Document Type
Thesis - Open Access
Award Date
2025
Degree Name
Master of Science (MS)
Department / School
Agronomy, Horticulture, and Plant Science
First Advisor
Adam J. Varenhorst
Abstract
The Dectes stem borer (Dectes texanus LeConte, Coleoptera: Cerambycidae) has emerged as an increasingly significant pest of soybean (Glycine max) in South Dakota. Although historically considered a minor concern, rising populations of this insect have led to significant preharvest lodging and subsequent yield loss in affected fields. The Dectes stem borer's larval feeding within the soybean stem interferes with nutrient flow, and as the season progresses, this internal feeding weakens stem integrity, amplifying lodging risks and causing considerable challenges for farmers and researchers. Since 2017, both the number and severity of Dectes stem borer infestations have been on the rise across South Dakota, emphasizing the urgent need for effective pest management strategies. Developing integrated pest management (IPM) approaches is essential to reduce the impact of this pest and protect soybean yield potential. The primary objective of this thesis is to provide a comprehensive review of the biology, behavior, economic impact, geographic distribution, and management strategies of Dectes stem borer within the context of soybean production. Specifically, this research focuses on two objectives: Evaluation of foliar-applied insecticide efficacies through optimized spray timings to manage Dectes stem borer populations and a survey of soybean fields across South Dakota to identify infestation hotspots, monitor pest distribution, and develop spatial maps to track the expansion of Dectes stem borer populations. The findings from these objectives highlight the importance of integrating pest management practices to sustain soybean production and reduce economic losses caused by Dectes stem borer. This work contributes to a broader understanding of Dectes stem borer ecology and lays the groundwork for implementing effective, region-specific pest management strategies.
Publisher
South Dakota State University
Recommended Citation
Loomis, Zachary, "Assessment and Management of Dectes Stem Borer, Dectes Texanus Leconte, In South Dakota Soybeans" (2025). Electronic Theses and Dissertations. 1554.
https://openprairie.sdstate.edu/etd2/1554
Rights Statement
