Oviposition Preference and Larval Performance of Drosophila suzukii (Diptera: Drosophilidae), Spotted-Wing Drosophila: Effects of Fruit Identity and Composition

A better understanding of the factors affecting host plant use by spotted-wing drosophila (Drosophila suzukii) could aid in the development of efficient management tools and practices to control this pest. Here, proxies of both preference (maternal oviposition behavior) and performance (adult emergence) were evaluated for 12 different fruits in the form of purees. The effect of the chemical composition of the fruits on preference and performance traits was then estimated. We synthesized the literature to interpret our findings in the light of previous studies that measured oviposition preference and larval performance of D. suzukii. We show that fruit identity influences different parts of the life cycle, including oviposition preference under both choice and no-choice conditions, emergence rate, development time, and number of emerging adults. Blackcurrant was always among the most preferred fruit we used, while grape and tomato were the least preferred fruits. Larvae performed better in cranberry, raspberry, strawberry, and cherry than in the other fruits tested. We found that fruit chemical compounds can explain part of the effect of fruit on D. suzukii traits. In particular, oviposition preference under choice conditions was strongly influenced by fruit phosphorus content. In general, the consensus across studies is that raspberry, blackberry, and strawberry are among the best hosts while blackcurrant, grape and rose hips are poor hosts. Our results generally confirm this view but also suggest that oviposition preferences do not necessarily match larval performances. We discuss opportunities to use our results to develop new approaches for pest management.

深入解析影响斑翅果蝇（Drosophila suzukii）寄主植物利用的相关因素，可为研发高效防控该害虫的工具与防控措施提供助力。本研究以果泥形式对12种不同水果开展实验，分别评估了寄主偏好的替代指标（雌成虫产卵行为）与适合度表现（成虫羽化率）；随后进一步解析了水果化学成分对寄主偏好与适合度相关性状的影响。我们整合现有文献，结合以往针对斑翅果蝇产卵偏好与幼虫适合度的研究，对本研究结果进行解读。研究结果显示，水果种类会影响斑翅果蝇生活史的多个环节，包括选择与非选择条件下的产卵偏好、羽化率、发育时长以及羽化成虫数量。黑醋栗始终是本研究中最受偏好的供试水果之一，而葡萄与番茄则是最不受偏好的供试水果。相较于其他供试水果，斑翅果蝇幼虫在蔓越莓、树莓、草莓与樱桃中的适合度表现更佳。研究发现，水果中的化学成分可部分解释寄主类型对斑翅果蝇相关性状的影响。具体而言，选择条件下的产卵偏好受水果磷含量的显著影响。总体而言，已有研究的共识为：树莓、黑莓与草莓属于斑翅果蝇的优质寄主，而黑醋栗、葡萄与玫瑰果则为劣质寄主。本研究结果总体验证了这一学术观点，但同时也表明产卵偏好与幼虫适合度未必完全匹配。最后，我们探讨了利用本研究结果开发新型害虫防控方案的可行路径。