Walton W E, Workman P D, Randall L A, Jiannino J A, Offill Y A
Department of Entomology, University of California, Riverside 92521, USA.
J Vector Ecol. 1998 Dec;23(2):149-60.
The effectiveness of larvicide and adulticide treatments against mosquitoes at a constructed wetland in San Jacinto, California was assessed with larval surveys, trapping of emerging adults, and collections of host-seeking females by carbon dioxide-baited traps. Bacillus thuringiensis var. israelensis (Bti, Bactimos pellets) applied at a rate of 19 kg/ha did not demonstrably affect Culex larval and emergent adult populations. Larval populations in the seven marshes of the wetland decreased from approximately one third-fourth instar larva/dip to undetectable levels following two applications of Bacillus sphaericus (Vectolex CG) at a rate of either 19 or 23.6 kg/ha. The largest decline in the number of adult mosquitoes emerging per day from vegetated regions of the wetland occurred after B. sphaericus treatments. The Culex erythrothorax host-seeking population declined about 80-fold during September beginning three weeks after the first treatment with B. sphaericus; however, the Culex tarsalis host-seeking population did not decline abruptly until mid-October 1997. This result suggests that immigration of females from other developmental sites might be an important factor influencing the Cx. tarsalis host-seeking population at the wetlands. Safety concerns required that insecticide applications were carried out during daylight hours, and two daytime applications of adulticide (Pyrenone) in early August were ineffective against mosquitoes resting in the thick vegetation.
通过幼虫调查、诱捕羽化后的成虫以及使用二氧化碳诱捕器收集寻找宿主的雌蚊，评估了在加利福尼亚州圣哈辛托的一处人工湿地中，杀幼虫剂和杀成虫剂对蚊子的防治效果。以19千克/公顷的剂量施用苏云金芽孢杆菌以色列变种（Bti，Bactimos颗粒剂），并未对库蚊幼虫和羽化后的成虫数量产生明显影响。在以19千克/公顷或23.6千克/公顷的剂量两次施用球形芽孢杆菌（Vectolex CG）后，湿地七个沼泽地中的幼虫数量从大约三分之一至四分之一龄幼虫/浸水处降至无法检测的水平。湿地植被区域每天羽化的成年蚊子数量在施用球形芽孢杆菌后下降幅度最大。在首次施用球形芽孢杆菌三周后的9月，寻找宿主的红胸库蚊数量下降了约80倍；然而，寻找宿主的致倦库蚊数量直到1997年10月中旬才突然下降。这一结果表明，来自其他发育地点的雌蚊迁入可能是影响湿地中致倦库蚊寻找宿主数量的一个重要因素。出于安全考虑，杀虫剂的施用需在白天进行，8月初两次白天施用杀成虫剂（Pyrenone）对栖息在茂密植被中的蚊子无效。
