人工食物含水量對大頭金蠅 (雙翅目：麗蠅科) 生長發育之影響

Influences of water content in artificial medium to the development of Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae)

莫語紓(Yu-Shu Moh)

指導教授 ： 蕭旭峰

國立臺灣大學/生物資源暨農學院/昆蟲學研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.00177

摘要

法醫昆蟲學 (forensic entomology) 是一門以昆蟲或節肢動物，來協助調查犯罪事件的學科。其中最重要的部分為估算死後時間間隔 (post-mortem interval, PMI)，即是介在人死亡後到屍體被發現的時間間隔。精確的估算死後時間間隔能有效縮小嫌疑犯的範圍，並幫助找尋失蹤人口。在許多案件中，科學家經常可以在屍體上找到麗蠅科蠅類的卵，目前法醫昆蟲學家經常利用蠅蛆之體長來進行死後時間間隔之估計。但蠅蛆之生長發育，容易受到許多生物或非生物因子影響。其中水這一因子便對其影響甚巨，由於蛆缺乏堅硬的外骨骼來維持體內水分散失，又其在取食食物時會分泌液體，可能改變食物中含水量，進而影響生長發育情形。往昔研究顯示蛆取食不同食物時，將會影響體長發育速度、化蛹率，然而大部分的研究主要聚焦於食物內之不同養分。為了解食物中含水量對蛆之生長發育有無影響，本研究以大頭金蠅 (Chrysomya megacephala (Fabricius)) 為實驗對象，控制不同食物水含量作為變因進行一系列研究。結果顯示當蛆取食高含水量食物，其體長、體重、蛹重增加，如取食低含水量食物則反之。此結果將影響死後時間間隔之估算，雖然水和蛆之間的關係仍需要更進一步進行研究，但水所帶來影響之重要性無法忽略。未來希望將此研究應用於校正死後時間間隔估算，進而用於實際案例。

關鍵字

大頭金蠅 ； 食物水含量 ； 死後時間間隔 ； 法醫昆蟲學

並列摘要

Forensic entomology is a subject which uses insects or other arthropods to solve problems in crime investigation, especially estimate post-mortem interval (PMI). PMI is the time length between a person's death and discovery of carcass, getting a precise estimate of time interval can help narrowing down suspect target in criminal cases. Entomologists can usually find several dipteran insects laying eggs on corpses, such as blow flies; for example in Taiwan, Chrysomya megacephala is a dominant blow fly species. Nowadays, entomologists usually examine maggots’ body size to estimate the PMI, but the larval developmental condition could be affected by many biotic and abiotic factors. Water plays a leading role in the larval survivorship because the blow fly larvae are lack of exoskeleton to protect them from dry environment. Previous studies has mentioned that different food influence larval size, age and pupation rate; however those studies mainly focused on the nutrition content of their diet. To understand the effects of water content, experiments were designed to simulate the conditions to study the effect of food water content on maggot development. Results showed when maggots intake more water than usual, they can grow longer and heavier, then the consequences further affect the PMI estimation. In contrast, when food water content is not enough, not only the larval survivorship will drop down dramatically, but also they grow smaller. The pupal weight also increased when larvae feed on food of higher water content. Although more studies are needed to know how water influences insect development, water effect is too important to be ignored. The future goals of these experiments will try to use these data to adjust PMI estimates and apply on real cases.

並列關鍵字

Chrysomya megacephala ； food water content ； post-mortem interval ； forensic entomology

參考文獻

傅耀賢、葉文斌、張鳴蘭、吳復生、陳怡燕、程建中。2002。高屏地區腐食性蠅類昆蟲相調查。台灣昆蟲 22: 281-290。

楊世綵。2009。大頭金蠅與紅顏金蠅之產卵偏好研究。國立台灣大學昆蟲學研究所碩士論文。79頁。

杜宇佳。2007。 大頭金蠅(Chrysomya megacephala (Fabricius))在人工飼料與天然飼料條件下生長發育之比較。國立中興大學昆蟲學研究所碩士論文。26頁。

莊懿愉。2013。 大頭金蠅（雙翅目：麗蠅科）蛆團溫度及其在死後間隔時間估算上之應用。國立台灣大學昆蟲學研究所碩士論文。47頁。

Adams ZJ, Hall MJ. 2003. Methods used for the killing and preservation of blowfly larvae, and their effect on post-mortem larval length. Forensic Sci Interna 138: 50-61.