The flight activity of the apple leaf midge, Dasineura mali (Kieffer), was determined in the field and laboratory. Males and females began emerging at the onset of the photophase. In the field, delta-shaped traps baited with 6 virgin females caught males exclusively, with the most abundant catches on the ground as compared to those at 1 and 2 m. Most males were captured at 1100 hours and males remained in the vegetation under the trees throughout the day. Sweep netting revealed that conspecifics mate in the vegetation under orchard trees in the morning hours, and females move from the ground to the orchard canopy to oviposit at 1000 hours. Gas chromatographic-electroantennographic detection (GC-EAD) analyses indicated the presence of an electrophysiologically active compound in solid phase microextraction (SPME) effluvial collections and pheromone gland extractions from virgin females.