Comprises at least a weight ratio of Formula (I) or Strigolactone derivative represented by (II) (a) and an insecticide compound (b) of 1 / 1~1 / 10 13 (a ) / (b) composition are in additional fungicide compound further include compositions in also by using this composition, increasing the prophylactically or therapeutically combat method as well as the yield of the crop and the pests and diseases of crops Method.少なくとも一般式(I)又は(II)で表されるストリゴラクトン誘導体(a)及び殺虫剤化合物(b)を1/1~1/1013の(a)/(b)の重量比で含んでいる組成物;付加的な殺菌剤化合物もさらに含んでいる組成物;この組成物を使用することによって、作物の有害生物及び病害と予防的又は治療的に闘う方法並びに作物の収量を増大させる方法。