Field evaluation of soybean genotypes for resistance to the invasive kudzu bug, Megacopta cribraria

Initially discovered in northeast Georgia in 2009, the invasive kudzu bug, Megacopta cribraria (Fabricius), has spread rapidly throughout the southeastern U.S. in subsequent years.  While M. cribraria primarily feeds on kudzu (Pueraria spp.), it has also become a serious pest of soybeans, Glycine max (Merrill), and other leguminous crops throughout its invasive range.  Currently, there are no commercially available soybean cultivars with known resistance to M. cribraria.  During the summers of 2013 and 2014, 40 soybean breeding lines were field-tested for resistance to M. cribraria in a randomized split-plot design, where split-plot factor was soybean genotype and whole plot factor was insecticide spray treatment.  Variation in soybean genotypes included traits for maturity group, pubescence type, leaf shape, drought tolerance, protein content, and insect and nematode resistance.  M. cribraria egg masses, nymphs and adults were counted during the growing season to identify potentially resistant soybean genotypes.  In both 2013 and 2014, results indicate the fewest M. cribraria adults and nymphs were found on non-nodulating soybean breeding line Nitrasoy, as well as narrow leaf, small-seeded soybean breeding lines N7103 and Vance.  In 2013, soybean yield was reduced by 33% (8.8 bu/ac) on average in unprotected plots due to M. cribraria feeding.  Soybean breeding lines N7103 and Vance both experienced less than 15% average yield loss in unprotected plots, while near isogenic insect resistant lines Benning H and E experienced less than 20% average yield loss.  These results can be used by soybean breeding programs to develop cultivars with resistance to M. cribraria.