Department of Entomology and Acarology, Luiz de Queiroz College of Agriculture, University of São Paulo, Piracicaba, Brazil.
Department of Entomology, Washington State University, Pullman, WA, USA.
Pest Manag Sci. 2022 Aug;78(8):3314-3323. doi: 10.1002/ps.6958. Epub 2022 May 17.
Plant defenses activated by European zoophytophagous predators trigger behavioral responses in arthropods, benefiting pest management. However, repellence or attraction of pests and beneficial insects seems to be species-specific. In the neotropical region, the mirid predator Macrolophus basicornis has proved to be a promising biological control agent of important tomato pests; nevertheless, the benefits of its phytophagous behavior have never been explored. Therefore, we investigated if M. basicornis phytophagy activates tomato plant defenses and the consequences for herbivores and natural enemies.
Regardless of the induction period of M. basicornis on tomato plants, Tuta absoluta females showed no preference for the odors emitted by induced or control plants. However, Tuta absoluta oviposited less on plants induced by M. basicornis for 72 h than on control plants. In contrast, induced plants repelled Bemisia tabaci females, and the number of eggs laid was reduced. Although females of Trichogramma pretiosum showed no preference between mirid-induced or control plants, we observed high attraction of the parasitoid Encarsia inaron and conspecifics to plants induced by M. basicornis. While the mirid-induced plants down-regulated the expression of genes involving the salicylic acid (SA) pathway over time, the genes related to the jasmonic acid (JA) pathway were up-regulated, increasing emissions of fatty-acid derivatives and terpenes, which might have influenced the arthropods' host/prey choices.
Based on both the molecular and behavioral findings, our results indicated that in addition to predation, M. basicornis benefits tomato plant resistance indirectly through its phytophagy. This study is a starting point to pave the way for a novel and sustainable pest-management strategy in the neotropical region. © 2022 Society of Chemical Industry.
欧洲植食性捕食者激活的植物防御机制会引发节肢动物的行为反应，有利于害虫管理。然而，害虫和有益昆虫的驱避或吸引似乎是特定于物种的。在新热带地区，盲蝽捕食者 Macrolophus basicornis 已被证明是防治重要番茄害虫的有前途的生物防治剂；然而，其植食行为的益处从未被探索过。因此，我们研究了 M. basicornis 的植食行为是否会激活番茄植物防御机制，以及对食草动物和天敌的影响。
无论 M. basicornis 在番茄植株上的诱导期如何，Tuta absoluta 雌虫对诱导或对照植株释放的气味均无偏好。然而，与对照植株相比，M. basicornis 诱导 72 小时后的植株上 Tuta absoluta 的产卵量减少。相比之下，诱导植株会驱避烟粉虱雌虫，并且产卵数量减少。尽管捕食性天敌三化螟pretiosum 雌虫对盲蝽诱导或对照植株没有偏好，但我们观察到 Encarsia inaron 及其同种寄生蜂对 M. basicornis 诱导的植株有很高的吸引力。虽然随着时间的推移，诱导植株下调了与水杨酸（SA）途径相关的基因表达，但与茉莉酸（JA）途径相关的基因上调，增加了脂肪酸衍生物和萜烯的排放，这可能影响了节肢动物的寄主/猎物选择。
基于分子和行为学的发现，我们的结果表明，除了捕食作用外，M. basicornis 通过其植食性间接有益于番茄植物的抗性。本研究为在新热带地区开辟一种新的可持续害虫管理策略铺平了道路。
