Soybean host plant resistance to Megacopta cribraria (F.) (Hemiptera: Plataspidae) and the potential role of leaf trichome density

Authors: LAHIRI, S. - North Carolina State University; REISIG, D. - North Carolina State University; REAY-JONES, F. - Clemson University; GREENE, J. - Clemson University; Carter Jr, Thomas; Mian, Rouf; FALLEN, B. - Clemson University

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/4/2019
Publication Date: 1/6/2020
Citation: Lahiri, S., Reisig, D.D., Reay-Jones, F.P., Greene, J.K., Carter Jr, T.E., Mian, R.M., Fallen, B.D. 2020. Soybean host plant resistance to Megacopta cribraria (F.) (Hemiptera: Plataspidae) and the potential role of leaf trichome density. Environmental Entomology. XX(XX), 2020, 1–10. https://doi.org/10.1093/ee/nvz158.
DOI: https://doi.org/10.1093/ee/nvz158

Interpretive Summary: Host plant resistance (HPR) has been used as important component of integrated pest management (IPM) to manage invasive insects attacking many crops in USA. Megacopta cribraria (F.) is an invasive pest of soybean that has spread across the southeastern USA since its initial discovery in 2009 in Georgia. Previous studies in the southeastern states have documented both the population dynamics of this pest and role of HPR in soybean, although the specific mechanisms of HPR remain unknown. The objectives of this study were to 1) quantify field resistance to M. cribraria in multiple soybean varieties in two states previously affected by severe M. cribraria infestations, North Carolina (NC) and South Carolina (SC), and 2) study the role of soybean trichome density in imparting resistance against M. cribraria. Soybean variety ‘Camp’ was least attractive to M. cribraria, through time and locations, suggesting consistent resistance. Other varieties showed variable performance among the locations and sampling dates. A significant difference in trichome density was evident. However, there was no correlation between trichome density and M. cribraria infestation. Compared to a previously published study in the same location, when M. cribraria adults emerging from overwintering dispersed into soybeans, in our study only first-generation adults dispersed into soybeans. Considering the current trend of significantly lower M. cribraria infestation rates in North and South Carolina, this pest may be finally succumbing to indigenous natural enemies and may be managed by incorporating integrated pest management approach, including host plant resistance.

Technical Abstract: Megacopta cribraria (F.) is an invasive pest of soybean that has spread across the southeastern USA since its initial discovery in 2009 in Georgia. Previous studies in the southeastern states have documented both the population dynamics of this pest and host plant resistance (HPR) among soybean varieties, although the specific mechanisms of HPR remain unknown. The objectives of this study were, therefore, to 1) quantify field resistance to M. cribraria in multiple soybean varieties in two states previously affected by severe M. cribraria infestations, North Carolina (NC) and South Carolina (SC); and 2) study the role of soybean trichome density in imparting resistance against M. cribraria. Soybean variety ‘Camp’ was least attractive to M. cribraria, through time and locations, suggesting consistent resistance. Other varieties showed variable performance among the locations and sampling dates. A significant difference in trichome density was evident. However, there was no correlation between trichome density and M. cribraria infestation. Compared to a previously published study in the same location, when M. cribraria adults emerging from overwintering dispersed into soybeans, in our study only first-generation adults dispersed into soybeans. Considering the current trend of significantly lower M. cribraria infestation rates in North and South Carolina, this pest may be finally succumbing to indigenous natural enemies and should be managed by incorporating integrated pest management tactics, such as HPR, that help conserve natural enemy populations.