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Larvicidal activity against the beet armyworm, Spodoptera exigua (Hübner), was measured after topical treatment for a series of N-tert-butyl-dibenzoylhydrazines having various substituents in the benzoyl (A-ring) moiety closer to the tert-butyl group, the other benzoyl (B-ring) moiety being unsubstituted. The effects of substituents on the larvicidal activity were analyzed using the classical quantitative structure-activity relationship (QSAR) procedure. Introduction of hydrophobic substituents with a small volume into any position was favourable to activity. The existence of electron-withdrawing substituents at ortho positions was also favourable to activity. For multi-substituted compounds, physico-chemically unknown unfavourable factors were suggested to remain after separating common substituent effects derived from QSAR for mono-substituted analogues. With the exception of the unsubstituted compound RH-5849, the effect of substituents in the A-ring moiety on the larvicidal activity was similar to those found with the lepidopteran rice stem borer, Chilo suppressalis (Walker). The larvicidal activity of RH-5849 against S exigua was significantly lower than the value predicted from the correlation between activities against S exigua and C suppressalis. Topical treatment with piperonyl butoxide, a synergist inhibiting oxidative metabolism, slightly enhanced the larvicidal activity of RH-5849 against S exigua. 相似文献
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Yoshiaki Nakagawa Guy Smagghe Soichi Kugimiya Kazunari Hattori Tamio Ueno Luc Tirry Toshio Fujita 《Pest management science》1999,55(9):909-918
Insecticidal activity against the Colorado potato beetle, Leptinotarsa decemlineata, was measured for a series of substituted N-tert-butyl-dibenzoylhydrazines, in which one of the benzoyl moieties closer to the tert-butyl group was fixed as being 2-chloro-substitued and the other variously substituted singly or doubly. The effects of substituents on the activity were quantitatively analysed using the classical quantitative structure–activity relationship (QSAR) procedure. The activity against the Colorado potato beetle increases with the molecular hydrophobicity. In addition, various types of steric effect are at work, depending upon the positions. Hydrogen-bonding acceptor substituents at the para position enhance the activity. There seem to be threshold (or optimum) values, albeit position-dependent, in the molecular hydrophobicity, above which the activity starts to decrease. This biphasic contribution of the molecular hydrophobicity to activity against coleopterous larvae is the most conspicuous difference in substituent effects from those found for similar compounds against lepidopterous pest insects, and may be the basis of the variations in the activity spectrum for certain compounds in this series. The introduction of bulkier substituents into the meta- and para-positions of the benzene ring, apart from the tert-butyl group, is unfavorable to activity. LD50 values against Colorado potato beetle larvae of methoxyfenozide (RH-2485) and tebufenozide (RH-5992) were in the order of 10−7 mol per insect, whereas those of RH-5849, and halofenozide (RH-0345) were very low, 10−9–10−10 mol per insect being selective to the coleopterous larvae. © 1999 Society of Chemical Industry 相似文献
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BACKGROUND: Dose–response relationships for antifeedant effects of H. lupulus extracts against larvae and adults of the Colorado potato beetle (CPB) were determined in laboratory conditions. The larval and adult beetles were fed on potato leaflets treated with H. lupulus extract ranging from 0.4 to 40 mg mL?1 in a no‐choice situation. Their feeding behavior was recorded, and larval growth and antifeedant indexes were calculated. RESULTS: H. lupulus treatments significantly affected larval growth rate, and at higher concentrations the larval weights were significantly reduced over the course of the assay. Adults of CPB were more sensitive to the extracts than the larvae, and, even at lower doses, adult beetles were arrested for longer periods than larvae. CONCLUSION: These results indicate that H. lupulus extracts may have potential for control of CPB, particularly in organic farms where conventional insecticides are not available. Copyright © 2012 Society of Chemical Industry 相似文献
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BACKGROUND: Neonicotinoid insecticides were first used commercially for Colorado potato beetle [Leptinotarsa decemlineata (Say), Coleoptera: Chrysomelidae] control in the United States in 1995, and since then have been critical for management of this pest. Field populations from the northeastern and midwestern United States were tested from 1998 to 2010 for susceptibility to imidacloprid and thiamethoxam using standard topical dose assays with adults. RESULTS: From 1998 to 2001, imidacloprid resistance was present in only a few locations in the eastern United States. By 2003, imidacloprid resistance was common in the northeastern Unites States. In 2004, imidacloprid resistance in Colorado potato beetle was detected for the first time in the midwestern United States. In 2003, the first case of resistance to thiamethoxam was found in a population from Massachusetts. Neonicotinoid resistance in summer‐generation adults was higher than in overwintered adults from the same locations. By 2009, 95% of the populations tested from the northeastern and midwestern United States had significantly higher LD50 values for imidacloprid than the susceptible population. CONCLUSIONS: The increasing resistance to neonicotinoid insecticides raises concerns for the continued effective management of Colorado potato beetles in potatoes and highlights the need for more rigorous practice of integrated pest management methods. Copyright © 2011 Society of Chemical Industry 相似文献
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Potato leaves were treated with 2, 20 or 200 g kg(-1) solutions of extracts of five plant species collected in Turkey, and then exposed to larvae of Colorado potato beetle, Leptinotarsa decemlineata (Say). During the first 24 h of exposure, leaf consumption was not affected by 2 g kg(-1) extracts, whereas significantly more leaf tissue remained on leaves treated with 20 g kg(-1) extracts of Arctium lappa L., Bifora radians M Bieb, Humulus lupulus L. or Xanthium strumarium L. than on untreated control leaves. Feeding was not affected by the 20 g kg(-1) extract of Verbascum songaricum Schrenk ex Fisch & Mey. Extracts of all species at 200 g kg(-1) reduced larval feeding, with H. lupulus and X. strumarium providing the greatest protection. Observations of larval behaviour over the first 15 min of exposure to these extracts revealed that the interaction of beetles with leaf tissue was significantly affected by plant extracts. Feeding frequency was not affected by 2 g kg(-1) extracts but was reduced by all higher concentrations. Feeding was inhibited completely by 20 g kg(-1) of H. lupulus extract and reduced significantly compared with the controls by all other extracts. Suppression of feeding was caused by all extracts at 200 g kg(-1), with V. songaricum providing 91% reduction in feeding duration. Rejection behaviour, in which larvae did not return to the leaf after their interaction with it, was rare on 2 g kg(-1) extracts but seen in over 60% of larvae on 20 g kg(-1) extracts and over 80% on 200 g kg(-1) extracts. The present results demonstrate that these extracts have significant ability to protect potato leaves for up to 24 h by prevention of feeding behaviour by L. decemlineata. Further studies are needed to determine the potential of these plant extracts, or their active components, for use in biologically based pest management strategies. 相似文献
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The Colorado potato beetle, Leptinotarsa decemlineata (Say), has developed resistance to many insecticides used for its control, recently including imidacloprid, a neonicotinoid compound. Other neonicotinoids are now being deployed to control this pest. A key point in the strategies of resistance management is the monitoring of resistance and cross-resistance. In the summer of 2003, imidacloprid-resistant adult Colorado potato beetles collected from Long Island, New York, USA were bioassayed using topical applications of imidacloprid and nine other neonicotinoids. Compared to a standard susceptible strain, the Long Island beetles showed 309-fold resistance to imidacloprid, and lower levels of cross-resistance to all other neonicotinoids, despite these never having been used in the field, i.e., 59-fold to dinotefuran, 33-fold to clothianidin, 29-fold to acetamiprid, 28-fold to N-methylimidacloprid, 25-fold to thiacloprid, 15-fold to thiamethoxam, 10-fold to nitenpyram, but less than 2-fold to nicotine. In injection bioassays, high resistance to imidacloprid was also found (116-fold). Piperonyl butoxide partially suppressed resistance to imidacloprid, but the resistance level was still over 100-fold, indicating that other mechanisms were primarily responsible for resistance. Low levels of resistance (8- to 10-fold) were found to the nicotinic activator, spinosad, in an imidacloprid-resistant strain collected from the same field in 2004. The cross-resistance seen with all the neonicotinoids tested suggests that the rotation of imidacloprid with other neonicotinoids may not be an effective long-term resistance management strategy. Rotation with spinosad also carries some risk, but it is unlikely that spinosad resistance in this case is mechanistically related to that for the neonicotinoids. 相似文献
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球孢白僵菌可湿性粉剂对马铃薯甲虫的防治效果 总被引：3，自引：0，他引：3
从受感染的马铃薯甲虫Leptinotarsa decemlineata（Say）分离出菌株1513,经鉴定为球孢白僵菌Beauveriabassiana（菌种保藏号为ACCC32222）。为了评价其对马铃薯甲虫的防治潜力,本研究测定了不同浓度白僵菌对不同龄期马铃薯甲虫幼虫的毒力作用。结果表明,在室温条件下（22～28℃）,处理9 d时1～2龄幼虫的僵虫率与孢子浓度成正比,其LC50为3.09×107孢子mL 1;处理8 d时,对3～4龄幼虫的LC50为9.92×107孢子mL 1;而孢子浓度为1×107孢子mL 1时,虫卵未受到明显的抑制。田间施菌2250 g hm 2时,在新疆新源县的防治效果较好,18 d时98.87%的虫体落地,地表僵虫率为53.91%;而在新疆尼勒克县,仅在土壤中发现僵虫,僵虫率为19.61%。 相似文献
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为明确马铃薯甲虫自然种群的抗寒性,利用热敏电阻测定仪对马铃薯甲虫不同虫态过冷却点和冰点进行了测定。结果表明:不同虫态过冷却点和冰点之间存在显著性差异,其中以卵和成虫的过冷却点最低,分别为:(-13.73±0.93)℃和(-7.89±0.07)℃,显著低于其他虫态。3龄幼虫的过冷却点和冰点最高,分别为:(-6.21±0.08)℃和(-2.80±0.08)℃;过冷却点由低到高顺序为:卵<成虫<1龄幼虫<蛹<4龄幼虫<2龄幼虫<3龄幼虫;冰点由低到高的顺序为:卵<1龄幼虫<成虫<2龄幼虫<蛹<4龄幼虫<3龄幼虫;同一虫态个体间的过冷却点频次分布出现不同程度的变异,但均服从正态分布。研究结果为制定马铃薯甲虫在我国潜在分布和风险分析提供了科学依据。 相似文献
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BACKGROUND: Novaluron is a benzoylphenyl urea chitin synthesis inhibitor that combines good activity against larval stages of the Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), with low mammalian toxicity. Previous studies suggest that it has deleterious sublethal effects on adults. RESULTS: Continuous exposure of adult Colorado potato beetles to novaluron-treated foliage as both ovipositional and feeding substrate did not affect their survivorship or the number of eggs produced, but viable larvae hatched only from the eggs that were laid on the first day of the experiment. Viability was restored after adult beetles spent 48-96 hours on untreated leaves. In a separate experiment, direct exposure to novaluron of eggs laid by unexposed beetles also reduced the number of larvae hatching. CONCLUSIONS: Results confirm a negative effect of novaluron on the number of progeny produced by the Colorado potato beetle. Direct toxicity did not explain all of the reduction in egg hatch observed, suggesting that novaluron probably acted on reproductive adults as well as on eggs after they were deposited. 相似文献
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Alyokhin A Dively G Patterson M Castaldo C Rogers D Mahoney M Wollam J 《Pest management science》2007,63(1):32-41
One of the major challenges in managing the Colorado potato beetle, Leptinotarsa decemlineata (Say) is its remarkable ability to develop resistance to virtually every insecticide that has ever been used against it. Resistance is particularly common throughout northeastern USA as far north as Maine. The first instances of resistance to imidacloprid have already been reported from several locations in New York, Delaware and southern Maine. Rotating insecticides with different modes of action may delay insecticide resistance, but successful implementation of this technique depends on a good understanding of resistance and cross-resistance patterns in populations of target pests. LC(50) values were measured for imidacloprid and thiamethoxam in Colorado potato beetle populations from a variety of locations in the USA and Canada using diet incorporation bioassays. The field performance of imidacloprid, thiamethoxam and clothianidin against imidacloprid-resistant beetles on a commercial potato farm in southern Maine was also evaluated. Correlation between LC(50) values for imidacloprid and thiamethoxam was highly significant, even when populations previously exposed to thiamethoxam were excluded from the analysis. There was no statistically detectable difference in the LC(50) values between populations exposed to both insecticides and to imidacloprid alone. Applications of neonicotinoid insecticides at planting delayed build-up of imidacloprid-resistant beetle populations on field plots by 1-2 weeks but failed to provide adequate crop protection. Consistently with bioassay results, there was also substantial cross-resistance among the three tested neonicotinoid insecticides. Results of the present study support the recommendation to avoid rotating imidacloprid with thiamethoxam as a part of a resistance management plan. 相似文献
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马铃薯甲虫Leptinotarsa decemlineata (Say)是我国马铃薯恶性入侵害虫。本研究利用聚集度指标检验、Taylor幂法则和Iwao回归法对马铃薯甲虫成虫、幼虫和卵在田间的空间分布型进行了研究。聚集度指标检测各虫态均为聚集分布,且种群聚集主要是由马铃薯甲虫各虫态本身的聚集行为,或由其本身的聚集行为与环境异质性共同作用所致。建立了马铃薯甲虫成虫、幼虫和卵在田间调查的理论抽样数学模型。田间抽样方法,成虫应采用大五点、对角线法;幼虫最适应采用Z字型法;卵最适应采用对角线法。 相似文献
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The acute and sublethal toxicities of novaluron, a novel chitin synthesis inhibitor, to a laboratory-reared insecticide-susceptible strain of Colorado potato beetle, Leptinotarsa decemlineata (Say), were determined. Novaluron exhibited excellent residual (120 h LC(50) = 0.42 mg litre(-1)) and good direct contact (120 h LC(50) = 27 mg litre(-1)) activity against second-instar larvae (L2). Hatch of eggs exposed by direct contact to novaluron solutions > or =100 mg litre(-1) was significantly reduced, as was the ability of emerged first-instar larvae to moult. L2 from eggs exposed to > or =100 mg litre(-1) novaluron weighed significantly less (P < 0.0001) than those from untreated eggs. However, L2 from eggs treated with 1 mg litre(-1) novaluron weighed significantly more (P < or = 0.05) than those from untreated eggs, suggesting novaluron can have a hormetic effect on L decemlineata larval development. Leptinotarsa decemlineata mating pairs fed foliage treated with novaluron at 25 or 75 g AI ha(-1) produced approximately 25% fewer egg masses and eggs per mass. Hatch of eggs on treated foliage was almost completely suppressed, and longevity of male beetles was reduced by approximately 50% when fed foliage treated with novaluron at 75 g AI ha(-1). 相似文献
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马铃薯甲虫（Leptinotarsa decemlineata (Say)）是马铃薯的一种毁灭性害虫,扩散迅速,防控困难,已被许多国家列为检疫对象。云南是我国马铃薯的主要产区,目前云南省马铃薯种植区尚未发现该虫的发生与危害。为探明马铃薯甲虫在云南省的风险性,本文依据国际有害生物风险分析原则,以云南省的气候、马铃薯种植情况及马铃薯甲虫的生物学特性为基础,利用外来入侵有害生物多指标综合评价体系,对马铃薯甲虫入侵云南的风险性进行了分析。结果表明,马铃薯甲虫入侵云南的风险值为2.24,属于高度风险类型。同时,根据马铃薯甲虫较高的入侵云南的潜在风险,本文还提出了对马铃薯甲虫入侵风险管理的对策。 相似文献
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Tereza Zichová František Kocourek Jaroslav Salava Kateřina Nad'ová Jitka Stará 《Pest management science》2010,66(8):853-860
BACKGROUND: Pyrethroids and organophosphates are the most frequently used insecticides for Colorado potato beetle, Leptinotarsa decemlineata (Say), control in the Czech Republic. Based on molecular methods, organophosphate and pyrethroid resistance alleles have been detected in samples from three sites. The accuracy of restriction fragment length polymorphism (RFLP) and bidirectional polymerase chain reaction amplification of specific alleles (Bi‐PASA) for detection of resistance alleles is compared. RESULTS: Leptinotarsa decemlineata from three sites showed higher frequencies of resistance alleles to organophosphates than to pyrethroids. The rates of occurrence of individuals homozygous resistant (RR) to pyrethroids ranged from 20.0 to 22.9%, while the rates of occurrence of individuals RR to organophosphates ranged from 52.9 to 66.7%. The incidences of individuals with resistance alleles to both organophosphates and pyrethroids ranged from 8.6 to 13.6%. No relationship was found between incidence of the pyrethroid resistance allele and site, while incidence of the organophosphate resistance allele differed significantly according to site. CONCLUSION: Both RFLP and Bi‐PASA were suitable for detecting resistance alleles to pyrethroids, and in most cases also for detecting resistance alleles to organophosphates. In contrast to Bi‐PASA, RFLP was also suitable for samples with lower DNA quality when testing for the resistance allele to pyrethroids. On the other hand, RFLP was not as accurate as Bi‐PASA in detection of the organophosphate resistance allele. Copyright © 2010 Society of Chemical Industry 相似文献
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Kai‐Yun Fu Qian Li Li‐Tao Zhou Qing‐Wei Meng Feng‐Gong Lü Wen‐Chao Guo Guo‐Qing Li 《Pest management science》2016,72(6):1231-1241