Data from: Behavioural and physiological responses to prey-related cues reflect higher competitiveness of invasive vs. native ladybirds

Understanding the traits that might be linked with biological invasions represents a great challenge for preventing non-target effects on local biodiversity. In predatory insects, the ability to exploit habitats for oviposition and the physiological response to prey availability differs between species. Those species that respond more readily to environmental changes may confer to their offspring a competitive advantage over other species. Here, we tested the hypothesis that the invasive Harmonia axyridis (Coleoptera: Coccinellidae) makes better use of information from a plant-prey (Vicia faba - Aphis fabae) system compared to the native Oenopia conglobata. Y-tube olfactometer bioassays revealed that both species used olfactory cues from the system, but H. axyridis exhibited a more complete response. This species was also attracted by plants previously infested by aphids, indicating the capacity to exploit volatile synomones induced in plants by aphid attack. Oocyte resorption was investigated when different olfactory stimuli were provided under prey shortage and the readiness of new oogenesis was measured when prey was available again. H. axyridis exhibited higher plasticity in oogenesis related to the presence/absence of plant-aphid volatiles. Our results support the hypothesis that H. axyridis is more reactive than O. conglobata to olfactory cues from the plant-prey system.解析与生物入侵相关的物种性状，乃是防范外来物种对本地生物多样性引发非靶标效应的重大挑战。在捕食性昆虫类群中，不同物种利用栖息地产卵的能力，以及对猎物可获得性的生理响应均存在显著差异。对环境变化响应更为灵敏的物种，可令其后代相较于其他物种获得竞争优势。本研究验证了如下假说：相较于本土物种多异瓢虫（Oenopia conglobata），入侵物种异色瓢虫（Harmonia axyridis，鞘翅目Coleoptera：瓢虫科Coccinellidae）可更充分地利用植物-猎物（蚕豆Vicia faba - 豆蚜Aphis fabae）系统中的信息。通过Y型管嗅觉仪生物测定实验发现，两种瓢虫均能利用该系统中的嗅觉线索，但异色瓢虫的响应更为完整。该物种还会被先前遭受蚜虫侵染的植株所吸引，表明其能够利用蚜虫侵染植株后诱导产生的挥发性互利素。本研究在猎物匮乏的条件下设置不同嗅觉刺激，探究了卵母细胞吸收情况；并在重新提供猎物时，检测了新一轮卵子发生的就绪状态。异色瓢虫在卵子发生过程中，对植物-蚜虫挥发性信号的存在与否表现出更高的可塑性。本研究结果验证了前述假说：相较于多异瓢虫，异色瓢虫对植物-猎物系统中的嗅觉线索响应更为灵敏。