Collections from black-light and malaise traps in the tree crown and D-Vac^® sampling and direct hand-sampling of the tree crown of pecan, Carya illinoensis Koch, revealed that several species of phytophagous pentatomids and coreids inhabit pecan. Nezara viridula (L.) and Euschistus servus (Say) were present during the entire season, overwintered in the orchard and caused damage to fruit. When caged on pecan clusters before shell-hardening, N. viridula caused 34-53% fruit drop, E. servus caused 73% fruit drop. Average ingestion of N. viridula adults, feeding on pecan kernel was 14 calories/feeding site compared to 6.5 calories/feeding site on soybean, Glycine max (L.). The effects of cowpea, Vigna unguiculata (L.), interplanting, pecan cultivar and vertical level in the tree crown were tested in a split-split plot design. Cowpea interplanting was associated with a high incidence of kernel spot in the lower level crown of “Schley” pecan trees. “Schley” pecans were more susceptible to damage than “Moneymaker” and “Stuart”. In “Schley” trees damage incidence was higher in the lower than the upper crown. Comparisons of the stylet sheaths of N. viridula and E. servus indicated that differences in sheath morphology were due to differences in shuck thickness rather than causal species.