寬腹斧螳雌蟲營養狀態與雄蟲被偵測與否對於性食行為的影響

Effect of female nutrition and detection of the male on the sexual cannibalism in praying mantids, <i> Hierodula patellifera </i> (Mantodea: Mantidae)

林偉爵(Wei-chueh Lin)

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(2017年)

https://doi.org/10.6342/NTU201703090

摘要

性食意指雌性殺死或取食同種雄性配偶的行為，而「螳螂弒夫」就是廣為人知的性食行為之一。近年來許多研究聚焦於性食發生的機制 (mechanism) 上，想了解雌螳螂在什麼情況下會攻擊雄蟲，而目前有三種被認為可能決定雌蟲攻擊與否的因子，分別是：雌蟲自身的營養狀況 (nutritional status)、雄蟲上背 (mount) 前的雌雄相對位置及雌蟲已交尾與否。本研究以寬腹斧螳 (Hierodula patellfiera) 為材料來檢驗前兩個因子對性食率的影響。多數研究指出性食率會隨著雌螳螂自身的營養狀況而變動，狀況越差的雌蟲越傾向攻擊雄蟲。然而，寬腹斧螳的性食率幾乎不受雌蟲營養狀況的影響，且不論狀況好壞皆具有極高性食率。此外，本研究以「雄蟲被雌蟲偵測的時機」取代雄蟲上背前的相對位置作為評估性食率的因子，並發現在被雌蟲偵測到後才上背的雄蟲有極高的性食率。綜合此二因子觀之，無論雌螳螂營養狀態如何，被偵測到的雄蟲幾乎難逃一死，此無差別的高攻擊性不僅為螳螂目中的首次記錄，也和多數前人的結果不符。長久以來，雌螳螂因營養狀態改變性食率的特性使得性食行為被認為可以提升雌蟲的適存度 (fitness)，因而在演化中出現或被保存。但當營養狀況極佳的雌蟲依然有高性食率，寬腹斧螳的性食行為是否是因提昇雌蟲適存度而演化則有待商榷，本種與其他螳螂在性食機制上的差異也代表了性食在螳螂目中多次演化的可能。

關鍵字

營養狀況 ； 被雌蟲偵測之時機 ； 性食率

並列摘要

Mantid is well-known for its sexual cannibalistic behavior, where females kill or consumer the conspecific mates. Recently, several studies were focused on the mechanism of sexual cannibalism, especially what effects the sexual cannibalism ratio. The nutritional status of females, relative orientation before mounting of males, and the mating status of females were considered as the possible factor influencing the occurrence frequency of sexual cannibalism. Hierodula patellifera are used to examine the effect of nutritional status and males mounting on cannibalism ratio in present study. A number of studies argued that cannibalism ratio was varied with the nutritional status of females, and poorly-fed females were more likely to consume their mates. However, the nutritional status has little effect on the cannibalism ratio in H. patellifera. Extremely high cannibalism ratio was observed in different nutritional status. Besides, “Timing detected by females” was used to evaluate the cannibalism ratio instead of relative orientation before mounting. The males detected by females before mounting were more likely to be consumed by females. In summary, females represent highly rapacity toward the detected males no matter they were well-fed or poorly-fed. This phenomenon is inconsistent with previous studies and first recorded in Mantodea. To date, most of the studies suggested that sexual cannibalism could increase the fitness of females, and thus being preserved or emerging in the evolutionary history. However, it is doubtful whether sexual cannibalism could increase the fitness of females or not when the well-fed ones still represent highly rapacity toward their mates. The variation in mechanism also indicate the possibility that sexual cannibalism may evolved several times in Mantodea.

並列關鍵字

nutritional status ； timing detected by female ； cannibalism ratio

參考文獻

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