Submitted to: Society for Invertebrate Pathology Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 9/6/1996
Publication Date: N/A
Technical Abstract: Although examples abound on how plant allelochemicals might affect the third trophic level, the effect of host-plant chemistry on insect susceptibility to infection by entomopathogenic fungi has not been as thoroughly studied. The objective of our study was to determine the in vitro effects of different allelochemicals on blastospore germination of the entomopathogenic fungus, Paecilomyces fumosoroseus (Wize) Brown & Smith (Deuteromycotina: Hyphomycetes), an effective biological control agent. The chemicals tested were catechol, chlorogenic acid, gallic acid, salicylic acid, tannic acid, saponin, and sinigrin, at three concentrations (100, 500, and 1000 ppm) in potato dextrose agar (PDA). With the exception of catechol at 1000 ppm, there were no significant differences in colony forming units between the chemicals and the control (PDA). The technique presented in this paper can be used for testing the toxicity of other chemicals against entomopathogenic fungi, as long as the chemicals are soluble in water or in solvents that are not toxic to the fungus. The technique is easy to set-up, and data can be collected within 2 days after experiment initiation.