异显著,毒力大小依次为溴氰菊酯毒死蜱高效氯氰菊酯高氯·甲维盐敌敌畏,试虫接触药剂1 h的LC50分别为0.060、0.588、1.741、99.670和600.496 mg·L-1;试虫经药剂处理1 h后在恢复筒观察24 h,其在各种药剂不同处理浓度下增加的死亡数不同;以溴氰菊酯为标准药剂,其相对毒力指数最大.     

杏树鬃球蚧防治药剂的筛选及田间防效

近年来杏树鬃球蚧在伊犁野果林暴发,严重威胁了野杏的生存和野果林生态系统。为了有效遏制杏树鬃球蚧危害,采用喷雾法在室内筛选出对杏树鬃球蚧表现出较高死亡率的药剂,并在杏树鬃球蚧越冬2龄若虫出蛰期和1龄若虫涌散期进行地面人工喷雾试验和无人飞机防治试验。结果表明,室内条件下5种药剂对杏树鬃球蚧若虫的校正死亡率在4.32%~81.19%,其中5%甲氨基阿维菌素苯甲酸盐微乳剂对出蛰期、涌散期若虫的校正死亡率最佳,分别高达81.19%、73.24%。田间试验结果表明,在杏树鬃球蚧越冬2龄若虫出蛰期,使用5%甲维盐微乳剂、5%高效氯氟氰菊酯水乳剂、20%啶虫脒可溶液剂进行防治,施药后第14天防效均达74%以上,其中5%甲维盐微乳剂6 000倍液防效高达91.33%;飞防作业区以吐尔根药后7~8 d的虫口减退率最高,为50.96%。在1龄若虫涌散期,使用5%甲维盐微乳剂、5%高效氯氟氰菊酯水乳剂、22%噻虫·高氟氯微囊悬浮-悬浮剂进行防治,施药后第14天防效均达71%以上,其中22%噻虫·高氟氯微囊悬浮-悬浮剂1 000倍液防效高达89.28%;飞防作业区虫口减退率为55.17%,防治效果为36.23%。可选用5%甲维盐微乳剂、5%高效氯氟氰菊酯水乳剂、20%啶虫脒可溶液剂和22%噻虫·高氟氯微囊悬浮-悬浮剂作为当前防治杏树鬃球蚧的理想药剂,可有效遏制杏树鬃球蚧的危害。     

12种杀虫剂对草地贪夜蛾和霍氏啮小蜂的选择毒力

【目的】评价12种杀虫剂对草地贪夜蛾（Spodoptera frugiperda）及其天敌霍氏啮小蜂（Tetrastichus howardi）的毒力和选择性,为协调草地贪夜蛾的化学防治和生物防治提供科学依据。【方法】通过玉米叶片浸渍法和试管药膜法,分别测定40%杀虫双、94%溴氰虫酰胺、98%噻虫嗪、94%茚虫威及金龟子绿僵菌（Metarhizium anisopliae）等12种杀虫剂对草地贪夜蛾2龄幼虫和霍氏啮小蜂成蜂的选择毒力,明确草地贪夜蛾和霍氏啮小蜂对常用杀虫剂的敏感性。【结果】在11种化学杀虫剂中,95%甲氨基阿维菌素苯甲酸盐对草地贪夜蛾2龄幼虫的毒力最强,24 h的半数致死浓度（LC₅₀）为0.42 mg/L,98%噻虫嗪的毒力最弱（24 h-LC₅₀为13.56 mg/L）;95%甲氨基阿维菌素苯甲酸盐对霍氏啮小蜂成蜂的毒力也最强（24 h-LC₅₀为0.09 mg/L）,94%茚虫威的毒力最弱（24 h-LC₅₀为4.45 mg/L）。11种化学杀虫剂的选择毒力指数（STR）排序为:94%茚虫威 > 96%氟苯虫酰胺 > 95%虫螨腈 > 95.3%氯虫苯甲酰胺 > 95%甲氨基阿维菌素苯甲酸盐 > 98%虱螨脲≈98%噻虫嗪 > 94%溴氰虫酰胺 > 81.2%乙基多杀菌素≈40%杀虫双 > 95%四氯虫酰胺,表明94%茚虫威在有效防治草地贪夜蛾的前提下对霍氏啮小蜂的保护性最强。金龟子绿僵菌对草地贪夜蛾和霍氏啮小蜂的LC₅₀和STR随时间的推移呈明显下降趋势,均在第4 d达最大值、第6 d为最小值,说明微生物杀虫剂发挥药效存在一个滞后过程。【结论】95%甲氨基阿维菌素苯甲酸盐的毒力最大,可作为防控草地贪夜蛾应急施药首选;金龟子绿僵菌和94%茚虫威的选择性大,可作为草地贪夜蛾综合防控的推荐用药;94%溴氰虫酰胺和98%噻虫嗪的毒力较小,不适宜用于草地贪夜蛾的化学防治。     

甜菜夜蛾抗茚虫威品系的生物适合度及抗性遗传方式

 【目的】测定甜菜夜蛾（Spodoptera exigua）抗茚虫威品系对8种常用杀虫剂的交互抗性、生物适合度及抗性遗传方式。【方法】生测方法确定交互抗性程度,组建种群生命表评价抗性品系的生物适合度,LD-P线与统计分析相结合研究抗性遗传方式。【结果】对茚虫威产生134倍抗性的甜菜夜蛾品系（RR-indox）除对甲维盐表现中等水平的交互抗性（12.59倍）外,对其它7种药剂均没有明显交互抗性。抗性品系相对敏感品系的生物适合度为0.44,表现出一定程度的生长发育和繁殖上的不利性。杂交后代（F1,R♀×S♂;F′1,S♀×R♂）的显性度分别为0.54和0.74,甜菜夜蛾对茚虫威的抗性为常染色体多基因,不完全显性遗传。【结论】茚虫威防治甜菜夜蛾应注意与无交互抗性药剂轮换使用,以延缓抗性的产生。     

2007年江浙地区二化螟抗药性检测

 【目的】2007年测定江苏、浙江地区二化螟对杀虫单、三唑磷、氟虫腈、阿维菌素及拟除虫菊酯类等9种杀虫剂的抗性,以及6类20种杀虫剂对东海二化螟的毒力,为指导用药提供科学依据。【方法】采用4龄幼虫点滴法测定。【结果】（1）瑞安、苍南、高淳种群对杀虫单具有极高水平抗性（164.8～248.1倍）,连云港和东海种群具有中等水平抗性（18.1和25.1倍）。（2）5个种群对三唑磷的敏感性变化很大,其中瑞安、苍南、高淳种群为极高水平抗性（204.8～1395.2倍）,连云港和东海种群未检测到明显的抗性（1.8和3.1倍）。（3）瑞安、苍南种群对氟虫腈为中等水平抗性（12.3和26.8倍）,其它3个种群为敏感水平（1.3～2.9倍）。（4）苍南种群对阿维菌素产生低水平的抗性（7.6倍）,其它种群尚处于敏感水平（0.9～2.0倍）。（5）瑞安、苍南种群对氯氟氰菊酯、氰戊菊酯、高效氯氰菊酯、高效氟氯氰菊酯及溴氰菊酯为中～高水平的抗性,其它3个种群对除氰戊菊酯以外的4种拟除虫菊酯为低～中水平的抗性（5.3～31.2倍）。（6）测试的20种药剂对东海种群二化螟的毒力次序为：阿维菌素、甲氨基阿维菌素>伊维菌素、高效氟氯氰菊酯＞丁烯氟虫腈、氟虫腈、氰戊菊酯、氯氟氰菊酯、溴氰菊酯、高效氯氰菊酯、虫酰肼≥辛硫磷、喹硫磷、呋喃虫酰肼、三唑磷、哒嗪硫磷＞马拉硫磷、毒死蜱、氟硅菊酯>杀虫单。【结论】不同地区二化螟种群对药剂的抗性存在差异,应根据当地的抗性水平有针对性地进行抗性治理。     

亚洲玉米螟的抗药性监测及双酰胺类药剂抗性靶标分子检测

[目的]研究监测和检测亚洲玉米螟田间种群对双酰胺类等药剂的抗性,为指导田间合理用药及抗性治理提供依据.[方法]于2018和2019年,采用人工饲料浸药法,测定新疆乌鲁木齐市、伊宁市、疏勒县、泽普县和昌吉市亚洲玉米螟田间种群对氯虫苯甲酰胺、溴氰虫酰胺、阿立卡(噻虫嗪·高效氯氟氰菊酯)和亮泰(阿维菌素·氯虫苯甲酰胺)的抗性...     

6种杀虫剂对小菜蛾的室内毒力及田间防效

[目的]筛选出防治小菜蛾的有效药剂。[方法]采用点滴法测定了甲氨基阿维菌素苯甲酸盐等6种杀虫剂对小菜蛾3龄幼虫的室内毒力,采用对水叶面喷雾法测定了其中杀虫效果较好的5种制剂对小菜蛾的田间防效。[结果]甲氨基阿维菌素苯甲酸盐对小菜蛾3龄幼虫的室内毒力最高,其LC50为0.17 mg/L;其次为氯虫苯甲酰胺、虫螨腈及多杀菌素,其LC50依次为0.44、0.84、1.25 mg/L;丁醚脲和氰氟虫腙的毒力最低,其LC50分别为10.43和11.17 mg/L。田间施药后6 d,5%氯虫苯甲酰胺SC 1 000倍液对小菜蛾的防效较好,高达82.33%;5.7%甲氨基阿维菌素苯甲酸盐WG 2 500倍液、10%虫螨腈SC 1 500倍液、25%丁醚脲EC 1 500倍液及2.5%多杀菌素EW1 500倍液难以控制其危害,防效分别为60.50%、58.02%、55.64%和55.40%。[结论]为小菜蛾的有效控制提供了理论依据。     

北京地区不同桃蚜种群的抗药性研究

 【目的】明确北京地区蔬菜主要害虫桃蚜的抗药性水平。【方法】采用室内生物测定方法检测北京地区6个田间种群和1个室内敏感种群对5种杀虫剂的敏感性,用双向等位特异PCR技术检测击倒抗性水平,并检测桃蚜体内2种抗性相关酶的活力。【结果】结果表明通州、顺义、大兴、海淀、延庆和门头沟6个田间种群和1个敏感种群桃蚜均对高效氯氰菊酯产生了高水平抗性,除延庆和门头沟外,抗性纯合子比例均在90%以上。门头沟、通州和延庆种群的桃蚜对毒死蜱和吡虫啉抗性倍数分别在2.05—4.24和32.03—41.27倍之间。除大兴种群对阿维菌素和甲氨基阿维菌素苯甲酸盐（抗性倍数分别为3.45和2.82）,海淀种群对阿维菌素的敏感性有所降低外（抗性倍数为2.66）,其它种群桃蚜对这2种药剂仍处于较敏感状态（抗性倍数在0.19—1.44）。羧酸酯酶活力与桃蚜对毒死蜱和吡虫啉的抗性倍数间存在明显的正相关性,乙酰胆碱酯酶活力与此2种杀虫剂的抗性倍数成负相关性。【结论】北京地区不同种群的桃蚜几乎对5种常用药剂均产生了不同程度的抗性。防治中应当停止使用高效氯氰菊酯,避免使用毒死蜱,部分地区可以交替使用阿维菌素、甲氨基阿维菌素苯甲酸盐和吡虫啉。     

19种杀虫剂对桃小食心虫卵的毒力测定

为明确19种杀虫剂对桃小食心虫的防治效果,为卵期喷药防治该虫提供依据,用浸渍法进行了室内毒力测定。结果表明,19种供试药剂的毒力差异较大,拟除虫菊酯类杀虫剂溴氰菊酯、高效氯氟氰菊酯、甲氰菊酯、高效氯氰菊酯、氰戊菊酯及混剂甲维氯氰对桃小卵活性较高,其LC50均小于0.3 mg/L;其次为室内甲维盐、氟虫腈、灭幼脲、丁烯氟虫腈、毒死蜱、噻虫嗪、虫螨腈;阿维菌素、噻嗪酮、茚虫威较低;氯虫苯甲酰胺毒力最低。在桃小卵期树上施药,可优先选用杀卵活性较高的拟除虫菊酯类药剂,与具有杀幼虫活性、持效期长的灭幼脲和氯虫苯甲酰胺混用,可有效防治桃小食心虫。     

甘蓝小菜蛾常用单剂及甲维盐混剂药效试验研究

进行了甘蓝小菜蛾杀虫剂的田间药效试验,结果表明:2种甲维盐混剂2.8%甲维盐.三氟氯氰菊酯微乳剂和55.8%甲维盐.毒死蜱乳油药后10 d防效分别为:87.30%、91.24%;4个单剂40%毒死蜱乳油、0.5%甲维盐微乳剂、25 g/L高效氯氟氰菊酯乳油、0.5%甲氨基阿维菌素苯甲酸盐乳油药后10 d防效分别为:80.18%、85.60%、82.90%、81.76%。可见4个单剂对甘蓝小菜蛾防效和持效效果相当,甲维盐混合剂总体防效和持效好于单剂。     

Lack of fitness cost and inheritance of resistance to abamectin based on the establishment of a near-isogenic strain of Tetranychus urticae

Many populations of the two-spotted spider mite, Tetranychus urticae Koch, have developed high levels of resistance to the pesticide abamectin in China and other countries. This study developed a near-isogenic line to understand better the inheritance, cross-resistance, and fitness costs associated with abamectin resistance in the field population of T. urticae in China. We introduced the trait that confers extremely high abamectin resistance in a field-collected population of T. urticae into a susceptible laboratory strain (IPP-SS) to generate an abamectin-resistant near-isogenic line (NIL-Aba). This process was carried out through multiple backcrossing to IPP-SS and via parthenogenesis and abamectin screening. Compared with IPP-SS, the NIL-Aba strain had a 25 147-fold resistance to abamectin and a high level of cross-resistance to bifenthrin (288.17-fold), an intermediate level to emamectin benzoate (42.57-fold), and low levels to bifenazate, chlorfenapyr, cyflumetofen, cyenopyrafen, and cyetpyrafen with resistance ranging from 3.18- to 9.31-fold. But it had no cross-resistance to profenofos. The resistance to abamectin in NIL-Aba was autosomal, incompletely dominant, and polygenic. Based on two sex life table parameters, no fitness cost was found in NIL-Aba. Establishing the NIL-Aba strain provides a reliable basis for an in-depth study of abamectin resistance in T. urticae. New information on toxicological characteristics and fitness cost should facilitate the management of abamectin resistance in field populations of T. urticae.