Trichogramma spp. (Hymenoptera: Trichogrammatidae) are generalist egg parasitoids widely used as biological control agents, yet with limited efficacy against Tuta absoluta (Meyrick; Lepidoptera: Gelechiidae), a key pest of tomato. Olfactory cues related to the host-plant complex influence the searching behavior in parasitoids. Studies have shown that female Trichogramma spp. can learn odor cues affecting their preference. We assessed if learning increases the response to tomato odor and whether it improves the parasitism rate of Trichogramma achaeae, Trichogramma evanescens, and Trichogramma dendrolimi. The parasitoids were either naive, reared for one generation on T. absoluta eggs, or conditioned associatively with an oviposition experience on a factitious host in the presence of tomato odor. Subsequently, their arrestment response (searching time) to T. absoluta-infested tomato leaves was observed in a static four-chamber olfactometer. Rearing the parasitoids on T. absoluta increased the arrestment time of T. dendrolimi strongly and that of T. evanescens slightly but not that of T. achaeae. In contrast, oviposition experience on a factitious host with the tomato odor (leaves or extract) increased the searching time of T. achaeae and T. evanescens strongly but did not improve the response of T. dendrolimi. Concerning parasitism improvement, only T. achaeae showed an increased parasitism rate after associative learning. Hence, the learning capacity of T. achaeae should be further explored to improve its biological control efficacy against T. absoluta.

赤眼蜂属 （膜翅目：Trichogrammatidae）是一种广泛用作生物防治剂的卵寄生蜂，但对番茄的主要害虫Tuta absoluta（Meyrick；鳞翅目：Gelechiidae）的功效有限。与寄主植物复合体相关的嗅觉线索影响寄生蜂的搜索行为。研究表明，雌性赤眼蜂属。可以学习影响他们偏好的气味线索。我们评估了学习是否增加了对番茄气味的反应，以及它是否提高了Trichogramma achaeae、Trichogramma evanescens和Trichogramma dendrolimi 的寄生率。寄生蜂要么是幼稚的，要么在T上饲养了一代。 绝对鸡蛋，或在番茄气味存在的情况下与人为宿主的产卵体验相关联。随后，在静态四室嗅觉计中观察到它们对T.  absoluta感染的番茄叶的逮捕反应（搜索时间） 。在T.  absoluta上饲养寄生蜂明显增加了T.  dendrolimi和T.  evanescens的捕获时间，但没有增加T.  achaeae。相比之下，在具有番茄气味（叶子或提取物）的人造宿主上的产卵经验增加了T.  achaeae和T. evanescens强烈但没有改善T.  dendrolimi 的反应。关于寄生的改善，只有T.  acaeae在联想学习后表现出寄生率增加。因此，应进一步探索T.  acaeae的学习能力，以提高其对T.  absoluta的生物防治效果。