Abstract: ObjectiveInfluence of Entomogenous Pestalotiopsis disseminata on nutrients metabolism of Hemiberlesia pitysophila Takagi was studied, in order to provide reference for mechanism of Entomogenous P. disseminata causing H. pitysophila Takagi dead and using Entomogenous P. disseminata to control H. pitysophila Takagi. MethodEntomogenous P. disseminata GXSTYJ03 strain was utilized to make the spore suspension of 1×107 spores/mL and infected H. pitysophila Takagi. Spraying sterile Tween was taken as control(CK) Contents of trehalose, glucose, protein and trehalase activity in H. pitysophila Takagi were detected for eight consecutive days. ResultAt all measurement times, trehalose content of treatment group were lower than that of CK group, as treatment time extended, trehalose content of treatment group de-clined and was significantly lower than that of CK group 3 d after infection(P<0.05, the same below). At all measurement times, trehalase activity of treatment group were higher than that of CK group, and was significantly higher on day 3 of infection and 5 d after infection. Glucose content increased rapidly 1-3 d after infection and reached the peak (3.1479 mmol/L) on day 3, then declined gradually, and the difference with CK group was insignificant on 4-6 d(P>0.05), and significantly lower than that of CK group after 6 d. Protein content of treatment group was lower than that of CK group at all measurement times, and was at significant or extremely significant level(P<0.01) 2 d after infection. ConclusionWhen Entomogenous P. disseminata GXSTYJ03 strain infecting H. pitysophila Takagi, trehalose, glucose and protein content decrease sharply, which is one of the lethal reasons.