The spotted-wing drosophila (SWD), Drosophila suzukii (Matsumura), is an invasive species native to East Asia and now widespread worldwide. Major economic damage is caused by the larvae developing within ripening soft-skin fruit. Currently, larval detection in fruit is limited to destructive methods and post-harvest control strategies heavily rely on the use of chemicals or cold to inhibit egg eclosion and larval growth. Feeding larvae are likely to induce substrate-borne vibrations in the berry that could be exploited as cues by predators or to develop a non-invasive pest detection method, an approach previously applied on leaves and wooden structures, but never on fresh fruit. We used a laser vibrometer to detect and characterize the incidental vibrations produced by D. suzukii larvae within fresh blueberries at five different pest age (48, 96, 168, 216 and 264 h). An innovative statistical analysis was performed to assess if infestation level (number of pupae) and pest age (hours after exposure) affect the spectrum and the amplitude of vibrations. The recordings of infested berries were characterized by the presence of a series of broad-band pulses (frequency range 0.1–2 kHz) without a regular temporal pattern, in an amplitude range between 12.1 and 946 µm/s. Furthermore, the analysis revealed the possibility to distinguish between different pest ages and infestation levels. By a spectral analysis of the recordings, the pest ages can be distinguished among each other, but for the age groups at 168 and 216 h after infestation. The vibration amplitude trend gradually increased up to 168–216 h after infestation, and then decreased until fly emergence. Low-infested blueberries showed a faster D. suzukii development time compared to high-infested blueberries. This was reflected into vibrational recordings, as low-infested blueberries exhibited peak amplitude at earlier stage compared to high-infested ones. Results suggest that D. suzukii larvae induce detectable vibrations by feeding within berries that are dependent on infestation level and pest age. We discuss the possible ecological role of such vibrations as cues for unintended receivers, such as predators and parasitoids, and their potential for innovative infestation detection methods.

斑翅果蝇 (SWD)、铃木果蝇(Matsumura) 是一种原产于东亚的入侵物种，现已广泛分布于世界各地。主要的经济损失是由成熟的软皮水果中发育的幼虫造成的。目前，水果中的幼虫检测仅限于破坏性方法，采后控制策略严重依赖使用化学品或低温来抑制卵羽化和幼虫生长。进食的幼虫可能会在浆果中引起基质传播的振动，这些振动可以被捕食者利用作为线索，或者开发出一种非侵入性害虫检测方法，这种方法以前应用于树叶和木质结构，但从未应用于新鲜水果。我们使用激光振动计来检测和表征5 个不同害虫年龄（48、96、168、216 和 264 小时）的新鲜蓝莓内铃木D. suzukii幼虫产生的偶然振动。进行了创新的统计分析，以评估侵扰水平（蛹数量）和害虫年龄（暴露后数小时）是否影响频谱和振动幅度。受感染浆果的记录的特征是存在一系列宽带脉冲（频率范围 0.1-2 kHz），没有规则的时间模式，幅度范围在 12.1 至 946 µm/s 之间。此外，分析揭示了区分不同害虫年龄和侵染水平的可能性。通过对记录的光谱分析，可以区分害虫年龄，但区分为侵染后 168 小时和 216 小时的年龄组。振动幅度趋势在侵染后168-216小时内逐渐增加，然后下降直至蝇羽化。与高感染的蓝莓相比，低感染的蓝莓表现出更快的铃木D. suzukii发育时间。这反映在振动记录中，因为与高感染蓝莓相比，低感染蓝莓在早期阶段表现出峰值振幅。结果表明，D. suzukii幼虫通过在浆果内取食来诱导可检测到的振动，振动取决于侵染程度和害虫年龄。我们讨论了这种振动作为非预期接收者（例如捕食者和拟寄生物）的线索的可能的生态作用，以及它们在创新侵扰检测方法中的潜力。