ABSTRACT
Present house fly Musca domestica L. and stable fly Stomoxys calcitrans (L) control techniques rely heavily on the use of insecticides, and these insecticides plus application-related costs constitute a significant production expense for dairy producers. All ten wild populations that were sampled statewide showed high levels of resistance to all of the insecticides currently used for fly control, with the exception of permethrin and Vapona. The parental stocks of the four parasitoids species used in the study were collected from dairy farms in and around Cayuga, Schuyler and Tompkins counties of New York State. The most likely explanation for this phenomenon was that 45% of the population was resistant to Rabon due to selection in the field. The similar response of males and females suggested that the resistance was not affected by the chromosomal ploidy in these parasitoids.
