摘要： Laboratory observations were made on the number of Wuchereria bancrofti microfilarae ingestedand the number developing into infective larvae in Culex pipiens pallens.Mosquitoes were fed oncarriers with three levels of microfilaria density,namely,ultra-low density,10 microfilariae per 1ml(?)enous blood which was undetectable with conventional diagnostic techniques;low density,about 5mff per 60 ul peripheral blood;moderate density,10 mff per 60 ul of peripheral blood.16 person-