Monitoring pesticide resistance of Tetranychus cinnabarinus in Kunming' s flower regions

采用玻片浸渍法测定了昆明地区花卉朱砂叶螨Tetranychus cinnabarinus (Boisduval)对阿维菌素、甲氨基阿维菌素苯甲酸盐、溴虫腈、丁醚脲、炔螨特和哒螨灵的抗性.结果表明,昆明北郊和呈贡地区玫瑰上的朱砂叶螨雌成螨对阿维菌素与甲氨基阿维菌素苯甲酸盐产生了极高的抗药性,阿维菌素对2个地区的朱砂叶螨的LC50分别为40.25 mg·L -1和19.67 mg·L-1,相对毒力指数分别为敏感品系的2 441.08倍和1 192.86倍;甲氨基阿维菌素苯甲酸盐对其LC50分别为118.18 mg·L-1和9.24 mg·L-1,相对毒力指数是敏感品系的2 805.73倍和219.35倍.昆明北郊的朱砂叶螨对溴虫腈的相对毒力指数是敏感品系的2 371.40倍,呈贡和晋宁分别为162.01倍和173.38倍.丁醚脲对北郊、呈贡和晋宁朱砂叶螨的LC50分别为244.58 mg·L-1、385.41 mg·L-1和54.93 mg·L-1,相对毒力指数在3.01倍～21.10倍之间.北郊、呈贡和晋宁的朱砂叶螨种群对炔螨特和哒螨灵的LC50分别为155.39 mg·L-1、424.49 mg·L-1和62.70 mg·L-1,其相对毒力指数是敏感品系的6.45倍、17.63倍和2.60倍.朱砂叶螨对药剂抗药性水平趋势从高到低为:阿维菌素、甲氨基阿维菌素苯甲酸盐＞溴虫腈、丁醚脲＞炔螨特、哒螨灵,抗性最高的地区为昆明北郊,晋宁相对较低.     

杀虫剂对小菜蛾、甜菜夜蛾、斜纹夜蛾的毒力研究

室内浸叶法试验表明,三种害虫中斜纹夜蛾、小菜蛾对供试杀虫剂的敏感程度一般比甜菜夜蛾高。灭虫灵对小菜蛾有很高的潜力,LC50为0．09mg/L,甜菜夜蛾、斜纹夜蛾对灭虫灵敏度程度较低,LC50在150mg/L左右。除尽对甜菜夜蛾,毒死蜱对斜纹夜蛾毒力最高,LC50分别为1．48mg/L和0．49mg/L,除尽、锐劲特、抑太保对小菜蛾、甜菜夜蛾、斜纹夜蛾都具有很高的毒力,可作为兼治这三种害虫的首选品种。     

两种虫酰肼类新化合物对五种鳞翅目害虫的生物活性

为了比较虫酰肼及其衍生物对鳞翅目 5 种害虫的毒力 ,以虫酰肼为对照药剂,分别采用浸叶法、浸虫法和点滴法测定了虫酰肼衍生物 0593 (Ⅲ f) 和 0673 对甜菜夜蛾 Spodoptera exigua（Hübner）、斜纹夜蛾 Prodenia litura (Fabricius)、小菜蛾 Plutella xylostella (Linnaeus)、棉铃虫 Helicoverpa armigera(Hübner)和玉米螟 Ostrinia furnacalis(Guenée)的毒力;通过浸叶法系统研究了虫酰肼和虫酰肼衍生物 0593 对甜菜夜蛾生长发育的影响。结果表明：0593 和 0673 对甜菜夜蛾 4 龄幼虫的触杀毒力分别是虫酰肼的 11.3 倍和 7.4 倍,对斜纹夜蛾 4 龄幼虫触杀毒力分别是虫酰肼的 30.4 倍和 24.7 倍,对小菜蛾 3 龄幼虫浸虫处理的毒力分别是虫酰肼的 4.7 倍和 4.5 倍 ,对棉铃虫3龄幼虫的触杀毒力分别是虫酰肼的 15.5 倍和 15.2 倍,对玉米螟 4 龄幼虫的触杀毒力分别是虫酰肼的 1.3 倍和 2.0 倍,较虫酰肼的毒力都有很大提高,而0593 和 0673 对 5 种害虫的毒力差异不显著。用虫酰肼和 0593 处理甜菜夜蛾 2 龄幼虫,都能导致存活幼虫陆续死亡;化蛹率和正常蛹数降低;成虫羽化率、单雌产卵量和卵的孵化率显著减少,对后代的繁殖力影响显著;在相同处理浓度下,0593 较虫酰肼对甜菜夜蛾后代繁殖力的不利影响更大。因此,0593 是较虫酰肼杀虫毒力更高、对生长发育和繁殖力不利影响更大的药剂,开发应用价值很大。     

高效氯氰菊酯对小菜蛾阿维菌素抗性、敏感种群的亚致死效应

在实验室条件下研究了高效氯氰菊酯亚致死剂量LC10 (43.44 mg/L)(小菜蛾阿维菌素抗性种群)和LC10( 12.61 mg/L)(敏感种群)对小菜蛾阿维菌素抗性(AV - R)、敏感(AV -S)种群的亚致死效应.结果表明:高效氯氰菊酯亚致死剂量12.61 mg/L处理小菜蛾阿维菌素敏感、抗性种群3龄幼虫后,...     

内蒙古小菜蛾种群数量动态及抗药性监测

2009—2011年对内蒙古呼和浩特市郊区十字花科蔬菜和武川县油菜上小菜蛾Plutella xylostella(L.)种群消长动态进行了调查,并比较了呼和浩特地区小菜蛾对11种杀虫剂的抗药性。结果表明,在呼和浩特郊区,小菜蛾成虫于4月上旬开始出现,一年中有4个发生高峰,分别为4月下旬或5月上旬、6月中旬、8月下旬和10月上旬;小菜蛾幼虫在春甘蓝和秋白菜整个生长期间均有发生,大约有4个发生高峰,分别为6月上中旬、6月下旬或7月上旬、9月上旬和10月上旬。在武川县,小菜蛾成虫于4月末或5月初开始发生,春夏季数量高于秋季,共有2个发生高峰,2009年为5月下旬和6月中旬,2010年为6月上旬和8月上中旬;小菜蛾幼虫在6月下旬开始出现,在油菜整个生长期间,小菜蛾幼虫约有3个数量高峰,分别为7月初、7月末和8月下旬,秋季数量高于春夏季。在供试的11种杀虫剂中,溴虫腈对小菜蛾幼虫的毒力最高,LC50为0.22 mg·L-1;其次为多杀菌素、氯虫苯甲酰胺、氟虫腈和BT,LC50分别为0.82⁰.83、1.09、1.36和3.41 mg·L-1;再次为茚虫威和阿维菌素,LC50分别为15.74 mg·L-1和6.030.83、1.09、1.36和3.41 mg·L-1;再次为茚虫威和阿维菌素,LC50分别为15.74 mg·L-1和6.03²3.47 mg·L-1;然后为丁醚尿、虫酰肼和啶虫隆,LC50分别为51.30、52.66和61.91 mg·L-1;最低为高效氯氰菊酯,LC50为462.6623.47 mg·L-1;然后为丁醚尿、虫酰肼和啶虫隆,LC50分别为51.30、52.66和61.91 mg·L-1;最低为高效氯氰菊酯,LC50为462.66⁶73.26 mg·L-1。抗药性测定表明,呼和浩特地区小菜蛾幼虫未对溴虫腈、虫酰肼、氯虫苯甲酰胺和丁醚尿产生抗性,对多杀菌素和氟虫腈为低抗性,对茚虫威和BT为中抗性,对高效氯氰菊酯、啶虫隆和阿维菌素为极高抗性。     

甲维盐·氟铃脲复配剂对甜菜夜蛾的时间-剂量-死亡率模型研究

以甜菜夜蛾 (SpodopteraexiguaH櫣ｂｎｅｒ) 2龄幼虫为试虫 ,测定了 5种配比的甲胺基阿维菌素苯甲酸盐(简称甲维盐 )与氟铃脲混配剂的毒力 ,测定结果建立了“时间 -剂量 -死亡率”模型。根据模型分析结果 ,甲维盐与氟铃脲混配后增效显著 ,5种配比中以甲维盐∶氟铃脲 =1∶10为最佳配比。其 2 4～ 6 0h 4个时段的共毒系数在 4 0 0～ 6 0 0之间 ,用 2 0、 1 0 μg·mL- 1浓度处理后的LT50 分别为 18 4 6和 30 5 8h     

小菜蛾对几种常用药剂的敏感性测定

采用叶片浸溃法,在2001年10月和2002年10月分别测定了福州上街蔬菜基地的小菜蛾,对10种杀虫剂的敏感性。结果表明,上街菜区小菜蛾对灭多威、杀虫双、辛硫磷、毒死蜱、杀灭菊酯和功夫菊酯等农药极不敏感,已不能有效控制小菜蛾的危害。而小菜蛾对氟啶脲、阿维菌素、氟虫腈和虫螨腈比较敏感。通过两次毒力测定比较(2002年10月的LC50;2001年10月的LC50),结果表明,大多数杀虫剂敏感性变化较小。但小菜蛾对阿维菌素敏感性明显下降,毒力倍数达6．65倍,对氟虫腈毒力倍数相差1．48倍。此外,2002年10月小菜蛾对功夫菊酯的LC50为2001年10月的2．02倍。用浸叶法和浸溃法测定多杀菌素、氟虫腈与虫螨腈推荐浓度对小菜蛾幼虫的毒杀作用。结果表明3种药剂浸叶法处理效果均较理想。     

抗夜蛾科苏云金芽孢杆菌WY-197菌株的生物学特性研究

苏云金芽孢杆菌 (Bacillusthuringiensis,Bt)WY 197菌株是从 4 0 0多株野生型Bt菌中筛选分离的1株对甜菜夜蛾和棉铃虫都具有高效杀虫活性的菌株。初步比较WY -197菌株和HD 1的形态特征、生理生化特性和伴孢晶体蛋白 ,结果表明 ,WY -197属于H3a3b3c血清型 (subsp .kurstaki) ;伴孢晶体形态主要为大小不一的菱形、小正方形。SDS -PAGE电泳图谱表明主要由 135ku和 6 5ku两种蛋白成分组成 ,在菌株生长形态、发酵培养特征、生理生化特性方面与生产菌株HD-1差别不大。采用生物测定的方法 ,进一步鉴定比较它们对甜菜夜蛾初孵、二龄、三龄幼虫和棉铃虫的毒效差异。结果表明 ,BtWY 197菌株发酵液对甜菜夜蛾初孵、二龄、三龄幼虫的LC50 分别为 0 .31、0 .6 1、2 .5 7μL/mL ,其中对甜菜夜蛾初孵幼虫的毒效是对照菌HD 1发酵液的 7倍 ,表明BtWY 197菌株对甜菜夜蛾三龄以下幼虫具有高毒力。对棉铃虫的毒力效价为 30 0 0IU/ μL ,略低于HD- 1菌株。     

甲维盐·毒死蜱及其复配对小菜蛾的毒力分析

以小菜蛾（Plutella xylostellar） 3龄幼虫为试虫测定了甲胺基阿维菌素苯甲酸盐、毒死蜱及两者5种不同配比的复配剂的毒力,测定结果建立了“时间-剂量-死亡率”模型.根据模型分析结果,甲胺基阿维菌素苯甲酸盐与毒死蜱混配后增效显著.在5种配比中以甲氨基阿维菌素苯甲酸盐∶毒死蜱 =1∶ 74为最佳配比,其24-60 h 4个时段的共毒系数在334到550之间;与单剂相比,该配比明显提高了24 h时段内和48-60 h时段的杀虫率.     

甜菜夜蛾对甲氧虫酰肼抗药性选育及其抗性生化机理初探

在室内用甲氧虫酰肼对甜菜夜蛾Spodoptera exigua(Hübner)幼虫进行抗药性选育,经过13代汰选,甜菜夜蛾抗性种群(Met-R)对甲氧虫酰肼的抗性倍数为4.19倍;交互抗性测定发现,Met-R甜菜夜蛾对毒死蜱、高效氯氰菊酯、虫螨腈、虫酰肼、甲胺基阿维菌素苯甲酸盐等药剂的交互抗性比值在1.05～2.07之间,不存在交互抗性。离体酶活性测定结果表明,Met-R甜菜夜蛾5龄幼虫中肠谷胱甘肽S-转移酶比活力是相对敏感种群(SS)甜菜夜蛾的2.44倍,存在显著性差异,说明谷胱甘肽S-转移酶活性增强可能与甜菜夜蛾对甲氧虫酰肼产生抗药性有关;但Met-R甜菜夜蛾全酯酶催化活性与SS的无显著性差异,说明其抗药性可能与酯酶无关。     

5%甲氨基阿维菌素苯甲酸盐微乳剂对6种环境生物的急性毒性

甲氨基阿维菌素苯甲酸盐是一种新型的抗生素类杀虫剂、杀螨剂,其大量使用可能会导致一系列的生态风险,因此有必要开展其对相关环境生物毒性的研究。测定了甲氨基阿维菌素苯甲酸盐对意大利蜜蜂、日本鹌鹑、斑马鱼、家蚕、大型溞和赤子爱胜蚓6种非靶标生物的急性毒性。5％甲氨基阿维菌素苯甲酸盐微乳剂对蜜蜂的急性经口LC50（48 h）为0．555 a．i．mg· L-1,对鹌鹑的经口LD50（7 d）为148．369 a．i．mg· kg-1,对斑马鱼的LC50（96 h）为0．368 a．i．mg· L-1,对家蚕的急性摄入毒性LC50（96 h）为0．005 a．i．mg· L-1,对大型溞的运动抑制毒性EC50（48 h）为0．020 a．i． mg· L-1,对蚯蚓的急性毒性LC50（14 d）为18．397 a．i．mg· kg-1。该农药对家蚕和大型溞均为剧毒,对蜜蜂和斑马鱼均为高毒,对鹌鹑中毒,对蚯蚓低毒。总体而言,甲氨基阿维菌素苯甲酸盐微乳剂对环境生物危害大,在使用过程中要注意。     

甲氨基阿维菌素苯甲酸盐微乳剂热贮稳定性研究

采用高效液相色谱法分析甲维盐微乳剂,以甲醇＋0．2％三乙胺溶液＋乙腈（V：V：V=30：30：40）为流动相,采用XterraRP184．6150mm色谱柱,检测波长245nm,测得54±2℃条件下14d分解率为3．42％。室内毒力测定热贮前后1％甲维盐微乳剂Lc50分别为0．499mg／L和0．524mg／L,热贮分解率为4．78％,与高效液相色谱测定结果基本一致。     

Baseline toxicity of emamectin and spinosad to Helicoverpa armigera (Lepidoptera: Noctuidae) for resistance monitoring

Acute toxicity studies of emamectin and spinosad against Helicoverpa armigera revealed that the pest is highly susceptible to both the insecticides. The median lethal dose (LD₅₀) of emamectin is 3.86 × 10⁻³ µg per larva. The median lethal concentrations (LC₅₀) of emamectin and spinosad were found to be 0.09 and 2.94 ppm, respectively. The discriminating doses were fixed based on the LC₉₅ of the susceptible population of H. armigera as 0.80 ppm for emamectin and 10 ppm for spinosad. Resistance was not observed when the discriminating doses of emamectin and spinosad were applied on field-collected populations of H. armigera from two intensive cotton growing areas, Coimbatore and Madurai, India.     

Could resistance to insecticides in Plutella xylostella (Lep., Plutellidae) be overcome by insecticide mixtures?

Abstract: To investigate if synergism occurs between pyrethroids, organophosphates and new insecticides, we tested representatives of these compounds (bifenthrin, chlorpyrifos, spinosad, indoxacarb and emamectin) against the diamondback moth (Plutella xylostella). Larvicidal activity of these insecticides was assessed separately and together on a susceptible strain (Lab‐UK) of P. xylostella as well as a field population collected from Multan. The field population showed significant resistance to chlorpyrifos (331 100‐fold), bifenthrin (45 200‐fold), emamectin (1800‐fold), spinosad (11‐fold) and indoxacarb (5600‐fold) when compared with the Lab‐UK population. When insecticides were mixed based on LC₅₀ and tested at serial concentrations against Lab‐UK, significant synergy (CI < 1) occurred between bifenthrin, spinosad and emamectin. In contrast, the interaction between bifenthrin and indoxacarb was additive (CI = 1). The toxicity of bifenthrin against the field population increased significantly (P < 0.01) when combined with spinosad, emamectin and indoxacarb. Synergistic effects could be attributed to the complementary modes of action by these insecticide classes acting on different components of nerve impulse transmission (which are not identical for bifenthrin and indoxacarb either). However, chlorpyrifos/bifenthrin mixture was not significantly different either from bifenthrin or chlorpyrifos alone, indicating an additive affect. In combination with spinosad and emamectin, tested against the resistant field population, the toxicity of chlorpyrifos increased significantly and even more so with indoxacarb. Mixtures could also give rise to multiple resistance that may extend across other chemical classes and thus become difficult to manage. Therefore, alternative strategies such as mosaics or rotations should be considered. That is, though synergistic effects have been found, this should not be followed up as a strategy to manage resistant field populations.     

Comparative efficacy of different pesticides against mango bark beetle Hypocryphalus mangiferae Stebbing (Coleoptera: Scolytidae)

Hypocryphalus mangiferae Stebbing is one of the most destructive insect pests of mango trees and is found to be associated with the transmission of causal organisms of mango sudden death disease. The present study was carried out to evaluate the toxicity of deltamethrin, bifenthrin, chlorpyrifos, emamectin benzoate, imidacloprid and spinosad in laboratory and field trials. Bioassay results showed that the toxicity of chlorpyrifos was significantly higher than deltamethrin but similar to bifenthrin. Deltamethrin and bifenthrin toxicity, however, increased significantly (P < 0.01) from day 1 to day 3. Spinosad was the least toxic compound while emamectin was the most toxic among new chemical insecticides tested, but its toxicity increased significantly from day 1 to day 5. Comparison of the efficacies of the insecticides using lethal times to produce 50% mortality (LT₅₀) and 90% mortality (LT₉₀) showed that the relative potencies of chlorpyrifos, emamectin, imidacloprid and spinosad were greater than bifenthrin and deltamethrin. The results of field trials showed the highest number of beetles emerged from the control twigs while significantly fewer beetles emerged from the twigs treated with bifenthrin (P < 0.05), which accounted for 12% for bifenthrin compared to that of the control. The present study demonstrated increased toxicities of systemic insecticides and chlorpyrifos compared to toxicities of deltamethrin and bifenthrin, suggesting these insecticides could be an alternative tool in a comprehensive H. mangiferae management program to eradicate the beetles from mango orchards.     

甜菜夜蛾田间种群对甲氨基阿维菌素苯甲酸盐和高效氯氰菊酯的代谢抗性机制

甜菜夜蛾Spodoptera exigua(Hübner)云南晋宁、上海奉贤和江苏六合种群对甲氨基阿维菌素苯甲酸盐抗性为45～437倍,对高效氯氰菊酯抗性为211～555倍,对其它药剂抗性不明显。这3个田间种群3龄幼虫多功能氧化酶、谷胱甘肽S-转移酶和酯酶的活力分别为室内敏感种群的2.7～8.4倍、1.9～8.6倍和1.6～5.7倍。多功能氧化酶抑制剂PBO和酯酶抑制剂DEF对甲氨基阿维菌素苯甲酸盐的增效比为1.2～4.3和1.3～7.7;PBO和DEF对高效氯氰菊酯的增效比为1.8～58和3.6～245;谷胱甘肽S-转移酶抑制剂DEM对这2种药剂均无增效作用。上述结果表明,解毒代谢增强可能是甜菜夜蛾田间种群对甲氨基阿维菌素苯甲酸盐和高效氯氰菊酯的重要抗性机理,与酯酶和多功能氧化酶活性升高有关,与谷胱甘肽S-转移酶活性升高无关。本文的研究结果还表明,对于代谢抗性机理复杂的多抗性田间种群,根据不同解毒酶抑制剂对药剂的增效作用判断不同解毒代谢酶在抗性形成中的作用更加可靠。     

苦豆子提取物及其7种生物碱单体对埃玛菌素的增效作用

以苦豆子（Sophora alopecuroids L．）种子的甲醇提取物、水提取物及其7种生物碱单体和小菜蛾（Plutella xylostella）幼虫为试材,对生物源杀虫剂埃玛菌素进行增效作用研究。结果表明,7种生物碱单体对埃玛菌素增效比值为1．013～1．565。其中,苦豆碱和槐胺碱的增效作用最为明显,增效比值分别为1．565和1．413;而苦参碱和槐定碱对埃玛菌素的增效作用较差,增效比值仅为1．138和1．013,这2种生物碱单体对埃玛菌素仅表现出联合作用。苦豆子甲醇提取物和水提取物对埃玛菌素增效活性大于各生物碱单体,增效比值分别为3．443和2．027。     

Cross-resistance and biochemical mechanisms of abamectin resistance in the B-type Bemisia tabaci

Abstract:  To understand the risk of resistance and the possible mechanisms of resistance to abamectin in B-type Bemisia tabaci (Gennadius) better, a resistant strain of B. tabaci was selected in the laboratory and cross-resistance pattern and resistance mechanisms to abamectin were investigated. The NJ-Abm strain of B. tabaci was derived from a field population (NJ) collected in Nanjing, China in 2002 with 18 generations of selection with abamectin in the laboratory. Compared with the unselected NJ strain, the selected NJ-Abm strain developed 14.5-fold resistance to abamectin and showed significant cross-resistance to emamectin benzoate (4.4-fold) and imidacloprid (3.4-fold), but no cross-resistance to fipronil. The oxidase inhibitor piperonyl butoxide (PBO) and glutathione S -transferase inhibitor diethyl maleate (DEM) produced significant synergism on abamectin in the NJ-Abm strain (with synergistic ratios of 3.9- and 4.1-fold respectively); however, the esterase inhibitor triphenyl phosphate (TPP) did not act synergistically with abamectin. Biochemical analysis confirmed that P450 monooxygenase activity and glutathione S -transferase activity of the NJ-Abm strain were elevated to 2.1- and 2.0-fold, respectively, compared with that of the NJ strain. This indicated that enhanced metabolism mediated by P450 monooxygenase and glutathione S -transferase is likely to be involved in abamectin resistance and cross-resistance to imidacloprid and emamectin benzoate in the NJ-Abm strain.     

苦豆子提取物与埃玛菌素混合剂剂对小菜蛾实验种群生长的影响

将苦豆子甲醇提取物和苦豆子水提取物分别与埃玛菌素混合,得到苦豆子甲醇提取物·埃玛菌素(简称苦醇·埃)和苦豆子水提取物·埃玛菌素(简称苦水·埃)2种混合剂,在室内用特定年龄生命表法,研究了2种混合剂低致死剂量对小菜蛾的影响,并对其F_1代幼虫、蛹以及成虫进行了观察。结果表明,埃玛菌素、苦醇·埃和苦水·埃3个处理对小菜蛾F_1代各龄期均有影响。其种群趋势指数(I)分别为6.23、4.81和5.70,而对照组种群趋势指数则为28.03。