Environmental Entomology (1983) 12, 515-521

T.L. Merriam and R.C. Axtell (1983)
Relative toxicity of certain pesticides to Lagenidium giganteum (Oomycetes: Lagenidiales), a fungal pathogen of mosquito larvae
Environmental Entomology 12 (2), 515-521
Abstract: Laboratory experiments were conducted to determine the relative toxicity of certain insecticides, herbicides, and fungicides to the vegetative growth and zoospore production in North Carolina (NC) and Louisiana (LA) isolates of Lagenidium giganteum. Zoospore production in both isolates was less tolerant than mycelia growth to most of the pesticides tested and, thus, the IC₅₀ values (inhibition concentration) for mycelia growth rate on agar underestimated toxicity. The most toxic pesticides to one or both isolates of L. giganteum were captan, gamma-BHC, DDT, toxaphene, chlorpyrifos, and fenthion. These pesticides produced at least 10% inhibition of mycelia growth rate or completely inhibited zoospore production at concentrations below 5 parts per million (ppm). The least toxic pesticides caused a 10% inhibition in mycelia growth rate and failed to inhibit zoospore production at concentrations greater that 50 ppm. These were diflubenzuron, permethrin, temephos, and propoxur (LA isolate only). Pesticides of intermediate toxicity were: malathion, carbaryl, methoprene, alachlor, and atrazine. The two isolates differed substantially in their tolerance of the following pesticides: malathion, chlorpyrifos, toxaphene, carbaryl, propoxur, permethrin, and methoprene. At their recommended rates of application for control of mosquito larvae, methoprene, fenthion, malathion, and temephos would probably be compatible with both isolates of L. giganteum.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
resistance to pesticides

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
Lagenidium giganteum (entomopathogen)			U.S.A. (mid S)
Lagenidium giganteum (entomopathogen)			U.S.A. (SE)