[Aims]In order to make full use of low-activity avermectin B2 produced in the fermentation process of avermectin Bl by account of 20％-30％,a controlled-release avermectin B2 poly siloxane microspheres(PSQ)with anti-ultraviolet degradation were prepared,in response to its drawbacks of easy photolysis and short residual efficacy.[Methods]AVMB2@PSQ was prepared by'sol-gel'method using methyltrimethoxysilane as precursor,its composition and morphology were characterized by FTIR,TGA,SEM,DLS,its sustained release and anti-ultraviolet photolysis properties were studied,and its laboratory activity against Bursaphelenchus xylophilus was determined by immersion method.[Results]AVMB2 was successfully embedded in PSQ.The AVMB2@PSQ microspheres with smooth spherical hollow structure having an average particle size of 1.1 μm were formed,and the pesticide loading rate was 32.74％.The dissolution rate of 12 h was 55.492％,which was significantly better than that of AVMB2(87.862％).The degradation rate was 39.074％under UV irradiation for 6 h,which was better than that of AVMB2(69.986％).The median lethal dose(LC50)for B.xylophilus at 48 h was 19.743 mg/L,which was 1.9 times better than that of AVMB2(37.992 mg/L).[Conclusions]AVMB2@PSQ microspheres with excellent sustained release and anti-ultraviolet degradation properties can improve the activity of AVMB2 against B.xylophilus.It provides a reference for the application of abamectin B2 in agricultural production to control pine wilt disease.
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