EFFECTS OF ENVIRONMENTAL-FACTORS ON ABUNDANCE OF ANOPHELES MINIMUS (DIPTERA, CULICIDAE) LARVAE AND THEIR SEASONAL FLUCTUATION IN TAIWAN

A survey a as conducted to study, the effects of environmental factors on abundance of Anopheles minimus Theobald and its seasonal fluctuati on in 5 locations in southern and eastern Taiwan for 1 yr. The 5 locat ions were Hualien, Taitung, Pingtung, Kaohsiung, and Tainan. Seasonal fluctuation was different for each of these 5 locations. Peaks were Fo und in November and May, November, December, January, and March in Hua lien, Taitung, Pingtung, Kaohsiung, and Tainan, respectively. The numb er of A. minimus larvae per dip was significantly correlated with tota l P, NH4-N, K+, Ca+2, Mg+2, and Mn+2 and significantly correlated with stream velocity and conductivity. Thus, the numbers of A. minimus lar vae were expressed by the following equation: y = -0.161 + 0.150 wat er velocity + 0.109 conductivity + 0.302 * total P + 0.026 * NH4-N - 0.120 K+ + 0.023 * Ca+2 + 0.131 * Mg+2 + 0.140 * Mn+2 (R-2 = 0.50). In Taiwan, both the A and B forms of A. minimus were found in Tainan, Pingtung, Taitung, Hualien, and Kaohsiung.