Location: Soybean and Nitrogen Fixation ResearchTitle: Host plant resistance to megacopta cribraria (Hemiptera: Plataspidae) in diverse soybean germplasm maturity groups V through VIII
|FRITZ, B - North Carolina State University|
|SORENSON, C - North Carolina State University|
|Carter Jr, Thomas|
|DEL POZO-VALDIVIA, A - North Carolina State University|
|REISIG, D - North Carolina State University|
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/10/2016
Publication Date: 3/27/2016
Citation: Fritz, B.J., Sorenson, C.E., Carter Jr, T.E., Del Pozo-Valdivia, A.I., Reisig, D.D. 2016. Host plant resistance to megacopta cribraria (Hemiptera: Plataspidae) in diverse soybean germplasm maturity groups V through VIII. Journal of Economic Entomology. 109:1438-1449.
Interpretive Summary: Initially discovered in Georgia in 2009, the exotic invasive kudzu bug (Megacopta cribraria Fabricius), a native of Asia, has now become a serious pest of soybean throughout the Southeast. Broad-spectrum insecticides control this new pest at present. However, there is always the potential that the kudzu bug could develop resistance to these chemicals. To reduce the threat of insecticide-resistant kudzu bug, we began a search to identify resistant soybean types that could be used as an attractive alternative approach for kudzu bug control. No commercial soybean cultivars have been identified as resistant. Thus, during 2013 and 2014, we compared 40 diverse soybean genotypes for resistance at a field site which had a history of kudzu bug infestation in North Carolina. Egg masses, nymphs, and adult insects were counted during the growing season to identify potentially resistant soybean. In both years, host plant resistance was observed. The fewest Kudzu bug adults and nymphs were found on the narrow-leaf small-seeded USDA varieties N7103 and Vance. Additionally, N7103 and Vance were among the least susceptible genotypes to Kudzu bug oviposition in the field. Insect-resistant breeding lines from the University of Georgia also displayed moderate levels of resistance to the Kuzdu bug. These results are novel and should provide the foundational basis for development of modern soybean varieties resistant to the kudzu bug.
Technical Abstract: Initially discovered in Georgia in 2009, the exotic invasive plataspid, Megacopta cribraria Fabricius has become a serious pest of soybean. Managing M. cribraria in soybean typically involves the application of broad-spectrum insecticides. Soybean host plant resistance is an attractive alternative approach; however, no commercial soybean cultivars have been identified as resistant. During 2013 and 2014, we compared 40 and 44 soybean genotypes, respectively, for resistance to M. cribraria in a split-plot design under natural insect infestation in small plot experiments. Soybean genotypes were selected to maximize diversity with respect to maturity group, pubescence type, leaf shape, seed size, nitrogen fixation, drought tolerance, seed protein content, and pest resistance. Megacopta cribraria egg masses, nymphs, and adults were counted during the growing season to identify potentially resistant soybean genotypes. Soybean seed yield was measured in insecticide protected and unprotected conditions to determine tolerance to M. cribraria feeding. In both years, a range of host plant resistance was observed. The fewest M. cribraria adults and nymphs were found on narrow-leaf small-seeded cultivars N7103 and Vance, as well as the non-nodulating cultivar Nitrasoy. Additionally, N7103 and Vance were among the least susceptible genotypes to M. cribraria oviposition in the field. Most Benning insect resistant NILs also displayed moderate levels of resistance to M. cribraria. Seed yields of Vance and N7103 were less affected by M. cribraria in 2013 than most other soybean genotypes. These results may be useful to soybean breeders to develop cultivars with resistance to M. cribraria.