Li Xuebo, Yang Yongqiang, Li Genping, Li Hongwei, Wang Qingshan, Wan Lihua
Key Laboratory of Evidence Identification in Universities of Shandong Province(Shandong University of Political Science and Law), Jinan 250014, China.
Department of Forensic Medicine, Chongqing Medical University, Chongqing 400016, China.
J Insect Sci. 2014 Jan 1;14. doi: 10.1093/jisesa/ieu036. Print 2014.
Variation in the type of tissue that larvae feed on can produce marked differences in developmental rate and body size, which can compromise predictions of minimum postmortem interval. A series of experiments were conducted to investigate the effect of fat content in the diet on larval growth in Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae), an important forensic blowfly species in China. Bionomical parameters such as body size, development time, mortality, and sex ratio were observed. The results indicated that fat content in the diet has a dramatic effect on the body size and larval development. More dietary fat content was beneficial for development of larvae in first and early second instar. But it was adverse in the later third instar. Significantly, a high-fat diet resulted in increased development rates and the production of undersized larvae and adults. Overall mortality of larvae and pupa was higher when more fat was added to the diet, but sex ratio of adults was not negatively affected. This study highlights that the fat content in the diet should be considered in the entomological research and forensic application when estimating minimum postmortem interval on the basis of larval body size and developmental stage.
幼虫取食的组织类型不同，会导致发育速度和体型产生显著差异，这可能会影响对最短死后间隔时间的预测。开展了一系列实验，以研究食物中脂肪含量对大头金蝇（Chrysomya megacephala (Fabricius)，双翅目：丽蝇科）幼虫生长的影响，大头金蝇是中国一种重要的法医昆虫。观察了诸如体型、发育时间、死亡率和性别比等生物学参数。结果表明，食物中的脂肪含量对体型和幼虫发育有显著影响。较高的食物脂肪含量有利于一龄幼虫和二龄初期幼虫的发育。但在三龄后期则不利。值得注意的是，高脂饮食导致发育速度加快，但产生的幼虫和成虫体型较小。当食物中添加更多脂肪时，幼虫和蛹的总体死亡率更高，但成虫的性别比未受到负面影响。本研究强调，在基于幼虫体型和发育阶段估计最短死后间隔时间时，昆虫学研究和法医应用中应考虑食物中的脂肪含量。
