Asymmetric oviposition behaviour between Drosophila suzukii and D. subpulchrella suggests competition for the shared niche in their native range

Release from competitors is one of the mechanisms ascribed to the ecological success of invasive species outside their native range (competitive release hypothesis). However, studies describing the natural competitors of invasive species in their homeland are limited. Drosophila suzukii, the spotted-wing drosophila, is an invasive pest of small fruits expanding its range worldwide, whereas D. subpulchrella, the most closely related species to D. suzukii, remains endemic to the native range of D. suzukii. D. subpulchrella is inferior to D. suzukii in terms of the host usage capability, and it has not been considered as a major competitor of D. suzukii. This study examined the interaction between the two species in egg-laying behaviour. A field survey revealed that 11% of wild berries were co-infected by both species. In the laboratory experiments, D. suzukii avoided oviposition substrates that had already been oviposited by either conspecific or D. subpulchrella females, whereas D. subpu..., , , # Asymmetric oviposition behaviour between *Drosophila suzukii* and *D. subpulchrella* suggests competition for the shared niche in their native range [https://doi.org/10.5061/dryad.1ns1rn946](https://doi.org/10.5061/dryad.1ns1rn946) ## Description of the data and file structure Field survey Wild berries (*Rubus hirsutus, R. palmatus, R. crataegifolius, R. microphyllus, Cerasus jamasakura, Morus australis*) were collected in a mountainous area (450 ~ 650 m of elevation) in Hachioji, Tokyo once in a week from May to June in 2023. The field consists of two sites, separated from each other by 600 m in the horizontal distance and 200 m in the altitude. At each site, berries were collected from several patches, each selected to be at least 20 m distant from the other patches. At each patch, 10 fruits were collected. The fruits were individually transferred into glass vials within the day and maintained at 20°C until adults emerged. The species and sex of the emerged Drosophila flies were...竞争释放假说（Competitive Release Hypothesis）指出，竞争者释放是入侵物种在原生分布范围以外实现生态成功的核心机制之一。然而，针对入侵物种在其原生分布区内自然竞争者的相关研究仍较为匮乏。 斑翅果蝇（Drosophila suzukii, Spotted-wing Drosophila）是一种危害小型浆果的入侵性害虫，其分布范围正逐步向全球扩张；而与斑翅果蝇亲缘关系最近的近缘种亚美果蝇（Drosophila subpulchrella），仅局限分布于斑翅果蝇的原生分布区域内。亚美果蝇在寄主利用能力上弱于斑翅果蝇，因此此前并未被视为斑翅果蝇的主要竞争者。 本研究针对两种果蝇的产卵行为交互作用展开了探究。野外调查结果显示，有11%的野生浆果同时被两种果蝇侵染。在实验室实验中，斑翅果蝇会避开已被同种或亚美果蝇雌虫产卵的基质，而亚美果蝇则……，# 斑翅果蝇与亚美果蝇的不对称产卵行为暗示二者在原生分布区内存在共享生态位的竞争 https://doi.org/10.5061/dryad.1ns1rn946 ## 数据与文件结构说明 ### 野外调查 2023年5月至6月，每周在日本东京八王子市的一处山地（海拔450~650米）采集野生浆果，涉及物种包括毛萼悬钩子（*Rubus hirsutus*）、掌叶悬钩子（*R. palmatus*）、山楂叶悬钩子（*R. crataegifolius*）、小叶悬钩子（*R. microphyllus*）、山樱花（*Cerasus jamasakura*）和鸡桑（*Morus australis*）。该调查区域包含两个采样点，两点间水平距离为600米，海拔差为200米。每个采样点内设置多个采样斑块，各斑块间间距至少为20米。每个斑块采集10颗浆果。采集的浆果于当日单独转移至玻璃管中，置于20℃环境下饲养至果蝇成虫羽化，后续将对羽化出的果蝇进行物种鉴定与性别分型……