The present invention relates to a process for the preparation of [(3S, 4R, 4aR, 6S, 6aS, 12R, 12aS, 12bS) -3- (cyclopropanecarbonyloxy) -6,12-dihydroxy- 11H, 12H-benzo [f] pyrano [4,3-b] pyridin- b] chromen-4-yl] methylcyclopropanecarboxylate (Compound II) and insecticidal Compound II in synergistically effective amounts. (I)본 발명은 [(3S,4R,4aR,6S,6aS,12R,12aS,12bS)-3-(시클로프로판카르보닐옥시)-6,12-디히드록시-4,6a,12b-트리메틸-11-옥소-9-(피리딘-3-일)-1,2,3,4,4a,5,6,6a,12a,12b-데카히드로-11H,12H-벤조[f]피라노[4,3-b]크로멘-4-일]메틸 시클로프로판카르복실레이트 (화합물 II) 및 살충 화합물 II를 상승작용적 유효량으로 포함한다.<;화학식 I>;