A series of experiments was conducted to determine the effect of imidacloprid on the number ofMetarhizium anisopliaeandBeauveria bassianaconidia found on the cuticle of first instarDiaprepes abbreviatusfollowing different treatments. Larvae treated withM. anisopliaeconidia and imidacloprid by dipping removed significantly fewer conidia from their cuticle when in contact with soil or a food source compared with fungal-treated larvae alone. In addition, moreM. anisopliaeandB. bassianaconidia were found on the cuticle of larvae treated with imidacloprid while exposed to soil at 7 and 14% moisture resulting in higher larval mortality and mycosis. Conidial attachment to cuticles of untreated larvae was higher at <1% compared with 7 and 14% soil moistures.M. anisopliaeconidia were distributed uniformly over the pleural membrane of the larval cuticle of both untreated and imidacloprid-treated larvae. However, fewer conidia were attached to specific sites such as setae and setal sockets of treated larvae. At 12 h after treatment, imidacloprid-treated larvae had fewer conidia removed from exposed cuticle, setae, and spiracles than did untreated larvae. Cuticular exposure to imidacloprid at doses >0.01% (AI) affected conidial attachment ofM. anisopliaenegatively. Conidial number decreased sevenfold at 0.1% (AI). Comparative data on the effect of imidacloprid formulation on conidial attachment showed that components of the inert ingredient were responsible for lower conidial attachment on larval cuticle at higher insecticidal doses.