Lagenidium giganteum (Oomycetes: Lagenidiales) is currently the most promising microbial agent for biological control of mosquito larvae. With increasing resistance of many mosquitoes to insecticides a well documented phenomenon, the availability of technically and commercially viable alternatives is obvious. The ultimate objective of the proposed research is to improve fermentation production of the sexual oospore stage of the fungus, and to sufficiently increase control of oospore germination by developing suitable maturation and formulation protocols, that L. giganteum can be economically produced on a large scale for field control of mosquitoes. Chemical and physical factors not known to affect fermentation production of oospores will be systematically modified to improve yields. Oospore yields will be related to the structure, concentration and cellular distribution of sterols and fatty acids, which have profound effects on oosporogenesis. Factors regulating oospore maturation and germination will be identified in the laboratory using direct microscopic observation and indirectly monitored using sentinel mosquitoes. This information will be used to develop oospore formulations for specific mosquito species, e.g. synchronously germinating spores for control of floodwater species and asynchronous preparations for control of multivoltine species under field conditions. It is anticipated that these investigations will lead to commercial production of L. giganteum oospores for mosquito control.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI022993-03
Application #
3134780
Study Section
Tropical Medicine and Parasitology Study Section (TMP)
Project Start
1986-07-01
Project End
1989-06-30
Budget Start
1988-07-01
Budget End
1989-06-30
Support Year
3
Fiscal Year
1988
Total Cost
Indirect Cost
Name
University of California Davis
Department
Type
Earth Sciences/Resources
DUNS #
094878337
City
Davis
State
CA
Country
United States
Zip Code
95618
Kerwin, J L; MacKichan, J K; Semon, M J et al. (1996) Sterol and steryl ester regulation of phospholipase A2 from the mosquito parasite Lagenidium giganteum. Lipids 31:1179-88
Kerwin, J L; Torvik, J J (1996) Identification of monohydroxy fatty acids by electrospray mass spectrometry and tandem mass spectrometry. Anal Biochem 237:56-64
Kerwin, J L; Wiens, A M; Ericsson, L H (1996) Identification of fatty acids by electrospray mass spectrometry and tandem mass spectrometry. J Mass Spectrom 31:184-92
Mackichan, J; Thomsen, L; Kerwin, J et al. (1995) Unsaturated fatty acids are the active molecules of a glucan-synthase-inhibitory fraction isolated from entomophthoralean protoplasts. Microbiology 141 ( Pt 10):2757-62
Woodring, J L; Kaya, H K; Kerwin, J L (1995) Lagenidium giganteum in Culex tarsalis larvae: production of infective propagules. J Invertebr Pathol 66:25-32
Kerwin, J L; Tuininga, A R; Wiens, A M et al. (1995) Isoprenoid-mediated changes in the glycerophospholipid molecular species of the sterol auxotrophic fungus Lagenidium giganteum. Microbiology 141 ( Pt 2):399-410
Kerwin, J L; Tuininga, A R; Ericsson, L H (1994) Identification of molecular species of glycerophospholipids and sphingomyelin using electrospray mass spectrometry. J Lipid Res 35:1102-14
Kerwin, J L; Dritz, D A; Washino, R K (1994) Pilot scale production and application in wildlife ponds of Lagenidium giganteum (Oomycetes: Lagenidiales). J Am Mosq Control Assoc 10:451-5
Kerwin, J L; Duddles, N D; Washino, R K (1991) Effects of exogenous phospholipids on lipid composition and sporulation by three strains of Lagenidium giganteum. J Invertebr Pathol 58:408-14
Kerwin, J L; Dritz, D A; Washino, R K (1990) Confirmation of the safety of Lagenidium giganteum (Oomycetes: Lagenidiales) to mammals. J Econ Entomol 83:374-6

Showing the most recent 10 out of 13 publications