LAUSR

Abstract The cat flea, Ctenocephalides felis (Bouche) (Siphonaptera: Pulicidae), is the most important ectoparasite of domestic pets. Its control is mainly based on chemical insecticides. In this study, the potential of fungi and nematodes to control this pest was evaluated. The various life stages of the cat flea were exposed to several variables: strains and species of entomopathogenic nematodes and fungi at different ambient temperatures and levels of relative humidity (RH), as well as in\on filter paper, sand or carpet as substrates. The nematode Steinernema feltiae (Nematoda: Steinernematidae) was most virulent against flea larvae, cocoons and adults, and the nematode Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae) was highly effective against flea cocoons on all substrates evaluated. Overall, the nematodes were most effective at 28o C and 95% RH. The fungus Metarhizium robertsii 2575 (Bischoff) (Hypocreales: Clavicipitaceae), was highly virulent against adult fleas. Flea eggs were resistant to both nematodes and the fungus evaluated. The results indicate high potential for use of microbial control agents against cat fleas. While the fungus, M. robertsii, could be effective in killing adult fleas on infested vertebrates, the nematodes S. feltiae and H. bacteriophora could be successful in controlling pre-imaginal stages on the soil.