Mass production of Coelomomyes, a fungus that kills mosquitoes.

In work on the control of mosquitoes by the fungus Coelomomyces, the main problem is a source of inoculum since the fungus has not been cultured artificially with production of sporangia. We reared the larvae of Anopheles quadrimaculatus in algal water instead of in water with soil. By addition of inoculum once or twice in small amounts, the larvae become infected, and many grow to large fourth instars whose bodies are filled with sporangia. Such larvae are perfect for inoculum. If inoculum is added in much larger amounts and so timed that sporangia will be discharging spores during the first, second, and third ecdyses up to 100%, infection occurs, most of the larvae dying as late second or early third instars. This type of infection is good for extermination of mosquitoes but not for production of inoculum. Crude field tests have averaged 60% infection.