Guo Yi, Gao Yundi, Chen Na, Tang Xin, Li Liangliang, Hu Gengwang, Wang Jiangfeng, Wang Yu
Department of Forensic Medicine, Soochow University, Ganjiang East Road, Suzhou 215000, China.
Shandong University of Political Science and Law, Jiefang East Road, Jinan 250014, China.
Insects. 2025 May 1;16(5):480. doi: 10.3390/insects16050480.
Aubertin, 1932, is a species of Calliphoridae widely distributed in Southeast Asia, with studies and case reports confirming the value of this species in estimating the minimum postmortem interval (PMI). However, data on the growth and development of this species' intra-puparial age are not yet complete. Here, we investigated the intra-puparial morphological changes of at seven temperatures, ranging from 16 °C to 34 °C. We also investigated the potential value of Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) coupled with chemometric methods for the intra-puparial age estimation of at 19 °C, 25 °C, and 31 °C. The spectral data within the wavenumber range of 1800-900 cm, collected from the second thoracic segment of all puparia, were processed. Through this procedure, the mean values of ATR-FTIR spectra of of puparia at each intra-puparial age under various constant temperature conditions were obtained. The results showed that at 16 °C, could not complete its developmental process, while it could do so at the remaining six constant temperatures. With an increase in temperature, the average duration of the intra-puparial period was reduced from the longest at 19 °C of 192 ± 0 h to 77.3 ± 4.6 h at 34 °C. The intra-puparial morphological changes were divided into 12 sub-stages, and the development of the compound eyes, mouthparts, antennae, thorax, legs, wings, and abdomen were divided into 6-8 sub-stages. The Partial Least Squares Discriminant Analysis (PLS-DA) classification model predicted better results compared to the Random Forest (RF) classification model, with an accuracy of 58.3%, 77.8%, and 100% at 19 °C, 25 °C, and 31 °C, respectively. In this study, each sub-stage of the pupa and the time range of structure emergence were recorded, and it was concluded that the spectral trends were time-dependent. Thus, ATR-FTIR combined with chemometrics could also be used as a tool to assist in estimating the intra-puparial stage of and provide a reference value for PMI.
奥贝廷蝇（Aubertin, 1932）是丽蝇科的一种，广泛分布于东南亚，已有研究和病例报告证实该物种在估计最短死后间隔时间（PMI）方面的价值。然而，关于该物种蛹内发育阶段的生长和发育数据尚不完整。在此，我们研究了在16℃至34℃的七个温度下奥贝廷蝇蛹内的形态变化。我们还研究了衰减全反射傅里叶变换红外光谱（ATR - FTIR）结合化学计量学方法在19℃、25℃和31℃下对奥贝廷蝇蛹内发育阶段进行估计的潜在价值。对从所有蛹的第二胸节收集的波数范围在1800 - 900 cm的光谱数据进行了处理。通过这个过程，获得了在各种恒温条件下不同蛹内发育阶段的奥贝廷蝇蛹的ATR - FTIR光谱平均值。结果表明，在16℃时，奥贝廷蝇无法完成其发育过程，而在其余六个恒温条件下则可以。随着温度升高，蛹内发育阶段的平均持续时间从19℃时最长的192±0小时缩短至34℃时的77.3±4.6小时。蛹内形态变化分为12个亚阶段，复眼、口器、触角以及胸、腿、翅和腹部的发育分为6 - 8个亚阶段。偏最小二乘判别分析（PLS - DA）分类模型的预测结果优于随机森林（RF）分类模型，在19℃、25℃和31℃时的准确率分别为58.3%、77.8%和100%。在本研究中，记录了奥贝廷蝇蛹的每个亚阶段以及结构出现的时间范围，并得出光谱趋势与时间相关的结论。因此，ATR - FTIR结合化学计量学也可作为辅助估计奥贝廷蝇蛹内发育阶段的工具，并为PMI提供参考价值。
