It feeds on several kinds of plants, mostly in the cabbage family (Brassicaceae), and can cause serious damage during outbreaks. Historically harlequin bugs have been problems restricted to southern areas of the US, but in recent years they have expanded their range northward and now can be common in many areas of Colorado. Harlequin bugs can be found in both eastern Colorado and areas of the West Slope, but most consistently occur as problems in the southeastern counties. Since harlequin bugs are not well adapted to cold temperatures, problems tend to be worse in seasons that follow mild winters. Harlequin bugs feed with mouthparts that allow them to pierce cells and remove fluids from the plant. When feeding occurs on mature leaves, this typically results in light colored cloudy spots at feeding sites.

Harlequin bugs feeding on young leaves are more damaging and kill large areas of plant tissues resulting in dead, brown patches. In high numbers harlequin bugs cause extensive wilting, distortion and may completely destroy all new growth.Īlthough most any plant in the cabbage family can host and be injured by harlequin bugs, some crops tend to be more consistently damaged, including turnips, kale, cabbage and mustard. Related ornamental flowering plants are also susceptible, such as sweet alyssum, Matthiola, and Erysimum. Harlequin bugs may also feed on a wide range of other non-brassica plants, particularly during outbreaks. Cleome (spider plant) is a plant that is particularly favored by harlequin bug. Harlequin bugs survive winter in the adult stage, hidden under plant debris and other insulating cover. With return of warming temperatures in spring they emerge and seek out food plants. Various winter annual weeds, such as wild mustards, flixweed, peppergrass, and shepherd’s purse, are widely available hosts that can support the spring generation. Winter canola and other brassica crops that survive through winter, such as kale, also serve as early season hosts.Įggs are laid in distinctive masses on the underside of leaves.

Harlequin bug pinbox