Effects of volatile infochemicals (SOS signals) emitted from plants infested with the diamondback moth (Plutella xylostella) on the American serpentine leafminer (Liriomyza trifolii)

虽然许多研究集中在天敌对被害虫草食动物侵染的植物发出的挥发性SOS信号的吸引作用，但对SOS信号对其他害虫物种的影响知之甚少。为此，我们研究了美洲斑潜蝇在寄主小菜蛾幼虫侵染的十字花科植物上的觅食和产卵行为，小菜蛾是十字花科植物的重要害虫。我们发现，潜叶蛾雌成虫能够避开寄生在十字花科植物上的挥发性SOS信号，从而避免在寄生植物上取食和产卵。我们还发现，食草性植物诱导的十字花科植物的直接防御系统可以显著降低取食于植物叶片内的潜叶蛾幼虫的存活率，这可能在一定程度上解释了潜叶蛾雌成虫避免受到其他草食动物侵染的十字花科植物的SOS信号。

Although many studies have focused on attraction of natural enemies to volatile SOS signals emitted from plants infested with pest herbivores, relatively little is known about the influence of SOS signals on other pest species. Thus, we investigated foraging and oviposition behavior of the American serpentine leafminer (Liriomyza trifolii) in the cruciferous plants (e.g. Brassica rapa) infested with larvae of their host, the diamond back moth (Plutella xylostella), an important pest of cruciferous plants. We found that leafminer females avoided volatile SOS signals emitted from P. xylostella-infested cruciferous plants and thus they refrained from eating and oviposting in the infested plants. We also found that direct defense systems of cruciferous plants induced by herbivory can drastically decrease the survival ratio of leafminer larvae feeding inside the leaves of the plants, which may partly explain why leafminer females avoid SOS signals from cruciferous plants infested with other herbovores.