Tarnished plant bug (TPB) (Lygus lineolaris Palisot de Beauvois; Hemiptera: Miridae), is the number one insect pest in U.S. Mid-South crops including cotton. Development and deployment of lines exhibiting partial resistance to TPB could reduce the quantity of insecticides needed to control this pest. We have evaluated TPB resistance of cotton lines in small plots since 2003. Insecticides were not applied for TPB. When TPB damage was readily seen in flowers of the susceptible check, examination for “dirty flowers” was made on six white flowers per day for 5 to 8 days. Cumulative percent dirty flowers over sampling days was then calculated for each plot. Over the last 21 years, we evaluated 2,724 lines in 102 different tests. Variation between supposed resistant and susceptible check cultivars were relatively consistent over tests. These data were used to quantify the level of TPB resistance in breeding strains and in 90 germplasm lines and cultivars released from the University of Arkansas Cotton Breeding Program, as well as cultivars and breeding lines in the annual Arkansas Cotton Variety Test and Regional Breeders’ Network Test. Over the years, nectariless and highly pubescent lines have consistently provided some TPB resistance. However, TPB resistance has been found in some nectaried and glabrous lines. These findings suggest the existence of different mechanisms for TPB resistance.
