The invention provides a composition attracting Oak Processionary Moth which is a serious insect pest to forests to be used for stably and efficiently catching the insect pest in coincidence with actual breeding. The composition comprises ( Z, Z ) - 11 , 13-hexadecadienyl acetate, ( E , Z )-11, 13-hexadecadienyl acetate, ( Z , Z )-11, 13-hexadecadienol and ( Z , E )-11, 13, 15-hexadecatrienyl acetate. The invention also provides a sustained-release attractant comprising the attracting composition contained in a sealed sustained-release container and a method for predicting breeding or for massively attracting and killing Oak Processionary Moth, comprising a step of setting a trapping apparatus in a forest, wherein the trapping apparatus is provided with the sustained-release attractant and a trap for catching insects which are attracted by the sustained-release attractant.
