Semester of Graduation
Summer 2025
Degree
Master of Science (MS)
Department
Entomology
Document Type
Thesis
Abstract
Soybean, Glycine max (L.) Merr. (Fabales: Fabaceae), is a major crop in Louisiana, where stink bugs (Hemiptera: Pentatomidae) are economically important pests that reduce seed quality and yield. Among them, the redbanded stink bug, Piezodorus guildinii (Westwood), is considered the most damaging species in the southern U.S. soybean system. Recently, Euschistus quadrator (Rolston), historically a minor pest, has increased in abundance and now dominates the brown stink bug complex in Louisiana soybean fields. While P. guildinii has been widely studied, little is known about E. quadrator.
Given the increasing pest complexity, sustainable management strategies are needed to target the entire stink bug complex. Host plant resistance is a promising IPM tool to reduce insecticide use and improve long-term control. Understanding species-specific biology, plant variety interactions, and population dynamics is essential to support Integrated Pest Management (IPM).
This study aimed to: (1) characterize the survival and reproductive biology of E. quadrator on soybean under laboratory conditions; (2) evaluate the susceptibility of commercial soybean varieties to P. guildinii using life table studies; and (3) assess field resistance of soybean varieties to stink bug infestations using a seed damage index and 100-seed weight as a yield proxy.
In laboratory experiments, first-instar nymphs of both species were reared on pods of different soybean varieties under controlled conditions. Development, survival, and reproduction were recorded, and demographic parameters were estimated using life table analysis. Field experiments over three seasons used replicated plots, weekly sweep net sampling to monitor stink bug pressure, and postharvest assessments of seed damage and 100-seed weight.
Results confirmed that E. quadrator can complete its life cycle on soybean, reinforcing its status as an emerging pest. For P. guildinii, differences among varieties in development and survival suggest antibiosis resistance. Field data showed notable variation in infestation and damage, with some varieties exhibiting antixenosis and tolerance. These findings indicate that commercial soybean varieties in the southern U.S. differ in their resistance to stink bugs, and this variation can be used to support sustainable IPM programs.
Date
7-11-2025
Recommended Citation
Martinez, Cristofer, "Host Plant Resistance to Stink Bugs in Commercial Soybean Varieties" (2025). LSU Master's Theses. 6190.
https://repository.lsu.edu/gradschool_theses/6190
Committee Chair
Davis, Jeffrey A.