Bombardier beetles (Coleoptera, Carabidae, Brachininae) possess a remarkable defense mechanism where a hot chemical spray is released from the tip of their abdomen, with an audible explosive sound. To date, the repellent properties of these chemicals have been tested against a limited number of taxa, such as amphibians and insects. To investigate the impact of bombardier beetle defenses on avian predators, feeding trials were conducted using the bombardier beetle (Pheropsophus jessoensis) and the Japanese quail (Coturnix japonica), a sympatric and generalist predator. All naïve, hand-reared quail attacked live beetles, indicating the absence of an innate aversion to them. However, most of the quail rejected consuming the beetles whether or not the beetles sprayed them with chemicals. Naïve quail also rejected dead P. jessoensis individuals. These results support the recent hypothesis that it is not essential for P. jessoensis to spray noxious chemicals to deter predators. We also found that some of the quail exposed to live P. jessoensis remembered to avoid them for up to 5 weeks. Our results provide the first evidence of the repelling effects of bombardier beetle defense mechanisms on avian predators.

中文翻译：

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防御禽类的庞巴迪甲虫。

庞巴迪甲虫（鞘翅目，腕足科，腕足科）具有显着的防御机制，其热化学喷雾从腹部尖端释放出来，并发出爆炸声。迄今为止，已经对这些化学物质的抗拒特性进行了针对数量有限的分类单元的测试，例如两栖动物和昆虫。为了研究庞巴迪甲虫防御对鸟类捕食者的影响，使用庞巴迪甲虫（Pheropsophus jessoensis）和日本鹌鹑（Coturnix japonica）进行了喂养试验），同胞兼全民捕食者。所有幼稚的，人工饲养的鹌鹑都袭击了活的甲虫，表明它们没有先天的厌恶感。但是，无论甲虫是否向其喷洒化学药品，大多数鹌鹑都拒绝食用甲虫。幼稚的鹌鹑还拒绝了死去的耶氏疟原虫个体。这些结果支持了最近的假说，即对于P. jessoensis而言，喷洒有毒化学物质以阻止捕食者不是必需的。我们还发现，暴露于活的耶氏疟原虫的一些鹌鹑记得要在长达5周的时间内避免食用它们。我们的结果提供了庞巴迪甲虫防御机制对鸟类掠食者的排斥作用的第一个证据。