Shabani Kordshouli Razieh, Grzywacz Andrzej, Akbarzadeh Kamran, Azam Kamal, AliMohammadi AliMohammad, Ghadi Pasha Masoud, Oshaghi Mohammad Ali
Department of Medical Entomology and Vector Control, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
Department of Ecology and Biogeography, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100 Toruń, Poland.
Sci Justice. 2021 May;61(3):227-234. doi: 10.1016/j.scijus.2021.02.001. Epub 2021 Feb 25.
Entomological material may be used to estimate the time since death occurred (postmortem interval, PMI) in forensically obscure cases. The method that is commonly used to calculate minimum post-mortem interval (mPMI, i.e., the least amount of time since one can be confident death occurred) is based on the relationship between insect development and ambient temerature. Isomegalen and isomorphen diagrams are among methods allowing to calculate the age of necorphagous insects, yet thermal summation models provide the most precise and acurate estimations. The digrams are prepared based on the length or the developmental stages of the larvae as a function of time and mean ambient temperature. A knowledge of thermal requirements, in particular lower temperature threshold (D) at which development of a species terminates, is of essential importance to calculate ADD (Accumulated Degree Days). In this study different temperature regimes were used to construct the isomorphen diagram, examinate changes in larval body length at different ambient temperatures and to estimate the thermal requirements for developemnt of Chrysomya albiceps, the most common dipteran species reported on human and animal cadavers in Iran. Six development events including hatching, 1st ecdysis, 2nd ecdysis, wandering, pupariation and eclosion were studied under eleven constant temperature regims (17-37 C). The development rate of Ch. albiceps increased as temperature increased. The larval length peaked at the end of third stage and then decreased at wandering stage. The maximum larval length occurred at 72 h post oviposition at either 31, 33, or 35 °C. At 17 °C, larvae did not hatch from eggs and at 37 °C wandering larvae did not proceed to pupariation, and thus larval development were analysed at the nine left over temperatures. The development stages required at least (D ± SE) 13.04 ± 0.37, 14.29 ± 0.45, 15.69 ± 0.56, 15.18 ± 0.56, 14.94 ± 0.48, and 11.23 ± 0.41 °C to reach one of the successive developmentl events, respectively. The estimated thermal summation constant (k) for those the six events were 10.43 ± 0.27, 19.31 ± 0.32, 27.87 ± 1.3, 55.94 ± 1.82, 66.69 ± 3.5, and 143.52 ± 5.61 ADD accordingly.
在法医学上难以明确死因的案件中，昆虫学材料可用于估计死亡时间（死后间隔时间，PMI）。计算最短死后间隔时间（mPMI，即自确定死亡发生以来的最短时间）的常用方法是基于昆虫发育与环境温度之间的关系。等变线图和等形态图是用于计算尸食性昆虫年龄的方法，但热积累模型提供了最精确和准确的估计。这些图表是根据幼虫的长度或发育阶段随时间和平均环境温度的变化而绘制的。了解热需求，特别是物种发育终止的较低温度阈值（D），对于计算积累度日（ADD）至关重要。在本研究中，使用不同的温度条件来构建等形态图，研究不同环境温度下幼虫体长的变化，并估计伊朗在人和动物尸体上最常见的双翅目物种白纹伊蚊发育的热需求。在11种恒温条件（17-37℃）下研究了包括孵化、第一次蜕皮、第二次蜕皮、化蛹、羽化和羽化在内的六个发育事件。白纹伊蚊的发育速度随温度升高而加快。幼虫体长在第三阶段末期达到峰值，然后在化蛹阶段下降。在31、33或35℃下产卵后72小时出现最大幼虫体长。在17℃时，幼虫未从卵中孵化出来，在37℃时，化蛹幼虫未进入蛹期，因此在剩下的九个温度下分析幼虫发育情况。达到连续发育事件之一所需的发育阶段至少分别需要（D±SE）13.04±0.37、14.29±0.45、15.69±0.56、15.18±0.56、14.94±0.48和11.23±0.41℃。相应地，这六个事件的估计热积累常数（k）分别为10.43±0.27、19.31±0.32、27.87±1.3、55.94±1.82、66.69±3.5和143.52±5.61 ADD。
