Tarnished plant bug (TPB) has now become the major cotton insect pest in many regions. We evaluate cotton varieties and advanced breeding lines for TPB resistance using “% dirty flowers” (discolored anthers in white flowers) measurement in small plots. TPB resistance of varieties have been relatively consistent over years. Some nectaried lines are as resistance as nectariless lines – suggesting that different modes of resistance are present. In large plots, TPB resistant varieties (established in small plots) required more time to reach treatment levels of TPB and thus, required few insecticide treatments.