Effects of a Chenopodium-based botanical insecticide/acaricide on Orius insidiosus (Hemiptera: Anthocoridae) and Aphidius colemani (Hymenoptera: Braconidae)

UDA-245 is a Chenopodium-based natural insecticide. Forty-eight hours after treatment with this compound, Orius insidiosus (Say) and Aphidius colemani Viereck showed slight contact toxicity at 5 g AI liter(-1). There was no residual toxicity to A colemani. These two beneficials are currently used in commercial flower and vegetable greenhouses for the management of thrips, spider mites, aphids and small caterpillars. In contrast, abamectin and insecticidal soap were toxic by contact to both species. UDA-245 did not reduce the number of eggs laid by treated O insidiosus. The eclosion of these eggs was also not adversely affected by UDA-245. The other two insecticides, abamectin and insecticidal soap had no effect on the emergence of A colemani from treated aphid mummies. However, abamectin decreased the percentage of aphid parasitism by A colemani following a residual treatment. The LC50 for UDA-245 for the two beneficials is slightly over twice the recommended field dose.     

Aphid parasitoids (Hymenoptera: Braconidae: Aphidiinae) on weeds from Ankara, Turkey

Studies were conducted during the years 2001–2003 to determine the parasitoids of Aphidoidea (Homoptera) species on weeds in Ankara province. Six genera and ten species of aphid parasitoids belonging to Braconidae were determined. The tritrophic associations of plant/aphid/parasitoid were analyzed. Forty-four associations of aphidiinae wasps, host aphids and host plants new to the Mediterranean region and 71 new associations for Turkish fauna were reported. http://www.phytoparasitica.org posting July 14, 2005.     

影响松毛虫赤眼蜂性比的因素

本文用柞蚕卵作室内繁殖松毛虫赤眼蜂的代寄主进行有关影响该蜂性此因子测定。试验在雌蜂不同年龄、寄主卵量、和雌蜂密度等三方面进行。结果表明,一粒柞蚕卵被超过4头雌蜂寄生时,产卵量多,未能完成发育子代数亦增加,而羽化率低,子代雌蜂比例下降。说明过少的寄主卵,复寄生机会增多,成蜂性比受影响。     

氰戊菊酯残留对菜蛾绒茧蜂成虫的致死和亚致死效应

室内测定了氰戊菊酯残留对菜蛾绒茧蜂成虫的致死和亚致死效应。结果发现,氰戊菊酯对菜蛾绒茧蜂成虫的毒力比对小菜蛾2龄幼虫的高10倍以上,因此可以肯定田间施用氰戊菊酯后,可以直接(喷雾)或间接(残留)杀死部分菜蛾绒茧蜂成虫。小菜蛾2龄幼虫LC_(50)剂量的氰戊菊酯残留显著降低了雌蜂的产卵量和供试小菜蛾幼虫的被寄生率,在氰戊菊酯残留存在的情况下,雌蜂的死亡率高于雄蜂,蜂子代存活率及性比显著低于对照。氰戊菊酯残留对菜蛾绒茧蜂的搜索行为也有显著的影响,雌蜂在叶片上停留的时间及用于搜索的时间均高于对照,表明残留对菜蛾绒茧蜂雌蜂的搜寻有刺激作用,但产卵寄生的发生次数与对照间无显著差异。文中对产生上述结果的原因进行了讨论。     

The contact toxicity of indoxacarb and five other insecticides to Orius insidiosus (Hemiptera: Anthocoridae) and Aphidius colemani (Hymenoptera: Braconidae), beneficials used in the greenhouse industry

The contact toxicity of indoxacarb, abamectin, endosulfan, insecticide soap, S-kinoprene and dimethoate to Orius insidiosus (Say) and Aphidius colemani Viereck were studied in the laboratory. These beneficials are often used in the greenhouses to manage various insect pests. Indoxacarb is slow acting and therefore, to estimate lethal dosages, observations should be continued for several days until data stabilize. Seven days after treatment, the LC50 was 0.119 g AI litre(-1) for O insidiosus adults and 0.019 g AI litre(-1) for A colemani. At that time, the recommended field concentration was 0.479 times the LC50 for O insidiosus adults and three times the LC50 for A colemani. In contrast, indoxacarb had no adverse effect on the reproductive capacity of wasps surviving a treatment or the developing wasps in the aphid mummy. Among the other insecticides S-kinoprene was the most innocuous while dimethoate was the most toxic to the two beneficials. The other insecticides had overlapping toxicities.     

Inoculation

Terpenes and biogenically related phenols commonly found in plant essential oils are known to be toxic to insect pests. Accordingly thymol was tested for acute toxicity via topical application to diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae) and its parasitoid, Cotesia plutellae (Kurdjunov) (Hymenoptera: Braconidae under laboratory conditions. Topical application to adult female parasitoids versus second instars of P. xylostella showed that thymol was about 62 times less toxic to the parasitoid than to the host larvae with 24 h LD₅₀ of 0.052 and 0.0008M, respectively. Although thymol was less toxic to the parasitoid, some biological parameters of the progeny at sublethal doses of surviving parasitoids were impaired such as rate of emergence and development time of larvae and pupae. The impact on detoxification enzymes was also studied and there was no significant induction in cytochrome P450 and carboxylesterase activities in both treated male and female wasps. Results obtained suggest that parasitoid is able to withstand the impact of thymol significantly.     

Manipulation of parasitoids for aphid pest management: progress and prospects

This paper describes research at IACR-Rothamsted on aphid parasitoid responses to semiochemical foraging stimuli, aimed at developing novel ways of manipulating these behaviours to overcome ecological constraints to biological and integrated pest control. Female parasitoids respond both to aphid sex pheromones acting as kairomones, and to aphid-induced plant volatiles, acting as synomones. A range of economically important parasitoid species respond to aphid sex pheromones, and their potential for enhancing parasitization of aphid populations has been demonstrated in the field. Commercial production of the pheromone from the plant Nepeta cataria L has been developed and strategies for its use in arable crops are being investigated. Aphid-induced plant volatiles are released systemically throughout the plant and are aphid species specific, probably induced by elicitors in aphid saliva. Aphid-infested plants can induce uninfested neighbours to release damage-related volatiles, plant-to-plant communication occurring via the rhizosphere. The plant compound cis-jasmone has been identified as a plant signal with potential for aphid control, inducing plant defence mechanisms that both deter colonising aphids and attract parasitoids and predators. Such compounds may represent a new generation of crop protectants and their further investigation and development will be aided by the tools generated by genomic and post-genomic biology.     

氯虫苯甲酰胺对桃小食心虫生长发育的亚致死效应

为明确亚致死浓度的氯虫苯甲酰胺连续处理对第4代桃小食心虫生物学特性的影响,本研究用LC10、LC30和LC50的氯虫苯甲酰胺处理的苹果分别继代饲养桃小食心虫（简称LC10、LC30和LC50种群）。以第4代初孵幼虫为起点记录其各阶段发育历期、存活率和繁殖力等数据,研究氯虫苯甲酰胺对桃小食心虫的亚致死效应。结果表明,LC30和LC50种群桃小食心虫的卵期与对照（CK）种群相比明显延长; LC50种群桃小食心虫的蛀果率、脱果率、幼虫存活率、世代存活率以及单雌平均产卵量均显著低于CK种群; CK、LC10、LC30和LC50种群单雌平均产卵量分别为(183.67±10.39)、(177.66±14.81)、(147.83±14.54)粒和(126.33±11.29)粒。桃小食心虫LC30和LC50种群与CK种群相比,内禀增长率、净生殖率和周限增长率显著降低,平均世代周期和种群加倍时间延长,相对适合度降低。     

棉蚜茧蜂[Lysiphlebia japonica (Ashmead)]对棉蚜不同虫态寄生选择的研究

研究表明,棉蚜茧蜂[Lysiphlebia japonica(Ashmead)]喜好寄生棉蚜2、3龄若蚜,寄生率分别为78.8％和87.2％;对4龄若蚜的寄生率为10.6％;1龄若蚜的寄生率仅为5％;棉蚜茧蜂一般不选择有翅蚜作为寄主。随着供蚜量的增加,未被寄生的蚜虫百分率从21.3％上升至63％;过寄生率从55.1％下降至8.37％;废卵率从53.1％降至7.9％。棉蚜茧蜂对健康棉蚜和被寄生过的棉蚜不能完全识别,存在过寄生现象。     

多杀菌素对菜蛾绒茧蜂的致死和亚致死效应

以对多杀菌素高抗的小菜蛾纯合子品系作寄主饲养菜蛾绒茧蜂,用多杀菌素田间推荐使用浓度(25 mg/L)分别处理处于卵期、幼虫期和蛹期的绒茧蜂,其中卵期和幼虫期通过处理寄主幼虫间接处理,并测定该药剂对成虫的毒力,系统观察该杀虫剂对绒茧蜂各虫期的致死和亚致死作用。与对照相比,绒茧蜂卵期或幼虫期其寄主受药后,可导致蜂幼虫死于寄主体内或啮出寄主的过程中,使结茧化蛹率下降43% ~56%,成虫羽化率下降19% ~33%,成蜂雌性比下降11% ~25%,而成虫大小、寿命和寄生力未受显著影响;在蛹期受药使成虫羽化率下降10%,成蜂寿命缩短,但对成虫寄生力无显著影响;对成虫24 h的LC99为4.31 mg/L。结果表明,多杀菌素可进入寄主作用于其体内的蜂卵和幼虫,或直接作用于蜂蛹和成虫,从而对绒茧蜂各个虫态产生显著的致死和亚致死效应,尤以对成虫高毒。     

Toxicity of neem to natural enemies of aphids

Neem [Azadirachta indica (A. Juss.)] seed oil (NSO) applied in three concentrations, 0.5%, 1% and 2%, to potted plants infested with green peach aphid,Myzus persicae (Sulzer), totally prevented adult eclosion of larval coccinellids,Coccinella undecimpunctata L., and reduced adult eclosion of syrphids,Eupeodes fumipennis (Thompson), to 11%, 7% and 0%, respectively, of the controls. Under the same conditions, NSO did not reduce the rate of parasitism ofM. persicae byDiaeretiella rapae (Mcintosh), but emergence of parasitoid adults from aphid mummies collected from treated plants was reduced to 35%, 24% and 0%, respectively, of the controls. Although topical treatment of predator larvae with NSO at concentrations of up to 5% did not affect survival, emergence of parasitoids from mummies dipped in aqueous emulsions of NSO at similar rates was reduced significantly. Under field conditions, sprays of NSO and neem seed extract to plants had no significant impact on the number of aphids parasitized. Although total numbers of predators were reduced, numbers of predators relative to aphid numbers were similar to those in controls. Neem insecticides may be suitable for use in integrated pest management programs, as under field use they appear to be relatively benign to aphid predators and parasitoids.     

Activation of defence in sweet pepper, Capsicum annum, by cis-jasmone, and its impact on aphid and aphid parasitoid behaviour

BACKGROUND: Two important pests of the sweet pepper, Capsicum annuum, are the peach potato aphid, Myzus persicae, and the glasshouse potato aphid, Aulacorthum solani. Current aphid control measures include the use of biological control agents, i.e. parasitic wasps, but with varying levels of success. One option to increase parasitoid efficiency is to activate plant defence. Therefore, sweet pepper plants were treated with the naturally occurring plant defence activator cis-jasmone, and its impact upon the behaviour and development of aphids and aphid parasitoids was investigated. RESULTS: Growth rate studies revealed that the intrinsic rate of population increase of A. solani and M. persicae on sweet pepper plants treated with cis-jasmone (cJSP) was not affected compared with untreated plants (UnSP), but the positive behavioural response of alate M. persicae towards the volatile organic compounds (VOCs) from UnSP was eliminated by cis-jasmone treatment 48 h previously (cJSP48). In addition, the aphid parasitoid Aphidius ervi preferred VOCs from cJSP48 compared with UnSP, and a significant increase in foraging time was also observed on cJSP. Analysis of VOCs collected from cJSP48 revealed differences compared with UnSP. CONCLUSION: There is evidence that treatment with cis-jasmone has the potential to improve protection of sweet pepper against insect pests. © Crown copyright 2012. Reproduced with permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.     

The effect of indoxacarb and five other insecticides on Phytoseiulus persimilis (Acari: Phytoseiidae), Amblyseius fallacis (Acari: Phytoseiidae) and nymphs of Orius insidiosus (Hemiptera: Anthocoridae)

A laboratory study assessed the contact toxicity of indoxacarb, abamectin, endosulfan, insecticidal soap, S-kinoprene and dimethoate to Amblyseius fallacis (Garman), Phytoseiulus persimilis Athias-Henriot and nymphs of Orius insidiosus (Say). Amblyseius fallacis is a predacious phytoseiid mite and an integral part of integrated pest management (IPM) programmes in North American apple orchards. The other two beneficials are widely used in greenhouses to manage various arthropod pests infesting vegetable and ornamental crops. Indoxacarb is a slow-acting insecticide, so toxicity data were recorded 7 days post-treatment when the data had stabilised. It showed no toxicity to O. insidiosus nymphs or to A. fallacis or P. persimilis adults. The LC50 values for O. insidiosus nymphs and P. persimilis could not be estimated with their associated confidence limits, because the g values were greater than 0.5 and under such circumstances the lethal concentration would lie outside the limits. The LC50 for A. fallacis was 7.6x the label rate. The fecundity of P. persimilis was reduced by 26.7%. The eclosion of treated eggs from both species of beneficial mites was not affected adversely. Among the other pest control products, S-kinoprene and endosulfan affected adversely at least one species of the predators, whereas dimethoate, abamectin and insecticidal soap were very toxic to all three beneficials. Indoxacarb should be evaluated as a pest control product in IPM programmes.     

新疆棉花蚜虫-寄生蜂食物网结构的分子检测体系

为明确新疆棉花蚜虫-寄生蜂的食物网结构,通过设计新疆棉花蚜虫和寄生蜂的特异性引物,建立并优化可以在物种水平上开展棉花蚜虫-寄生蜂食物网结构分析的分子检测方法,该方法包括3个多重PCR检测体系（cMP1、cPriMP2和cHypMP3）和1个单一PCR（cSP1）检测体系,并应用建立的方法对采自库尔勒、阿克苏、昌吉的2 383头僵蚜样品进行分子检测。结果表明,4个体系的灵敏度均较高,其中蚜虫cMP1体系的检出限为500 DNA拷贝数,初级寄生蜂cPriMP2体系的检出限为5 000 DNA拷贝数,重寄生蜂cHypMP3和cSP1体系的DNA检出限分别为500拷贝数和100拷贝数。该方法能够快速且准确地鉴定4种棉花蚜虫、4种初级寄生蜂和7种重寄生蜂,特异性良好。使用该方法对供试僵蚜样品进行检测并成功绘制出新疆棉花蚜虫-初级寄生蜂-重寄生蜂食物网,定量分析了不同初级寄生蜂对蚜虫的寄生作用及重寄生蜂与初级寄生蜂之间形成的食物网络关系。表明所建立的分子检测方法可以用于评估不同种类寄生蜂在新疆棉花蚜虫种群控制中的生态功能,解析物种间的食物网关系。     

茶足柄瘤蚜茧蜂引种研究

茶足柄瘤蚜茧蜂,于1983年由美国俄克拉何马州引到陕西省泾阳县,可寄生于麦二叉蚜、棉蚜、豆蚜、酸模蚜、禾谷缢管蚜、玉米蚜。1983～1986年在棉田、小麦田、杂草地及植物园温室分别放蜂21307、11508、2933和19562头。1987年调查放蜂结果:棉田棉蚜僵蚜出蜂172头中,未见引进蜂;小麦田禾谷缢管蚜和麦二叉蚜分别出蜂34和314头,各有引进蜂1头;杂草地豆蚜出蜂420头中,有引进蜂6头;在植物园温室扶桑与海桐上僵蚜率分别为49.3％和32.2％,全是引进蜂。对影响茶足柄瘤蚜茧蜂在陕西定殖的因素作了讨论。     

Toxicity of biorational insecticides: activity against the green peach aphid, Myzus persicae (Sulzer)

The relationship between dose for each of four biorational insecticides (pyrethrins, neem extract, capsiacin extract, insecticidal soap) and mortality of the green peach aphid (Myzus persicae) was determined using a laboratory bioassay. These insecticides were toxic to aphids and paired mixtures of the insecticides provided synergistic activity as measured by aphid mortality under the laboratory bioassay conditions. Capsiacin extracts were found to provide low levels of mortality alone but acted synergistically in mixtures with the other insecticides and provided higher than expected levels of mortality. Activity as determined in the laboratory for each insecticide was not evident under field-use conditions in five separate experiments. Under field conditions and using common application methods, these insecticides did not provide significant levels of control of aphids.     

甜菜夜蛾核多角体病毒对斑痣悬茧蜂发育及存活的影响

研究了甜菜夜蛾核多角体病毒对斑痣悬茧蜂Meteorus pulchricornis发育及存活的影响。正在蜕皮的甜菜夜蛾Spodoptera exigua 2龄幼虫被斑痣悬茧蜂寄生后,当其发育到3龄与4龄时分别饲以95%致死浓度(LC_(95))或10×LC_(95)甜菜夜蛾核多角体病毒(SpeiNPV),研究表明:甜菜夜蛾核多角体病毒对斑痣悬茧蜂发育及存活产生不利的影响,影响程度取决于寄生与饲毒的间隔期以及饲毒量。被寄生的甜菜夜蛾幼虫发育到第3龄(即被寄生后第1天,1dpp)分别饲以LC_(95)或10×LC_(95) SpeiNPV的处理,没有寄生蜂老熟幼虫从寄主体内钻出;被寄生的甜菜夜蛾幼虫发育到第4龄(4 dpp)分别饲以LC_(95)或10×LC_(95) SpeiNPV的处理,分别有25.62%与16.31%寄生蜂老熟幼虫从寄主体内钻出。甜菜夜蛾是否饲毒对寄生蜂的出蜂率、化蛹率及羽化率影响显著;饲毒浓度影响寄生蜂的出蜂率、化蛹率,但不影响羽化率。甜菜夜蛾饲毒与否对寄生蜂幼虫及蛹的发育历期无显著影响,但饲毒甜菜夜蛾体内寄生蜂幼虫、蛹及成蜂显著小于未饲毒的甜菜夜蛾体内寄生蜂幼虫、蛹及成蜂。     

Impact of two synthetic pyrethroids and methomyl on management of the cabbage aphid,brevicoryne brassicae (L.) and its associated parasitoid,diaeretiella rapae (M'Intosh)

The effectiveness of two synthetic pyrethroids, cypermethrin and fenvalerate, and of methomyl applied to cabbage plants was tested against the cabbage aphid, Brevicoryne brassicae (L.), and its parasitoid, Diaeretiella rapae (M'Intosh). Dosage rates chosen were equivalent to the manufacturer's maximum and minimum recommendations. Methomyl was considerably more toxic to B. brassicae adults than the two synthetic pyrethroids used. Fenvalerate, at the lowest rate used (71 g ha^?1), showed satisfactory effectiveness in reducing aphid adult population on treated plants by c. 77% below that of the control. All insecticides and rates used significantly reduced the emergence of parasitoid adult D. rapae from mummified aphids compared to the control. Fenvalerate clearly had less impact on emergence than cypermethrin or methomyl at any dosage used, while methomyl has appeared to be the most toxic compound in this respect. Longevity of parasitoid adults was highly affected by insecticide application, particularly those adults emerging from mummified aphids exposed to methomyl or cypermethrin. However, only a slight difference in longevity was seen at the lower rate of 71 g ha^?1 of fenvalerate. At the lowest dosage rates used, methomyl and cypermethrin reduced the F₁-progeny of adult parasitoid females by 70.5% and 58.3%, respectively, of the control, whereas fenvalerate reduced the progeny by only 36.4%.     

不同作物上棉蚜及其主要天敌的发生规律

随着化学农药的大面积推广使用,棉蚜的抗药性问题变得越来越突出,结合使用生物防治法来延缓或治理棉蚜抗药性问题已迫在眉睫。本研究在常规管理棉田条件下,对不同作物混栽区苗期6种作物上棉蚜及其主要天敌的种群动态进行了调查。结果表明,西葫芦上的棉蚜种群数量最大（峰值,11016.7头/百株）,其次是四季豆（峰值,6323.3头/百株）,棉花、黄瓜、豇豆和甜瓜上的棉蚜则相对较少,且其种群动态发生具有一致性。6种作物上的主要天敌的种群发生都滞后于棉蚜的发生,并以寄生蜂的种群密度最大,且具有指数增长效应。在本试验条件下,西葫芦上棉蚜数量多,僵蚜基数大,是室内饲养寄生蜂的良好寄主。     

Selectivity of pesticides used on cotton (Gossypium hirsutum) to Trichogramma pretiosum reared on two laboratory-reared hosts

The side-effects of pesticides (insecticides, fungicides, herbicides and plant growth regulators) used on cotton were tested on adults and pupae of Trichogramma pretiosum Riley reared in the laboratory on two different hosts, the Angoumois grain moth (Sitotroga cerealella Olivier) and the Mediterranean flour moth (Ephestia kuehniella (Zeller)). The eggs of the host enclosing the parasitoid pupae received direct pesticide sprays, while the adults of the parasitoid were exposed to the pesticides through contact with residues on sprayed eggs offered to parasitism. Alpha-cypermethrin, carbosulfan, deltamethrin, endosulfan, profenofos and zeta-cypermethrin were highly noxious to the parasitoid, significantly reducing the percentage of emergence and parasitism of T. pretiosum developing in E. kuehniella or S. cerealella eggs. However, the pupal stage of the parasitoid developing in S. cerealella eggs was less susceptible to alpha-cypermethrin and deltamethrin. Lufenuron and metamidophos greatly reduced the percentage of adult emergence from eggs of both hosts, while novaluron only interfered on this variable when the wasps were developing in E. kuehniella eggs. However, lufenuron and monocrotophos had no effect on the parasitoid pupae of T. pretiosum developing in E. kuehniella eggs. Chlorfluazuron, diafenthiuron, diflubenzuron, fentin hydroxide, mepiquat chloride, novaluron, thiacloprid and triflumuron did not affect T. pretiosum emergence when eggs of S. cerealella enclosing pupae of the wasps were surface treated. The pesticides azoxystrobin, carbendazin + thiram, mepiquat chloride and novaluron had no effect on the ability of the wasps to parasitise E. kuehniella eggs. However, only mepiquat chloride did not affect the percentage of F1 wasps emerging from E. kuehniella eggs. The remaining pesticides moderately reduced the percentage of emergence and parasitism of the wasps when they had contact with the chemicals during their pupal or adult stage. Thus there were differences in pesticide toxicity according to the host used for parasitoid development. These differences were hypothesised to occur because of differences in egg morphology and parasitoid performance.