The movement of adult longhorned beetles (Coleoptera: Cerambycidae) between forest habitat patches is poorly understood. In particular, it is not known how adults in this family perceive different parts of the landscape, i.e. are some types of land cover easier to fly through than others due to differential resource availability or probability of mortality, or physical barriers to movement. Understanding the relative costs of movement may be particularly important in areas where forest patches are highly fragmented, as a critical habitat fragmentation threshold may exist above which individuals of a given species cannot find new patches to colonize. Knowledge of where this threshold exists, and which types of land cover have the greatest influence on it, could be used to promote the movement of beneficial species, i.e. those that recycle dead-wood, or limit the movement of harmful species, i.e. live-wood borers or new invasives. Least-cost path modeling is one method of incorporating costs of movement through different types of land cover into a calculation of the ‘effective’ distance between habitat patches. We are using the least-cost path tool in a Geographical Information System (ArcGIS 9.1™) to examine the relative costs of movement through different types of land cover for two species of longhorned beetle: the red-headed ash borer Neoclytus a. acuminatus (Fabricius), and the pole borer Parandra b. brunnea (Fabricius). Preliminary results suggest that these two species perceive the landscape differently, thus different species may have different critical fragmentation thresholds.