Chemical defense and tonic immobility in early life stages of the Harlequin cabbage bug, Murgantia histrionica (Heteroptera: Pentatomidae)

Antipredation strategies are important for the survival and fitness of animals, especially in more vulnerable life stages. In insects, eggs and early juvenile stages are often either immobile or unable to rapidly flee and hide when facing predators. Understanding what alternative antipredation strategies they use, but also how those change over development time, is required to fully appreciate how species have adapted 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. Our results show that the eggs are significantly more chemically defended than the first two mobile life stages, b...

反捕食策略对动物的生存与适合度至关重要，尤其在其更脆弱的生命阶段。在昆虫中，卵及幼龄早期阶段面对捕食者时常无法移动，或难以迅速逃离与藏匿。要全面理解物种如何适应生物威胁，需明确它们采用的替代反捕食策略，以及这些策略随发育时间的变化规律。斑色蝽（Murgantia histrionica）是一种蝽象，从卵到成虫均具有醒目的色彩，成年个体已知会从十字花科宿主植物中积累防御性硫代葡萄糖苷（glucosinolates）。我们旨在评估这种化学防御是否同样存在于其卵及若虫早期龄期，并量化其在不同生命阶段的波动规律。同时，我们还研究了该物种首次被记录的替代反捕食策略——强直静止（tonic immobility）。我们的结果表明，卵的化学防御水平显著高于前两个可移动的生命阶段，b...