畜牧場的庫蠓發生之研究

Abstract

Culiciodes spp. are the major vectors of bovine ephemeral fever. These investigations showed that the population density of Culicoides spp. was low in Winter, and increased in Spring, then the highest population density were found in Summer and Autumn. The results of Culicoides circadian rhythm showed that both Culicoides oxytoma and Culicoides nipponensis occurred in dairy. These investigations showed Culicoides spp. active in all day, and the low population of Culicoides spp. was active at noon, and then the highest population was active at dusk and dawn. By using the correlation analysis, the relative humidity were most correlative with activity of Culicoides population, whereae the temperature was not correlative with it. The numbers of outdoor and indoor were significantly different. However Culicoides were occurred mostly indoor. The numbers of females and males were significantly different. Female was more easily caught by light trap than male. The numbers of bloodfed and non-bloodfed midges were significantly different. The non-bloodfed midges were more than the bloodfed ones. In view of Culicoides control, the light trap could catch non-bloodfed female and do not turn off the trap could get most effective in control. The survey of Culicoides spp. in different animal farms showed that Culicoides oxytoma were the major species in many animal farms, while Culicoides arakawae was the major one in poultry farms. We found that find Culicides spp. was mainly active inside dairy, and the in numbers declined greatly at a distance 30m away from farm houses. Six different insecticides of pyrethroids exhibited that cyphenothrin was the most effective pyrethoid against female adults of Culicoides among three pyrethroids tested, and that cyphenothrin in combination with tetramethrin was more effective than without combination. Pyrethroide are lower toxic in mammal, so it can use in emergency control.

庫蠓 (Culicoides spp.) 在養牛場為傳播牛流行熱 (bovine ephemeral fever)之主要病媒昆蟲。2009年在牛、羊、鹿、豬、雞、鴕鳥等六種動物養殖場的庫蠓調查，總計記錄嗜牛庫蠓(Culicoides oxystoma)、日本庫蠓(Culicoides nipponensis)、荒川庫蠓(Culicoides arakawae)、短跗庫蠓(Culicodies brevitarsis Kieffer)、加氏庫蠓(Culicodies jacobsoni Macfie)、嗜蚊庫蠓(Culicoides anopheles Edwards)、原野庫蠓(Culicoides homotomus)、森下庫蠓(Culicodies morisitai)等八種庫蠓種類；其中以嗜牛庫蠓為各動物場中發生之主要庫蠓種類。 在南台灣養牛場庫蠓棲群動態調查顯示，庫蠓密度在春天起開始緩慢增加，高峰則是出現在夏季或秋季，至冬天時數量明顯下降。嗜牛庫蠓為南台灣養牛場主要庫蠓種類，佔調查蟲數之94.83～99.78%；其次為日本庫蠓，佔5.17～0.22%。在連續24小時的調查結果顯示，庫蠓於養牛場全日發生，其日周活動呈雙波峰型之日律動現象，主高峰多會出現在日落時段，日出前後則會出現一個次高峰。庫蠓在養牛場的日周活動與環境相對濕度具有明顯相關性，與環境溫度則無明顯相關性。分析燈光誘集庫蠓組成，雌蟲所佔比例高達71.87%至95.89%；且被捕獲的雌蟲吸血比例高達71.87%至93.41%，顯示燈光誘集防治庫蠓，不但具有良好誘殺效果，且有助降低傳染病流行之風險。在庫蠓於養牛場活動範圍之調查顯示，庫蠓主要在畜舍內活動，畜舍外之庫蠓數量即大幅下降。 測試速安寧(百滅寧, permethrin)、必滅水(賽酚寧, cyphenothrin)、顧及得(賽滅寧, cypermethrin)、百治滅寧、亞力寧、保家寧等六種市售殺蟲劑商品對庫蠓雌成蟲殘效性殺蟲藥效，結果顯示嗜牛庫蠓雌蟲致死率與六種殺蟲劑稀釋濃度均呈負相關性。嗜牛庫蠓雌成蟲對三種不同類型市售除蟲菊酯之感受性，結果顯示三種類LC50 及 LC90 並無太大差異，但是其中以(cyphenothrin) 為主要成分之必滅水則只有別的藥劑的一半，顯示出其效用較好，而加入混合劑之治滅寧 (cyphenothrin) 則較未加入治滅寧 (cyphenothrin) 之效果好，由於合成除蟲菊於哺乳類相對低毒性，以此可用於緊急防治上。