As part of a long-term arthropod biodiversity study, we operated six Malaise traps in Dyke Marsh Wildlife Preserve (DMWP), Virginia from April 1998 through December 1999 and obtained 104 adult mecopterans in five species. They were present in samples from late May through early November. Samples indicate that as a group, the mecopterans were more abundant in the forest than in the marsh and the forest-marsh ecotone, and the mecopterans had a female-biased sex ratio. Two of the trapped species are uncommon or of limited distribution in North America. Malaise traps can be used efficiently to survey and monitor certain mecopteran species in DMWP and similar places. To understand the mecopteran biodiversity and phenology in the Preserve more completely, it would be worthwhile to survey the entire Preserve for at least 10 yr with all appropriate sampling methods.