During the 30-day period following eclosion, egg production by ♀ milkweed bugs, Oncopeltus fasciatus (Dallas), fed various non-host seeds, i.e., sunflower, walnut, almond, cashew or peanut, ranged from 9–32% of the milkweed-fed controls for mated females and from 0–16% of the controls for virgin females. Treatment with an optimal dose of a juvenoid increased egg production of mated and virgin females fed non-host seeds to as much as 73 and 77% of their respective controls fed milkweed seeds. Juvenoid treatment increased egg production of mated females both reared as nymphs and fed as adults on sunflower seeds from 5–40% of the production of milkweed-fed females. The apparent feeding frequency of juvenoid-treated females on each of the non-host seeds was at least equal to that of females fed milkweed seeds. Both the presence of males and juvenoid treatment of virgin females increased the number of females observed feeding. It is suggested that the capacity of a food plant to stimulate the release of juvenile hormone in adult females is an important criterion for an adequate host. The possibility is raised that applications of juvenoids for insect control may sometimes increase the population of immature stages of target or non-target insects on suboptimal species or varieties of plants.