Clark K, Evans L, Wall R
School of Biological Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG, UK.
Forensic Sci Int. 2006 Jan 27;156(2-3):145-9. doi: 10.1016/j.forsciint.2004.12.025.
Estimates of post-mortem interval based on forensic analysis of the age of blowfly larvae on a corpse, are generated from standardised larval development curves. These are derived from studies of the growth of larvae reared, usually, on liver and at a range of temperatures. However, it is possible that the species or organ on which the larvae feed, might significantly alter the rate of growth. The present study therefore compared the development of the blowfly Lucilia sericata (Meigen) (Diptera: Calliphoridae) fed on lung, liver and heart, from both cows and pigs. Half of the tissue samples used were liquidised while half were not, to assess whether structural differences in the food source were important. Larvae grew significantly faster and gave rise to larger adults when reared on pig compared to cow tissue and when reared on lung and heart compared to liver. Larvae completed feeding and wandered from the food source 31h earlier and grew 2mm longer when reared on lung compared to liver. Tissue structure had no or little effect on development. For the forensic entomologist, these results highlight the importance of recording the position of larvae removed from a body and the care that should be used when extrapolating development rates from standard curves based on larvae fed on only a single medium, particularly where that is liver.
基于对尸体上丽蝇幼虫年龄的法医分析来估计死后间隔时间，是通过标准化的幼虫发育曲线得出的。这些曲线通常源自对在肝脏上饲养且处于一系列温度下的幼虫生长情况的研究。然而，幼虫取食的物种或器官可能会显著改变其生长速度。因此，本研究比较了以牛和猪的肺、肝和心脏为食的丝光绿蝇（Meigen）（双翅目：丽蝇科）的发育情况。所用的组织样本一半进行了液化处理，另一半未进行液化处理，以评估食物来源的结构差异是否重要。与以牛组织为食相比，以猪组织为食时，幼虫生长明显更快，成虫体型也更大；与以肝脏为食相比，以肺和心脏为食时，幼虫生长更快。与以肝脏为食相比，以肺为食时，幼虫提前31小时完成取食并离开食物源，且体长增加2毫米。组织结构对发育没有或几乎没有影响。对于法医昆虫学家来说，这些结果凸显了记录从尸体上取下的幼虫位置的重要性，以及在根据仅以单一培养基（特别是肝脏）饲养的幼虫的标准曲线推断发育速率时应谨慎使用的问题。
