Laboratorio de Toxicología y Química Forense, Ciencia Forense, Facultad de Medicina, Universidad Nacional Autónoma de México. ZC, Mexico City, Mexico.
Laboratorio de Entomología, Ciencia Forense, Facultad de Medicina, Universidad Nacional Autónoma de México. ZC, Mexico City, Mexico.
J Med Entomol. 2020 Sep 7;57(5):1421-1431. doi: 10.1093/jme/tjaa088.
One of the problems faced by entomotoxicological studies is the large variability of experimental set-ups and the absence of harmonized protocols to compare the data and results obtained by different research groups. Among the wide range of influencing factors on the development and growth of insects, food substrates are remarkably relevant. This article proposes a standardized growth medium to be employed in future entomotoxicological studies on the scuttle fly Megaselia scalaris (Loew, 1866), (Diptera: Phoridae). This species plays an important role in forensic cases related to the decomposition of human remains found indoors and/or in concealed environments, because of their small size and ability to enter these locations at an earlier time than many other insects. Because of these traits, it can be used for the estimation of the minimum postmortem interval (mPMI). We achieved the formulation of a medium that overcomes two traditional disadvantages of culture media used to raise necrophagous Diptera, the unknown media composition and different growth rates from those reared in tissue. The proposed medium is a known composition formulation, free of xenobiotics, in which M. scalaris shows growth rates and development times similar to those obtained when it is reared in tissue. This new diet might be used in future studies to test the effect of substances of forensic interest (prescription or illicit drugs, poisons, etc.) on the larval development time, helping to adjust the estimation of mPMI based on the presence of such substances. Additionally, the formulation revealed some interesting data about nutritional requirements of this species.
在昆虫毒理学研究中面临的问题之一是实验设置的巨大可变性以及缺乏协调的协议来比较不同研究小组获得的数据和结果。在影响昆虫发育和生长的众多因素中，食物基质是非常重要的。本文提出了一种标准化的生长培养基，用于未来对室内和/或隐蔽环境中发现的人类遗骸分解相关法医案例中重要作用的虱蝇（Megaselia scalaris）（双翅目：蚤蝇科）的昆虫毒理学研究。由于其体型小，并且比许多其他昆虫更早进入这些地点，因此它在法医案例中起着重要作用。由于这些特征，它可以用于估计最小死后间隔时间（mPMI）。我们成功地制定了一种培养基，克服了用于培养嗜尸性双翅目昆虫的传统培养基的两个缺点，即培养基成分未知和与组织中培养的不同生长速度。所提出的培养基是一种已知成分的配方，不含异生素，在该培养基中，虱蝇的生长速度和发育时间与在组织中培养时相似。这种新的饮食可能会在未来的研究中用于测试法医关注物质（处方或非法药物、毒物等）对幼虫发育时间的影响，有助于根据这些物质的存在来调整 mPMI 的估计。此外，该配方还揭示了有关该物种营养需求的一些有趣数据。
