Effect of reduced risk pesticides on greenhouse vegetable arthropod biological control agents

BACKGROUND: Arthropod biological control agents (BCAs) are commonly released for greenhouse vegetable insect pest management. Nevertheless, chemicals remain a necessary control tactic for certain insect pests and diseases and they can have negative impacts on BCAs. The compatibility of some formulated reduced risk insecticides (abamectin, metaflumizone and chlorantraniliprole) and fungicides (myclobutanil, potassium bicarbonate and cyprodinil + fludioxonil) used, or with promise for use, in Canadian greenhouses with Orius insidiosus (Say), Amblyseius swirskii (Athias‐Henriot) and Eretmocerus eremicus (Rose & Zolnerovich) was determined through laboratory and greenhouse bioassays. RESULTS: Overall, the insecticides and fungicides were harmless as residues to adult BCAs. However, abamectin was slightly to moderately harmful to O. insidiosus and A. swirskii in laboratory bioassays, whereas metaflumizone was slightly harmful to E. eremicus. CONCLUSIONS: In general, these products appear safe to use prior to establishment/release of these adult BCAs. Copyright © 2010 Society of Chemical Industry     

Baseline toxicity of several pesticides to Hyaliodes vitripennis (Say) (Hemiptera: Miridae)

Hyaliodes vitripennis (Say) is a univoltine indigenous predacious mirid. It has been reported in several orchards where IPM programmes are used. It is a generalist, and feeds on phytophagous mites in addition to other arthropods. In Quebec, a foliar application of imidacloprid, deltamethrin or lambda‐cyhalothrin is used at least once per season to manage arthropod pests such as leafhoppers and leaf‐eating caterpillars. Meanwhile, several applications of metiram, flusilazole, myclobutanil and mancozeb are made to control apple scab [Venturia inaequalis (Cooke) Winter]. In laboratory trials, comparison of lethal concentrations of the three insecticides against H vitripennis nymphs and adults showed no significant difference. However, when lethal concentrations were compared between two growth stages for each insecticide, a significant difference was noted between adults and nymphs treated with lambda‐cyhalothrin, adults being more susceptible than nymphs. No such difference could be detected for imidacloprid or deltamethrin. When LC₅₀ values were compared with the manufacturer's label rates, deltamethrin and imidacloprid were toxic to the nymphs and adults, and lambda‐cyhalothrin was slightly toxic to the nymphs and moderately toxic to the adults. Among the fungicides evaluated in the laboratory, myclobutanil showed moderate toxicity to adults at the manufacturer's label rate. The remaining fungicides had no toxic effects to adults or nymphs, even at four times the manufacturer's label rate. © 2001 Society of Chemical Industry     

防治芹菜上重要害虫的替代药剂筛选及其膳食暴露风险评估

为了筛选防治芹菜上重要害虫的替代药剂,在上海市及银川市开展5%吡虫啉颗粒剂、0.5%阿维菌素颗粒剂及5%氯虫苯甲酰胺悬浮剂在芹菜上的田间试验,通过液相色谱-串联质谱法检测3种农药在芹菜上的残留量,并分别对3种农药进行膳食暴露风险评估。结果表明,5%吡虫啉颗粒剂、0.5%阿维菌素颗粒剂及5%氯虫苯甲酰胺悬浮剂分别以推荐剂量施用于芹菜后,收获期吡虫啉及阿维菌素在芹菜上最大残留量分别为0.97 mg/kg及0.01 mg/kg,氯虫苯甲酰胺安全间隔期内(1 d)在芹菜上的最大残留量为5.24 mg/kg,均低于其在芹菜上的最大残留限量值。中国居民摄入吡虫啉、阿维菌素、氯虫苯甲酰胺的慢性暴露风险(%ADI)最大值为5.17%,急性暴露风险(%ARfD)最大值为11.20%,均远低于100%,膳食暴露风险低。结果表明吡虫啉、阿维菌素、氯虫苯甲酰胺可替代高毒农药用于芹菜上关键虫害的防治。     

Lethal and sub-lethal effects of spinosad on bumble bees (Bombus impatiens Cresson)

Recent developments of new families of pesticides and growing awareness of the importance of wild pollinators for crop pollination have stimulated interest in potential effects of novel pesticides on wild bees. Yet pesticide toxicity studies on wild bees remain rare, and few studies have included long-term monitoring of bumble bee colonies or testing of foraging ability after pesticide exposure. Larval bees feeding on exogenous pollen and exposed to pesticides during development may result in lethal or sub-lethal effects during the adult stage. We tested the effects of a naturally derived biopesticide, spinosad, on bumble bee (Bombus impatiens Cresson) colony health, including adult mortality, brood development, weights of emerging bees and foraging efficiency of adults that underwent larval development during exposure to spinosad. We monitored colonies from an early stage, over a 10-week period, and fed spinosad to colonies in pollen at four levels: control, 0.2, 0.8 and 8.0 mg kg(-1), during weeks 2 through 5 of the experiment. At concentrations that bees would likely encounter in pollen in the wild (0.2-0.8 mg kg(-1)) we detected minimal negative effects to bumble bee colonies. Brood and adult mortality was high at 8.0 mg kg(-1) spinosad, about twice the level that bees would be exposed to in a 'worst case' field scenario, resulting in colony death two to four weeks after initial pesticide exposure. At more realistic concentrations there were potentially important sub-lethal effects. Adult worker bees exposed to spinosad during larval development at 0.8 mg kg(-1) were slower foragers on artificial complex flower arrays than bees from low or no spinosad treated colonies. Inclusion of similar sub-lethal assays to detect effects of pesticides on pollinators would aid in development of environmentally responsible pest management strategies.     

Toxicity and horizontal transfer of chlorantraniliprole against the Asian subterranean termite Coptotermes gestroi (Wasmann): effects of donor:recipient ratio, exposure duration and soil type

BACKGROUND: The effectiveness of chlorantraniliprole and other insecticides (bifenthrin, fipronil, indoxacarb, imidacloprid and chlorfenapyr) were tested against Coptotermes gestroi (Wasmann). Four experiments were conducted: a topical bioassay, a horizontal transfer study, an insecticide bioavailability test and a feeding bioassay. RESULTS: The topical bioassay showed that chlorantraniliprole was significantly less active to C. gestroi at 24 h post‐treatment compared with the other insecticides tested. Nevertheless, it is likely that a lesser amount of chlorantraniliprole was required to cause 50% mortality of C. gestroi at 7 and 14 days post‐treatment. The exposure duration and donor:recipient ratio affect the mortality of recipient termites. Mortality after exposure to chlorantraniliprole in sandy clay was significantly lower than in sand; however, by 14 days, > 90% of donor and recipient termites died in both substrates, irrespective of concentration. Fipronil and imidacloprid showed faster action, and high to moderate toxicity to C. gestroi. Termite workers also ceased to feed after exposure for 1 h to 50 mg kg^?1 chlorantraniliprole‐treated sandy clay. CONCLUSION: Chlorantraniliprole demonstrated delayed toxicity at the lowest label rate (50 mg kg^?1) in sandy clay. Its slow action will enable greater transfer of toxicant between nestmates, while feeding cessation will promote greater social interaction between healthy and exposed termites. Copyright © 2011 Society of Chemical Industry     

中国主要蜜源作物上登记的农药品种及其中杀虫剂对蜜蜂的初级风险评估

对目前中国主要蜜源作物上登记的农药品种进行了梳理,并采用现有的风险评估标准方法,对其中毒死蜱、吡虫啉等共61种杀虫剂对蜜蜂的风险进行了初级评估。结果表明:在58种喷雾施用的杀虫剂中,35种对蜜蜂的风险商值均大于1,风险为不可接受;其余23种的风险商值小于1,风险为可接受;所评估的6种土壤或种子处理内吸性杀虫剂中,5种对蜜蜂的风险商值大于1,风险为不可接受,仅氯虫苯甲酰胺的风险商值小于1,风险为可接受。但由于文中是以药剂在所登记作物上的单次最高施药剂量为暴露量进行的初级评估,并未考虑农药在花粉、花蜜中的降解及降雨引起的淋洗损耗,以及施药时间与作物花期之间的关系等影响因素,因而使得评估结果具有较大的保守性。研究结果一方面可为这些农药的合理使用和管理提供参考,另一方面提示了目前中国关于农药对蜜蜂的初级风险评估程序需进一步优化。     

Susceptibility of tomato borer,Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) populations from Turkey to 7 different insecticides in laboratory bioassay

The tomato borer, Tuta absoluta (Meyrick), was first recorded in Turkey in August 2009 and rapidly became a serious pest in the Mediterranean and Aegean coastal regions in field and greenhouse grown tomatoes. Currently, insecticides are considered one of the major tools for the management of T. absoluta in Turkey. This study, investigated the efficacy of 7 different insecticides, against T. absoluta in laboratory bioassays. To determine the lethal concentration (LC) values and feeding activity of the larvae, tomato leaf parts mined by 1–3 day old L1 larvae were dipped into different insecticide concentrations. Mortality was recorded 5 days after insecticide treatments. Spinosad, chlorantraniliprole + abamectin or indoxacarb treatment resulted in 100% mortality with minimal or no feeding in all populations at their recommended doses of 120, 50.4 and 60 mg a.s. L^?1, respectively. In general, the LC₉₉ values of populations for these insecticides were similar and also lower than that of the recommended field doses. The effect of pyridalyl was low, resulting in low mortality with serious feeding damage at the dose of 125 mg a.s. L^?1. The efficacies of abamectin, metaflumizone and azadirachtin were found to be moderate to low at the recommended doses (4.5, 240 and 50 mg a.s. L^?1, respectively). However, these insecticides may affect pupation and adult emergence rates hence further studies are recommended to investigate these insecticides.     

九种常用农药在桃树生长后期使用的安全性

为了评价桃生长后期使用农药的安全性，以桃早熟品种‘金陵黄露’为材料，分别在桃果收获前7和14 d，按最高推荐剂量及2倍最高推荐剂量混合施用9种农药，包括4种杀虫剂 (阿维菌素、氯虫苯甲酰胺、氯氟氰菊酯和吡虫啉) 和5种杀菌剂 (苯醚甲环唑、腈苯唑、嘧菌酯、甲基硫菌灵和多菌灵)，研究了桃果中的农药残留量变化及不同农药在桃枝、桃叶、果皮和果肉中的分布规律，以及套袋在桃生长后期阻控农药吸收中发挥的作用。结果表明:在桃收获前7 d，按2倍最高推荐剂量施用其中3种杀菌剂 (苯醚甲环唑、腈苯唑、嘧菌酯) 和4种杀虫剂 (阿维菌素、氯虫苯甲酰胺、氯氟氰菊酯、吡虫啉)，7种农药在桃全果中的残留量均低于中国国家农药残留限量标准(MRL)；而过量施用多菌灵和甲基硫菌灵，桃全果中多菌灵残留量显著高于MRL标准，且随着施药后时间的延长，增加了多菌灵由果皮或枝叶向果肉迁移的风险。套袋处理后，桃全果中多菌灵的残留量远低于中国MRL标准，同时显著减少了桃全果中其他8种农药的残留量。9种供试农药在桃树不同组织中的分布规律一致，由高到低依次为果皮>全果>桃叶≥果肉≥桃枝。本研究表明，不同农药品种在桃生长后期消解规律存在差异，其中多菌灵和甲基硫菌灵超量使用会增加多菌灵在桃果中残留超标的风险，而套袋处理可减少桃果中的农药残留。该结果对去除桃果中农药残留、降低膳食摄入风险有一定指导意义。     

Topical and residual toxicity of six pesticides to <Emphasis Type="BoldItalic">Orius majusculus</Emphasis>

The toxicity of six pesticides (four insecticides and two fungicides) to Orius majusculus (Reuter) (Hemiptera: Anthocoridae) adults and nymphs was determined using different exposure methods. Mortality upon topical exposure to abamectin, endosulfan and spinosad at recommended field doses ranged from 56% to 100% after 24 h. However, in leaf residue tests, toxicity to both life stages decreased significantly, ranging from 0% to 33% mortality. Benomyl and copper salts + mancozeb (fungicides) were much less toxic to O. majusculus, with less than 15% mortality of either adults or nymphs in topical and residue bioassays. In persistent toxicity tests, insects were exposed to the same three insecticides for 4 days; mortality varied from 38% to 100%. Egg hatching was not significantly affected when abamectin, endosulfan and spinosad were topically applied. Number of eggs laid per female in choice and no-choice tests did not differ significantly from the control. The insecticides did not show considerable repellent effect in the choice tests. Topical, residue and systemic uptake methods were also compared to determine the differences in the toxicity levels of imidacloprid, a systemic insecticide. However, 100% mortality occurred with all methods.     

21种化学药剂对新疆棉田主要害虫毒力及对多异瓢虫的安全性

为明确现阶段棉田常用化学杀虫剂对新疆维吾尔自治区（简称新疆）棉花主要害虫的毒力以及对新疆本地优势天敌多异瓢虫Hippodamia variegata的安全性,于室内分别测定当前21种棉田常用化学药剂对新疆棉田3种主要害虫棉蚜Aphis gossypii、截形叶螨Etranychus truncatus和棉铃虫Helicoverpa armigera以及优势天敌多异瓢虫的毒力,比较不同药剂对各种害虫和天敌的相对毒力指数以及益害毒性比。结果表明,药剂处理24 h后,10种蚜虫防治药剂对棉蚜成蚜的半致死浓度LC₅₀由高到低依次为氟啶虫胺腈、啶虫脒、吡虫啉、环氧虫啶、噻虫嗪、丁硫克百威、烯啶虫胺、呋虫胺、螺虫乙酯和吡蚜酮,其中益害毒性比较高的药剂主要有氟啶虫胺腈和螺虫乙酯;5种叶螨防治药剂对截形叶螨成螨的LC₅₀从高到低依次为阿维菌素、哒螨灵、四螨嗪、噻螨酮和炔螨特,其中益害毒性比较高的药剂主要有四螨嗪、噻螨酮和阿维菌素;6种鳞翅目害虫幼虫防治药剂对棉铃虫3龄幼虫的LC₅₀由高到低顺次为甲氨基阿维菌素苯甲酸盐（简称甲维盐）、氯虫苯甲酰胺、茚虫威、灭多威、毒死蜱和高效氯氰菊酯,其中益害毒性比较高的药剂主要有甲维盐和氯虫苯甲酰胺。综合上述2个方面结果,氟啶虫胺腈、阿维菌素、甲维盐和氯虫苯甲酰胺不仅对棉花害虫毒力效果强,而且对有益天敌安全性高。     

不同类型杀虫剂对水稻二化螟及稻纵卷叶螟的田间防治效果评价

基于同时防治水稻二化螟及稻纵卷叶螟的杀虫药剂较少的现状,2014年采用田间小区试验探索了有机磷类、沙蚕毒素类、酰肼类、多杀菌素类、取代苯基吡唑类、缩氨基脲类、噁二嗪类、大环内酯抗生素类及双酰胺类等9类16种杀虫剂对二化螟和稻纵卷叶螟的防治效果。结果表明,200g/L氯虫苯甲酰胺SC和10%阿维·氟酰胺SC能有效控制二化螟和稻纵卷叶螟危害,且速效作用好、持效期长达28d,药后7~28d对二化螟和稻纵卷叶螟的防治效果分别为84.85%~93.37%和80.40%~86.16%。60g/L乙基多杀菌素SC、1.8%阿维菌素EC、20%氟苯虫酰胺WG、40%氯虫·噻虫嗪WG、6%阿维·氯苯酰SC和10%四氯虫酰胺SC对二化螟的防治效果好而对稻纵卷叶螟有一定的兼治作用,药后7~28d防治效果分别为81.13%~97.17%和62.17%~85.26%。240g/L氰氟虫腙SC对稻纵卷叶螟的防治效果好而对二化螟有较好的兼治效果,药后7~28d防治效果分别为76.98%~92.16%和76.37%~80.98%。1%甲氨基阿维菌素苯甲酸盐ME对二化螟及稻纵卷叶螟的防治效果较好,速效性好且持效期较长,药后7~28d防治效果分别为69.29%~83.61%和68.84%~82.95%。此外,5%丁虫腈EC和30%茚虫威WG分别对二化螟和稻纵卷叶螟高效,而20%三唑磷EC、40%水胺硫磷EC、29%杀虫双AS和240g/L甲氧虫酰肼SC难以有效控制二化螟和稻纵卷叶螟危害。在水稻生产实践中,建议轮换使用双酰胺类和大环内酯抗生素类杀虫剂、乙基多杀菌素和氰氟虫腙防治二化螟和稻纵卷叶螟。     

不同类型杀虫剂对温室白粉虱若虫的毒力研究

利用一龄若虫浸渍法测定了不同类型杀虫剂对温室白粉虱四季青种群的毒力,发现白粉虱对噻嗪酮、阿维菌素极其敏感,对吡虫啉和联苯菊酯次之,而对马拉硫磷和ＤＤＶＰ不敏感。     

Potency of some novel insecticides at various environmental temperatures on<Emphasis Type="Italic">Myzus persicae</Emphasis>

An attempt was made to achieve low environmental risk control of insect pests using sublethal concentrations of insecticides, enhanced by the effect of high temperatures (>25°C). For each of the insecticides imidacloprid, abamectin, pirimicarb and azadirachtin, the lethal and sublethal concentrations were determined for the green peach aphidMyzus persicae (Sulzer) (Homoptera: Aphididae) and its predator, the lady beetleHarmonia axyridis (Pallas). The lady beetle was more tolerant of all four insecticides, as well as of high temperatures below 40°C, compared with the prey. The joint action of sublethal concentrations of insecticides and high temperatures was investigated to determine the sublethal concentrations and temperatures that would be effective in controlling the aphids, but not detrimental to the beneficial lady beetle. The results suggested a synergistic effect of sublethal insecticide concentrations and high temperatures against the green peach aphid.     

常用杀虫剂对异色瓢虫的毒力及其保护酶的影响

为明确杀虫剂对异色瓢虫Harmonia axyridis(Pallas)幼虫、成虫的毒力及其体内保护酶的影响,采用喷雾法测定了7种杀虫剂对异色瓢虫3龄幼虫和成虫的毒力,同时测定了3种杀虫剂对3龄幼虫和成虫体内超氧化物歧化酶(superoxide dismutase)、过氧化物酶(peroxidase)和过氧化氢酶(catalase)活性的影响。结果显示:7种杀虫剂对3龄幼虫的毒力大小为阿维菌素、啶虫脒吡虫啉、虫酰肼哒螨灵噻嗪酮吡蚜酮,对成虫的毒力大小为阿维菌素、啶虫脒虫酰肼、吡虫啉哒螨灵噻嗪酮吡蚜酮,吡蚜酮对异色瓢虫最安全。亚致死浓度LC10药剂可促进保护酶活性的提高,但随着浓度提高和处理时间增长,3种酶的活性总体呈逐渐下降趋势,表明低浓度的杀虫剂对异色瓢虫体内酶活性存在一定的不利影响。     

Toxicities and sublethal effects of seven neonicotinoid insecticides on survival, growth and reproduction of imidacloprid-resistant cotton aphid, Aphis gossypii

BACKGROUND: Imidacloprid has been a major neonicotinoid insecticide for controlling Aphis gossypii (Glover) (Homoptera: Aphididae) and other piercing–sucking pests. However, the resistance to imidacloprid has been recorded in many target insects. At the same time, cross‐resistance of imidacloprid and other insecticides, especially neonicotinoid insecticides, has been detected. RESULTS: Results showed that the level of cross‐resistance was different between imidacloprid and tested neonicotinoid insecticides (no cross‐resistance: dinotefuran, thiamethoxam and clothianidin; a 3.68–5.79‐fold cross‐resistance: acetamiprid, nitenpyram and thiacloprid). In the study of sublethal effects, imidacloprid at LC₂₀ doses could suppress weight gain and honeydew excretion, but showed no significant effects on longevity and fecundity of the imidacloprid‐resistant cotton aphid, A. gossypii. However, other neonicotinoid insecticides showed significant adverse effects on biological characteristics (body weight, honeydew excretion, longevity and fecundity) in the order of dinotefuran > thiamethoxam and clothianidin > nitenpyram > thiacloprid and acetamiprid. CONCLUSION: The results indicated that dinotefuran is the most effective insecticide for use against imidacloprid‐resistant A. gossypii. To avoid further resistance development, the use of nitenpyram, acetamiprid and thiacloprid should be avoided on imidacloprid‐resistant populations of A. gossypii. Copyright © 2011 Society of Chemical Industry     

Risk posed to honeybees (Apis mellifera L,Hymenoptera) by an imidacloprid seed dressing of sunflowers

In a greenhouse metabolism study, sunflowers were seed‐treated with radiolabelled imidacloprid in a 700 g kg^?1 WS formulation (Gaucho® WS 70) at 0.7 mg AI per seed, and the nature of the resulting residues in nectar and pollen was determined. Only the parent compound and no metabolites were detected in nectar and pollen of these seed‐treated sunflower plants (limit of detection <0.001 mg kg^?1). In standard LD₅₀ laboratory tests, imidacloprid showed high oral toxicity to honeybees (Apis mellifera), with LD₅₀ values between 3.7 and 40.9 ng per bee, corresponding to a lethal food concentration between 0.14 and 1.57 mg kg^?1. The residue level of imidacloprid in nectar and pollen of seed‐treated sunflower plants in the field was negligible. Under field‐growing conditions no residues were detected (limit of detection: 0.0015 mg kg^?1) in either nectar or pollen. There were also no detectable residues in nectar and pollen of sunflowers planted as a succeeding crop in soils which previously had been cropped with imidacloprid seed‐treated plants. Chronic feeding experiments with sunflower honey fortified with 0.002, 0.005, 0.010 and 0.020 mg kg^?1 imidacloprid were conducted to assess potential long‐term adverse effects on honeybee colonies. Testing end‐points in this 39‐day feeding study were mortality, feeding activity, wax/comb production, breeding performance and colony vitality. Even at the highest test concentration, imidacloprid showed no adverse effects on the development of the exposed bee colonies. This no‐adverse‐effect concentration of 0.020 mg kg^?1 compares with a field residue level of less than 0.0015 mg kg^?1 ( = limit of detection in the field residue studies) which clearly shows that a sunflower seed dressing with imidacloprid poses no risk to honeybees. This conclusion is confirmed by observations made in more than 10 field studies and several tunnel tests. © 2001 Society of Chemical Industry     

Toxicity of diafenthiuron to honey bees in laboratory,semi‐field and field conditions

BACKGROUND: Cardamom, an important spice crop often attacked by many insect pests, is controlled mainly using synthetic insecticides. As honey bees play a vital role in pollination in cardamom, the impact of insecticides on honey bees needs to be explored to assess its safety. RESULTS: Risk assessment based on contact toxicity revealed diafenthiuron to be a non‐selective insecticide to bees with a low selectivity ratio (the ratio between the LD₅₀ for beneficial and pest species). A dose of diafenthiuron that killed 90% of cardamom borer, Conogethes punctiferalis Guenee, was found to kill 100% of Indian bees. Based on the hazard ratio (the ratio between the field‐recommended dose and the LD₅₀ for the beneficial), diafenthiuron was found to be slightly to moderately toxic to bees. Diafenthiuron, even at low concentrations of LC₁ (the concentration that killed 1% of bees), was found to affect the foraging and homing behaviour of Indian bees. Of bees fed with 30 µg mL^?1 of diafenthiuron, 40% were found missing on the third day after exposure. However, diafenthiuron did not affect bee visits to the cardamom fields. CONCLUSION: Diafenthiuron is more highly toxic to Apis cerana indica F. than to C. punctiferalis by contact, using selectivity ratio and probit substitution methods of risk assessment, but the hazard ratio revealed diafenthiuron to be a slightly to moderately toxic chemical. Diafenthiuron was found to affect the foraging and homing behaviour of bees at sublethal concentrations. Thus, sublethal effects are more relevant in risk assessment than lethal and acute effects. Copyright © 2010 Society of Chemical Industry     

Multiple resistance of Botrytis cinerea from kiwifruit to SDHIs,QoIs and fungicides of other chemical groups

BACKGROUND: Botrytis cinerea Pers.: Fr. is a high‐risk pathogen for fungicide resistance development that has caused resistance problems on many crops throughout the world. This study investigated the fungicide sensitivity profile of isolates from kiwifruits originating from three Greek locations with different fungicide use histories. Sensitivity was measured by in vitro fungitoxicity tests on artificial nutrient media. RESULTS: Seventy‐six single‐spore isolates were tested for sensitivity to the SDHI fungicide boscalid, the QoI pyraclostrobin, the anilinopyrimidine cyprodinil, the hydroxyanilide fenhexamid, the phenylpyrrole fludioxonil, the dicarboxamide iprodione and the benzimidazole carbendazim. All isolates from Thessaloniki showed resistance to both boscalid and pyraclostrobin, while in the other two locations the fungal population was sensitive to these two fungicides. Sensitive isolates showed EC₅₀ values to boscalid and pyraclostrobin ranging from 0.9 to 5.2 and from 0.04 to 0.14 mg L^?1 respectively, while the resistant isolates showed EC₅₀ values higher than 50 mg L^?1 for boscalid and from 16 to > 50 mg L^?1 for pyraclostrobin. All QoI‐resistant isolates carried the G143A mutation in cytb. Sensitivity determinations to the remaining fungicides revealed in total eight resistance phenotypes. No isolates were resistant to the fungicides fenhexamid and fludioxonil. CONCLUSION: This is the first report of B. cinerea field isolates with resistance to both boscalid and pyraclostrobin, and it strongly suggests that there may be a major problem in controlling this important pathogen on kiwifruit. Copyright © 2010 Society of Chemical Industry     

Acute toxicity of chlorantraniliprole to non‐target crayfish (Procambarus clarkii) associated with rice–crayfish cropping systems

BACKGROUND: Chlorantraniliprole, a novel anthranilic diamide insecticide, was recently introduced into the United States where rice–crayfish crop rotations are practiced to control rice water weevil (Lissorhoptrus oryzophilus Kuschel) infestations. Chlorantraniliprole has high margins of mammalian safety and excellent insecticidal efficacy, but its toxicity to non‐target crayfish is uncertain. In this study, the acute toxicity of chlorantraniliprole to the red swamp crayfish Procambarus clarkii Girard was determined using aquatic and feeding assays. RESULTS: The aquatic 96 h median lethal toxicity (LC₅₀) data indicate that technical‐grade chlorantraniliprole is highly toxic (US EPA category) to crayfish with an LC₅₀ of 951 µg L^?1 (95% CL = 741–1118 µg L^?1). A no observed effect concentration (NOEC) of 480 µg L^?1 was recorded. Neither the 36 day chronic feeding study, where crayfish fed on chlorantraniliprole‐treated rice seed in aquaria, nor the 144 h acute feeding test, where crayfish fed on rice seeds treated with chlorantraniliprole, produced mortality or abnormal behavior. CONCLUSION: Chlorantraniliprole is three orders of magnitude less acutely toxic to P. clarkii than lambda‐cyhalothrin and etofenprox, two pyrethroid insecticides also used in rice, and is less likely to cause acute crayfish toxicity in rice pond ecosystems. Based on acute toxicity data, the use of chlorantraniliprole should be more compatible with rice–crayfish crop rotations than pyrethroids. Copyright © 2010 Society of Chemical Industry     

Genetic structure and fungicide sensitivity of Botrytis cinerea populations isolated from grapevine in northern Italy

Grey mould, caused by Botrytis cinerea, is a disease severely affecting grape production in northern Italy. However, little information is available on the variability of B. cinerea populations associated with grapevine. The mode of reproduction, sensitivity to fungicides, and for the first time in Italy, the genetic structure of B. cinerea populations isolated from grapevine in a northern Italian region are reported. Botrytis cinerea isolates (317) were completely genotyped for six microsatellite loci and characterized for the presence of the transposable elements Boty and Flipper, for the mating type and for resistance to cyprodinil, fludioxonil, boscalid and fenhexamid. All the isolates were found to belong to B. cinerea Group II, indicating the absence of B. pseudocinerea in the investigated areas. The populations possess a high genotypic diversity, different frequencies of transposable elements and a mixed mode of reproduction. At a regional level, B. cinerea populations belong to a large and interconnected pathogen population that includes the major grape‐growing districts. The populations were generally sensitive to fungicides, with a low proportion (8%) of isolates resistant to cyprodinil, fludioxonil and boscalid. A small genetic distance was found between B. cinerea populations. However, the populations geographically isolated from the others by a mountain range showed a small but statistically significant genetic differentiation and a different pattern of fungicide resistance. The results show that northern Italian B. cinerea populations possess a high evolutionary potential and adaptive capacity.