Field evaluation of cotton expressing Mpp51Aa2 as a management tool for cotton fleahoppers, Pseudatomoscelis seriatus (Reuter)

Authors: ARTHUR, BRADY - Texas A&M University; Suh, Charles; MCKNIGHT, BENJAMIN - Texas A&M University; PARAJULEE, MEGHA - Texas A&M University; YANG, FEI - University Of Minnesota; KERNS, DAVID - Texas A&M University

Submitted to: Toxins
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/3/2023
Publication Date: 11/5/2023
Citation: Arthur, B.P., Suh, C.P., McKnight, B.M., Parajulee, M.N., Yang, F., Kerns, D.L. 2023. Field evaluation of cotton expressing Mpp51Aa2 as a management tool for cotton fleahoppers, Pseudatomoscelis seriatus (Reuter). Toxins. 15:644. https://doi.org/10.3390/toxins15110644.
DOI: https://doi.org/10.3390/toxins15110644

Interpretive Summary: The cotton fleahopper is considered one of the most damaging insect pests of cotton in Texas and Oklahoma. Current control methods rely heavily on applications of insecticides, but multiple and timely applications are usually required to provide adequate control. Thus, there is a need to identify alternative management strategies for this pest. One possibility may be the use of a genetically modified cotton variety known as ThryvOn, which was initially developed for lygus bugs. Based on a three-year field study, we found that the genetically modified plants delayed nymphal development, suppressed adult populations, and reduced feeding damage equivalent to levels provided by insecticides. In light of these benefits, ThryvOn may be a viable option for managing cotton fleahoppers, particularly in areas where lygus bugs are also present.

Technical Abstract: The cotton fleahopper (Pseudatomoscelis seriatus Reuter) is considered a highly economically damaging pest of cotton (Gossypium hirsutum L.) in Texas and Oklahoma. Current control methods rely heavily on the use of foliar applied chemical insecticides but considering the cost of insecticides and the critical timeliness of applications, chemical control methods are often not optimized to reduce potential yield losses from this pest. The Bacillus thuringiensis (Bt) Cry51Aa2 protein has proven effective against thrips and plant bugs with piercing and sucking feeding behaviors, but the impact of this toxin on cotton fleahoppers has not been investigated. To evaluate the Cry51Aa2 trait’s effectiveness towards cotton fleahopper, field trials were conducted in 2019, 2020, and 2021 comparing a cotton cultivar containing the Cry51Aa2 trait to a non-traited isoline cultivar under insecticide-treated and untreated conditions. Populations of cotton fleahopper nymphs and adults were estimated weekly by visually inspecting cotton terminals. Square retention was also assessed during the first week of bloom to provide some insight on how the Bt trait may influence yield. While cotton fleahopper population differences between the traited and non-traited plants were not consistently noted during the pre-bloom squaring period, there was a consistent increase in square retention in cotton expressing Cry51Aa2 relative to non-traited cotton. Additionally, cotton expressing Cry51Aa2 offered similar square protection relative to non-traited cotton treated with insecticides for cotton fleahopper. These findings indicate that the Cry51Aa2 protein should provide benefits of delayed nymphal growth, population suppression, and increased square retention.