The diapause of the blister leafminer Agrornyza nigripes was studied together with its parasitization by Dacnusa nipponica. It was found that (99%) of puparia went into diapause by the end of wheat growing season. Flies emerged in two successive seasons (1993-1995), (1994-1996) and (1995-1997) and the majority (92.9%) emerged in the first diapause season. The emergent period was prolonged from late November until late March with two peaks; by the third week of Decem­ber and the first week of March. The parasitoid D.nipponica was found to follow the same pattern of the host emergence. It increased progres­sively with a distinct peak by the second week of February. This correla­tion of emergence is highly important for biological control. Parasitism of live puparia was generally higher on diapause puparia than active ones. The highest value of actual total parasitism was 82.9% on the puparia collected in the third week of MArch.