Unexpected reactions of a generalist predator towards defensive devices of cassidine larvae (Coleoptera, Chrysomelidae)
Unexpected reactions of a generalist predator towards defensive devices of cassidine larvae (Coleoptera, Chrysomelidae)
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多面性捕食者对卡西丁幼虫（鞘翅目、叶科）防御装置的意外反应
DOI：
10.1007/s004420050715
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发表时间：
1999
期刊：
影响因子：
2.7
通讯作者：
M. Hilker
中科院分区：
文献类型：
--
作者：
C. Müller;M. Hilker
摘要对昆虫与天敌间的相互作用的研究表明，昆虫粪便可以作为天敌的防御装置，作为吸引天敌的利它素来源，也可以作为微生物的重要能量来源。在本研究中，我们调查了幼虫粪便的影响，从叶甲虫的亚科Cassidinae对一个多面手的捕食者，蚂蚁红蚁。大部分的幼虫会将排泄物连同分泌物一起收集在后端的两个可移动的刺上，作为所谓的腹部防御盾。这些腹盾对M.本文研究了三种单食或寡食艾菊的红腹小蜂：齿颈小蜂（Cassida denticollis）和红腹小蜂（C. sanguinosa具有这种粪盾，而C.有仅由分泌物制成的盾形的柱头。生物测定表明，具有粪便和皮肤屏障的幼虫受到蚂蚁M的攻击。红更经常比幼虫的盾牌已被删除。这种盾对蚂蚁的吸引力与其他研究形成对比，其他研究发现，金蝇幼虫的腹部盾作为防御机制，对抗像蚂蚁这样的多面手捕食者。为了描述盾牌的吸引力线索，我们研究了可能的化学和物理刺激。嗅觉仪生物测定用M.红色和化学分析表明，植物来源的挥发性物质从粪便盾的C。denticollis吸引蚂蚁，而C. stigmatica没有。皮盾也散发出艾菊的挥发物，但数量要少得多。排除接触表面化学物质的粪便盾减少蚂蚁的攻击行为，而水分含量的变化的粪便盾没有影响。视觉刺激不能被排除作为增强蚂蚁的反应粪便盾牌与他们有吸引力的挥发物，并建议发挥主要作用，蚂蚁的反应对皮肤盾牌。这种新的有吸引力的影响，腹盾的幼虫的讨论，特别是相对于宿主植物化学和可能的功能的盾牌，可能超过的负面后果的吸引力的捕食者M。红宝石。
Abstract Studies of multitrophic interactions show that insect faeces may act as a defensive device against predators, as kairomone source for attraction of antagonists and as a significant energy source for micro-organisms. In the present study, we investigated effects of larval faeces from leaf beetles of the subfamiliy Cassidinae towards a generalist predator, the ant Myrmica rubra. Most cassidine larvae collect their faeces together with exuviae as so-called abdominal defensive shields on two movable spines at the posterior tip. The effects of these abdominal shields towards M. rubra were studied in three cassidine species, which feed mono- or oligophagously upon tansy (Chrysanthemum vulgare): Cassida denticollis and C. sanguinosa which possess such faecal shields and, for comparison, C. stigmatica with shields made of exuviae only (=skin shield). Bioassays revealed that larvae with both faecal and skin shields were attacked by the ant M. rubra more often than larvae whose shields had been removed. This attractiveness of shields towards ants contrasts with other studies, which found that abdominal shields of chrysomelid larvae act as defensive mechanisms against generalist predators like ants. To characterize the attractive cues of the shields, we studied possible chemical and physical stimuli. Olfactometer bioassays with M. rubra and chemical analyses revealed that plant-derived volatiles from faecal shields of C. denticollis attracted the ant, whereas odour from skin shields of C. stigmatica did not. Skin shields also emitted volatiles which derived from tansy, but in much lower quantities. Exclusion of contact to surface chemicals of a faecal shield reduced the ants' aggressive behaviour, whereas a change in the moisture content of a faecal shield had no influence. Visual stimuli cannot be ruled out as enhancing the ants' reaction towards faecal shields with their attractive volatiles, and are suggested to play a major role in the ants' response towards skin shields. This novel attractive effect of the abdominal shields of cassidine larvae is discussed, especially with respect to host plant chemistry and possible functions of the shields that might outweigh the negative consequences of the attraction of the predator M. rubra.