溴虫腈、茚虫威与氟啶脲混配对小菜蛾毒力最佳配比筛选及田间防效研究

为了延缓小菜蛾Plutella xylostella(L.)抗药性的产生和发展,本研究选用常用的3种化学杀虫剂,即氟啶脲、溴虫腈、茚虫威,采用交互测定法进行了最佳配比的筛选,并根据孙云沛法计算其共毒系数,最后筛选出具增效作用的混配配方,氟啶脲∶溴虫腈(有效成分含量为13.20∶1.72),共毒系数为241;氟啶脲∶茚虫威(有效成分含量为2.20∶3.60),共毒系数为142。田间试验结果表明氟啶脲与溴虫腈混配2000倍液药后7d校正防效为84.24%,与其他处理的校正防效具有极显著差异;氟啶脲与茚虫威混配1000倍液药后7d校正防效为85.08%,与其他处理的校正防效有显著性差异。     

高原春油菜田小菜蛾种群动态和抗药性的监测

【目的】为了准确掌握典型春油菜种植区小菜蛾Plutella xylostella(L.)种群变化动态和抗药性现状。【方法】诱捕法调查了青海高原小菜蛾成虫发生动态、室内用浸渍法测定了小菜蛾田间种群的抗性倍数,并进行了田间药效试验。【结果】青海省小菜蛾一般一年发生3代,但2 500 m以上的地区第3代成虫数量较第1代、第2代明显下降。在我省高原春油菜区,每日20:00至次日晨4:00是小菜蛾成虫发生主要的时间段。小菜蛾在青海省不能越冬。湟中点小菜蛾对溴虫腈产生低水平抗性;对多杀菌素、丁醚脲产生中等抗性水平;对Bt、高效氯氰菊酯、茚虫威产生高水平的抗性;对阿维菌素、啶虫隆、氯虫苯甲酰胺产生极高水平抗性。互助点小菜蛾对溴虫腈、丁醚脲产生低水平抗性;对多杀菌素、啶虫隆产生中等抗性水平;对Bt、氯虫苯甲酰胺、茚虫威产生高水平抗性;对阿维菌素产生极高水平抗性。小菜蛾的抗性监测结果与田间药效结果基本一致,溴虫腈的抗性倍数最低,田间防治效果好于其他参试药剂。【结论】青海省小菜蛾年发生代数较少,且不能越冬。春油菜田小菜蛾已对大部分农药产生了抗药性。     

北京和河北地区小菜蛾的抗药性动态

【目的】了解北京和河北地区小菜蛾Plutella xylostella(L.)对主要防治药剂的抗药性现状,为小菜蛾的有效防治提供参考。【方法】2011—2015年,采用浸叶法监测了小菜蛾对9种药剂的抗药性。【结果】小菜蛾对氯虫苯甲酰胺、多杀菌素和丁醚脲均为敏感水平,对Bt制剂、虫螨腈和茚虫威个别年份出现中等抗性水平,但总体上为敏感状态,对阿维菌素和氟啶脲保持中等抗性水平,对高效氯氰菊酯为中等至高水平抗性。【结论】在北京和河北地区高效氯氰菊酯不适用于小菜蛾的防治,少用或暂停使用阿维菌素,其它药剂可交替或轮换使用。     

几种杀虫剂防治荔枝蝽的应用效果及其评价

为了筛选出对荔枝蝽Tessaratoma papillosa高效低毒低投入的药剂,在室内采用喷雾法初步测定了16种常用杀虫剂对荔枝蝽成虫的活性,进一步测定了辛硫磷、丁醚脲和氟啶虫胺腈等3种药剂对荔枝蝽成虫、1龄若虫和2龄若虫的室内毒力,并开展了3种杀虫剂对荔枝蝽的田间防效试验。室内毒力结果表明：甲氰菊酯、杀虫双、阿维菌素、甲氨基阿维菌素苯甲酸盐、哒螨灵、茚虫威、虫螨腈、多杀霉素、乙基多杀霉素、灭蝇胺、异丙威等11种药剂对荔枝蝽成虫活性较低,辛硫磷、丁醚脲和氟啶虫胺腈对荔枝蝽有较高的杀虫活性,3种药剂对成虫72 h后的LC50分别为102.32、226.88和207.59 mg/L,对1龄若虫分别为42.41、120.90和87.59 mg/L,对2龄若虫分别为62.65、180.20和148.75 mg/L。在田间防效试验中,辛硫磷对荔枝蝽成虫药后1 d的防效高达82.46%;氟啶虫胺腈对荔枝蝽成虫药后1 d防效达89.23%,药后7 d防效维持在85.03%;丁醚脲对荔枝蝽成虫的最高防效为71.63%,与高效氯氟氰菊酯的防效相当。辛硫磷、丁醚脲和氟啶虫胺腈的防效投入比分别为9.68、36.25和176.41。辛硫磷投入低、速效性好且光解快,可作为防治荔枝蝽的应急药剂使用,氟啶虫胺腈和丁醚脲防效较好,但投入高,可作为对荔枝蝽有重要潜在研究价值的药剂。     

十一种农药对小菜蛾的毒力及其天敌草间小黑蛛的安全性

通过室内试验,评价了11种农药对3龄小菜蛾Plutella xylostella(L.)幼虫的毒性及其天敌草间小黑蛛的安全性。研究结果表明,苏云金杆菌、氟虫腈、溴虫腈、多杀菌素和丁醚脲对小菜蛾3龄幼虫的杀虫效果最好,致死率达100%;啶虫隆和巴丹效果次之,致死率分别为90.0%和87.5%。对于草间小黑蛛Erigonidium graminicolum(Sunderall)幼蛛,丁醚脲、苏云金杆菌、虫酰肼、啶虫隆的初始毒性和持续毒性均较低,接触药膜48h后致死率都低于30%;而对于草间小黑蛛成蛛,除阿维菌素、高效氯氰菊酯和巴丹外,其余8种农药毒性较低,死亡率低于20%;综合11种农药对小菜蛾和蜘蛛的毒性,苏云金杆菌、丁醚脲、多杀菌素的选择毒性最好,优先推荐在蜘蛛等天敌多的季节使用。     

农药助剂对茚虫威防治番茄潜叶蛾的减量增效作用

为评价农药助剂对15%茚虫威悬浮剂防治番茄潜叶蛾Tuta absoluta(Meyrick)的减量增效作用,分别向减量10%、20%、30%的15%茚虫威悬浮剂药液中添加500 ppm的有机硅silwet 408、矿物油、芦荟精油助剂,测定其对番茄潜叶蛾的田间防效。结果显示：相同浓度下,添加农药助剂后的防效均显著高于15%茚虫威悬浮剂的防效,相对常规用量通过添加有机硅Silwet 408、矿物油或芦荟精油可使农药减量10%～20%。田间应用将15%茚虫威悬浮剂按照常规用量减量10%～20%,通过添加有机硅Silwet 408、矿物油或芦荟精油可有效防治番茄潜叶蛾。     

不同药剂对小菜蛾的控制作用及其安全性评价

采用田间喷雾方法测定了丁醚脲、氟虫腈、虫螨腈、苏云金杆菌4种杀虫剂对小菜蛾的控制效果及对甘蓝的安全性,结果表明,丁醚脲、氟虫腈、虫螨腈、苏云金杆菌对小菜蛾均有较好的控制效果,药后7d均能有效控制小菜蛾的为害,且对甘蓝安全无药害。     

真菌新型激活蛋白对Bt制剂的增效作用

激活蛋白是从交链孢属 (Alternaria)真菌分离的新型多功能蛋白 ,以棉铃虫和小菜蛾幼虫为供试昆虫 ,用饲料染毒法、浸叶法和浸虫法测定了激活蛋白对Bt的增效作用。结果表明 ,用Bt∶激活蛋白为 1∶0 0 3的含毒饲料饲喂 2龄棉铃虫幼虫 ,其增效指数为 2 2倍。Bt∶激活蛋白以 1∶0 0 95和 1∶0 6混合后分别浸叶后 ,饲喂棉铃虫和小菜蛾幼虫 ,其增效指数分别为 2 7和 5 5倍。单独用激活蛋白饲喂棉铃虫幼虫无致死活性 ,但当Bt与激活蛋白以 1∶0 75混合后 ,毒杀效果显著增强 ,对Bt的增效指数为 18 5倍。     

几种常见杀虫剂对玉米草地贪夜蛾的控制作用

草地贪夜蛾是一种刚入侵我国的世界性迁飞害虫,严重威胁玉米生产安全。本试验选择200 g/L氯虫苯甲酰胺悬浮剂、200 g/L氯虫苯甲酰胺悬浮剂+激健、200 g/L氯虫苯甲酰胺悬浮剂+5%甲维盐微乳剂、150 g/L茚虫威悬浮剂、25%甲维·茚虫威水分散粒剂、60 g/L乙基多杀菌素悬浮剂6个处理开展了田间防控草地贪夜蛾的试验。结果发现,施药后1 d,60 g/L乙基多杀菌素悬浮剂速效性最好,校正防效高达89.24%;药后3 d,60 g/L乙基多杀菌素悬浮剂校正防效最高为94.35%,200 g/L氯虫苯甲酰胺悬浮剂及其与激健、甲维盐复配处理校正防效均在85.00%以上;药后7 d,仍以60 g/L乙基多杀菌素悬浮剂校正防效最高达96.38%,200 g/L氯虫苯甲酰胺悬浮剂及其与激健、甲维盐复配处理校正防效均在90.00%以上,150 g/L茚虫威悬浮剂、25%甲维·茚虫威水分散粒剂校正防效相对略低。本试验首次采取药剂复配和加入激健助剂防控草地贪夜蛾,对延缓害虫抗性、减少农药使用、降低农药残留、科学防控草地贪夜蛾具有积极的指导作用。     

常用杀虫剂对小菜蛾天敌卷蛾分索赤眼蜂的影响

在实验室条件下测定田间常用的11种杀虫剂对小菜蛾Plutella xylostella(L.)卵寄生性天敌卷蛾分索赤眼蜂Trichogrammatoidea bactrae Nagaraja的影响。结果表明,高效氯氰菊酯、丁醚脲、阿维菌素、多杀霉素、溴虫腈、氟虫腈和杀螟丹对卷蛾分索赤眼蜂成蜂有极明显触杀毒性,成蜂接触药膜8h后的死亡率达到89.31%～100%,丁醚脲、阿维菌素和多杀霉素能极显著降低成蜂的寄生力,溴虫腈和氟虫腈处理卵和幼虫期均显著降低卷蛾分索赤眼的成蜂羽化率,杀螟丹对卷蛾分索赤眼蜂各虫态都有极强的毒性,其处理后成蜂的羽化率几乎都为0。试验结果说明,氟啶脲、茚虫威、苏云金杆菌和虫酰肼对卷蛾分索赤眼蜂成蜂及各发育虫态均较安全,可在田间任何时候使用,而高效氯氰菊酯、丁醚脲、多杀霉素和阿维菌素的使用则应尽量避开卷蛾分索赤眼蜂成蜂期。     

小菜蛾对定虫隆抗性种群的选育及交互抗性研究

用昆虫生长调节剂(insect growth regulator,简称IGR)定虫隆(chlorfluazuron)对源自深圳田间的小菜蛾(SZ-S)Plutella xylostella(L.)在室内进行抗性种群选育,经过8代饲养和6次药剂汰选,获得抗性种群(CH-R),与相对敏感种群Sz—S比较,抗性指数(R1)为23.78倍。CH-R种群在去除选择压力条件下饲养5代,抗性逐渐下降。抗性汰选前后分别测定了10种药剂的剂量—死亡毒力回归线,发现CH—R抗性种群对三氟氯氰菊酯、氯氰菊酯、辛硫磷、喹硫磷、灭多威、磺胺脲类衍生物—杀螨隆、微生物杀虫剂Bt和齐墩螨素无明显交互抗性,抗性倍数为0.4-1.7;对两种沙蚕毒素类杀虫剂杀螟丹和杀虫丹的敏感性却有所上升,有负交互抗性趋势。活体增效剂试验表明,增效醚(PBO)和三苯基磷酸酯(TPP)对定虫隆均有一定的增效活性,PBO的增效比最高为29倍,能够完全抑制对定虫隆的抗性,说明多功能氧化酶可能是主导抗性机制之一。     

11种不同类型杀虫剂对卷蛾分索赤眼蜂繁殖的亚致死效应

在实验室条件下通过药膜法研究了11种不同类型的杀虫剂对卷蛾分索赤眼蜂Trichogrammatoidea bactrae Nagaraja成蜂的毒性, 并研究了杀虫剂对其繁殖的亚致死效应, 旨在评估各药剂对卷蛾分索赤眼蜂成蜂的安全性, 为小菜蛾Plutella xylostella防治过程中杀虫剂的合理施用提供科学依据。研究结果表明, 卷蛾分索赤眼蜂成蜂对阿维菌素最敏感, 致死中浓度LC₅₀和亚致死浓度LC₃₀分别为0.1984和0.1660 mg/L, 其次为氟虫腈（0.2027和0.1903 mg/L）、溴虫腈（0.3069和0.2038 mg/L）、多杀霉素（1.3630和1.0481 mg/L）、杀螟丹（8.1042 和6.7891 mg/L）、高效氯氰菊酯（10.3647和5.8035 mg/L）和丁醚脲（11.5318 和9.9212 mg/L）。经亚致死浓度LC₃₀的阿维菌素、溴虫腈、杀螟丹、丁醚脲、多杀霉素和氟虫腈处理后, 卷蛾分索赤眼蜂的寿命（1.00~1.67 d）显著缩短, 寄生卵量（0~21.70粒/雌）明显降低, 种群参数（净生殖力R₀、内禀增长率r_m、周限增长率λ和世代平均历期T）明显低于对照（P<0.05）。田间推荐浓度的茚虫威、氟啶脲、苏云金杆菌Bacillus thuringiensis、虫酰肼对卷蛾分索赤眼蜂寿命及产卵量均没有不利影响, 但能通过缩短其世代平均历期T, 从而使净生殖力R₀、内禀增长率r_m和周限增长率λ增加。而经亚致死浓度LC₃₀的高效氯氰菊酯处理后, 卷蛾分索赤眼蜂的寿命（3.77 d）显著延长, 寄生卵量（55.47粒/雌）明显提高, 种群参数明显高于对照(P<0.05)。结果说明, 氟啶脲、茚虫威、苏云金杆菌和虫酰肼对卷蛾分索赤眼蜂较安全; 丁醚脲对卷蛾分索赤眼蜂成蜂的寄生能力影响极大, 在田间施用时应当尽量避开卷蛾分索赤眼蜂成蜂的盛发期。     

Effects of various insecticides on the development of the egg parasitoid Trichogramma dendrolimi (Hymenoptera: Trichogrammatidae).

The toxicity of six insecticides, acephate, methomyl, ethofenprox, cartap, chlorfluazuron, and Bacillus thuringiensis (Bt) was tested on different developmental stages of the egg parasitoid, Trichogramma dendrolimi (Matsumura). Each of the insecticides tested showed different degrees of toxicity to the parasitoid, Ethofenprox showed the highest toxicity and cartap showed relatively higher toxicity compared with the other insecticides. The development of the parasitoids treated with these two insecticides was normal, similar to that of the control group. Only the emergence of adult wasps from host eggs was disturbed. Emergence of the host, Mamestra brassicae larva was reduced following treatment with ethofenprox, cartap and methomyl. However, adult female wasps, which emerged from host eggs treated with the insecticides had the ability to oviposit normally.     

Compatibility and interaction between Bacillus thuringiensis and certain insecticides: perspective in management of Tuta absoluta (Lepidoptera: Gelechiidae)

Bacillus thuringiensis var. kurstaki (Berliner) (Bt) has been suggested as a biological control agent for Tuta absoluta (Meyrick). The objective of this study was to determine the interaction between abamectin, azadirachtin, indoxacarb, chlorantraniliprole, dichlorvos and metaflumizone with Bt. Effect of recommended doses of the chemical insecticides on colonisation of Bt was also investigated in culture medium. Except for metaflumizone, none of the chemicals tested reduced the colonisation of Bt compared with control. Interaction between Bt and the chemical insecticides on 2nd-instar larvae was also assessed. In interaction tests, Bt was applied at LC₅₀ level, 0, 12, 24 or 36 h after treating the larvae with LC₁₀ or LC₂₅ of the chemical insecticides. An antagonistic effect was observed in all treatments where Bt was applied immediately after the chemical insecticide. Also, antagonism was observed when treatment with Bt was done 12 h after azadirachtin and metaflumizone applications. Applying Bt 12 and 24 h after treatment with LC₂₅ of chlorantraniliprole, dichlorvos and abamectin resulted in synergism. But, synergism with LC₁₀ of dichlorvos and abamectin was observed only after 12 h. Additive effect was observed in the rest of the time and concentration combinations. Based on the results obtained, simultaneous use of the chemical insecticides tested and Bt is not recommended for T. absoluta control; and an appropriate time interval should be taken into consideration accordingly.     

Insecticide toxicity to the borer <Emphasis Type="Italic">Neoleucinodes elegantalis</Emphasis> (Guenée) (Lepidoptera: Crambidae): developmental and egg-laying effects

Neoleucinodes elegantalis (Guenée) (Lepidoptera: Crambidae) is one of the major pests of solanaceous plants in South America. It is considered a great threat by the European and Mediterranean Plant Protection Organization due to the serious economic damage that it causes on tomato farms; therefore, controlling this pest is a challenging task in South America. Controlling N. elegantalis at the egg stage is the best way to prevent it from damaging crops; however, thorough studies about the effectiveness of chemicals on the different life stages of this insect pest are lacking. In this study, the effects of different chemical classes were evaluated on N. elegantalis adults, female oviposition behavior, larvae, eggs, and embryonic development. None of the tested insecticides demonstrated toxicity to the adults; however, the results showed that cartap hydrochloride affects oviposition behavior. Moreover, methomyl and cartap hydrochloride exhibited high toxicity against the eggs and larvae, with higher than 80% of mortality. These insecticides interrupted larval hatching and caused alterations in the chorion layer. Flubendiamide and deltamethrin demonstrated toxicity on N. elegantalis larvae; however, lufenuron, indoxacarb, methoxyfenozide, and chlorantraniliprole demonstrated low toxicity on both eggs and larvae, with lower than 70% of mortality. Fruit treated with cartap hydrochloride had a deterrent effect. The ovicidal activity revealed by methomyl and cartap hydrochloride might provide new approaches regarding insecticide effects on eggs. Methomyl, cartap hydrochloride, flubendiamide, and deltamethrin demonstrated toxicity on larvae. The evaluation of the chorion of the eggshell in this study has clarified the toxic effect of methomyl and cartap hydrochloride on eggs.     

小菜蛾对杀虫双和杀螟丹抗药性遗传的DNA随机扩增多态性研究

利用室内选育119代的抗杀虫和抗杀螟丹小菜蛾Plutella xylostella品系和敏感品系,通过反复回交建立近等基因系。用Operon公司全盛的80个引物对抗杀虫比近等基因系和抗杀螟丹近等基因系小菜蛾基因组DNA进行PCR扩增;在抗杀虫双近等基因系中3个引物分别产生了1条特异扩增带,2个引物分别产生了2条特异扩增带,1个引物产生3条特异拉增带;在抗杀螟丹近等基因系中,有4个引物分别产生了1条特异扩增带,1个引物产生了2条特异扩增带,在培育近等基因系的多次回交过程中,与抗性有关的遗传因子被逐步换到敏感品系的基因组中,因此可以认为这些特异带与小菜蛾对杀虫双和杀螟丹的敏感性有关。     

小菜蛾对杀螟丹抗性遗传的研究

利用室内选育的抗杀螟丹小菜蛾Plutella xylostella (L.)品系和敏感品系研究了该品系的抗性遗传形式,结果表明,小菜蛾对杀螟丹的抗性形式为常染色体多基因遗传,并呈不完全显性。该品系对６种常用杀虫剂的抗性谱测定结果表明,对杀虫双有较严重的正交互抗性;对敌敌畏、杀扑磷有低度交互抗性;对溴氰菊酯、灭多威和叶蝉散等药剂无交互抗性。还发现该品系对杀螟丹的抗性与乙酰胆碱酯酶和羧酸酯酶活性无关。