Burying beetles (Nicrophorus) are model parents among insects, with all studied species known to regurgitate flesh from vertebrate carcasses to their offspring. However, most studies focus on a very few species, yet the interpretation of the function and importance of care is typically generalized to all burying beetles. Here we characterize subtle variation within and between individuals and sexes, and how this variation differs between two species of burying beetle. We find that Nicrophorus orbicollis exhibits low variance, with a normal distribution of parental care provided during peak care periods. In N. vespilloides, however, the distribution is more uniform as values of care are spread across the possible phenotypic spectrum. This suggests that there is stabilizing selection on care in N. orbicollis, but relaxed or disruptive selection in N. vespilloides. Although repeatability was similar between both species, transitions from other care behaviors into feeding were more common in N. orbicollis than N. vespilloides. Thus, while parenting is coarsely similar across the genus, variation in its expression should not be extrapolated to all Nicrophorus. We suggest that subtle variation both within and among species merits greater attention, and could inform us about the factors that lead to different distributions of care.

中文翻译：

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Nicrophorus orbicollis 和 Nicrophorus vespilloides 两种埋葬甲虫的亲子差异

埋葬甲虫（Nicrophorus）是昆虫中的模范父母，所有研究过的物种都知道将脊椎动物尸体的肉反刍给它们的后代。然而，大多数研究都集中在极少数物种上，但对护理功能和重要性的解释通常适用于所有埋葬甲虫。在这里，我们描述了个体和性别内部和之间的细微变化，以及这种变化在两种埋葬甲虫之间有何不同。我们发现 Nicrophorus orbicollis 表现出低方差，在高峰护理期间提供的父母护理呈正态分布。然而，在 N. vespilloides 中，由于护理价值分布在可能的表型范围内，因此分布更加均匀。这表明在 N. orbicollis 中存在稳定的护理选择，但在 N. orbicollis 中存在放松或破坏性选择。胡须。尽管两个物种之间的可重复性相似，但在 N. orbicollis 中，从其他护理行为到进食的转变比 N. vespilloides 更常见。因此，虽然整个属的亲子关系大致相似，但不应将其表达的变化外推到所有 Nicrophorus。我们建议物种内部和物种之间的细微变化值得更多关注，并且可以告诉我们导致不同护理分布的因素。