Studies conducted from May through Nov., 1979 determined that the distribution and abundance ofScaphytopius acutus acutus(Say) (Homoptera: Cicadellidae), a vector of peach (Prunus persicaBatsch) X-disease, in a Connecticut peach orchard were related to the distance from wild host species at the orchard edge and to the relative abundance of wild host plants in the orchard ground cover. Greatest numbers of adultS. acutusfor spring and summer generations were captured on yellow sticky traps located among wild host plants at the orchard edge while fewest were caught on traps in peach trees furthest from the edge. Density of nymphs and adults on peach trees and in ground cover in 32 plots along a transect through the orchard increased with the relative abundance of wild host plants in the ground cover and decreased with distance from the orchard edge.Host preference experiments conducted in the laboratory revealed that both generations ofS. acutuswere most highly attracted to red clover,Trifolium pratenseL. (Leguminosae), for feeding and oviposition. However, this plant comprised less than 1% of the orchard ground cover. Peach was preferred as a food host by both generations over 8 wild host species, which comprised 94% of the ground cover. Oviposition preference experiments indicated that peach was among the least preferred hosts for both generations while several rosaceous species, in particular strawberry,Fragaria virginianaDuchesne and blackberry,Rubus allegheniensisPorter, comprising 65% of the ground cover, were most highly preferred for oviposition. The differential utilization of peach and wild rosaceous hosts byS. acutusfor feeding and oviposition would encourage frequent movement of adults between peach and the ground cover.