The tarnished plant bug overwinters as an adult in leaf debris and other protected areas. Adults become active in April and begin egg laying in weeds. The tiny nymphs are slender, pale green insects that resemble aphids . The nymphs turn brown during the last instar. The entire life cycle is completed in 30-40 days with two to four overlapping generations occurring each year.
Most damage takes place just after petal fall.
Early June bearing varieties can escape most tarnished plant bug injury because pest populations are small and consist of less damaging early instars. Late maturing cultivars are more susceptible to damage. Plantings near alfalfa fields, woods, or weedy areas are more prone to damage. Alternative hosts, especially weeds and seed-producing plants should be eliminated around the planting. Regular mowing or weeding may help, but should be avoided just before or during the blossom period.