Both sexes of overwinteringLygus lineolaris(Palisot de Beauvois) adults visit apple buds and blossoms (where they feed and cause injury) as well as apple foliage, twigs, and small branches. With the ultimate aim of developing a visual monitoring trap, we compared responses of the adults to 15×20-cm sticky-coated rectangles of different hues and shades hung in apple trees. Non-UV reflecting Gloss White and Zn white, Zoecon Yellow, and clear Plexiglas rectangles captured equivalent numbers of adults, significantly more than other hues of yellow, green, orange, blue, red, black, UV-reflecting aluminum foil, or Pb white rectangles. The fact that captures on clear Plexiglas were as great or greater than captures on pigmented rectangles approximating the spectral reflectance pattern of apple buds, blossoms, foliage, or bark suggests that the adults are not specifically oriented to the hue of tree structures which they visit. Significant differences in captures between certain pigments do suggest, however, that visual stimuli play at least some (still undetermined) role in the orientation of adults within or to trees. Additional findings indicate that a sticky-coated, non-UV reflecting white or Zoecon Yellow rectangle, hung vertically at ca. 0.7 m above ground, is the most efficient method yet devised for detectingL. Lineolarisadults in apple trees.