Responses of the olfactory receptor neurons of the corn stalk borer Sesamia nonagrioides to components of the pheromone blend and their inhibition by a trifluoromethyl ketone analogue of the main component

Two types of olfactory hairs and three types of olfactory receptor neurons (ORN) have been characterized on the antennae of male Sesamia nonagrioides Lef for the first time. Type A sensilla housed a cell which fired large spikes in response to (Z)-11-hexadecenyl acetate (Z11-16:Ac), the major component of the sex pheromone, and a second cell firing smaller spikes in response to (Z)-11-hexadecenal (Z11-16:Ald), a minor component of the pheromone blend. Type B sensilla housed one cell firing large spikes to Z11-16:Ac and a cell firing smaller spikes to another minor component of the pheromone blend, (Z)-11-hexadecenyl alcohol (Z11-16:OH). No cell responding to dodecyl acetate, another minor component of the natural extract, was found. Fluorinated ketones were tested as inhibitors of the cell responses to pheromone compounds. The fluorinated derivatives tested, (Z)-11-hexadecenyl trifluoromethyl ketone (Z11-16:TFMK), n-hexadecyl trifluoromethyl ketone (16:TFMK), (Z,E)-9,11-tetradecadienyl trifluoromethyl ketone (Z9,E11-14:TFMK), 3-octylthio-1,1,1-trifluoropropan-2-one (OTFP), (Z)-11-tetradecenyl trifluoromethyl ketone (Z11-11:TFMK) and 1,1-difluoro-(Z)-11-hexadecenyl methyl ketone (Z11-16:DFMK), had no or only weak excitatory effects. However, the neuron responses to the pheromone compounds were significantly decreased in the presence of a constant stimulation with Z11-16:TFMK and the effect was reversible. The latencies of the responses to the acetate and aldehyde cells were significantly increased. The effects were not specific, since Z11-16:TFMK also inhibited the responses of the ORNs of Spodoptera littoralis Boisd. Correspondingly, Z9,E11-14:TFMK, an analogue of the main component of the pheromone of this latter insect, inhibited responses of S nonagrioides ORNs. Implications of these results on the utilization of Z11-16:TFMK as a communication disruptant are discussed.     

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.     

高剂量性信息素环境对草地贪夜蛾求偶和交配行为的影响

本文在风洞中模拟形成高浓度性信息素Z7-12:Ac、Z9-14:Ac和 Z11-16:Ac 环境,研究草地贪夜蛾Spodoptera frugiperda (Smith)的求偶和交配行为,为进一步开发交配干扰技术提供技术参数和依据。研究结果表明,在高剂量性信息素环境下,草地贪夜蛾雄蛾的暗期活动时间延后,而雌蛾的活动节律则没有变化,雌雄蛾之间产生了活动节律的时间差。同时,雌雄交配率和交配持续时间显著下降,交配日龄则显著延迟2 d。由于交配日龄延迟,产卵量及其孵化率也相应降低。性信息素喷射时间间隔对草地贪夜蛾性信息素释放滴度有显著影响,当间隔时间为5、10、20 min时,雌蛾释放的性信息素滴度显著下降,以5 min为最低。因此,高剂量性信息素环境不仅影响雄蛾对性信息素的定向,对雌雄蛾间化学通讯和交配也有显著影响。     

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.     

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.     

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。     

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.     

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。     

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).     

Sublethal effects of larval treatment with deltamethrin on moth sex pheromone communication system of the Asian corn borer, Ostrinia furnacalis

The first, third, and fifth instar larvae of Asian corn borer, Ostrinia furnacalis (Guenée) (Lepidoptera: Pyralidae), were treated with a lethal dose 30% of deltamethrin to determine its sublethal effects on chemical communication of the adult survivors. The capability of all males surviving deltamethrin to contact the pheromone source in a wind tunnel was significantly reduced, but those treated as the first and third instars also exhibited lower percentages of `orientation,' `up-wind flight,' and `approaching' behaviors than the control males. Female moths from the deltamethrin treatment exhibited similar calling periodicity and percentages to the control moths during 10-h scotophase. However, approximately 20% of the females that survived the pyrethroid in the first and third instars contained significantly higher amounts of sex pheromone and wider coefficients of variation of the ratio of E12-tetradecenyl acetate to its Z isomer in those female survivors. There was no significant difference in the pheromone titers and coefficients of variation in control females and the females treated in the fifth instars. The present study indicates that the Asian corn borer may possess a compensation system by which the males that survived treatment at larval stage present a lower response to the pheromone, while the female survivors produce and release more pheromone.     

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.     

粘虫雌蛾性信息素特征成分鉴定及其不同配比的室内引诱效果

为确定粘虫Mythimna separata(Walker)雌蛾的性信息素特征成分及其不同配比的室内引诱效果,采用气相色谱-质谱和气相色谱-触角电位联用技术检测了雌蛾性腺浸提液,并利用Y型嗅觉仪测定了粘虫雄蛾对不同配比性信息素特征成分的选择反应。结果显示,从粘虫的求偶雌蛾性腺浸提液中可分离到顺-11-十六碳烯醛、十六碳醛和顺-11-十六碳烯醇3种特征成分,在色谱柱中的保留时间依次为15.82、16.06和17.27 min,含量分别为3.37、1.83和0.10 ng,比例约为34∶18∶1。无论是天然存在于雌蛾性腺还是人工合成的顺-11-十六碳烯醛均能够激发雄蛾的电生理反应。顺-11-十六碳烯醛、十六碳醛和顺-11-十六碳烯醇不同配比对雄蛾表现出不同的引诱活性,最大引诱率达87%,极显著高于对照溶剂石蜡油对雄蛾的引诱率。表明顺-11-十六碳烯醛、十六碳醛和顺-11-十六碳烯醇为中国粘虫种群的雌蛾性信息素特征成分,且其不同配比对雄蛾有不同的引诱活性。     

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.     

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.     

杀虫剂对蛾类昆虫生殖行为影响的研究进展

综述了近年来国内外关于杀虫剂对蛾类昆虫求偶、性信息素合成及释放、定向行为、交配和产卵等生殖行为影响的研究进展。经杀虫剂处理后,许多雌蛾的求偶行为受到抑制、性信息素含量降低,雄蛾对性信息素的反应和交配成功率下降,但药剂对产卵量和卵孵化率没有明显影响。而部分药剂可增强雄蛾对性信息素的反应,刺激雌蛾信息素含量异常增高和使活性组的比例发生漂移。     

亚致死剂量溴氰菊酯对亚洲玉米螟雄蛾性信息素通讯行为的影响

用亚致死剂量溴氰菊酯处理亚洲玉米螟雄蛾后,存活雄蛾对信息素定向行为反应受到较大的影响。雄蛾的起飞潜伏期延长,不应率增加,到达诱芯率大幅度下降。反应下降程度与剂量的相关性显著。以雄蛾的行为反应率机率值(Z)对药剂处理剂量对数(X)和处理天数(Y)进行二元回归分析,回归方程分别为:起飞:Z=6.979-6.559X 0.162Y;定向:Z=5.258-2.611X-0.039Y;逆飞:Z=4.982-2.457X-0.061Y;到达:Z=3.399-1.011X 0.168Y。     

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.     

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.     

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。     

二化螟性诱剂和诱盆设置技术的研究

通过对二化螟性诱剂水盆诱捕器及其设置高度比较研究,结果表明：诱捕器的口径大小以２４ｃｍ为佳,绿色水盆的诱蛾量比其他颜色的要大;在越冬代诱捕中,诱盆的高度在２０ｃｍ左右效果较好;性诱剂离水面的高度对二化螟雄蛾的诱捕有一定影响,其高度在０.５～１.０ｃｍ的诱蛾量最高。