Pilot scale production and application in wildlife ponds of Lagenidium giganteum (Oomycetes: Lagenidiales).

Lagenidium giganteum, a facultative parasite of mosquito larvae, has recently been registered by the U.S. Environmental Protection Agency for operational mosquito control. We report here the first pilot scale production of the mycelium formulation. Scale-up from 10 to 650 liters was accomplished by a proportionate increase of medium components and volume of water. Foaming of the culture medium had not been encountered previously, but was a serious problem in pilot scale production due to the very rapid growth of a large volume of L. giganteum. Addition of an antifoaming agent did not adversely affect growth, but reduced the ability of the fungus to sporulate. Despite what was effectively a 100-fold reduction in the desired application rate due to reduced sporulation, L. giganteum infected sentinel mosquito larvae and reduced field populations for more than 2 months following application.