多炔类化合物对美洲大蠊的触杀活性及对乙酰胆碱酯酶和腺苷三磷酸酶活性的影响

采用药膜法测定了人工合成的11个多炔类化合物对美洲大蠊Periplaneta americana初孵若虫的触杀活性。结果表明,当化合物处理浓度为20 μg/cm²时,致死率达70%以上的有: 化合物2 (1-叔丁基-4-羟甲基-丁二炔)、化合物9 (1-苯甲基-4-甲基-丁二炔)和化合物10 (O-炔丙基硫代磷酸二乙酯)。经毒力测定,化合物9和化合物10的LC₅₀分别为3.91 μg/cm²和1.50 μg/cm²。化合物2、化合物7 (1-苯基-4-邻硝基苯基-丁二炔)和化合物10对美洲大蠊乙酰胆碱酯酶(AChE)具有抑制活性,抑制率分别为12.00%、27.24%和62.22%。化合物2和化合物10对Na⁺-K⁺-ATPase具有抑制活性,抑制率分别为44.55%和31.44%;而化合物5 (1-苯基-4-（3,4-亚甲基二氧）苯基-丁二炔)和化合物6 (1-苯基-4-间硝基苯基-丁二炔)对该酶具有激活活性,激活率分别为24.98%和20.99%。化合物2、化合物4 （1-苯基-4-对甲氧基苯基-丁二炔）和化合物7对Ca²⁺-Mg²⁺-ATPase具有抑制活性,抑制率分别为49.02%、38.53%和35.32%, 其他化合物对该酶具有激活活性,其中激活活性最高的为化合物5,激活率达81.12%。     

紫背金盘(Ajuga nipponensis)次生物质对桔全爪螨(Panonychus citri)的驱避作用

研究了紫背金盘Ajuga nipponensis Makino各溶剂提取物和部分化合物对桔全爪螨Panonychus citri McGregor雌成螨及其产卵的驱避作用.结果表明,石油醚萃取物、乙酸乙酯萃取物具有较强的生物活性.在0.1 g · L-1时, 石油醚和乙酸乙酯萃取物对该螨处理1d后的产卵忌避率分别为:84.86%、69.88%;2d后为89.49%、82.19%;对雌成螨驱避率分别为:85.08%、68.66%;2d后为50.96%、69.84%.乙酸乙酯萃取物经分离得到四类化合物,结果表明:馏分Ⅰ为长链脂肪酸混合物,具有较强生物活性,2000μg/ml和1000μg/ml处理1d后,产卵忌避率分别为:80.77%、74.77%;2d后为73.81%、72.59%.2000μg/ml处理1d后对雌成螨的驱避率为:69.88%;2d后为74.24%.刺槐素Ⅱ、新克罗烷化合物Ⅲ和β-蜕皮甾酮Ⅳ在2000μg/ml均不表现活性.对馏分Ⅰ中的4个主要化合物单体进行活性测定,结果表明:十六烷酸、十六烷酸甲酯、十六烷酸乙酯和十八烷酸甲酯在2000μg/ml处理时,1d后,产卵驱避率分别为:75.18%、61.76%、59.18%和66.49%;2d后产卵驱避率为:66.67%、31.15%、46.75%和44.84%;雌成螨驱避率分别为:1d后,67.53%、63.79%、59.26%和68.00;2d后,67.23%、43.96%、48.23%和64.19%.在1000μg/ml处理时,1d 后,产卵驱避率分别为:59.21%、59.16%、57.02%和61.40%;1d后,雌成螨驱避率分别为:69.64%、61.43%、55.76%和64.00%.     

小菜蛾成虫对健康和机械损伤薄荷的嗅觉反应

【目的】比较健康和机械损伤的薄荷Mentha spicata对小菜蛾Plutella xylostella成虫嗅觉反应的影响,为筛选小菜蛾植物源驱避剂提供科学依据。【方法】利用触角电位(EAG)仪和Y型嗅觉仪分别测定小菜蛾雌、雄成虫对健康和机械损伤薄荷的触角电位和嗅觉行为反应,通过田间试验测定雌蛾产卵选择的忌避反应。【结果】健康薄荷和机械损伤薄荷均能引起小菜蛾雌、雄成虫触角电位反应,但损伤薄荷引起的触角电位反应值显著高于健康薄荷(P0.05);室内行为选择试验结果显示,损伤薄荷对小菜蛾雄性成虫有显著驱避作用(P0.05),驱避指数为53.33%,对雌性成虫有极显著驱避作用(P0.01),驱避指数达到80%;田间产卵选择试验发现,损伤薄荷对小菜蛾雌成虫产卵有极显著驱避作用(P0.01),产卵忌避指数达到71.32%。但是健康薄荷对小菜蛾雌、雄成虫的行为选择和雌性成虫的产卵选择均无显著驱避作用(P0.05)。【结论】机械损伤薄荷对小菜蛾成虫有较强的驱避效果,可以对其进行驱避活性挥发物质的筛选或作为驱避源来防治小菜蛾的危害。     

亚洲玉米螟雌蛾产卵偏好寄主植物的筛选及对葎草挥发性化学成分的电生理反应

【目的】鉴定亚洲玉米螟Ostrinia furnacalis雌蛾在寻找产卵寄主时起重要作用的植物挥发性化学物质,以探索亚洲玉米螟和寄主之间的化学通讯机制。【方法】首先利用田间产卵和风洞行为试验,从酸模叶蓼Polygonum lapathifolium、苘麻Abutilon theophrasti、葎草Humulus scandens、玉米Zea mays和稗草Echinochloa crusgalli 5种寄主植物中筛选出亚洲玉米螟雌蛾的产卵偏好寄主;并结合顶空吸附采样法,收集该寄主植物挥发性化学物质;再应用全二维气相色谱与飞行时间质谱联用系统(GC×GC-TOFMS)鉴定植物挥发性物质的化学成分及含量;最后利用气相色谱-触角电位联用仪(GC-EAD)测定亚洲玉米螟雌蛾对提取物中化学成分的触角电位反应。【结果】田间产卵试验结果表明,亚洲玉米螟雌蛾在不同寄主植物上的落卵量依次为玉米酸模叶蓼葎草稗草苘麻。风洞行为试验结果表明,亚洲玉米螟雌蛾对葎草的产卵趋性显著高于其他寄主植物。GC×GCTOFMS结果表明,葎草的植物挥发性化学物质主要成分有45种,其中,萜烯类相对含量高达86.29%,醛类、酮类和酯类相对含量合计仅占15.83%。GC-EAD结果显示,芳樟醇、α-葎草烯、桧烯、月桂烯、2-正戊基呋喃、壬醛、α-法呢烯、反式-罗勒烯和苯甲醛等9种挥发性物质能引起亚洲玉米螟雌蛾明显的电生理反应。【结论】亚洲玉米螟雌蛾对不同产卵寄主的选择具有显著差异性,寄主植物的理化因素是造成选择差异性的主要因素,葎草的植物挥发性化学物质对亚洲玉米螟有较强的吸引作用;芳樟醇、α-葎草烯、桧烯、月桂烯、2-正戊基呋喃、壬醛、α-法呢烯、反式-罗勒烯和苯甲醛9种挥发性化学物质对亚洲玉米螟产卵寄主的选择有重要作用。     

艾叶精油对玉米螟赤眼蜂的影响及两者对米蛾的联合作用

玉米螟赤眼蜂是生物防治中一种重要的天敌昆虫,为探明艾叶精油对玉米螟赤眼蜂的影响及两者对米蛾的联合防治效果,本文研究了艾叶精油熏蒸、触杀、驱避活性对玉米螟赤眼蜂的影响及艾叶精油和玉米螟赤眼蜂对米蛾的联合作用。结果表明,艾叶精油熏蒸和触杀处理对玉米螟赤眼蜂卵具有明显影响,寄生在米蛾卵上的玉米螟赤眼蜂卵经0.1、0.2、0.3、0.4、0.5、0.6μg/cm3艾叶精油熏蒸处理72h后玉米螟赤眼蜂的羽化率分别为56.67%、49.33%、44.00%、33.33%、26.00%和14.67%;寄生在米蛾卵上的玉米螟赤眼蜂卵经100、200、300、400、500、600mg/L艾叶精油触杀处理72h后玉米螟赤眼蜂的羽化率分别为54.00%、45.33%、38.00%、28.67%、18.00%和6.00%,均与对照组表现出显著性差异。艾叶精油驱避活性对玉米螟赤眼蜂成蜂也有明显的影响,300mg/L艾叶精油对玉米螟赤眼蜂的驱避率79.05%,随着时间间隔和距离间隔的增加,这种影响作用降低;联合应用艾叶精油与玉米螟赤眼蜂时先释放玉米螟赤眼蜂,24h后再滴加艾叶精油的防治效果最佳,米蛾的死亡率可高达96%。     

蕉藕与几个玉米品种对亚洲玉米螟产卵的诱集作用

通过触角电位(EAG)和嗅觉仪等技术,测定了自然和室内条件下,蕉藕和几个玉米品种对亚洲玉米螟的产卵诱集作用。结果表明:(1)自然条件下,蕉藕叶片上亚洲玉米螟的落卵量显著高于供试玉米品种。(2)室内条件下,亚洲玉米螟在涂有0.1g.ml-1和10g.ml-1浓度蕉藕叶片粗提物的玻璃板上的平均落卵量显著高于供试玉米品种。EAG反应结果显示,亚洲玉米螟对蕉藕和4个玉米品种叶片粗提物均可产生EAG反应,多数反应相对值之间无显著差异。但在0.1g.ml-1浓度时,交配雌蛾对蕉藕叶片粗提物的反应相对值显著高于供试玉米品种。行为测定结果表明,蕉藕叶片粗提物对亚洲玉米螟交配雌蛾、处女雌蛾和雄蛾均有较强的诱集作用,其平均诱捕率显著高于供试玉米品种。经相关性分析显示,田间试验与行为反应结果之间有极显著的相关性。综合表明,蕉藕对亚洲玉米螟有显著的产卵诱集作用,且这种作用在0.1g.ml-1至10g.ml-1的范围内有随叶片粗提物浓度降低而升高的趋势。     

芦荟提取物对桔小实蝇产卵驱避活性研究

【目的】研究库拉索芦荟Aloe vera L.提取物对桔小实蝇Bactrocera dorsalis Hendel的产卵驱避活性,筛选出对桔小实蝇有效的产卵调节剂。【方法】采用甲醇、丙酮、乙酸乙酯、二氯甲烷和石油醚5种溶剂对芦荟植物进行超声波提取,对5种提取物进行产卵驱避活性测定,确定产卵驱避活性较高的提取溶剂。进一步采用非选择性与选择性试验测定其对桔小实蝇产卵驱避活性的剂量效应,并对该提取物的持效期进行测定。【结果】发现5种芦荟取物对桔小实蝇均有一定的产卵驱避活性,而其中驱避活性最高的为丙酮提取物。通过选择性试验与非选择性试验发现丙酮提取物的产卵驱避率随提取物浓度的增加而增加,粗提物含量为10mg/mL时产卵驱避活性最强,分别为68.81%和89.43%。随着时间的增加,丙酮提取物的驱避活性逐渐下降,至第5天时产卵孔数与溶剂对照无显著差异,至第6天时产卵量与溶剂对照无显著差异。【结论】芦荟丙酮提取物对桔小实蝇有较高的产卵驱避活性,在植物源驱避剂方面具有一定开发前景,但持效期较短,可通过剂型改良来提高应用效率。     

甘蔗、玉米气味对亚洲玉米螟成虫产卵和幼虫取食的影响

【目的】农作物间套作对害虫的影响很大程度上取决于害虫的行为反应,通过研究玉米/甘蔗套作系统中植物气味对亚洲玉米螟Ostrinia furnacalis(Guenee)行为的影响,将为利用化学生态手段防治套作田中的害虫提供依据。【方法】通过昆虫触角电位实验、成虫产卵和幼虫取食实验,测定了甘蔗、玉米植株及二氯甲烷漂洗物对亚洲玉米螟成虫产卵、幼虫取食的影响。【结果】亚洲玉米螟成虫在甘蔗植株上的落卵量(卵粒数、卵块数)与玉米植株差异不显著,取食甘蔗植株的幼虫数量显著低于玉米植株。亚洲玉米螟对甘蔗、玉米叶片漂洗物均可产生EAG反应,且在同一浓度下的反应值之间无显著差异。成虫产卵量(卵粒数、卵块数)在0.1 gE/mL浓度的甘蔗和玉米漂洗物间差异不显著;幼虫对经甘蔗叶片漂洗物处理过的饲料的相对取食率均低于65.00%,显著低于玉米漂洗物处理的饲料。【结论】甘蔗和玉米气味对亚洲玉米螟产卵的影响没有差异,但甘蔗气味会导致初孵幼虫表现出很强的逃逸行为。     

亚洲玉米螟对玉米果穗挥发物的定向行为反应

为了明确玉米果穗挥发物对亚洲玉米螟Ostrinia furnacalis(Guenée)定向行为的影响,本研究采用气相色谱-质谱联用(GC-MS)、气相色谱-触角电位(GC-EAD)技术以及行为实验测定了亚洲玉米螟对玉米果穗挥发物的电生理及行为反应。结果表明:玉米果穗气味对其未交配雄蛾、雌蛾均具有引诱作用;从中分离出35种化合物,其中(+)-环苜蓿烯含量最高,达到(2391.60±161.34)ng;6种化合物能引起亚洲玉米螟未交配成虫的GC-EAD反应,其中顺-3-己烯-1-醇、(+)-环苜蓿烯、β-石竹烯对未交配雄蛾、雌蛾定向行为具有引诱作用。     

挥发性信息化合物对玉米螟赤眼蜂寄主选择行为的影响

在实验室条件下,利用“Y”型嗅觉仪测定了源于寄主亚洲玉米螟Ostrinia furnacalis (Guenée) 鳞片、卵表以及不同生理阶段的雌蛾附腺的不同浓度的提取物对玉米螟赤眼蜂Trichogramma ostriniae Pang et Chen寄主选择行为的影响,并对其引诱作用大小进行了比较。结果表明： 亚洲玉米螟鳞片的正己烷提取物在0.5 mg/mL和 1 mg/mL浓度时对玉米螟赤眼蜂有明显的引诱作用; 寄主卵的正己烷提取物在5块卵/mL和10块卵/mL浓度时对玉米螟赤眼蜂有显著的引诱作用,而在40块卵/mL浓度时对玉米螟赤眼蜂有极显著的驱避作用; 玉米螟赤眼蜂对亚洲玉米螟交配未产卵和产卵后前期的雌蛾附腺提取液有反应,而对处女蛾和产卵后期的附腺提取液没反应。卵表提取物和附腺提取物比鳞片提取液对赤眼蜂引诱作用强,两者对赤眼蜂的引诱作用没有明显差异。     

An improved aphid electroantennogram

Excised antennae have been used to record aphid electroantennograms (EAGs) but these preparations have small, rapidly declining responses and a short usable life. An improved EAG technique is described and evaluated using alate virginoparae of the black bean aphid, Aphis fabae, and a series of plant volatiles. EAG recording with fine-tip glass electrodes inserted into the surface of the intact antenna of a whole insect preparation gave stable EAG peaks of a few mV and EAG peak amplitude decreased by only 22% over an 8 hour recording period. The EAG responses showed typical dose-dependent characteristics. There was variation in EAGs from different preparations, so normalisation of the EAG responses against a standard stimulus is still necessary. The thirty compounds tested elicited an EAG response profile largely similar to that reported previously from excised antennae. EAG responses recorded with the electrode at three different positions, between the 5th-6th (A), 4th-5th (B), and 3rd-4th (C) antennal segments, were smaller when recorded closer to the head. Position B produced larger EAG responses than those at C although there was no olfactory receptor between position B and C.     

Electroantennogram responses of the stable fly, Stomoxys calcitrans, to components of host odour

Abstract. Electroantennograms (EAGs) were recorded from laboratory-reared male and female Stomoxys calcitrans (L.) in response to a range of synthetic chemicals known to be electrophysiologically-active for other biting flies. Of the eight compounds initially tested, only two - 1-octen-3-ol and 3-methylphenol - consistently elicited larger electroantennograms (EAGs) than did control treatments; 1-octen-3-ol was the most potent. EAG recovery time was inversely correlated with EAG amplitude. EAGs recorded with primary C₂-C₁₂ carbon chain-length primary aliphatic alcohols peaked at octan-1–ol with pentan-1-ol, hexan-1-ol and heptan-1-ol also eliciting EAG responses significantly larger than the controls. When different C₈ carbon chain compounds and nonane were tested: 1-octen-3-ol elicited the largest EAGs followed by, in decreasing activity, octan-1-ol, 1-bromooctane, octan-3-ol, octanal, 2-octanone, octanoic acid and nonane. The EAG response of 1-octen-3-ol increased sigmoidally with dose, with the threshold at between 2 and 20 ng, and the peak response at 200 μg on filter paper. EAGs larger than control were also elicited by entrained ox odour and ox breath. The behavioural implications are discussed.     

Electrophysiological and behavioural identification of host kairomones as olfactory cues for Culicoides impunctatus and C. nubeculosus

Electroantennograms (EAGs) were recorded from wild‐caught parous, female Culicoides impunctatus (Goetghebuer) in response to components of host odour. Nine synthetic compounds were found to be electrophysiologically active, eliciting EAGs which were significantly different from solvent control. An EAG hierarchy was established, in which 1‐octen‐3‐ol elicited the highest amplitude EAGs, followed by acetone, lactic acid and butanone. The overall responses to phenolic compounds were reduced compared to the non‐phenolics. Subsequent behavioural analyses of the effects of these compounds when tested singly revealed 1‐octen‐3‐ol, acetone and butanone to be attractive over specific stimulus doses. Exposure to supra‐optimal doses modified the insects’ behaviour; insects either ceased to respond or were repelled. Lactic acid was attractive at the lowest dose tested but was repellent at high doses. Behavioural responses to the phenolic components of host odour and lactic acid were similar, generally causing arrestment at low doses and repelling at the higher doses tested. A comparison of EAG profiles and behavioural assays between laboratory‐reared Culicoides nubeculosus (Meigen) and C. impunctatus suggested that the same kairomones are utilized by both species, with C. nubeculosus being less sensitive than C. impunctatus. The EAG hierarchy of C. nubeculosus to the four non‐phenolics was identical to that of C. impunctatus.     

小地老虎雄蛾对雌蛾性信息的EAG反应

利用触角电位记录（EAG）技术,测定了小地老虎Agrotis ypsilon (Rottemberg) 雄蛾对性信息素标准化合物Z7-12：Ac（A）、Z9-14：Ac（B）、Z11-16：Ac（C）、Z5-10：Ac（D）和Z8-12：Ac（E）的EAG反应。结果表明：这些标准化合物均能引起EAG反应,其中组分A（Z7-12：Ac）引起的反应最强,为5.65 mV,组分B（Z9-14：Ac）和C（Z11-16：Ac）居中; 组分D（Z5-10：Ac）的EAG反应值最小,为2.50 mV。二元混合物、三元混合物、四元混合物和全组分的EAG反应较高,其EAG反应值均显著高于单组分的反应值。三元混合物ABC的反应值最高,与5头雌蛾腺体的正己烷浸提液的EAG值相当。在使用剂量为0.01 ng～100 μg反应内,小地老虎雄蛾触角对性信息素各组分及其混合物的剂量反应曲线大致呈“S”形。从不同日龄雄蛾对标准化合物的反应中,发现在羽化后第3天达到最高值,之后则随日龄增加EAG反应降低。     

中红侧沟茧蜂对棉花挥发性物质的触角电位反应

中红侧沟茧蜂Microplitis mediator (Haliday) 是棉铃虫 Helicoverpa amigera (Hübner)的主要寄生蜂之一。在寻找害虫的过程中,害虫的寄主植物释放出的气味起着至关重要的作用。本文测定了中红侧沟茧蜂雌蜂对棉花中17种气味物质的触角电位反应,比较了雌雄茧蜂对6种气味反应的差别,并且测定了雌蜂对4种气味物质的剂量 反应。结果表明,在所测的气味物质中,中红侧沟茧蜂对脂肪族化合物的反应最强,对芳香族化合物的反应居中,而对萜类化合物的反应较弱。对所测的气味物质的反应,雌雄茧蜂之间的差异不显著。雌蜂对正己醛、苯乙酮、正壬醇的反应阈值为25 μL, 对苯甲醛的反应阈值为250 μL,在所测的浓度范围内,对4种化合物的反应均未达到饱和。     

粘虫雄蛾触角对其性信息素的电生理反应

用自行组装的触角电位仪,测定了粘虫Mythimna separata雄蛾蛾龄对标准化合物顺-11-十六碳烯醛(Z11-16：A1d)、顺-9-十六碳烯醛(Z9-16:Ald)和十六碳醛(16：A1d)的EAG反应的影响,分析了雄蛾触角对3种标准化合物的剂量-反应关系,发现粘虫雄蛾对Zll-16,Ald和Z9-16：Ald的剂量-反应曲线呈现出典型的“S”型,并且反应阐值较低。而对16：A1d几乎没有反应。最为重要的是检测了粘虫雄蛾对雌蛾腺体提取物的EAG反应,反应值的大小与样品中所提取的雌蛾腺体数目成正比。通过检测粘虫雄蛾对羽化不同天数,以及同一天羽化、在暗期不同时辰提取的雌蛾腺体提取物的EAG反应,证实了粘虫雄蛾的反应曲线与雌蛾释放性信息素的时辰节律呈正相关。还比较了烟青虫和粘虫雄蛾对粘虫雌蛾腺体提取物的EAG反应,间接证实了粘虫雌蛾腺体提取物中可能含有次要组分Z9-16;A1d。     

ELECTROANTENNOGRAM RESPONSES OF LYSIPHLEBIA JAPONICA ASHMEAD (HYMENOPTERA: APHIDIIDAE) TO SOME COTTON PLANT VOLATILES AND COTTON APHID PHEROMONES

Abstract Electroantennogram responses (EAGs) of Lysiphlebia japonica (Ashmead) (Hymenoptera: Aphidiidae) to cotton plant volatiles and cotton aphid pheromones were measured with EAG recording techniques. No sexual difference of EAG responses was found to all test samples under concentration of 10 μl/ml. The most effective chemicals were 1-heptanol, hexanal, heptanal, saturated primary-alcohols with six-carbon to nine-carbon chain and benzaldehyde. Both male and female showed the highest EAGs to green leaf volatiles (GLVs) and moderate EAGs to terpenoids among which geraniol was the most active. Cotton aphid pheromones elicited relative high EAGs. Among the four plant extracts, cotton leaf extract was the most effective. Dose curves were constructed from six female wasps' EAGs to four chosen chemicals, in which GLVs showed lower thresholds than terpenoids. According to the results above, we may draw the following conclusions: GLVs could be more important in longer distance orientation, while terpenoids may be more important in shorter ranges. Aphid pheromones may be effective attractants to parasitoids. Preadult experience can influence the antenna1 sensitivity of the parasitoid.     

Comparison of the olfactory sensitivity of two sympatric steppe grasshopper species (Orthoptera: Acrididae) to plant volatile compounds

Two Oedipodinae grasshopper species Oedaleus decorus asiaticus B.-Bienko and Angaracris baraben-sis Pall. (Orthoptera: Acrididae) are important pests on the natural grasslands in Inner Mongolia and often require insecticide treatment during outbreaks[1]. They both prefer overgrazed steppes and xerophytous habi-tats, and have thus been suggested as indicator species for steppe deterioration in typical steppe zones of In-ner Mongolia[2]. The two species have a sympatric distribution and sync…     

棉铃虫成虫对性信息素的电生理和行为反应研究

通过EAG和风洞实验,研究了棉铃虫雌雄成虫对性信息素组分和诱芯(Z-11-16Ald∶Z-9-16Ald=97∶3)的电生理反应。其中棉铃虫雌、雄蛾对诱芯的平均EAG反应测定值分别为1.06mV和4.32mV,分别高出对照(无性信息素空白诱芯)0.67mV和0.366mV,差异均达到极显著水平(雌蛾：t＝25.020, P≤0.01;雄蛾：t＝44.269,P≤0.01);棉铃虫雌蛾对性信息素组分(Z-11-16-Ald和Z-9.16Ald)的EAG反应值随浓度增加而增加;雄蛾在被剪除触角后与雌蛾不能正常交配,而雌蛾在被剪除触角后仍有40%的交配率,比正常雌雄蛾的交配率(70%)有所下降;在风洞实验中,雄蛾没有顺风远离诱源的飞行行为,趋向诱源的比率为81.8%,与对照有显著差异。研究表明性信息素组分对棉铃虫的交配活动有明显的影响。     

Defining Interaction between Electroantennogram Responses of Epiphyas postvittana (lepidoptera: Tortricidae) to Pheromone and Other Volatiles

The potential for electroantennograms (EAGs) to assist in the measurement of atmospheric pheromone concentrations was examined in laboratory and field experiments by using multiple stimuli, the main component of the pheromone of Epiphyas postvittana, (E)-11-tetradecenyl acetate, its Z-isomer (a behavioral antagonist), and alpha-terpineol (a representative host-plant odor) were presented to the antenna simultaneously to simulate field conditions. The EAG results were compared with predictions from two models describing responses to combined stimuli. Responses are defined as log-additive if they can be described with the equation [EAG((total)) =a (log ([P(x)]+[B(y)])+c] and as linear-additive if the EAG follows the equation [EAG((total)) =a (log [P(x)])+c+a'(log [B(y)])+c'] where [B(y)] is the concentration of the stimulant background odor and [P(x)] is the concentration of an additional odor stimulus. The EAGs elicited by the added stimuli were inversely related to the concentration of the volatile in the background. EAGs elicited by all combined stimuli followed the log-additive model. Our laboratory results were validated in field tests; alpha-terpineol represents the volatiles present in orchard air. In spite of this interaction between the perception of pheromone and plant volatiles, the field EAG can be used for the measurement of atmospheric pheromone concentrations, where background odor concentrations are relatively constant.