Abstract The objective of this work was to determine the best conditions for the use of synthetic sex attractants to monitor Illiberis pruni Dyar (Lepidoptera: Zygaenidae, Procridinae) in the Helan Mountain National Nature Reserve, Ningxia, China. Traps with binary blends of 2‐butyl (7Z)‐dodecanoate (300 µg) and 2‐butyl (9Z)‐tetradecanoate (300 µg) at a ratio of 1:1 caught the most moths. Catches were significantly different across 5–45 m inter‐trap distances; the optimal trapping radius was 25 m. Trap height did not affect catches. The slope aspect, temperature, and humidity significantly influenced catches. More moths were caught as temperatures increased and relative humidity decreased. Traps placed on shady slopes caught significantly more moths than did traps placed on sunny slopes. This study elucidates how various factors influence the effectiveness of traps. The implications of these findings could facilitate safer and more environmentally friendly in situ management of I . pruni .