Compatibility of insect growth regulators and Beauveria bassiana (Balsamo)vuillemin in controlling green peach aphid (Homoptera : Aphididae) on greenhouse chrysanthemums

In laboratory and greenhouse studies, the compatibility of a spore suspensi on of Beauveria bassiana (Balsamo) with insect growth regulators (IGRs) was determined. When B. bassiana was applied over residues of 7 different IGRs , infectivity of greater wax moth larvae, Galleria mellonella (L), exposed to leaf rinsates was reduced by two of the IGRs. Azadirachtin and diflubenz uron reduced the infectivity of B. bassiana by up to 50%. Fenoxycarb, cyrom azine, S-kinoprene, pyriproxyfen, and buprofezin did not significantly redu ce the infectivity of B. bassiana. Under greenhouse conditions, the populat ion levels of green peach aphid, Myzus persicae (Sulzer), on chrysanthemums , were not significantly different when Botanigard(R) (B. bassiana strain G HA) was used independently or in combination with the [GR S-kinoprene. In l aboratory tests. 100% of wax moth larvae were infected with B, bassiana whe n they were exposed to leaf washes 24 h post Botanigard application to chry santhemum foliage. Infectivity decreased rapidly with less than 15% of the larvae infected with B. bassiana when exposed to leaf washes 48 hr post Bot anigard application to foliage.