Boonsriwong Worachote, Sukontason Kom, Vogtsberger Roy C, Sukontason Kabkaew L
Department of Parasitology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand.
J Vector Ecol. 2011 Jun;36(1):2-10. doi: 10.1111/j.1948-7134.2011.00135.x.
The alimentary canal is a major organ system that is often involved in the transmission of pathogens to humans from insects that serve as vectors of disease. In this study, we investigated the alimentary canal of the blow fly, Chrysomya megacephala (F.) (Diptera: Calliphoridae), highlighting the description for dissection and morphometric analysis of each organ. Dissection was performed in a phosphate buffer solution (pH=7.4) on 3(rd) instar larvae (three to four days old) and on both male and female adults (seven days old). Larval dissection was accomplished using two fine forceps to open the specimens from the posterior end and proceed anteriorly toward the cephalic segment. Meticulous dissection of the anterior end was vital for observation of the delicate salivary ducts, crop duct, and esophagus. Overall length of the 3(rd) instar alimentary canal measured 89.15 mm (range 81.40-99.70 mm). The midgut comprised the longest portion, measuring 46.35 mm (range 40.00-52.00 mm; n = 30) of the entire canal. Adult dissection was also performed from abdomen to head. Morphometric analyses revealed that the alimentary canal of males and females were relatively similar. No statistical differences were found between the entire length of the alimentary canal from mouth to anus (excluding all branches of the salivary glands, crop, and Malpighian tubules) of males and females. The alimentary canals of males measured 36.23 mm (range 32.60-41.20 mm) in length; whereas, those of females measured 37.23 mm (range 32.70-42.15 mm). Two-thirds of the entire canal length was comprised of midgut in each sex.
消化道是一个主要的器官系统，常常参与作为疾病传播媒介的昆虫将病原体传播给人类的过程。在本研究中，我们对大头金蝇（Chrysomya megacephala (F.)，双翅目：丽蝇科）的消化道进行了研究，重点描述了各器官的解剖方法及形态计量分析。解剖在磷酸盐缓冲溶液（pH = 7.4）中对3龄幼虫（3至4日龄）以及雌雄成虫（7日龄）进行。幼虫解剖时使用两把精细镊子从后端打开标本，然后向前朝头部节段进行。前端的精细解剖对于观察纤细的唾液导管、嗉囊导管和食管至关重要。3龄幼虫消化道的总长度为89.15毫米（范围81.40 - 99.70毫米）。中肠占整个消化道最长部分，为46.35毫米（范围40.00 - 52.00毫米；n = 30）。成虫解剖也是从腹部到头部进行。形态计量分析表明，雌雄消化道相对相似。在从口到肛门的消化道总长度（不包括唾液腺、嗉囊和马氏管的所有分支）方面，雌雄之间未发现统计学差异。雄性消化道长度为36.23毫米（范围32.60 - 41.20毫米）；而雌性消化道长度为37.23毫米（范围32.70 - 42.15毫米）。两性中，整个消化道长度的三分之二由中肠组成。
