Strains of Metschnikowia species, in particular Metschnikowia pulcherrima, have been isolated from apple and shown to have antagonistic activity against Penicillium expansum, the causative agent of blue mold on apples. A unique feature of the strains is demonstrated activity at cold storage temperatures. The present invention is thus drawn to novel Metschnikowia isolates which are effective biological control agents against blue mold and to biocontrol compositions which include at least one of the isolates.