Wells Jeffrey D, MacInnis Amber E, Dsouza Maurell A, Abdin Zain Ul, Mughawi Sara Al, Khloofi Mohammad Al, Sajwani Mariam, Maidoor Maryam Al, Saeed Ashwaq, Ahli Hamdan, Shamsi Rawdha Al, Mheiri Reem Al
Department of Biological Sciences, Florida International University, Miami, FL 33199, USA.
Department of Biological Sciences, Florida International University, Miami, FL 33199, USA.
Forensic Sci Int. 2021 Nov;328:110999. doi: 10.1016/j.forsciint.2021.110999. Epub 2021 Sep 15.
The carrion insect species that most quickly deposit offspring on a corpse are, when available, likely to yield a more useful estimate of postmortem interval (PMI) compared to later arrivals. This is in part because the age of the oldest larva will be as close as possible to the PMI when doing a development analysis, and because the preappearance interval (PAI), the time the corpse was exposed before insect colonization, corresponds to the narrowest window of time since death for an insect-free corpse when doing a succession analysis. Given replicated training data a prediction of exposure time for a corpse can be in the form of a confidence set, and the maximum value of that set for an insect-free corpse is a probabilistic version of PAI. To discover the insect species likely to be useful in the early postmortem period in the United Arab Emirates we exposed 216 rat carcasses outdoors at two sites in Dubai over three-day periods during winter. Rats were sampled twice each day without replacement and kept in the lab to allow carrion insects to complete development to the adult stage. The fly species produced in this way were Sarcophaga dux, S. ruficornis, Wohlfahrtia nuba, W. indigens (Sarcophagidae), Chrysomya albiceps (Calliphoridae), and Musca domestica (Muscidae). To the best of our knowledge this is the first record of W. indigens larvae feeding on carrion. While adult C. albiceps and M. domestica were abundant on the carcasses, C. albiceps colonized too slowly to be useful for this type of succession analysis within this time frame, and M. domestica emerged from a single rat. The Sarcophagidae were rapid colonizers, and under these conditions the probability is>90% that a carcass would remain free of S. dux larvae not more than 57 h and free of W. nuba larvae for not more than 51 h.
与后来到达尸体的昆虫相比,在有条件的情况下,能最快在尸体上产卵的食腐昆虫物种,可能会给出更有用的死后间隔时间(PMI)估计。部分原因在于,在进行发育分析时,最老幼虫的年龄会尽可能接近PMI;还因为在进行演替分析时,尸体在昆虫定殖之前暴露的时间(预现间隔时间,PAI),对应着无昆虫尸体自死亡以来最窄的时间窗口。给定重复的训练数据,对尸体暴露时间进行预测可能采用置信集的形式,而无昆虫尸体的该集合的最大值就是PAI的概率版本。为了找出在阿拉伯联合酋长国死后早期可能有用的昆虫物种,我们在冬季的三天时间里,于迪拜的两个地点将216具大鼠尸体放置在户外。每天对大鼠进行两次不放回采样,并置于实验室中,以使食腐昆虫发育至成虫阶段。以这种方式产生的蝇类物种有红头肉蝇、红角肉蝇、污蝇、本土污蝇(麻蝇科)、白纹丽蝇(丽蝇科)和家蝇(蝇科)。据我们所知,这是本土污蝇幼虫取食腐肉的首次记录。虽然白纹丽蝇成虫和家蝇在尸体上数量众多,但白纹丽蝇定殖速度太慢,在这个时间框架内对这种演替分析没有用处,而家蝇仅从一只大鼠尸体中羽化出来。麻蝇科是快速定殖者,在这些条件下,一具尸体在不超过57小时内没有红头肉蝇幼虫、不超过5小时内没有污蝇幼虫的概率大于90%。