Biological control of Tetranychus truncatus by Euseius utilis

Ma Min;Du Kang;Li Shengcai;Fan Qinghai;College of Agriculture,Shanxi Agricultur University;Plant Health & Environment Laboratory,Ministry for Primary Industries;

Euseius;;Euseius utilis;;Tetranychus truncatus;;Inhabita area;;Predation number;;Interference reaction

[Objective]To study the predation ability of Euseius utilis.[Methods]for using the predator to control spider mites,at room temperature,by changing inhabit area,different developmental stage of Tetranychus truncatus,densities of predator and interference within species on function responses analyzed the predator of Euseius utilis.[Results]The results showed that the dalily maximum number of Tetrauychus truncatus preyed theoretically by the Euseius utilis was 7.2when the habitat area was 10cm~2.The habitat area was too smaller or too widely all restrain the ability of the predator.The female Euseius utilis like eggs,nymphs over adults of T.truncatus,but preferred nymphs.The selection coefficients of Adult female、nymph、egg were 0.70,1.23,1.06.Intraspecific interference could strongly affect predation of Euseius utilis.The predation rate decreased accordingly with the rising of predator density and gradual decline of average amount of prey.The relationship of predation rate and predator density could be written as the equation E=1.47P~(-0.247).[Conclusion]The Euseius utilis could control T.truncatus,and it could be as a biocontrol agent against T.truncatus.