Institute of Legal Medicine, University Hospital Frankfurt, Goethe-University, Kennedyallee 104, Frankfurt am Main D-60596, Germany; Department of Aquatic Ecotoxicology, Faculty of Biological Sciences, Goethe-University, Max-von-Laue-Str. 13, Frankfurt am Main D-60438, Germany.
Institute of Legal Medicine, University Hospital Frankfurt, Goethe-University, Kennedyallee 104, Frankfurt am Main D-60596, Germany.
Forensic Sci Int. 2024 Apr;357:111972. doi: 10.1016/j.forsciint.2024.111972. Epub 2024 Feb 27.
The cosmopolitan blow fly Lucilia sericata is often used in forensic case work for estimating the minimum postmortem interval (PMI). For this, the age of immature specimens developing on the dead body is calculated by measuring the time taken to reach the sampled developmental stage at a given temperature. To test whether regional developmental data of L. sericata is valid on a global scale, the time taken to reach different developmental stages was compared between a population from Mexico and one from Germany at two different constant temperatures. The German population of L. sericata was collected in Frankfurt/Main, while the Mexican population originated near Oaxaca de Juarez and was transported to Germany in the larval stage. Only the F1 generation was used to avoid adaption of the Mexican flies. Eggs were immediately placed at 20 °C and 30 °C. Five times 30 freshly eclosed larvae per replicate (n = 5) were then transferred to a cup of minced meat in separate containers. The larvae were checked every 8 h for migration, pupariation or emergence of adult flies. The time at which the first individual and 50 % of the specimens per container entered each of these stages, was recorded. Significant differences in the time of development between the two populations were observed at both temperatures. At 20 °C, the first specimens of the Mexican population reached all developmental stages a little (< 1 day to < 2 days) earlier than the German L. sericata. At 30 °C, the Mexican flies also reached the post-feeding stage slightly earlier (0.2 days). However, at 30 °C, the German flies started pupariation significantly earlier (after 5 days) than the Mexican flies (6.9 days) and the adults from Germany also emerged earlier (10.5 days compared to 13.1 days). The same pattern was observed when looking at 50 % of the total number of specimens per container. A comparison with previously published developmental studies was difficult as the experimental design varied widely between studies. However, the results were within the range of most studies. Our study has shown that age estimation can vary widely depending on the population on which the reference data used for the calculations are based. This highlights the importance of using local and population-specific developmental data for estimating the age of blow flies in case work.
多世界性丽蝇 Lucilia sericata 通常用于法医案件工作中，以估计最小死后间隔时间（PMI）。为此，通过测量在给定温度下达到采样发育阶段所花费的时间来计算在尸体上发育的未成熟标本的年龄。为了测试 L. sericata 的区域性发育数据在全球范围内是否有效，在两个不同的恒温下，比较了来自墨西哥的一个种群和来自德国的一个种群达到不同发育阶段所需的时间。德国的 L. sericata 种群是在法兰克福/美因河畔收集的，而墨西哥种群起源于瓦哈卡德胡亚雷斯附近，并在幼虫期被运往德国。仅使用 F1 代以避免墨西哥蝇的适应。鸡蛋立即在 20°C 和 30°C 下放置。每个重复（n = 5）将 5 次 30 个刚羽化的幼虫转移到装有肉末的杯子中。幼虫每 8 小时检查一次以迁移、化蛹或成虫出现。记录每个容器中第一个个体和 50%的标本进入每个阶段的时间。在两种温度下，两个种群之间的发育时间存在显著差异。在 20°C 时，墨西哥种群的第一批标本到达所有发育阶段的时间都比德国 L. sericata 早一点（<1 天至<2 天）。在 30°C 时，墨西哥蝇也更早地进入了食后阶段（0.2 天）。然而，在 30°C 时，德国蝇的化蛹时间明显早于（5 天后）墨西哥蝇（6.9 天），德国蝇的成虫也更早出现（10.5 天比 13.1 天）。当观察每个容器中总标本数的 50%时，观察到相同的模式。由于实验设计在不同的研究之间差异很大，因此与之前发表的发育研究进行比较很困难。然而，结果在大多数研究的范围内。我们的研究表明，年龄估计可能因用于计算的参考数据所基于的种群而异。这突出了在案件工作中使用当地和特定种群的发育数据来估计丽蝇年龄的重要性。
