Disruption of responses to pheromone by (Z)-11-hexadecenyl trifluoromethyl ketone,an analogue of the pheromone,in the cabbage armyworm Mamestra brassicae

The effects of (Z)-11-hexadecenyl trifluoromethyl ketone (Z11-16:TFMK) a fluorinated pheromone analogue, on the responses to sex pheromone of the male cabbage armyworm, Mamestra brassicae, have been investigated in an actograph and by electroantennography (EAG). In spite of its structural proximity with the natural pheromone, Z11-16:TFMK was poorly active in EAG, and not active on male behaviour. When permeated in the air, Z11-16:TFMK reversibly inhibited the electroantennographic responses to (Z)-11-hexadecenyl acetate (Z11-16:Ac), the main component of the sex pheromone. In the actograph, the latency of the activation was increased and the intensity of the behavioural activity of males in response to Z11-16:Ac was significantly reduced in the presence of Z11-16:TFMK. These results, along with others previously reported by us, provide new pointers to the possible use of Z11-16:TFMK in pest-control strategies.     

Inhibition of pheromone response in Sesamia nonagrioides by the pheromone of the sympatric corn borer, Ostrinia nubilalis

Sesamia nonagrioides Lef. and Ostrinia nubilalis (Hübn.) are two corn borers present in the Mediterranean area that share a similar feeding habitat. The female sex pheromones of the two species consist of (Z)-11-hexadecenyl acetate, (Z)-11-hexadecen-1-ol, (Z)-11-hexadecenal and dodecyl acetate (77:8:10:5 w/w) and (Z)-11-tetradecenyl acetate and (E)-11-tetradecenyl acetate (97:3 w/w) respectively. Although the pheromones share no common components, previous work had shown the inhibition of the response by O. nubilalis males to their own pheromone owing to the presence of S. nonagrioides pheromone. In this study, the pheromone of O. nubilalis and its two components separately were shown to inhibit the attraction of S. nonagrioides males to the synthetic female pheromone in both laboratory wind-tunnel bioassay and field trapping studies. In the wind tunnel, the number of contacts of S. nonagrioides males with the source were significantly (P < 0.05) reduced by the single pheromone components of O. nubilalis. In the field, the addition of 1% of O. nubilalis pheromone significantly (P < 0.05) reduced the catches of S. nonagrioides males. The components of both pheromones also elicited electroantennographic responses from antennae of male S. nonagrioides moths. The ecological consequences and the possibilities of applying this cross-inhibition for mating disruption techniques are discussed.     

Inhibition of pheromone action in Sesamia nonagrioides by Haloacetate analogues

The electrophysiological activity of some halogenated analogues of the major component of the sex pheromone of the corn stalk borer Sesamia nonagrioides Lef. (1) is presented. The analogues comprise a series of fluoro-, chloro- and bromoacetate analogues 4 – 10 as well as trifluoromethyl ketone 11. The fluoro derivatives 4 – 6 displayed remarkable electro-antennogram (EAG) intrinsic activities in comparison with the parent acetate 1, while the remaining analogues elicited significantly lower response. The compounds have also been tested as inhibitors of the sex pheromone perception in EAG and in the field. In the laboratory. fluoro analogues 4 – 6 were better inhibitors than chloro derivatives 7 – 9 , which in turn behaved similarly to the bromoacetate 10 . Trifluoromethyl ketone 11, however, was a poor inhibitor of the pheromone action. In the field, baits of mixtures of compounds 5 – 11 with the corn stalk borer pheromone in 10 :1 ratio inhibited the concomitant attraction of the clover cutworm moth Scotogramma irifolii Rott., while the difluoro analogue 5, trichloroacetate 9 and trifluoromethyl ketone 11 also diminished the number of catches of the armyworm Mythimna unipuncta Haw. The monofluoroacetate 4. trifluoro analogue 6 and bromo derivative 10 significantly disrupted the pheromone action of the corn borer, whereas trifluoromethyl ketone 11 synergistically increased the number of males attracted to the pheromone trap alone. Addition of 11 to baits containing the corn borer pheromone caught S. nonagrioides selectively with regard to the other habitat-sharing species M. unipuncta and S. trifolii.     

Regional differences in pheromone responses of diamondback moth in Indonesia

Trap captures with two‐ and three‐component blends of synthetic sex pheromone for the diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae), were assessed in Indonesia. In West Java, the two‐component blend containing 10g of (Z)‐11‐hexadecen‐1‐ol acetate and (Z)‐11‐hexadecena| in a 4:6 ratio captured the greatest number of diamondback moths. Three and five virgin females were more attractive than the two‐component lures, which were as attractive as lures that also contained (Z)‐9‐tetradecen‐1‐ol acetate. In North Sulawesi, a 100 g dose of the two‐component blend attracted more males than the 10 g dose but was not significantly more potent than five virgin females. These results suggests that pheromone production and bioactivity should be assessed in separate populations prior to attempts to develop pheromone‐based monitoring or mating disruption programmes.     

Optimized mixture of sex pheromonal components for trapping of maleSpodoptera littoralis in Israel

The sex pheromone gland extracts ofSpodoptera littoralis (Boisd.) in Israel were reexamined by capillary gas chromatography and capillary gas chromatography combined with mass spectrometry. The following compounds were identified: (Z)-9-tetradecenyl acetate (46%), (Z,E)-9,11-tetradecadienyl acetate (33%), (Z,Z)-9,11-tetradecadienyl acetate (4%), (E)-11-tetradecadienyl acetate (9%), (Z)-11-tetradecenyl acetate (7%), and (Z,E)-9,12-tetradecadienyl acetate (0.5-1%). Field tests with various combinations of the major attractant (Z,E)-9,11-tetradecadienyl acetate and the minor components indicated that the best lure forS. littoralis in Israel is 2 mg (Z,E)-9,11-tetradecadienyl acetate containing 0.2-1% of (Z,E)9,12-tetradecadienyl acetate.     

Sex pheromone traps for monitoring the honeydew moth,Cryptoblabes gnidiella: Effect of pheromone components,pheromone dose,field aging of dispenser,and type of trap on male captures

The effects of pheromone components, pheromone dose in the dispenser, aging of dispenser in the field, and trap type on trapping efficiency of males of the honeydew moth,Cryptoblabes gnidiella (Mill.) (Lepidoptera: Pyralidae), were investigated. At dosages of 2 or 0.2 mg, a binary blend containing (Z)-11-hexadecenal (Z11–16: Aid) and (Z)-13-octadecenal (Z13–18:Ald) (1:1) was as effective in attracting males as a quaternary blend containing Zll-16:Ald, (E)-11-hexadecenal (Ell-16:Ald), Z13–18:Ald and (E)-13-octadecenal (E13–18:Ald), (10:1:10:1). Within the range of 20 to 2000 μg pheromone/dispenser, response of males increased positively with the pheromone dose; however, a load of 10 or 20 mg/dispenser was significantly less attractive to males than 2 mg/dispenser. The effect of aging of the dispenser in the field on trapping efficiency was significant. Captures in traps baited with 3- and 4-week-old septa were lower than those in traps baited with 1- or 2-week-old septa. The gradual loss of attractancy exhibited by rubber septa indicates that septa should be renewed within 2-3 weeks. The release rate of the pheromone was measured in a flow system and monitored with Zl1– 16:Ald only. The emission was almost constant for 18 days and then decreased gradually until the 34th day. The nonsticky IPS trap was as effective in capturing honeydew moth males as the sticky Pherocon 1C trap. The possibility of using the nonsticky, non-saturating and easy-to-handle IPS traps may lead to better and easier monitoring of honeydew moth populations.     

Synthesis of allylic trifluoromethyl ketones and their activity as inhibitors of the sex pheromone of the leopard moth, Zeuzera pyrina L. (Lepidoptera: Cossidae)

BACKGROUND: Trifluoromethyl ketones (TFMKs), structurally related to the pheromones, are good inhibitors of pheromone communication in insects. To determine their activity on Zeuzera pyrina L. (Lepidoptera: Cossidae), a polyphagous pest, the authors have prepared two diunsaturated TFMK analogues of the major (3) and the minor (4) pheromone components, and two monounsaturated ones (5, 6). Their biological activity in electroantennogram (EAG), wind tunnel and field tests is presented. RESULTS: The synthetic strategy to obtain the allylic TFMKs 3 and 5 is based on the reactions of diene 10 and 1‐octadecene with trifluoroacetaldehyde ethyl hemiacetal, followed by Dess–Martin oxidation of the resulting homoallylic trifluoromethyl alcohols. In EAG, topical application of analogues 3 and 4 on male antennae significantly reduced the pheromone response. In the wind tunnel, compound 4 reduced the number of contacts with the pheromone source. In the field, traps baited with mixtures of pheromone and inhibitors captured significantly fewer males than the pheromone alone. CONCLUSION: An efficient synthesis of allylic TFMKs is reported, with good overall yield, regiospecificity and diastereoselectivity. These compounds are good inhibitors of the pheromone in electrophysiology, wind tunnel and field tests. The results show the importance of two unsaturations at positions 2 and 13 of the trifluoroacyl group in the structure of the analogues, the latter being critical for inhibitory activity. Copyright © 2011 Society of Chemical Industry     

海灰翅夜蛾性信息素研究进展

本文概述了海灰翅夜蛾性信息素的分离与结构鉴定,并按照碳碳三键还原法、Z-型烯烃复分解法、Wittig反应法和Z-烯基铜锂法等构建碳碳双键的方法,重点总结了海灰翅夜蛾性信息素的主要活性成分 (9Z,11E)-9,11-十四碳二烯-1-醇乙酸酯的化学合成方法;同时对海灰翅夜蛾性信息素的生物活性与应用研究进行了简述,对其应用前景和研究方向进行了展望。     

棉铃虫不同地理种群性信息素通讯系统的比较分析

棉铃虫性信息素已普遍用于种群测报和防治,但其效果在不同地区不尽一致。为探讨这种不稳定性产生的原因,我们对黄河流域、长江流域及新疆地区不同地理种群棉铃虫的性信息素通讯系统进行了比较分析。就雌蛾性信息素的产生而言,连续两年的测定结果表明,性信息素腺体中2个主要组分（Z11-16：Ald和Z9-16：Ald）的含量在不同种群间变化较大,而两者间的相对比例（Z11/Z9）虽然个别种群有显著差异但幅度很小,总体被控制在狭窄的范围（97：3~92：8）;对同一地区的不同年份间进行比较,也得到了类似结果。就雄蛾对性信息素的反应,我们根据雌蛾腺体及田间常用诱芯中的Z11/Z9比例,配制99：1~90：10共4个不同比例的诱芯,在河南安阳、山东惠民和新疆昌吉进行了田间雄蛾诱捕试验。结果发现,在安阳和惠民其诱蛾量在不同比例的诱芯间无显著差异,而在昌吉地区的诱蛾量随Z11/Z9比例的降低而增高,且99：10比例的诱芯显著高于99：1的诱芯,表明新疆地区雄蛾对Z11/Z9感受的最佳比例范围更窄,且偏向于低的Z11/Z9比例。分析认为,新疆和内地棉铃虫种群在性信息素通讯系统间存在一定的差异,而内地不同种群间基本一致。研究结果为开发和使用区域针对性的棉铃虫性信息素诱芯提供了重要参考。     

甜菜夜蛾性信息素组分的鉴定及其田间试验

采用气相色谱仪(GC)及气质联用仪(GC-MS)等技术对我国甜菜夜蛾性信息素组分的鉴定结果表明,雌蛾性信息素腺体中含有4种组分,分别为Z9,E12-14:Ac(A)、Z9-14:OH(B)、Z9-14:Ac(C)和Z9,E12-14:OH(D);田间和室内种群各组分的比例(A:B:C:D)分别为47:18:18:17和43:18:23:16,比例及滴度在两种群间未有显著差异;雄蛾田间引诱测定表明,组分A、B显示性信息素活性。几种不同配比的硅橡胶塞诱芯在田间均显示极高的诱蛾活性,以9:1的AB二元诱芯(剂量100μg)最高,其诱蛾量与黑光灯相当,两者呈显著的正相关性,表明该诱芯可替代黑光灯用于甜菜夜蛾的种群测报。利用性诱捕器进行田间种群监测显示,1999年浙江省慈溪市的甜菜夜蛾共发生6代,以第4、5代发生量最高。     

合成性诱剂对粘虫雄蛾的引诱活性

本文叙述合成性诱剂对粘虫Mythimna separata Walker雄蛾的引诱活性。在北京第二代粘虫发生期间的试验表明,顺—11—十六烯醛对粘虫雄蛾有很强的引诱活性。在顺—11—十六烯醛中加入少量顺—11—十六烯醇乙酸酯(1—10％),能显著地提高诱蛾活性。同时表明在日本活性很高的粘虫诱芯(顺—11—十六烯醇乙酸酯及顺—11—十六烯醇比例为8:1或9:1)在中国北方诱到的粘虫雄蛾数量极少。在中国北方第三代粘虫发生期,以顺—11—十六烯醛和顺—11—十六烯醇乙酸酯(9:1或9.5:0.5)为组分的诱芯对粘虫雄蛾也显示了较弱的引诱活性。     

Effects of pheromone loading, dispenser age, and trap height on pheromone trap catches of the oriental fruit moth in apple orchards

The effects of field aging (0–28 days) and pheromone loading rate on the longevity of red rubber septa loaded with the sex pheromone blend of the oriental fruit mothGrapholita molesta (Busck), were evaluated in North Carolina apple orchards in 2002. Separate field tests examined the influence of trap height and pheromone loading rate of rubber septa on trap catches of adultG. molesta males in an abandoned orchard. The loss of the major pheromone component, (Z)-8-dodecenyl acetate (Z8–12:OAc), from red rubber septa over a 4-week period exhibited a relatively constant release rate with 30, 100 and 300 μg pheromone. Trap catch was significantly higher in pheromone traps placed in the upper canopy than in those in the lower canopy. Pheromone traps baited with 100μg lures caught more moths compared with those loaded with 300 μg. There was no apparent relationship between pheromone trap catch and septa age, with trap catch appearing to be primarily a function ofG. molesta population density. http://www.phytoparasitica.org posting May 14, 2006.     

梨小食心虫性诱剂和β-环糊精包合物的制备与表征

为了研发环境友好、缓慢释放、具有水溶性的昆虫性诱剂控制释放剂,本研究以梨小食心虫性诱剂的主要成分顺-8-十二碳烯醇乙酸酯(Z8-12:Ac)为研究对象,通过磁力搅拌法制备Z8-12:Ac与β-环糊精(β-CD)包合物;采用薄层色谱和傅里叶红外光谱法检验包合物的形成;正交试验设计确定最佳包合条件。结果表明:最佳包合条件是以水为溶剂、β-CD的质量浓度为0.044 g/m L、m(Z8-12:Ac)∶m(β-CD)=0.20∶4.0、包合反应温度为60℃和反应时间为5 h。研究结果可为研发高性能性诱剂产品以及田间应用技术提供参考。     

草地贪夜蛾性信息素的合成

草地贪夜蛾性信息素具有不伤害天敌、不产生抗药性、对环境安全等优点。其主要活性成分为:(Z)-7-十二碳烯-1-醇乙酸酯、(Z)-9-十二碳烯-1-醇乙酸酯、(Z)-9-十四碳烯-1-醇乙酸酯、(Z)-11-十六碳烯-1-醇乙酸酯、(E)-7-十二碳烯-1-醇乙酸酯和 (9Z, 12E)- 9,12-十四碳二烯-1-醇乙酸酯。本文研究了一种高效、简捷的合成草地贪夜蛾性信息素的新方法,其关键步骤包括:醛与官能团化鏻盐的Wittig偶联、炔的烷基化以及丙二酸与丙醛的Knoevenagel 缩合等反应。其中醛与羟基鏻盐的Wittig反应及Knoevenagel 缩合反应首次用于草地贪夜蛾性信息素的合成。     

Identification of novel inhibitors of calling and in vitro [14C]acetate incorporation by pheromone glands of Plodia interpunctella

Some octopamine agonists were found to suppress in vitro biosynthesis of the calling pheromone of the Indian meal moth, Plodia interpunctella. Isolated pheromone-gland preparations incorporated sodium [14C]acetate at a linear rate for 3 h when incubated with the pheromone biosynthesis activating neuropeptide (PBAN). This incorporation was dependent on the dose of PBAN (up to 0.5 microM). Thin-layer chromatography of a pheromone-gland extract revealed quantitative incorporation of radioactivity into a product exhibiting the same mobility as (Z,E)-9,12-tetradecadienyl acetate, the main component of the calling pheromone of P interpunctella. Twenty-seven octopamine agonists were initially screened using a calling behaviour bioassay of female P interpunctella. Four derivatives with activity in the nanomolar range were identified which were, in order of decreasing pheromonostatic activity: 2-(2,6-diethylphenylimino)thiazolidine > 2-(2,6-diethylphenylimino)oxazolidine > 2-(2,6-dimethylphenylimino)thiazolidine > 2-(2-ethylphenylimino)oxazolidine. These compounds also showed in vitro inhibitory activity in intracellular de novo pheromone biosynthesis. The results of the present study indicate that these derivatives could provide useful information in the characterization and differentiation of octopaminergic receptor types and subtypes.     

Sex pheromone traps for detecting and monitoring the raisin moth,cadra figulilella,in date palm plantations

Field tests were carried out to determine whether pheromone traps, baited with (Z,E)-9,12-tetradecadienyl acetate (Z9,E12-14:Ac) impregnated in rubber septa (Maavit, Israel), could provide a reliable tool for monitoring the raisin moth,Cadra figulilella (Gregson), in date palm plantations. No significant differences were detected between captures of males in traps baited with 1 or 10 mg pheromone/dispenser. However, traps baited with 1 mg pheromone captured significantly more males than those baited with 0.1 mg pheromone/dispenser. No differences were found between captures of males in traps hung at a height of 8 m (near the bunches) or 2–3 m (on palm trunks). Two peaks of male capture were detected, one in May-June and the other during September-October (ripening period). Results indicate a positive relationship between captures in traps and infestation levels by larvae. Pheromone traps baited with 1 mg Z9,E12–14:Ac impregnated in rubber septa and hung on palm trunks (at a height of 2–3 m), were very useful for monitoringC. figulilella populations and for determining the accurate timing of insecticide applications.     

大豆食心虫性信息素的化学结构触角电位及田间诱蛾效果

用气相色谱(GC)和气相色谱-质谱(GC-MS)分析,证明反-8,反-10-十二碳二烯醇醋酸(B)是大豆食心虫[Leguminivora glycinivorella(Mats.)]性信息素的组分。通过触角电位(EAG)测试,发现反-10-十二碳烯醇醋酸酯(A)、B 和反-7,顺-9-十二碳二烯醇醋酸酯(C)对该虫雄蛾触角有强烈刺激作用。大量田间诱蛾试验表明,由 A 和 B 两化合物组成的性引诱剂,对该虫雄蛾有很高的引诱活性。其中 A 和 B 按5∶2混合,剂量50μg/诱捕盆,单盆每日最多诱捕雄蛾达776头,诱捕雄蛾总数是1头活雌蛾的16.8倍。顺-10-十二碳烯醇醋酸酯(D)和反-10-十四碳烯醇醋酸酯(E)降低 AB 的引诱活性,甘油作为缓释剂,能延长诱芯的有效期,即诱蛾活性。上述结果表明,我国大豆食心虫性信息素不同于日本大豆食心虫性信息素。小面积防治应用试验效果明显。     

二化螟性诱芯中不饱和十六醛的比例对诱捕效果的影响

作者于2006年夏季在河南信阳地区系统比较了二化螟性诱芯中Z11-/Z9-16∶Ald及Z13-18∶Ald剂量对2个世代的二化螟雄蛾诱捕量的影响。结果表明,二化螟越冬代成虫诱捕试验中,2个最佳配方中Z11-/Z9-16∶Ald分别为9∶1和8∶2,而比例在7∶3~1∶9之间的诱芯则无引诱作用。如果保持诱芯中Z11-16∶Ald和Z9-16∶Ald的剂量一致且质量比控制在2∶1,则二化螟诱捕量随诱芯中所含Z13-18∶Ald剂量的增加而下降。所有诱芯在二化螟第一代引诱效果显著下降,但该时期组分为Z11-16∶Ald(2)、Z9-16∶Ald(1)、16∶Ald(0.7)和Z13-18∶Ald(0.37)的诱芯诱捕量显著优于其他配比。     

Use of pheromone traps for the proper timing of fumigation in the storage environment1

We have broadly divided the methods of storage insect manipulation into curative and preventive measures. Sex and aggregation pheromoncs combined with additional sensory stimuli in adhesive bait traps can be utilized as a preventive measure which may lead to insectistasis (a state wherein the insect population density is diminished to the extent of allowing storage without significant impairment). Insectistasis can be readily achieved by continual supervision of store rooms, use of adhesive bait traps in combination with a limited number of curative measures (e.g. gaseous or contact insecticides) timed according to the extent of trap catches. The sensory stimuli causing male storage moths (Phycitinae) to fly towards these bait traps involve, in sequence, a circadian rhythm, increasing or decreasing light (intensity approximately 1–10 Lux), an air current, a vertical rectangular figure and the main pheromone component. The antennae of male Anagasta kuehniella, Ephestia elutella and Plodia interpunctella comprise two types of receptor cells, of which one is selectively responsive to (Z,E)-9,12-tetradecadienyl acetate (TDA) and (Z)-9-tetradecenyl acetate (TA), while the other responds to (Z,E)-9,12-tetradecadien-l-ol (TDO).     

Night observations on the cotton leafworm,Spodoptera littoralis: Reliability of pheromone traps for population assessment and efficacy of widely separated pheromone dispensers for mating disruption

Night observations on the cotton leafworm,Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae), were conducted in pheromone-treated and untreated plots in which males, females, mating pairs on plants, and males caught in traps were collected. Results indicated that emergence of a new population was rapid (8-9 days) and that the number of virgin females and of mating pairs on plants reached a peak 5–6 days prior to that of males captured in pheromone traps. Males responded to pheromone traps most actively when the actual virgin female popution had already declined considerably. Dispensers adsorbed with(Z,E)-9,11-tetradecadienyl acetate and located 25 m apart, effectively reduced male captures in traps. However, the number of native mating pairs observed in the treated field during the night was not reduced. Few releasers at wide spacing, even with high amounts of the major pheromonal component, were ineffective in causing mating disruption ofSpodoptera littoralis.