Wydra Jędrzej, Smaga Łukasz, Matuszewski Szymon
Laboratory of Criminalistics, Adam Mickiewicz University, Św. Marcin 90, Poznań 61-809, Poland.
Wielkopolska Centre for Advanced Technologies, Adam Mickiewicz University, Uniwersytetu Poznańskiego 10, Poznań 61-614, Poland.
Forensic Sci Res. 2024 Feb 25;9(1):owad049. doi: 10.1093/fsr/owad049. eCollection 2024 Mar.
Postmortem interval may be estimated based on the age of insect evidence collected on a death scene. Reference data that are used in such estimation frequently comprise thermal summation constant (i.e. ), which is equal to the insect age upon completion of immature development expressed in accumulated degree-days or degree-hours (ADD or ADH). Essentially, is a central point of an insect group and it may poorly represent insect evidence that is near the limits of variation for the group. Accordingly, it was postulated to calibrate for particular insect evidence and insect size and sex were found to be useful for this purpose in some of the species. However, the calibration is only possible by using the model that correlates with insect size. Since very few such models were published, this lack of data limits the calibration of in forensic casework. In this article, we develop a formula that is useful for the calibration of without the use of " versus size" model (and related datasets). The formula uses from the general thermal summation model for a species (with its standard error), size range for the species (retrieved from entomology literature), and size measurements for particular insect evidence. The calibration of with the formula was validated using the (Coleoptera: Staphylinidae) and (Coleoptera: Silphidae) datasets. It was particularly useful while analyzing unusually small and large insects, in case of which the formula reduced the inaccuracy of from the general model on average by ~25 ADD in and ~40 ADD in . We discuss the limitations and prospects of the calibration protocol that employs the formula.
死后间隔时间可根据在死亡现场收集到的昆虫证据的年龄来估算。用于此类估算的参考数据通常包括热积累常数（即 ），它等于未成熟发育完成时的昆虫年龄，以累积度日或度时（ADD 或 ADH）表示。本质上， 是某一昆虫群体的一个中心点，它可能无法很好地代表该群体变异极限附近的昆虫证据。因此，有人推测要针对特定的昆虫证据校准 ，并且发现昆虫的大小和性别在某些物种中对此目的有用。然而，只有通过使用将 与昆虫大小相关联的模型才能进行校准。由于发表的此类模型非常少，这种数据的缺乏限制了法医案件工作中 的校准。在本文中，我们开发了一个公式，该公式在不使用“ 与大小”模型（及相关数据集）的情况下对校准 很有用。该公式使用某一物种通用热积累模型中的 （及其标准误差）、该物种的大小范围（从昆虫学文献中获取）以及特定昆虫证据的大小测量值。使用埋葬虫（鞘翅目：埋葬甲科）和埋葬甲（鞘翅目：埋葬甲科）数据集对用该公式进行的 校准进行了验证。在分析异常小和大的昆虫时，该公式特别有用，在这种情况下，该公式在埋葬虫中平均将通用模型中 的不准确性降低了约 25 ADD，在埋葬甲中降低了约 40 ADD。我们讨论了采用该公式的校准方案的局限性和前景。
