Morphological Redescription and Population Fluctuation of Frog Flies, Caiusa violacea Séguy (Diptera: Calliphoridae), in Taiwan

臺灣蛙蠅－紫絳蠅（雙翅目：麗蠅科）形態重新描述與族群數量波動調查

黃悠然(Yu-Zen Huang) ； 蕭旭峰(Shiuh-Feng Shiao)

《台灣昆蟲》 36卷2期 (2016/06) Pp. 66-73

https://doi.org/10.6662/TESFE.2016008

摘要

The frog fly Caiusa violacea Séguy is a dipteran species whose larvae develop in amphibian egg clutches which they then consume. In Taiwan, frog flies lay eggs on the foam nests of tree frogs, such as Polypedates braueri, Rhacophorus prasinatus, R. aurantiventris, and R. moltrechti. This species was misidentified as C. coomani Séguy but was later confirmed to be C. violacea Séguy, the only species of this genus recorded in Taiwan. This study aimed to determine the population fluctuation of C. violacea and its host connections in northern Taiwan. Samples were collected every two weeks from study sites at the Taipei Zoo. The results showed that the population size of C. violacea is larger between June and October, when the temperature is higher and rainfall is abundant. This period is approximately the breeding season of P. braueri. Because of the seasonal coincidence of the emergence of flies and the reproduction of frogs, we conclude that P. braueri is the major host of C. violacea in northern Taiwan. In addition, we provide a morphological redescription of C. violacea to facilitate identification.

關鍵字

Frog flies ； Caiusa ； tree frog ； population dynamics ； parasitoid

並列摘要

蛙蠅為幼蟲期於兩棲類卵塊中生長並取食其卵的雙翅目昆蟲。已知台灣的蛙蠅寄主有布氏樹蛙、翡翠樹蛙、橙腹樹蛙和莫氏樹蛙。台灣的蛙蠅曾被誤鑑定為印度阜蠅，但後來被確認為紫絳蠅，也是台灣目前唯一紀錄的蛙蠅種類。本研究進行了紫絳蠅的一年間族群波動調查。研究進行期間，每兩星期由台北市立動物園內樣區採取樣本。結果顯示，紫絳蠅族群在六月至十月間達高峰，與高氣溫和高降雨量有關。由高峰時間與樹蛙繁殖期推測，紫絳蠅在台灣北部低海拔地區的主要寄主應為布氏樹蛙。當溫度高於攝氏19度時，族群數量與兩週前的雨量顯著相關，顯示雨量為紫絳蠅數量波動之重要影響因子。

並列關鍵字

蛙蠅 ； 紫絳蠅 ； 族群波動 ； 樹蛙 ； 卵泡