4种杀虫剂对南亚实蝇各虫态不同日龄的毒力测定

为明确南亚实蝇Bactrocera tau Walker不同发育阶段、不同日龄以及不同性别成虫对常用杀虫剂的敏感度,本研究采用胃毒法测定了杀虫剂对南亚实蝇室内种群幼虫和成虫的活性,采用浸泡法测了杀虫剂对卵和蛹的活性.结果表明4种杀虫剂对南亚实蝇不同日龄各虫态的毒杀活性存在差异,随日龄增加,各虫态对不同药剂的耐药性增加,且耐药性的强弱不同.高效氟氯氰菊酯EC对南亚实蝇卵、2日龄和5日龄幼虫具有较好的毒杀活性,LC50分别为2.88 mg/L、2.08 mg/L和6.39 mg/L,辛硫磷EC、多杀霉素SC以及高效氯氰菊酯EC的杀虫活性较差,LC50分别为4.71 mg/L、3.95 mg/L和11.60 mg/L;幼虫对高效氟氯氰菊酯EC的耐药性增长较快,对多杀霉素SC的耐药性增加较慢;多杀霉素SC对2日龄和5日龄的蛹和雌雄成虫的毒杀活性较高,但耐药性增加较快,蛹对辛硫磷EC的耐药性增长较慢,雌雄成虫均对高效氯氰菊酯EC耐药性增长较慢,不同日龄的雌成虫的耐药性均高于雄成虫.由于南亚实蝇世代重叠严重,在成虫暴发期之前,可将高效氟氯氰菊酯EC作为首选药剂使用,在成虫暴发期之后防治时可将多杀霉素SC作为优选药剂使用,防治最佳时期为各虫态的初期.     

Toxicity of insecticides to obliquebanded leafroller, Choristoneura rosaceana, larvae and adults exposed previously to neem seed oil

Adult and sixth instar obliquebanded leafroller, Choristoneura rosaceana (Harris), exposed previously as fifth instar larvae to sub-lethal concentrations of neem, Azadirachta indica A. Juss., seed oil contained in artificial diet were more susceptible to topically applied pyrethroid, carbamate and organophosphate insecticides than C. rosaceana reared on control diets. Increased susceptibility to insecticides did not result from reduced vigour, as measured by reductions in adult or larval weights, but is instead correlated with previously demonstrated reductions in detoxication enzyme activities. The modest increases in susceptibilities, not exceeding ca. 4.5-fold, for C. rosaceana exposed to neem were achieved with subjects from a susceptible laboratory colony; a larger response could be expected for resistant field populations having elevated detoxication enzyme levels. Neem-based insecticides could be useful tools for the management of orchard pests that have developed resistance to synthetic neurotoxins. These findings also contribute to a better understanding of the numerous physiological changes that occur in larval Lepidoptera following exposure to neem extracts.     

Prospects for biological control of the western flower thrips,Frankliniella occidentalis,with the entomopathogenic fungus,Metarhizium anisopliae,on chrysanthemum

The potential of Metarhizium anisopliae (Metsch.) Sorok. for the control of Frankliniella occidentalis (Pergande) on chrysanthemum cuttings was evaluated in greenhouse experiments. The fungus significantly reduced both the adult and larval populations of F. occidentalis, although the level of control of larval populations was much lower than for adults. Combined application of M. anisopliae and Methomyl (Lannate), however, resulted in a significant reduction of both the larval and adult stages. The use of both control agents might be helpful in reducing the selection pressure for resistance to chemical insecticides, thereby delaying or preventing the build-up of resistant populations in greenhouses.     

Leaf growth signals the onset of effective plant resistance against Hessian fly larvae

For plant resistance that is induced rather than constitutive, the precise timing of a sequence of events must be considered (i.e., initial detection of the insect by the plant's surveillance systems, up-regulation of signaling and defense pathways, achievement of effective levels of defense, and finally down-regulation of signaling and defense). Here, we provide a timeline for the interaction between resistant wheat ( Triticum aestivum L.) (Poaceae) and the Hessian fly, Mayetiola destructor (Say) (Diptera: Cecidomyiidae). To create this timeline, we measured the daily growth of the third, fourth, and fifth leaves of susceptible and resistant plants. Because each leaf had a different spatial relationship to the site of larval attack (i.e., the sheath epidermal cells of the third leaf) and a different pattern of growth relative to the 3–5 days that larvae attacked resistant plants, we learned different things from each leaf. The third leaf shows how quickly responses of susceptible and resistant plants diverge (i.e., 36–60 h after initial larval attack). The fourth leaf shows that, for both susceptible and resistant plants, negative effects of larval attack extend beyond the third leaf. These negative effects are more severe for susceptible plants, but even in resistant plants continue for several days after larvae have died. The fifth leaf is interesting because it shows how rapidly the resistant plant recovers from larval attack. Thus, 204–348 h after initial attack, a time when the fourth leaf of resistant plants is showing reduced growth and the fifth leaf of susceptible plants is showing zero growth, the fifth leaf of resistant plants shows a small increase in growth. Grasses with resistance gene-mediated resistance may have a two-fold strategy, using resistance mechanisms to stop Hessian fly larvae from further attack and tolerance mechanisms to protect resources for future plant growth.     

Life stage variations in insecticidal susceptibility and detoxification capacity of the beet webworm, Pyrausta sticticalis L. (Lep., Pyralidae)

Abstract:  Adults and larvae of the beet webworm Pyrausta sticticalis (Lep., Pyralidae) are susceptible in varying degrees to insecticides of different chemical classes. Comparative toxicity tests as well as the synergistic effects of piperonyl butoxide, S,S,S-tributyl phosphorotrithioate and diethylmaleate showed that variation in toxicities of beet webworm developmental stages to organophosphorus compounds and carbaryl is partly due to the activities of detoxification enzymes. Specific activities of monooxygenases, esterases and glutathione S-transferase were higher in fifth instars than in adults. Studies of the post-treatment fate of ¹⁴C-labelled malathion and ³H- trans -permethrin after application indicated that both compounds had a rapid rate of cuticular penetration, internal accumulation and excretion of applied toxicants and their metabolites by larvae. Adults of beet webworm had a lower sensitivity of acetylcholine esterase to the inhibition of carbaryl than the larvae.     

Effect of the synergist, piperonyl butoxide, on the development of deltamethrin resistance in yellow fever mosquito, Aedes aegypti L. (Diptera: Culicidae)

The larvae and adults of Aedes aegypti were tested for the potential to develop resistance to the synthetic pyrethroid, deltamethrin, alone or a combination of deltamethrin with the synergist, piperonyl butoxide (PBO). Although continuous larval selection for 40 generations resulted in 703-fold resistance, the resistance ratio in the adults was only 1.3. Similarly, adult selections with deltamethrin showed a resistance ratio of less than four after 40 generations, indicating differential response to deltamethrin selection in the two developmental stages of the insect. When the susceptible larvae were subjected to selection pressure of deltamethrin and PBO in the ratio of 1:5 for 20 generations, the speed of selection for deltamethrin resistance slowed down by 60%. The F24 larvae obtained from the strain selected with deltamethrin alone were further subjected to selection pressure with synergized deltamethrin, which resulted in 89% reversal in deltamethrin resistance in just one generation. However, long-term selection with the insecticide-synergist combination returned resistance close to original levels in 15 generations. The data indicate the involvement of cytochrome P450-dependent detoxification as the primary mechanism of development of resistance to deltamethrin in the larvae. Implications of the results on the management of larval and adult stages of Ae. aegypti are discussed.     

Demographic effects of deltamethrin resistance in the Chagas disease vector Triatoma infestans

Triatoma infestans (Heteroptera: Reduviidae) Klug is the main vector of Chagas disease in Latin America. Resistance to deltamethrin was reported in Argentina and recently associated with reproductive and longevity trade‐offs. The objectives of the present study were to describe the demographic consequences of deltamethrin resistance in T. infestans and to establish possible target stages for chemical control in susceptible and resistant colonies. A stage‐classified matrix model was constructed based on the average stage length for susceptible, resistant and reciprocal matings' progeny. The differences between colonies were analysed by prospective and retrospective analysis. The life table parameters indicated reduced fecundity, fertility and population growth in resistant insects. The retrospective analysis suggested the latter was associated with lower reproductive output and increased fifth‐instar nymph stage length. The prospective analysis suggested that the adult stage should be the main target for insecticide control. Although, fifth‐instar nymphs should also be targeted when resistance has been detected. The presented results show demographic effects of deltamethrin resistance in T. infestans. While the older stages could be the main targets for chemical control, this approach is impeded by their higher tolerance to insecticides. It is concluded that the different mode of action insecticides would be more effective than a dose increase for the control of deltamethrin‐resistant T. infestans.     

茚虫威和六伏隆对小菜蛾卵、幼虫和成虫的药效（英文）

化学防治是世界各地防治小菜蛾Plutella xylostella (L.)的主要方法。选择对小菜蛾各发育阶段高效的杀虫剂有助于很好地控制这一害虫。本研究用浸叶法测定了茚虫威和六伏隆对小菜蛾卵、幼虫和成虫的毒性。茚虫威和六伏隆对小菜蛾卵的LC₅₀值分别为201.40 和 37.32 mg/L。茚虫威和六伏隆对3龄幼虫也有很好的毒性（茚虫威的LC₅₀ 为 4.82 mg/L; 六伏隆的LC₅₀ 为1.48 mg/L)。对成虫的毒性结果表明, 这两种杀虫剂对成虫均没有理想的毒性（茚虫威的LC₅₀ 为845.20 mg/L; 六伏隆的LC₅₀ 为3 438 mg/L)。根据计算的LC₅₀值, 六伏隆对小菜蛾卵和幼虫的毒性比茚虫威高, 但是茚虫威对成虫的毒性更高。     

禾谷缢管蚜ABC转运蛋白基因的克隆、分子特性及表达分析

【目的】ABC（ATP-binding cassette）转运蛋白是一类重要的跨膜蛋白超家族,某些ABC转运蛋白基因在一些害虫的抗药性品系中表达显著提高。本研究旨在克隆禾谷缢管蚜 Rhopalosiphum padi ABC转运蛋白基因RhpaABCG9,RhpaABCG20和RhpaABCG23 cDNA全序列,分析这3个基因在该虫不同发育阶段和不同抗药性品系中的表达模式,为阐明ABC转运蛋白在禾谷缢管蚜抗药性中的作用和其他生理功能,以及深入分析该虫抗药性机理奠定基础。【方法】采用RT-PCR与RACE技术,克隆了基因cDNA全序列;利用实时荧光定量PCR技术,研究这3个基因在禾谷缢管蚜不同生长发育阶段和不同抗药性品系中的表达变化。【结果】获得了RhpaABCG9,RhpaABCG20和RhpaABCG23 3个基因cDNA全序列,其开放阅读框长度分别为2 103,2 436 和2 082 bp,分别编码700, 811和693个氨基酸。结构分析表明,3个蛋白均具有ABC转运蛋白家族典型的结构特征;系统进化分析结果显示,3个蛋白氨基酸序列分别与豌豆蚜Acyrthosiphon pisum各对应氨基酸的序列一致性最高。实时荧光定量PCR分析结果表明,这3个基因在禾谷缢管蚜不同发育时期均不同程度表达。RhpaABCG20在各个发育时期的表达变化差异不显著;RhpaABCG9表达量在4龄若蚜最高,在1龄若蚜最低;RhpaABCG23 表达量在3龄若蚜最高,1龄若蚜最低,其他阶段差异不显著。禾谷缢管蚜异丙威抗性品系中,RhpaABCG20表达量显著高于敏感品系,而RhpaABCG9和RhpaABCG23表达量均低于敏感品系,但差异不显著;禾谷缢管蚜吡虫啉抗性品系中,RhpaABCG20和RhpaABCG23表达量显著高于敏感品系,而RhpaABCG9表达上调不显著。【结论】RhpaABCG9,RhpaABCG20和RhpaABCG23基因可能参与禾谷缢管蚜体内农药的运输,并与禾谷缢管蚜的抗药性具有一定的关系。本研究结果为进一步深入分析禾谷缢管蚜的抗药性机制,以及该虫的抗药性治理与综合防治奠定了基础。     

牧草盲蝽实时定量PCR内参基因的筛选

【目的】筛选出适合牧草盲蝽Lygus pratensis在不同条件下稳定表达的内参基因。【方法】选取编码牧草盲蝽α-微管蛋白、β-微管蛋白、肌动蛋白、延伸因子、琥珀酸脱氢酶复合体A、泛素、转录起始因子TFIID亚基、谷胱甘肽S-转移酶、核糖体蛋白L32及TATA盒结合蛋白的10条基因为候选内参基因,采用qRT-PCR技术测定其在牧草盲蝽不同性别成虫、成虫不同组织、不同龄期、对功夫菊酯不同抗性成虫、不同温度及不同杀虫剂分别处理后的成虫共6类样品中的表达量;采用BestKeeper, geNorm, NormFinder及RefFinder 4种计算程序对各候选基因的表达稳定性进行评价。【结果】依据获得的有效qRT-PCR数据前提,利用不同计算方法综合分析得出：在牧草盲蝽成虫不同组织中和对功夫菊酯不同抗性成虫中最稳定表达的内参基因均为RPL32;不同温度处理、不同性别成虫中、不同杀虫剂处理和不同龄期牧草盲蝽中最稳定表达的内参基因分别为UBQ, SDHA, β-tubulin和TAF。通过geNorm软件判断配对变异数确定的内参基因最佳数目,结合RefFinder对基因表达稳定性综合排序的结果可得：牧草盲蝽不同成虫组织中、不同性别成虫中、不同龄期、对功夫菊酯不同抗性成虫中、不同温度及杀虫剂分别处理的成虫等各组的最优内参基因组合分别为RPL32+TAF, SDHA+GST, TAF+GST+UBQ, RPL32+GST, UBQ+ACT+β-tubulin和β-tubulin+TAF+RPL32。【结论】本研究获得的牧草盲蝽在不同条件下表达最稳定及最适内参基因组合,都可用于后续的基因定量表达研究。     

Prospects for biological control of the western flower thrips,Frankliniella occidentalis,with the entomopathogenic fungus,Metarhizium anisopliae,on chrysanthemum

The potential of Metarhizium anisopliae (Metsch.) Sorok. for the control of Frankliniella occidentalis (Pergande) on chrysanthemum cuttings was evaluated in greenhouse experiments. The fungus significantly reduced both the adult and larval populations of F. occidentalis, although the level of control of larval populations was much lower than for adults. Combined application of M. anisopliae and Methomyl (Lannate^®), however, resulted in a significant reduction of both the larval and adult stages. The use of both control agents might be helpful in reducing the selection pressure for resistance to chemical insecticides, thereby delaying or preventing the build-up of resistant populations in greenhouses.This revised version was published online in October 2005 with corrections to the Cover Date.     

Phase-independent responses to phase-specific aggregation pheromone in adult desert locusts, Schistocerca gregaria (Orthoptera: Acrididae)

Abstract. Volatiles from solitary-reared (solitarious) and crowd-reared (gregarious) adult male desert locusts, Schistocerca gregaria (Forskal) (Orthoptera: Acrididae), were quantitatively and qualitatively different.In particular, solitarious males did not emit phenylacetonitrile, a key component of the aggregation pheromone produced by gregarious adult males.In laboratory bioassays, solitarious and gregarious adults of both sexes responded similarly to the natural aggregation pheromone blend, the major pheromone component phenylacetonitrile, and a synthetic pheromone blend comprising benzaldehyde, guaiacol, phenylacetonitrile and phenol.EAG measurements showed significant differences in the responsiveness of adults of the two phases to the four synthetic components at high doses; however, the general response patterns were similar.These results suggest that the gregarious adult male aggregation pheromone may play a role in the arrestment and subsequent recruitment of solitarious individuals into gregarious or gregarizing groups during the early stages of a locust outbreak.     

Effects of spinosad, spinosad bait, and chloronicotinyl insecticides on mortality and control of adult and larval western cherry fruit fly (Diptera: Tephritidae)

Effects of spinosad, spinosad bait, and the chloronicotinyl insecticides imidacloprid and thiacloprid on mortality of the adults and larvae of western cherry fruit fly, Rhagoletis indifferens Curran (Diptera: Tephritidae), were determined in the laboratory and the field. Spinosad and spinosad bait caused higher adult mortality than imidacloprid, which caused higher mortality than thiacloprid. Only spinosad bait prevented oviposition. All materials were more toxic to adults when ingested than when topically applied. Spinosad bait had the greatest residual toxicity on leaves, killing 100% of adults when aged for 14 d in the field. When materials were sprayed on infested cherries, numbers of live larvae in fruit after 8 d were lower in imidacloprid and thiacloprid than in spinosad and spinosad bait treatments, which did not differ from the control, but all materials reduced larval emergence over 30 d. In the field, spinosad and spinosad bait were as effective in suppressing larval infestations as azinphos-methyl and carbaryl, whereas imidacloprid was effective in most cases and thiacloprid was generally less effective than azinphos-methyl and carbaryl. Overall, results in the laboratory and field show that spinosad and chloronicotinyl insecticides differed significantly in their effectiveness against adults and larvae of R. indifferens but that spinosad, spinosad bait, and imidacloprid seem to be acceptable substitutes for organophosphate and carbamate insecticides for controlling this fruit fly.     

桔小实蝇实验种群对敌百虫、高效氯氰菊酯和阿维菌素的抗性增长规律

桔小实蝇Bactrocera doralis (Hendel)是华南地区水果蔬菜上重要害虫,近年来暴发成灾,造成巨大的经济损失。使用化学杀虫剂是防治该虫的重要方法。在长期、频繁接触杀虫剂条件下该虫的抗药性产生、发展规律等问题值得深入研究。本文采用LC₅₀、LC_80-90两种剂量汰选成虫、幼虫,研究了桔小实蝇对敌百虫、高效氯氰菊酯和阿维菌素3种药剂的抗性增长规律。通过不接触药剂继代饲养获得了对3种杀虫剂的敏感品系,建立了毒力回归方程,明确了毒力敏感基线LC₅₀分别为1.6024 mg/L,3.0964 mg/L和0.6074 mg/L。不同药剂种类、不同汰选方式时桔小实蝇的抗药性发展速度是不同的。以成虫死亡率50%左右作为选择压力,桔小实蝇对敌百虫的抗性发展最快,汰选至14代抗性增长至84.6倍;其次是高效氯氰菊酯,抗性增长至27.1倍;而对阿维菌素的抗性仅上升至7.7倍 。在成虫和幼虫80%～90%死亡率左右的选择压力下,桔小实蝇对高效氯氰菊酯的抗性发展最快,汰选14代后抗性增长至125.4倍; 其次是敌百虫,抗性增大至49.9倍;对阿维菌素抗性增长相对较缓慢,11代后为17.9倍。在成虫80%～90%死亡率左右的选择压力下,汰选14代、14代、11代后桔小实蝇对高效氯氰菊酯、敌百虫、阿维菌素分别增大至58.7倍、37.6倍、11.9倍。对成虫、幼虫均进行汰选桔小实蝇抗药性发展更快。建立了不同汰选方式时桔小实蝇实验种群汰选代数与对3种杀虫剂的抗性程度之间的关系方程,其中高效氯氰菊酯、敌百虫处理符合韦布尔曲线模型,阿维菌素处理符合幂曲线方程。     

Pleiotropy of insecticide resistance in the codling moth, Cydia pomonella

The codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), has developed resistance to various insecticides. Relative fitness of one susceptible strain (Sv) and two strains selected for resistance to diflubenzuron (Rt) and deltamethrin (Rv), respectively, was measured in the absence of insecticide selection pressure. Mating rate, fecundity, fertility, developmental time, fifth instar weight, and adult longevity were compared. Both resistant strains were less fecund and fertile, developed more slowly, weighed less, and had shorter life-spans than the susceptible strain. These results indicate that biological constraints are associated with insecticide resistance in the codling moth. We also found that fitness estimates of the Rv strain did not differ statistically from those of the Rt strain. Enhanced mixed-function oxidase and glutathione-S-transferase activities have been shown to be involved in insecticide resistance in both Rt and Rv strains. This suggests that the fitness cost described in both resistant strains was mainly associated to metabolic resistance. The impact of such deleterious pleiotropy of insecticide resistance in C. pomonella in terms of resistance management in the field is discussed.     

Life stage toxicity and residual activity of insecticides to codling moth and oriental fruit moth (Lepidoptera: Tortricidae)

The codling moth, Cydia pomonella (L.), and oriental fruit moth, Grapholita molesta (Busck), are two key pests of apple (Malus domestica Borkh.) in North Carolina. Growers extensively relied on organophosphate insecticides, primarily azinphosmethyl, for > 40 yr to manage these pests. Because of organophosphate resistance development and regulatory actions, growers are transitioning to management programs that use new, reduced-risk, and OP-replacement insecticides. This study evaluated the toxicity of a diversity of replacement insecticides to eggs, larvae, and adults, as well as an assessment of their residual activity, to codling moth and oriental fruit moth. Laboratory-susceptible strains of both species were used for all bioassays. Fresh field-harvested apples were used as a media for assessing the ovicidal activity of insecticides. For larval studies, insecticides were topically applied to the surface of lima bean-based diet, onto which neonates were placed. Toxicity was based on two measures of mortality; 5-d mortality and development to adult stage. Ovicidal bioassays showed that oriental fruit moth eggs were generally more tolerant than codling moth eggs to insecticides, with novaluron, acetamiprid, and azinphoshmethyl having the highest levels of toxicity to eggs of both species. In contrast, codling moth larvae generally were more tolerant than oriental fruit moth to most insecticides. Methoxyfenozide and pyriproxyfen were the only insecticides with lower LC50 values against codling moth than oriental fruit moth neonates. Moreover, a number of insecticides, particularly the IGRs methoxyfenozide and novaluron, the anthranilic diamide chlorantriliprole, and the spinosyn spinetoram, provided equal or longer residual activity against codling moth compared with azinphosmethyl in field studies. Results are discussed in relation to their use in devising field use patterns of insecticides and for insecticide resistance monitoring programs.     

The status and seasonal changes of organophosphate and pyrethroid resistance in Turkish populations of the house fly, Musca domestica L. (Diptera: Muscidae).

Field strains of the house fly (Musca domestica L. Diptera: Muscidae) were collected in April and September 2002 from cow farms (Antalya, Izmir) and garbage dumps (Adana, Ankara, Istanbul, Sanliurfa) in Turkey. The resistance levels of first to fifth generation offspring were evaluated against six insecticides (cypermethrin, cyphenothrin, deltamethrin, permethrin, resmethrin, fenitrothion). Resistance levels for pyrethroid group insecticides ranged from 23.27 (permethrin-Istanbul fall strain) to 633.09 (cypermethrin-Izmir spring strain) and for fenitrothion ranged from 5.78 (Istanbul fall strain) to 51.04 (Antalya spring strain). Our results showed that pyrethroid resistance was high and changed from spring to fall in relation to usage and application frequencies of these compounds at the study sites. Although fenitrothion resistance levels were determined to be lower than pyrethroids, these levels were still high and led to control failure. Flies from cow farms were more resistant than those from garbage dumps, but resistance levels for Sanliurfa and Adana strains were also high in relation to usage of different insecticides for agricultural purposes. Although resistance levels against different pyrethroids decreased from spring to fall, these levels still indicated the presence of a strong selective pressure on the populations.     

Effects of pirimicarb,buprofezin and pymetrozine on survival,development and reproduction of Coccinella undecimpunctata (Coleoptera: Coccinellidae)

The effects of pirimicarb (a neurotoxin), buprofezin (an insect growth regulator) and pymetrozine (an antifeedant) on Coccinella undecimpunctata were assessed by studying the survival and development of all immature stages and the survival and reproductive performance of adults. Insecticides were sprayed at doses recommended by the manufacturers for the control of aphids and/or whiteflies. None of the three insecticides had a significant effect on the survival of C. undecimpunctata eggs. When sprayed on larvae, buprofezin significantly reduced survival to adulthood to <33%, compared to >45% for the control and other insecticide treatments. Rates of adult survival, fecundity, and fertility, and the percentage of egg hatch, were not significantly different between control and insecticide treatments. Thus, larval stages were more susceptible to insecticides than were adults. In general, pirimicarb and pymetrozine had no adverse effects on immature or adult stages of C. undecimpunctata, and hence are suitable for IPM of sucking pests.