High-level expression and purification of recombinant wheat germ agglutinin in Rachiplusia nu larvae

•An integrated process to express and purify WGA A was developed.•Recombinant WGA A was expressed using BEVS in Sf9 cells and R. nu larvae.•An aqueous two-phase system was applied for larval extract clarification.•Chitosan mini-spheres were used to purify WGA A.•Five infected R. nu larvae produced the same amount of WGA A as 1.6×108 Sf9 cells.