Z-Gly-Val-Ser-Phe-Val-Leu-OMe and related peptides were synthesized by the conventional solution method and their attractant and repellent activities for Aedes aegypti (mosquito) and Blattella germanica (cockroach) were examined. Z-Val-Leu-OMe exhibited potent repellent activity against not only Aedes aegypti but also Blattella germanica.