肥须亚麻蝇幼虫不同发育阶段气门形态学变化

为了满足实际工作中利用蝇类幼虫日龄推断尸体死后间隔时间的需求，本文采用显微镜观察不同龄期肥须亚麻蝇 Parasarcophaga crassipalpis (Macquart)幼虫气门的形态学变化，通过计算机图像分析系统对幼虫的前、后气门等可用于判断幼虫生长发育的形态学指标进行测量。结果表明：肥须亚麻蝇幼虫前、后气门随时间而发生规律性的变化，幼虫前气门色素管部的平均光密度及其长宽比，以及后气门的平均光密度这 3 项指标是推算幼虫日龄较理想的指标，对法医学中尸体死亡时间的推测具有重要的指示意义。此外，叠龄期作为幼虫发育的必经阶段，可为特殊时间点的推测提供可靠依据。

Chronometrical morphology changes of larval spiracle at different developmental stages of Parasarcophaga crassipalpis (Macquart) (Diptera:Sarcophagidae)

Larval spiracle morphology of Parasarcophaga crassipalpis(Macquart)was studied in detail under microscope,and the corresponding morphological indexes were collected and analyzed by digital image processing equipment.The results showed that structural traits of anterior and posterior spiracles regularly changed along with larval growth.When the 2nd and 3rd instars overlapped,special morphological features occurred.This stage could be an ideal age indicator to determine the decisive time for possible use in forensic entomology.Measurements of the ratio of length and width of anterior spiracle chamber and the average optical density of anterior and posterior spiracles were confirmed as larval age markers.This study further confirms the correlation between morphological indexes and postmortem interval as long as the investigator accounts for the development data of the species.