COMPARISION OF TWO PROPAGULES TYPES of Beauveria bassian against Trialeurodes vaporariorum

Abstract

Beauveria bassiana invades their host initially through yeast<br><br>bodies, a obligatory parasitic cycle among most entomopathogenic fungi.<br><br>virulence of B.bassiana (ATCC 74040) which cultured on SDAY in Yeastlike<br><br>cycle toward third nymphal stage of Trialeurodes vaporariorum were<br><br>investigated. The conidia of fungus in this phase developed by budding<br><br>from germinating conidia after 24h incubation. Average size of cells were<br><br>5-10 μm. Colony of fungus were initially circular some later were cover<br><br>with mycelia. On the basis of isolate type,timing and growth rate of yeast<br><br>inoculum productin varied. Conidia and yeast-like had similar virulence<br><br>against Trialeurodes vaporariorum , and average mortality were 65.4 %<br><br>with 106 cells/ml. and 78.5 % with 10 7 cells/ml.,respectively. The results<br><br>of bioassay indicated that the Yeast-like bodies are effective inoculum for<br><br>B. bassiana against insects rather than conidia against some pests. Production<br><br>of well-defined yeast phase culture may be essential work for using