昆虫病原真菌与硅藻土混用对四纹豆象的毒力效果(英文)

在室内条件下检测了白僵菌Beauveria bassiana (Balsamo) Vuillemin 菌株IRAN-187C 和金龟子绿僵菌Metarhizium anisopliae (Metschnikow) Sorokin菌株A-396分别与硅藻土（DE）制剂InsectoSec混用对四纹豆象Callosobruchus maculatus成虫的毒力效果。结果表明：硅藻土与致死剂量和亚致死剂量的真菌分离物混用导致了四纹豆象成虫的高死亡率,且这些处理均缩短了真菌的致死中时(LT₅₀)。LC₅₀ 的白僵菌B. bassiana菌株IRAN-187C和 LC₅₀ 的DE混用对四纹豆象的LT₅₀ (122.2 h)最低,在95%置信限上与LC50 的金龟子绿僵菌M. anisopliae菌株A-396 与LC₅₀的DE混用得到的LT₅₀ (128.2 h) 相当,说明两种真菌分离物与DE混用对四纹豆象成虫都具有较好的毒力效果。用四纹豆象成虫检测3个温度（22, 27和30℃）和2个相对湿度（40%和55%）组合对DE活性的影响,结果显示30℃和40%相对湿度条件下得到的LT₅₀ (110.11 h)最低,说明高温低湿条件下DE活性较高。     

球孢白僵菌对象虫金小蜂安全性评价和亚致死效应研究

为明确球孢白僵菌Beauveria bassiana对烟草甲Lasioderma serricorne(Fabricius)幼虫、成虫的致病力以及对象虫金小蜂Anisopteromalus calandrae(Howard)的安全性,本研究采用浸渍法测定球孢白僵菌对烟草甲和象虫金小蜂的LC₁₀、LC₂₅、LC₅₀,以球孢白僵菌亚致死浓度LC₁₀和LC₂₅胁迫象虫金小蜂成虫后,分析其F₁代实验种群生存、发育和繁殖的变化。结果表明：(1)在1×10⁹孢子/mL的球孢白僵菌浓度下,烟草甲幼虫的致死率可达到92.62%,烟草甲成虫的致死率为100.00%,象虫金小蜂成虫的致死率可达98.73%,亚致死浓度LC₁₀和LC₂₅分别为2.125×10⁵和7.114×10⁵孢子/mL。(2)受LC₁₀和LC₂₅胁迫处理象...     

阿维菌素对白背飞虱发育和繁殖的亚致死效应（英文）

【目的】探究阿维菌素对白背飞虱Sogatella furcifera的亚致死效应。【方法】采用稻茎浸渍法，分别以阿维菌素亚致死浓度LC₁₀(0.016 mg/L)和LC₂₅(0.031 mg/L)处理白背飞虱3龄若虫，统计F₀代雌雄成虫寿命、单雌产卵量；记录F₁代的发育历期、繁殖力、存活率及雌雄成虫寿命、内禀增长率(r)、周限增长率(λ)、净增殖率(R₀)和平均世代周期(T)，组建年龄-阶段两性生命表。【结果】与对照(蒸馏水)相比，白背飞虱3龄若虫在LC₁₀和LC₂₅浓度阿维菌素的胁迫下，F₀代单雌产卵量均显著降低，但孵化率未受影响；LC₂₅浓度阿维菌素处理后，白背飞虱雄成虫寿命与对照组相比显著延长，但LC₁₀阿维菌素处理显著缩短了雌成虫寿命。在F₁代中，LC₁₀和LC₂₅浓度处理组的单雌产卵量分别为17...     

氯虫苯甲酰胺对白背飞虱实验种群的亚致死效应

为正确评估防治水稻鳞翅目害虫的新型杀虫剂氯虫苯甲酰胺对非靶标害虫白背飞虱Sogatella furcifera (Horváth)的影响, 本文采取稻茎浸渍法测定了氯虫苯甲酰胺对白背飞虱的毒力, 利用生命表技术研究了氯虫苯甲酰胺对白背飞虱的亚致死效应。结果表明： 氯虫苯甲酰胺对白背飞虱3龄若虫和成虫的LC₅₀分别为19.26 mg/L和19.69 mg/L。以氯虫苯甲酰胺LC₁₀和LC₂₅剂量分别处理白背飞虱3龄若虫后, F₀和F₁代雌虫产卵量及其寿命均降低, 尤其LC₂₅处理与对照间存在显著差异（P<0.05）, F₀和F₁代雌虫寿命分别缩短了1.80 d和2.62 d, F₀和F₁代雌虫产卵量分别减少了52.94粒和78.45粒。药剂处理对F1代各虫态发育历期也有一定影响。根据不同剂量处理后白背飞虱各发育阶段的存活率和成虫的繁殖力, 组建了生殖力生命表, 发现LC₁₀和LC₂₅剂量处理的种群内禀增长率rm分别降低了11.25%和34.41%, 净增殖率R0分别降低了36.56%和74.57%, 而世代平均历期T和种群加倍时间t均延长。结果说明, 氯虫苯甲酰胺LC₁₀和LC₂₅剂量可抑制白背飞虱种群的增长; 大田中使用氯虫苯甲酰胺防治鳞翅目害虫时, 可抑制同时发生的非靶标害虫白背飞虱田间种群增长。     

四种基质表面上常规杀虫剂对四纹豆象的药效评价（英文）

在害虫治理中, 在消费或贮藏粮食加工产品的建筑设施或场所进行害虫防治需要将杀虫剂施用在各种基质表面上。为了测定不同基质表面上杀虫剂的药效, 将四纹豆象Callosobruchus maculatus (F.)成虫接触田间推荐剂量的阿维菌素、 溴氰菊酯和毒死蜱。结果表明： 施用在玻璃、 瓷砖、 塑料和纸盘表面上, 阿维菌素对四纹豆象成虫的致死率分别为63.33%, 22.41%, 12.9%和11.9%, 而溴氰菊酯在这4种基质表面上对四纹豆象成虫的致死率分别为 55%, 44.2%, 41.3%和 37.4%。在所有基质表面上接触毒死蜱, 四纹豆象成虫的死亡率均为100%。对数据进行的Probit 分析表明, 毒死蜱制剂在玻璃、 瓷砖、 塑料和纸盘上对四纹豆象成虫 的LC₅₀ 值分别为 8.66, 13.6, 29.16和 56.5 μg/mL, 阿维菌素制剂的相应数值分别为119.4, 446.2, 774.2 和 836.4 μg/mL, 溴氰菊酯制剂的相应数值分别为 1 008, 1 131, 1 210和 1 336 μg/mL。据此推断, 毒死蜱对四纹豆象的毒性最强, 且在玻璃、 瓷砖、 塑料和纸盘表面上的毒性依次降低。     

溴氰虫酰胺亚致死剂量对甜菜夜蛾生长发育及体内解毒酶活性的影响

【目的】探讨溴氰虫酰胺对甜菜夜蛾 Spodoptera exigua (Hübner)的亚致死效应,为甜菜夜蛾的综合防治和溴氰虫酰胺的合理使用提供理论依据。【方法】采用饲料混毒法,测定溴氰虫酰胺对甜菜夜蛾3龄幼虫的毒力,确定其亚致死剂量（LC₁₀和LC₂₅）,并分别用该亚致死剂量处理甜菜夜蛾3龄幼虫,研究其对甜菜夜蛾的生长发育和体内3种解毒酶活性的影响。【结果】以LC₁₀ 和LC₂₅剂量处理甜菜夜蛾3龄幼虫后,幼虫生长受到显著抑制,虫重抑制率分别为11.55%和27.68%;LC₁₀和LC₂₅处理组3龄幼虫到化蛹天数分别比对照组延长0.07和0.20 d;化蛹率显著低于对照组（80.93%）,分别为63.89%和49.43%;成虫寿命显著缩短1.11 d和2.08 d;单雌产卵量和卵孵化率也低于对照组。亚致死剂量溴氰虫酰胺处理甜菜夜蛾幼虫后24-96 h,羧酸酯酶活性和谷胱甘肽-S转移酶活性表现出相似的变化趋势,呈先激活升高、后被抑制降低;而多功能氧化酶活性在药剂处理48 h和72 h均受到不同程度的抑制作用,这种抑制作用与浓度成正比。【结论】亚致死剂量的溴氰虫酰胺对甜菜夜蛾的生长发育有显著抑制作用,对其幼虫体内解毒酶活性也有不同程度的抑制作用。     

丁硫克百威和阿维菌素对柑橘大实蝇成虫运动行为的亚致死效应

柑橘大实蝇 Bactrocera minax (Enderlein)是一种为害柑橘类果实的毁灭性害虫。评价亚致死浓度的丁硫克百威和阿维菌素对其成虫运动行为的影响,可为预防和控制该害虫提供理论基础。本文通过不同亚致死浓度的丁硫克百威和阿维菌素处理柑橘大实蝇成虫,并于药后1 h和6 h检测其起飞率、水平和垂直爬行距离。结果表明,与空白对照组（CK）相比,LC5 、LC10 丁硫克百威处理后1 h的雌、雄虫起飞率分别显著降低66.7%、50.0%、43.3%和40.0%;LC5 丁硫克百威处理的成虫垂直爬行距离也明显降低34.6%,而LC10丁硫克百威处理的成虫水平爬行距离却显著增加24.7%。与空白对照组（CK）相比,LC5 、LC10 、LC25 阿维菌素的处理后1 h的柑橘大实蝇雌、雄成虫起飞率分别显著降低33.3%、23.3%、23.3%、33.3%、53.3%和46.7%;LC5 和LC25 阿维菌素处理的成虫水平爬行距离分别明显降低24.2%和38.0%。LC10和LC25 阿维菌素处理的成虫垂直爬行距离也分别明显降低25.2%和84.4%。结果还表明,丁硫克百威和阿维菌素对柑橘大实蝇成虫的水平爬行能力、垂直爬行能力和起飞能力的亚致死效应与其浓度相关。丁硫克百威的亚致死浓度处理对柑橘大实蝇成虫水平爬行能力的影响存在性别差异,而阿维菌素的亚致死浓度处理对该成虫起飞能力和水平爬行能力的影响亦存在性别差异。此外,丁硫克百威和阿维菌素对柑橘大实蝇成虫水平爬行能力和垂直爬行能力的亚致死效应与药剂处理后时间长短相关。     

亚致死浓度氯虫苯甲酰胺可降低亚洲玉米螟的种群增长

为了探讨氯虫苯甲酰胺对亚洲玉米螟Ostrinia furnacalis (Guenée)的抗性风险评估, 为科学使用氯虫苯甲酰胺防治亚洲玉米螟提供理论基础, 本研究在实验室条件下采用饲料混毒法测定了新型杀虫剂氯虫苯甲酰胺对亚洲玉米螟的毒力, 利用生命表技术研究了氯虫苯甲酰胺对亚洲玉米螟 3龄幼虫的亚致死效应。结果表明： 氯虫苯甲酰胺对亚洲玉米螟3龄幼虫的LC₁₀, LC₄₀ 和LC₅₀分别为0.038, 0.098 和0.123 mg a. i. /L。以氯虫苯甲酰胺LC₁₀和LC₄₀剂量分别处理亚州玉米螟3龄幼虫后, 幼虫和蛹的发育历期明显延长, 成虫寿命缩短, 产卵量也显著降低, 但对蛹重（雌： P=0.337, 雄： P=0.121）、卵孵化率（P=0.087）和性比（P=0.379）无显著影响。处理种群的净增值率（R₀）、内禀增长率（r_m）和周限增长率（λ）显著低于对照种群（P<0.0001）。结果提示, 氯虫苯甲酰胺的亚致死浓度可降低亚洲玉米螟的种群增长。     

甲氰菊酯和阿维菌素对柑橘全爪螨的亚致死效应

通过叶碟饲养的方法, 利用生命表技术,研究了甲氰菊酯和阿维菌素亚致死剂量LC₂₀处理柑橘全爪螨若螨后,对试验种群当代(F₀)和后代(F₁、F₂代)生长发育及繁殖的影响.结果表明: 甲氰菊酯LC₂₀处理若螨后,当代雌成螨产卵量显著增加;F₁、F₂代的产卵前期缩短,后代雌性比例增大,且均与对照差异显著;同时,F₁和F₂代种群内禀增长率(r_m)和周限增长率(λ)增大,世代历期(T)和种群加倍时间(Dt)缩短,且F₂代与对照相比差异显著.用阿维菌素LC₂₀处理若螨后,当代种群雌成螨产卵量显著下降; F₁和F₂代的产卵量也显著下降,但后代雌性比例增大,产卵前期显著缩短;F₁和F₂代的种群r_m和λ增大,T和Dt缩短,且F₂代比F₁代更为明显.总体来看,甲氰菊酯和阿维菌素亚致死浓度LC₂₀对柑橘全爪螨的影响并不完全相同,甲氰菊酯能够促进当代种群的发展,而阿维菌素对当代种群有一定的抑制作用;但两种杀螨剂亚致死浓度处理柑橘全爪螨对后代种群都有一定的促进作用.研究结果对柑橘全爪螨综合防治策略的制定有一定的指导意义.     

氰氟虫腙对小菜蛾阿维菌素抗性和敏感种群的亚致死效应(英文)

在实验室条件下采用生命表技术研究了氰氟虫腙亚致死剂量（LC₂₅）对小菜蛾Plutella xylostella阿维菌素抗性（AV-R）和敏感（AV-S）种群的亚致死效应, 旨在为小菜蛾对阿维菌素的抗性治理提供理论基础。结果表明： 氰氟虫腙对小菜蛾3龄幼虫抗性种群的LC₅₀和LC₂₅分别为0.24 mg/L和0.09 mg/L; 对敏感种群的LC₅₀和LC₂₅分别为0.20 mg/L和0.07 mg/L。氰氟虫腙亚致死剂量0.09 mg/L 处理小菜蛾后, 对处理代的影响表现为显著降低处理种群的化蛹率、 蛹重、 羽化率、 繁殖力; 明显延长蛹期, 缩短成虫产卵期和寿命; 对子代种群的影响表现为显著降低卵的孵化率、 幼虫各龄期的存活率, 延长发育历期。处理种群的内禀增长率（r_m）、 周限增长率（λ）和净增值率（R₀）显著低于对照种群（P<0.0001）。亚致死剂量的氰氟虫腙对小菜蛾抗性种群的影响大于敏感种群, 对处理代种群的影响大于子代种群。氰氟虫腙亚致死剂量可以极大地影响小菜蛾尤其是阿维菌素抗性种群的种群动态, 因此氰氟虫腙对于小菜蛾的抗性治理具有积极的作用。     

Host resistance enhances susceptibility of Callosobruchus maculatus (Coleoptera: Chrysomelidae) to herbal extract of Echinophora platyloba

It has been argued that resistant cultivars may enhance the susceptibility of insect pests to insecticides, and thus can reduce crop production costs by lowering the rate of insecticide application. Here we studied the susceptibility of the cowpea seed beetle, Callosobruchus maculatus (Coleoptera: Chrysomelidae), reared on either a susceptible or resistant cultivar of the mung bean (Vigna radiate ), to a herbal extract taken from the prickly parsnip, Echinophora platyloba (Umbelliferae). After selection of a susceptible (Parto) and a resistant (Sahar) cultivar, the median lethal concentration (LC₅₀) of the herbal extract was determined as 24.41 and 20.28 μL/250 mL air against beetles reared on susceptible and resistant cultivars, respectively. Rearing on resistant cultivar had a significant effect on biological parameters of C. maculatus regardless of insecticide application. However, herbal extract showed a significant interaction with host resistance in terms of oviposition rate and pre‐adult development time. These results provide evidence that the resistant cultivar increases the susceptibility of C. maculatus to herbal extract. The use of plant resistance in combination with narrow‐spectrum insecticides seems to be of both economic and environmental importance, as it can reduce the costs of crop production and lower the doses of insecticides required for satisfactory pest control.     

Lethal and sub‐lethal effects of spinosad on the life‐history traits of army worm,Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae), and its fitness cost of resistance

Spodoptera litura is one of the most destructive polyphagous insect pests, with more than 120 host‐plant species. In our present study, a field‐collected population of S. litura when selected with spinosad for 11 consecutive generations resulted in the development of 3921‐fold resistance to spinosad as compared to the susceptible strain. The spinosad‐resistant strain of S. litura had a relatively high fitness cost (0.17) as compared to the susceptible strain. Furthermore, the lethal and sub‐lethal effects of different concentrations of spinosad were checked on the susceptible strain at different levels; i.e., LC₄₀, LC₃₀, LC₂₀ and LC₁₀, which revealed that the impact of spinosad on the life‐history traits of S. litura increased with the increase in concentration of spinosad. A significant impact of spinosad was recorded on the larval duration, pre‐pupal weight, pupal duration, pupal weight, reproductive potential and adult emergence. The outcomes of the current research clearly indicate that fitness cost of spinosad and its sub‐lethal effects have a significant impact on population dynamics of S. litura, for which it can be incorporated in integrated pest management.     

Lethal,sublethal and transgenerational effects of the novel chiral neonicotinoid pesticide cycloxaprid on demographic and behavioral traits of Aphis gossypii (Hemiptera: Aphididae)

Aphis gossypii Glover (Hemiptera: Aphididae) is a key pest in cotton crops, notably owing to its increasing resistance to commonly used pesticides. Such resistance prompts for the development of integrated pest management (IPM) programs that include novel pesticides being effective against the aphid. In the present study, we assessed lethal and sublethal effects of cycloxaprid, a novel chiral neonicotinoid pesticide developed in China, on A. gossypii. The lethal concentration at 50% (LC₅₀) value of cycloxaprid on A. gossypii was estimated, using the dipping method, at 7.73 mg/L. The impact of a sublethal concentration (LC₁₀) and a lethal concentration (LC₄₀) of cycloxaprid on A. gossypii population growth and feeding behavior (using electrical penetration graph technique [EPG]), and its transgenerational effect were further assessed. Adult longevity and fecundity significantly decreased after exposure to LC₄₀ or LC₁₀ of cycloxaprid. Cycloxaprid with sublethal concentrations (especially LC₄₀) had negative effects on phloem ingestion by A. gossypii. Additionally, the offspring of the adults exposed to LC₄₀ of cycloxaprid had shorter nymphal development duration and adult longevity than the control, and those from LC₁₀ and LC₄₀ treatments had lower adult fecundity and net productive rate. We demonstrated that cycloxaprid is a pesticide showing both lethal and sublethal activities, and transgenerational effects on A. gossypii; it may be useful for implementation in IPM programs against this aphid pest.     

Screening and secretomic analysis of enthomopatogenic Beauveria bassiana isolates in response to cowpea weevil (Callosobruchus maculatus) exoskeleton

The production of cowpea (Vigna unguiculata), an important self-sustained crop in Latin America and Africa, is severely affected by damage by the cowpea weevil Callosobruchus maculatus. The presence of a single larva in stored seeds can lead to losses of almost 40%. Control of C. maculatus currently relies on the inefficient use of chemical insecticides and post-harvest treatments. The use of entomopathogenic fungus became a reliable alternative for coleopteran pest control and has been extensively investigated. Among them, Beauveria bassiana and Metarhizium anisopliae were widely evaluated in order to measure their virulence toward many insects. In this report, we evaluated the insecticidal activity of ten strains of B. bassiana and the most lethal fungi strains were analyzed for proteinaceous secretions by two dimensional electrophoresis and for enzyme activities, including chitinolytic, proteolytic and alpha-amylolytic activities. This study could, in the near future, help to establish novel biotechnological tools to use for cowpea weevil control.     

Contact and fumigant activities of Citrullus colocynthis formulations against Callosobruchus chinensis (Coleoptera: Bruchidae)

The efficacy of two different formulations of Citrullus colocynthis extracts (emulsifiable and powder) were tested as contact and fumigant toxicants against cowpea weevil adults, Callosobruchus chinensis. The emulsifiable concentrate showed repellent activity against the adults. No eggs were laid by females in the choice test at 1.0% concentration compared with 150.0 eggs in control. Using the same concentration, the females deposited 1.4 eggs in the non-choice test compared with 78.2 eggs in control. The concentration of 2.5 μl/38.5 ml air of citrullus emulsifiable caused 100% mortality to adults during one day in the fumigation test. Also, the vapor of citrullus emulsifiable was highly effective against eggs of cowpea weevil, where, at 2.5 μl/38.5 ml air, no eggs hatched. Both formulations affect the different biological aspects of cowpea weevil, however, citrullus emulsifiable concentrate was more potent than the citrullus powder.     

Feeding response of the cotton aphid,Aphis gossypii,to sublethal rates of flonicamid and imidacloprid

The cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is an important sap‐sucking pest of many plants, including melons and peppers. This study was conducted to determine the effects of sublethal exposure to flonicamid and imidacloprid and the mechanisms by which these insecticides affect the feeding behavior of A. gossypii. The median lethal concentrations (LC₅₀) of flonicamid and imidacloprid for adult A. gossypii were 2.40 and 1.92 mg l^?1, respectively. The lower lethal concentrations of flonicamid were 1.01 mg l^?1 (LC₃₀) and 0.29 mg l^?1 (LC₁₀), and those of imidacloprid were 0.82 mg l^?1 (LC₃₀) and 0.24 mg l^?1 (LC₁₀). The developmental period of A. gossypii nymphs at LC₃₀ was 3.6 days for both insecticides, which was shorter than that of the untreated controls (4.2 days). Longevity and total fecundity of A. gossypii adults were decreased at the sublethal concentrations of both insecticides. The lowest net reproductive rate was observed in A. gossypii treated with the LC₃₀ of flonicamid. Feeding behavior analyses using an electrical penetration graph showed that sublethal concentrations of flonicamid and imidacloprid had significant effects on the duration of phloem ingestion. Higher doses of flonicamid induced starvation by inhibiting phloem ingestion, whereas imidacloprid acted as a contact toxin rather than an inhibitor of feeding behavior.     

Toxicity assessment of insecticides commonly used in rice pest management to the fry of common carp, Cyprinus carpio, a food fish culturable in rice fields

Toxicity of four insecticides commonly used in rice pest management, chlorpyrifos, dimethoate, carbaryl and carbosulfan, to the fry of common carp was assessed through median lethal concentrations (LC₅₀) and in vivo inhibition of the brain acetylcholinesterase (AChE) enzyme at sublethal concentrations. The 96‐h LC₅₀ values for these four insecticides were determined to be 0.008, 26.11, 7.85 and 0.60 mg L^?1 respectively. Exposure of fish to a series of sublethal concentrations (0.5–5% LC₅₀) of each insecticide for 14 days resulted in concentration‐dependent inhibition in AChE activity in comparison with the controls. AChE activity was greatly inhibited in the fish exposed to sublethal concentrations of chlorpyrifos. Upon transfer to insecticide‐free water, AChE activities in fry exposed to 0.5 and 1% LC₅₀ concentrations of carbaryl and carbosulfan were restored to the control level within 7–21 days whereas the fish exposed to chlorpyrifos or dimethoate did not fully recover from the insecticide‐induced anticholinesterase action. Of the four insecticides tested, chlorpyrifos was the most toxic for the fry of common carp. Although dimethoate was least toxic for the fish under acute exposure, the restoration level of normal AChE activity was slower under chronic exposure in comparison with carbaryl and carbosulfan. Hence, the use of carbamates, especially carbaryl, to control insect pests of rice in rice‐cum‐carp culture systems is recommended when considering survival, restoration of the normal AChE activity and stamina of the cultured fish.     

Lethal and sublethal effects of thiacloprid on survival,growth and reproduction of Helicoverpa armigera (Lepidoptera: Noctuidae)

The cotton bollworm Helicoverpa armigera (Hübner) is the most destructive pest of cotton, tomato and chickpea in Iran. In this study, the lethal and sublethal effects of thiacloprid were evaluated against cotton bollworm under laboratory condition at 26?±?1?°C, 70?±?5% RH and a photoperiod of 16:8 (L:D). Bioassay experiments were conducted on first larval instars by mixing the insecticide dilutions with artificial diet. The LC₅₀ value of thiacloprid was 329?mg a.i./l. Sublethal effects of LC₃₀ concentration of thiacloprid was studied on biological parameters. In the study of sublethal effects, thiacloprid at LC₃₀ concentration significantly increased larval and pupal developmental times and reduced adults longevity compared with control but showed no significant effects on fecundity of cotton bollworm. Sublethal effects of thiacloprid also significantly reduced pupal weight compared with control. In general, sublethal effects studies showed that thiacloprid had adverse effects on biological parameters of the pest. Thus, our data suggest that thiacloprid had moderate potential against cotton bollworm.