Department of Animal Taxonomy and Ecology, Faculty of Biology, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 6, 61-614, Poznań, Poland.
Department of Ecology and Biogeography, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100, Toruń, Poland.
Forensic Sci Int. 2020 Apr;309:110212. doi: 10.1016/j.forsciint.2020.110212. Epub 2020 Feb 19.
Suicide by hanging is one of the most common causes of death, worldwide. Therefore, studies of insects associated with hanging cadavers are important for developing entomological tools capable of estimating the postmortem intervals in such cases. We conducted a two-year experiment, in the spring, summer, and autumn of 2012 and 2013, studying the entomofauna of 12 hanging and 12 ground, decomposing pig carcasses in a hornbeam-oak forest, in western Poland. Both carcass treatments showed colonization by similar insect species. Among the 224 taxa collected, 61 and 52 were minimally abundant (≥10 individuals) during the adult stage on at least one hanging and at least one ground carcass, respectively. During the spring and autumn, more adult flies were attracted to hanging carcasses, whereas during the summer, their numbers were similar on both hanging and ground carcasses. Adult beetles were higher in number on hanging carcasses during the spring, but during the summer and autumn, they were slightly more abundant on ground pig carcasses. Irrespective of the carcass treatment, Dryomyzidae, Muscidae, and Piophilidae were the most abundant flies, whereas representatives of Geotrupidae, Histeridae, and Silphidae were the dominant families in the studied beetle community. Only Anoplotrupes stercorosus (Scriba) and Hydrotaea similis Meade adults and Calliphora vomitoria (Linnaeus) larvae reached minimal abundance on all carcasses during all seasons. Carcass treatment only affected the numbers of minimally abundant fly species at the larval stage due to their higher numbers on ground pig carcasses. Although differences in the residency patterns of insects were observed between carcass treatments, they were not significant. In general, adult insects tended to be present for slightly longer times on hanging carcasses than on ground carcasses, whereas beetle larvae had longer presences on ground pig carcasses. Fly larvae were present on ground carcasses for the same amount of time as on hanging carcasses. More broken residency patterns were observed among the adult insects and beetle larvae that colonized hanging carcasses. Fly larvae that colonized ground carcasses had more breaks within the presence periods than fly larvae colonizing hanging carcasses. Neither treatment significantly affected the time of insect appearance on carrion. Most species appeared at the same time or at within one- or two-day intervals on both treatments. Seasonal differences in insect appearance were found, with most species colonizing quickly during the summer. The implications of these findings for forensic entomology are discussed.
自缢是全球范围内最常见的死亡原因之一。因此，研究与悬尸有关的昆虫对于开发能够估计此类案例死后时间的昆虫学工具非常重要。我们进行了一项为期两年的实验，在 2012 年和 2013 年的春季、夏季和秋季，在波兰西部的山毛榉-橡木森林中研究了 12 具悬挂和 12 具地面腐烂猪尸的昆虫区系。两种尸体处理方式都显示出类似的昆虫物种的定殖。在收集的 224 个分类群中，有 61 种和 52 种在成虫阶段至少在一具悬挂和一具地面尸体上的丰度最小（≥10 个个体）。在春季和秋季，更多的成虫苍蝇被吸引到悬挂的尸体上，而在夏季，它们在悬挂和地面尸体上的数量相似。在春季，悬挂尸体上的成虫甲虫数量更高，但在夏季和秋季，地面猪尸上的数量略多。无论尸体处理方式如何，Dryomyzidae、Muscidae 和 Piophilidae 都是最丰富的苍蝇，而 Geotrupidae、Histeridae 和 Silphidae 的代表则是研究甲虫群落中的主要科。只有 Anoplotrupes stercorosus (Scriba) 和 Hydrotaea similis Meade 成虫和 Calliphora vomitoria (Linnaeus) 幼虫在所有季节的所有尸体上都达到了最小丰度。由于地面猪尸上的数量更多，尸体处理方式仅影响幼虫阶段最小丰度苍蝇种类的数量。尽管观察到昆虫在尸体处理方式之间的居留模式存在差异，但这些差异并不显著。一般来说，成虫昆虫在悬挂尸体上停留的时间略长于地面尸体上，而甲虫幼虫在地面猪尸上停留的时间更长。蝇类幼虫在地面尸体上的停留时间与悬挂尸体上的停留时间相同。在定殖悬挂尸体的成虫昆虫和甲虫幼虫中，观察到更多的中断居留模式。定殖地面尸体的蝇类幼虫在存在期内的中断次数比定殖悬挂尸体的蝇类幼虫多。两种处理方式都没有显著影响昆虫在尸体上出现的时间。大多数物种在两种处理方式上同时出现，或者在一到两天的间隔内出现。在昆虫出现方面发现了季节性差异，大多数物种在夏季迅速定殖。讨论了这些发现对法医昆虫学的意义。
