Monitoring the seasonal flights of the Latticed heath, Chiasmia clathrata (Lepidoptera: Geometridae), was carried out using home made sticky delta traps baited with pheromone caps purchased from CSALOMON® (Plant Protection Institute, Hungary, Budapest). The monitoring was conducted in alfalfa fields in Pazardzhik and Sofia regions in Bulgaria during 2007–2009. The flight of C. clathrata at the investigated sites started at the very beginning of April and lasted until the middle-end of September. Three relatively well-defined peaks, indicating three generations, were recorded in Sofia region. Thus, the flight period and the flight of the separate generations of the pest were defined more accurately than it has been reported earlier. Pheromone baits, products of CSALOMON ® are potent and species specific tools for detecting the presence and seasonal monitoring of C. clathrata.