. Selection of Cladosporium spp., Verlieillium leeanii, and IEpieoeeum sp. as
blo-ccntrol.aqents against whiteflies and aphids was conducted on the bases of
their pathogenecity (0 insect pests, safety to plant hosts andlor their abilities to
produce extracellular enzymes to degrade the insect integument. In vitro, the tested
fLingi' were active against the two-selected insects, in spite of the superiority of
Cladosporium spp. to the others. In addition, the tested fungi caused higher
mortality percentages among the whitefly populations than aphids. Among the five
examined strains of each fungus,. the isolates COMW3, COMW4 of Cladosporium;
CfMW3. CfMW4 of V. leean;; and GbDW3 and GbDW4 of IEpieoecum were very
highly virulence as bio-control agents against the tested Insect pests.Cladosporium spp.. Verticillium leeanii, and Epicoecum sp. produced several .extracellular cuticle-degrading proteases, which are chymoelastase. being a determinant of pathogenicity. Multiple extracellular enzymes such as Lipase, Prolienase and Chitinase were detected inthe culture media of Cladosporium spp., V. iecenii, and Epicoeeum st: High chitinase and protienase activities were present in all fungal isolates grown on chitin and gelatin media. Meanwhile. lipase was produced only with the isolates COMW3. COMW4 of Cladosporium; CfMW3. CfMW4 of V. leeanii and GbDW3 and GbDW4 of Epieoceum. No cellulose hydrolysis was detected in cellulose media. Therefore, the two isolates of each fungal species were capable to produce insect cuticle degrading enzymes. The implications of entomopathogens producing multiple forms of enzymes are discussed in terms of pathogenicity and future research prospects. The study of correlation between isolate virulence and enzyme activity (or the three candidates fungal pathogens was fulfilled to elucidate the mechanisms by which the fungal isolates differed from one to another within the fungal species.