自然条件下盐酸吗啡对肥须亚麻蝇幼虫发育积温和头咽骨的影响

目的 自然条件下,通过盐酸吗啡对石家庄地区优势蝇种肥须亚麻蝇（Parasarcophaga crassipalpis）幼虫发育积温与头咽骨影响的研究，探讨利用积温和头咽骨形态学指征推断死后间隔时间（PMI）的可行性。方法 自然条件下，用不同剂量盐酸吗啡注射后处死的兔肉上饲养肥须亚麻蝇。观察并留取幼虫标本一次直至达到离食期。将幼虫烫死并保存。计算实验期间的日均温累加为积温（ADH）。体视显微镜下分离出幼虫头咽骨并在光学显微镜下观察、拍照。利用计算机图像分析系统对头咽骨的形态学指征进行测定。结果 (1) 自然条件下，盐酸吗啡一定程度上改变了肥须亚麻蝇幼虫的积温和历期。 (2) 自然条件下，幼虫头咽骨的骨化面积和平均光密度均随积温的增加而逐渐增高，直至三龄期结束。二者达到最大值的积温明显大于面积达到最大值的积温。结论 (1)自然条件下，盐酸吗啡显著改变了肥须亚麻蝇幼虫发育积温。故积温并非准确推断PMI的理想指标。(2)自然条件下，口钩和咽骨的骨化面积、平均光密度均随积温的增加呈现良好的线性趋势，并一直维持到三龄期后，此4项指标是推测PMI的理想指标。

Effect of morphine hydrochloride on growth accumulated degree hour and cephalopharyngeal skeleton of the larvae of Parasarcophaga crassipalpis under natural condition

Objective To explore the effect of morphine hydrochloride on growth accumulated degree hour(ADH)and cephalopharyngeal skeleton of larvae of Parasarcophaga crassipalpis under natural condition, and to prove the feasibility of predicting the postmortem interval(PMI)using ADH and the shape indexes of cephalopharyngeal skeleton. Methods The larvae of Parasarcophaga crassipalpis were fed under natural condition with rabbit meat injected with morphine hydrochloride before death. The larvae were collected at 12 h intervals until the end of the stage(the larvae did not eat any more). The larvae were fixed in boiling water and were stored as specimen. The average daily temperature during the experiment was calculated for ADH. Then the cephalopharyngeal skeletons were isolated, observed, and then photographed under light mircoscope. Finally the morphology of the cephalopharyngeal skeleton was analyzed by digital image processing system. Results (1)Under natural conditions, the ADH was changed by morphine hydrochloride to a certain degree.(2)The area of the cephalopharyngeal skeleton maintained at a certain level when entered the third instar. The sclerotized area and the average optical density of the cephalopharyngeal skeleton were increased with the increase of ADH till the end of the third instar. The ADH that the sclerotized area and the average optical density reached the maximum was obviously higher than the one that the area of the cephalopharyngeal skeleton reached the maximum. Conclusion Morphine hydrochloride can obviously change the growth ADH of larvae of Parasarcophaga crassipalpis under natural conditions. The sclerotized areas and the average optical densities of the pharyngeal sclerite of the larvae show a good linearity with ADH till the end of the third instar, which can deduce PMI when combined together.