Host-feeding patterns of Culex tritaeniorhynchus and Anopheles sinensis (Diptera : Culicidae) in a ricefield agroecosystem

金沢大学理工研究域 自然システム学系
水田発生性蚊類成虫の吸血選択を調べるために, 佐賀県西有田町で1996及び1997年の5月から9月に成虫採集を行った。ドライアイス付加ライトトラップと吸虫管により合計31,804頭のコガタアカイエカとシナハマダラカ雌成虫を採集した。調査したすべての牛舎と豚舎ではライトトラップ採集により多数の成虫が捕獲されたが(牛舎7,933,豚6,441,鶏舎5,267), 鶏舎では吸血蚊がほとんど採集されなかった。コガタアカイエカとシナハマダラカの吸血率は, 牛舎と豚舎ではそれぞれ62%(N=7,113), 74%(N=7,261)であったが, 鶏舎では5%以下(N=5,267)であった。ELISAによる吸血源同定の結果, 両種とも鶏よりも牛と豚を選択していることが示された。また, 牛舎と隣接した鶏舎から採集された吸血蚊も90%以上(N=143)が牛を吸血していた。鶏よりも豚と牛から吸血する傾向は採集場所(棚田周辺か平野部), 採集方法(ライトトラップか吸虫管)を問わず観察された。 Adults of rice-field mosquitoes were collected between May and September of 1996 and 1997 in Nishi Arita, Saga Prefecture, Japan, to determine their feeding pattern in an area where animals were available in large numbers. In total, 31,804 female Culex tritaeniorhynchus and Anopheles sinensis were collected from animal sheds using dry ice-baited light traps and mouth aspiration. Light traps in all the animal sheds captured large numbers of mosquitoes (cowsheds 7,933,pigsties 6,441 and chicken sheds 5,267 mosquitoes), although few fed upon the chickens. Overall, 62% (N=7,113) of fed Cx. triaeniorhynchus and 74% (N=7,261) of An. sinensis were caught by light traps at the cowsheds and pigsties compared to less than 5% (N=5,267) at the chickens sheds. The type of animal in the shed was the most important factor determining the feeding rates. Blood-meal identification by direct ELISA indicated that both Cx. tritaeniorhynchus and An. sinensis preferred cows and pigs to chickens. Over 90% (N=143) of the fed mosquitoes collected from one chicken shed had fed upon cows in an adjoining cowshed. The tendency to feed upon cows and pigs more than on chickens was observed both in the hillside (terraced) and lowland ricefields. This trend is shown in the results obtained by both the aspirator and light trap collection methods.