An insecticide-free hatching inhibitor of blood-sucking pest eggs, which is easy to handle and can control these eggs in addition to adults of lice and fleas, insecticide composition of blood-sucking pests, and insect killing of blood-sucking pests It is an object to provide a method. The hatching inhibitor of blood-sucking pest eggs of the present invention is a fatty acid ester containing a fatty acid residue and an alcohol residue, both of the fatty acid residue and the alcohol residue have a branched structure, and It consists of a fatty acid ester in which the alcohol residue has more carbon atoms than the fatty acid residue.殺虫剤を含まずに、取扱いが容易で、シラミ及びノミの成虫に加えこれらの卵をも駆除できる吸血性害虫卵の孵化阻害剤、吸血性害虫の殺虫組成物および吸血性害虫の殺虫殺卵方法を提供することを課題とする。本発明の吸血性害虫卵の孵化阻害剤は、脂肪酸残基およびアルコール残基を含む脂肪酸エステルであって、前記脂肪酸残基および前記アルコール残基のいずれもが分岐構造を有し、かつ、前記アルコール残基の炭素数が前記脂肪酸残基の炭素数よりも多い脂肪酸エステルからなる。
