Three commercial biocides, Biovar® (entomopathogenic fungus, Beauveria bassiana), Protecto® (entomopathogenic bacterium, Bacillus thuringiensis) and Virotecto® (entomopathogenic virus), Granulosis virus were tested against Myzus persicae (Sulker), Thrips tabaci Lind and Gosmlyce (= Polymmatus) baeticus L. and their predators on alfalfa crop under field conditions. The biocides were sprayed three times. Ten alfalfa branches were sampled and checked from each treatment just prior to treatments and after 1, 3 and 5 days following application. Biovar was the most effective biocide that reduced the infestation of aphids, thrips and butterfly by 73.9, 55.9 and 53.6%, respectively. Protecto was more effective against butterfly reducing the infestation by 69.3% but it was less effective against aphids and thrips with infestation reduction of 36.5 and 31.6%. Virotecto was least effective formulation against the tested pests causing 41.8, 39.6 and 20.6% reduction of infestation with aphids, butterfly and thrips, respectively. Also, all tested biocides are broad spectrum and exhibited toxicity to the associated predators. Rate of mortality in the associated predators was biocide-dependent and differed from one biocide to the other. INTRODUCTION In the recent years, the concern about producing bioorganic crops, free from pesticides residues, environmental considerations and pollution has greatly increased. This, ¡n turn, led to shifting research efforts to biological control programs. One of the requirements of this mission is using biocides specially in forage crops such as alfalfa and clover (Collier, 1999 and Sakurai t&., 2001). ltis well known that the entomopathogenic fungus (Beauveria bassiana), the entomopathogenic bacterium (Bacillus thuringiensis) and granulose virus are widely used against scores of insect pest in different agreoecosystems, in general, and forage crop ecosystem in particular. These entomopathogenic microorganisms are available in markets in several commercials formulations (Leatheredale, 1970; Barson, 1977; Vail et al., 1991, Scoth et aI., 1993; James and Ligghthart, 1994, and Lopez-Meza and Ibarra, 1996. Alfalfa (Medicago satival) is a very important forage crop in Egypt. This crop is the main refuge and reservoir for hundreds of natural enemies such as anthocrorid, coccinellids, chrysopids, mantids, parasitic wasps and several insect pests that cause much damage. Of which, Myzus persicae (Sulker), (Homoptera: Aphididae), Thrips tabaci Lind (Thysanoptera: Thripidae) and Gosmylce (Polymmatus) baetricus L. (Lepidoptera: Lycaenidae) are considered the most important and abundant pests on this crop.