Department of Crop Protection, PPG-Fitotecnia, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil.
Bull Entomol Res. 2021 Oct;111(5):560-567. doi: 10.1017/S0007485321000249. Epub 2021 Apr 5.
Anastrepha fraterculus (Diptera: Tephritidae) is a major barrier to fruit production and exportation. In Brazil, the native parasitoid Aganaspis pelleranoi (Hymenoptera: Figitidae) and the exotic parasitoid Diachasmimorpha longicaudata (Hymenoptera, Braconidae) stand out as biological control agents. Knowledge of the factors that affect interactions among parasitoids, A. fraterculus, and host fruits may enhance the use of these agents in biological control programmes. This study evaluated the chemotaxis and parasitism of A. pelleranoi and D. longicaudata females reared on A. fraterculus larvae and kept on an artificial diet, red guava (Psidium guajava) or apple (Malus domestica). Females of both parasitoid species that emerged from larvae raised on artificial diet, guava or apple, were tested to Y olfactometer choice tests. In the parasitism tests, both parasitoid species were made to choose between A. fraterculus larvae brushed with water, apple pulp or guava pulp. D. longicaudata females from artificial diet (control) did not distinguish between fruit odours; however, females of D. longicaudata from larvae kept in apple or guava directed to the odours of their original fruit. The greatest parasitism for D. longicaudata occurred in the units that contained the pulp in which the larvae grew. A. pelleranoi from artificial diet preferred guava odours, including the females kept in apple. Similar results were observed in the parasitism bioassays. Our results found that A. fraterculus larval feeding influenced search behaviour and parasitism of D. longicaudata, whereas A. pelleranoi rearing experience did not affect its host choices.
小眼实蝇（双翅目：实蝇科）是水果生产和出口的主要障碍。在巴西，本土寄生蜂 Aganaspis pelleranoi（膜翅目： Figitidae）和外来寄生蜂 Diachasmimorpha longicaudata（膜翅目，Braconidae）是生物防治的重要手段。了解影响寄生蜂、小眼实蝇和宿主果实相互作用的因素，可以提高这些生物防治因子在生物防治计划中的利用效率。本研究评估了在人工饲料、番石榴（Psidium guajava）或苹果（Malus domestica）上饲养的小眼实蝇幼虫和 A. pelleranoi 雌蜂的化学定向性和寄生性。从人工饲料、番石榴或苹果饲养的小眼实蝇和 A. pelleranoi 雌蜂都进行了 Y 型嗅觉仪选择测试。在寄生测试中，两种寄生蜂都被置于 A. fraterculus 幼虫与水、苹果果肉或番石榴果肉之间进行选择。来自人工饲料（对照）的 D. longicaudata 雌蜂无法区分水果气味；然而，来自在苹果或番石榴中饲养的幼虫的 D. longicaudata 雌蜂会被其原始水果的气味所吸引。D. longicaudata 对其幼虫生长的果肉表现出最大的寄生率。来自人工饲料的 A. pelleranoi 更喜欢番石榴的气味，包括在苹果中饲养的雌蜂。在寄生生物测定中也观察到了类似的结果。我们的研究结果表明，小眼实蝇幼虫的取食经历影响了 D. longicaudata 的搜索行为和寄生率，而 A. pelleranoi 的饲养经历并不影响其对宿主的选择。
