DESTRUCTION OF THE LARVAE OF ANOPHELES GAMBIAE GILES BY A COELOMOMYCES FUNGUS

A mortality of 95%, or higher, has been found to occur among larvae of Anopheles gambiae in several breeding-areas at Livingstone, Northern Rhodesia, resulting from parasitization by an aquatic fungus of the genus Ceolomomyces. During six weeks of almost continuous rainfall the pathogen maintained this high percentage kill in pools in nine different areas. After the rains had practically ceased some of the pools were kept filled with river water and the activity of this parasite continued. Coelomomyces was successfully introduced into an uninfected breeding-pool. Larvae of culicine mosquitos occurring in infected pools seldom develop the A. gambiae disease and larvae of Anopheles squamosus Theo. showed only a low percentage of parasitization. The author stresses that laboratory research should be aimed at culturing the pathogen in an artificial medium. Exhaustive field trials of a practical nature, for spreading infections among A. gambiae populations, are required before there can be any question of employing this organism as a biological control agent.