Evaluation and Utilization of Resistance to Tarnished Plant Bug in Cotton - Survival of Nymphs on a Frego Bract Compared to a Nectariless Line in Field and Laboratory Trials

Field and laboratory trials conducted in 2010 and 2011 were aimed at evaluating techniques for screening cottons with host plant resistance to tarnished plant bug (Lygus lineolaris (Palisot de Beauvois). Nymphs (either small or large) were released on terminal cuttings or in field cages of RBCDHGPIQH-1-97, an early fruiting, frego bract line that is considered susceptible to TPB and Arkot 9608ne, a nectariless line moderately resistant to TPB. Earlier field and lab trials have shown plant bugs prefer feeding on squares of frego compared to the Arkot line. In field caged trials as well as lab feeding trials using main stem cuttings from field collected plants, results indicated significantly greater survival of plant bug nymphs after 3 days on the frego compared to Arkot line. Very high survivorship with no differences between lines was observed in cage and main stem cuttings trials with greenhouse grown cotton. Techniques used in the trial show promise for expanding host plant resistance screening protocols. If confirmed, resistance of varieties and breeding lines could be compared simply by taking plant cuttings from existing field tests.