Under appropriate environmental conditions, oospores will germinate, resulting in the production of infective biflagellate zoospores similar to those produced during asexual reproduction. Scanning EM of an encysted zoospore germinating and forming an appressorium on the epicuticle of a larva. Scanning EM of an infected larva showing complete digestion of the internal organs of a mosquito host. E.Petersen , both Relative Effectiveness Operational levels of mosquito control have been obtained by ground or aerial application of L. giganteum at rates ranging from ca. For instance, control of floodwater Aedes species in early fall, in which there is synchronous hatch of large numbers of eggs in relatively cold water, would require treatment at the higher rates.
Sporulation then occurs in the treated site to initiate infection.
Research is continuing on improving oospore yields, which would be much more useful in large scale operational mosquito control programs. L. giganteum is a facultative parasite, and has been grown in large fermentation tanks using inexpensive culture media. Multi-hectare aerial applications have been made in rice fields and in refuges for migratory birds, primarily in California, where both efficacy and safety to nontarget organisms has been documented. Because the mycelial cells are relatively rugged, the low volume spraying equipment used by many mosquito abatement agencies for application of insecticides is readily adapted to application of this parasite. IC50 values for inhibition of mycelial growth commonly range from ca.