Antipredation strategies contribute to the lifetime reproductive success of organisms, particularly in more vulnerable life stages that look to survive until reproduction. In insects, eggs and larval stages are often immobile or unable to rapidly flee and hide from predators. Understanding what alternative antipredation strategies they use, but also how these change over development time, is required to fully appreciate how species adapt to biotic threats. Murgantia histrionica is a stink bug, conspicuously colored from egg to adult, known to sequester defensive glucosinolates from its cruciferous hosts as adults. We sought to assess whether this chemical defense is also present in its eggs and early nymphal instars and quantified how it fluctuates among life stages. In parallel, we looked at an alternative antipredation strategy, described for the first time in this species: tonic immobility (i.e., death feigning). We also qualitatively investigated ultraviolet reflectance in eggs and adults as a proxy of conspicuousness against UV-absorbing leaves. Our results show that the eggs are significantly more chemically defended than the first two but not third mobile life stages, yet compound concentrations do not statistically differ across nymphal instars. Tonic immobility is favored by hatchlings, but less so by subsequent instars. Eggs also had obvious ultraviolet reflectance, suggesting that they would contrast against a leaf substrate and, considering their chemical load, that they may be aposematic. We argue that there are two possible interpretations of our results. One is that, throughout ontogeny, tonic immobility is a useful defensive strategy until adequate chemical protection is achieved over an extended feeding period. The other is that both aposematism and tonic immobility are used by this species, but variation in strategy use throughout ontogeny is decoupled.

反捕食策略有助于生物体一生的繁殖成功，特别是在更脆弱的生命阶段，这些阶段希望生存到繁殖。在昆虫中，卵和幼虫阶段通常不动或无法迅速逃离和躲避捕食者。要充分了解物种如何适应生物威胁，需要了解他们使用的替代反捕食策略，以及这些策略如何随发育时间变化。紫荆是一种臭虫，从卵到成虫都有明显的颜色，已知在成虫时从十字花科宿主中隔离防御性硫代葡萄糖苷。我们试图评估这种化学防御是否也存在于它的卵和若虫早期，并量化它如何在生命阶段之间波动。同时，我们研究了在该物种中首次描述的另一种反捕食策略：强直不动（即假装死亡）。我们还定性研究了鸡蛋和成虫的紫外线反射率，作为对吸收紫外线的叶子的显眼性的代表。我们的结果表明，与前两个但不是第三个移动生命阶段相比，这些卵在化学上的防御能力明显更强，但若虫龄期的化合物浓度在统计上没有差异。刚孵出的宝宝喜欢强直不动，但随后的龄期就少了。鸡蛋也有明显的紫外线反射，这表明它们会与叶基质形成对比，并且考虑到它们的化学负荷，它们可能是无色的。我们认为对我们的结果有两种可能的解释。一个是，在整个个体发育过程中，强直不动是一种有用的防御策略，直到在延长的喂养期内获得足够的化学保护。另一个是该物种同时使用 aposematism 和强直不动，但在整个个体发育过程中策略使用的变化是分离的。在整个个体发育过程中，强直不动是一种有用的防御策略，直到在延长的喂养期内获得足够的化学保护。另一个是该物种同时使用 aposematism 和强直不动，但在整个个体发育过程中策略使用的变化是分离的。在整个个体发育过程中，强直不动是一种有用的防御策略，直到在延长的喂养期内获得足够的化学保护。另一个是该物种同时使用 aposematism 和强直不动，但在整个个体发育过程中策略使用的变化是分离的。