Natural enemies locate their herbivorous host and prey through kairomones emitted by host plants and herbivores. These kairomones could be exploited to attract and retain natural enemies in crop fields for insect pest control. The parasitoid Encarsia formosa preferentially parasitises its whitefly host, Trialeurodes vaporariorum, a major pest of tomato Solanum lycopersicum, thus offering an effective way to improve whitefly control. However, little is known about the chemical interactions that occur in E. formosa-T. vaporariorum-S. lycopersicum tritrophic system. Using behavioural assays and chemical analyses, we investigated the kairomones mediating attraction of the parasitoid to host-infested tomato plants. In Y-tube olfactometer bioassays, unlike volatiles of healthy tomato plants, those of T. vaporariorum-infested tomato plants attracted E. formosa, and this response varied with host infestation density. Coupled gas chromatography/mass spectrometric analyses revealed that host infestation densities induced varying qualitative and quantitative differences in volatile compositions between healthy and T. vaporariorum adult-infested tomato plants. Bioassays using synthetic chemicals revealed the attractiveness of 3-carene, β-ocimene, β-myrcene and α-phellandrene to the parasitoid, and the blend of the four compounds elicited the greatest attraction. Our results suggest that these terpenes could be used as an attractant lure to recruit the parasitoid E. formosa for the control of whiteflies in tomato crop fields.

天敌通过寄主植物和草食动物释放的海洛酮来定位其草食寄主和猎物。这些海洛酮可以被用来吸引和保留农田中的天敌，以控制害虫。拟寄生的福美car虫（Encarsia formosa）优先寄生于其粉虱寄主Trialeurodes vaporariorum，它是番茄茄属的主要害虫，因此提供了改善粉虱防治的有效途径。然而，鲜为人知的是，在大肠埃希氏菌-蒸腾拟南芥-番茄链霉菌中发生的化学相互作用三养系统。使用行为分析和化学分析，我们研究了介乎寄生虫对寄主感染的番茄植物的吸引力的海洛酮。在Y形管嗅觉计生物检测，健康的番茄植物的不同挥发性物质，那些的温室白粉虱-infested番茄植物吸引E.台塑，并且该响应与主机侵染密度变化。气相色谱/质谱联用分析表明，宿主侵染密度可导致健康鼠笼草和气单胞菌之间挥发性成分的定性和定量变化。成虫侵染的番茄植物。使用合成化学物质进行的生物测定显示，3-胡萝卜素，β-烯丙基，β-月桂烯和α-芹烯对异寄生虫具有吸引力，并且四种化合物的混合物引起了最大的吸引力。我们的研究结果表明，这些萜烯可以用作诱饵来招募寄生性大肠埃希氏菌，以控制番茄田中的粉虱。