Location: Southern Insect Management ResearchTitle: Effectiveness of Beauveria bassiana against Piezodorus guildinii (Hemiptera: Pentatomidae), a key pest of soybeans in the Neotropics
Submitted to: Biocontrol Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/13/2020
Publication Date: 2/23/2020
Citation: Parys, K.A., Portilla, M. 2020. Effectiveness of Beauveria bassiana against Piezodorus guildinii (Hemiptera: Pentatomidae), a key pest of soybeans in the Neotropics. Biocontrol Science and Technology. 30:5 451-461. https://doi.org/10.1080/09583157.2020.1731426.
Interpretive Summary: Redbanded stink bugs are a pest of soybeans across the Americas in warmer regions. Two different strains of a entomopathogenic fungus were tested for their potential to control redbanded stink bugs. Both a commercial formulation and a locally isolated strain were tested in four concentrations. The laboratory methods simulated in-field conditions, and both of the fungal pathogens tested killed redbanded stink bugs. Differences were observed through out the study between the two pathogens. These pathogens are environmentally friendly and have no harvest interval, making them potentially attractive to growers who need to control pest populations.
Technical Abstract: Redbanded stink bugs, Piezodorus guildinii (Westwood), are a neotropical pest of soybean production across the southern United States and the Neotropical Americas. Two strains of Beauveria bassiana (Bals.-Criv) Vuill. (Hypocreales: Cordycipitaceae) were evaluated for potential control of redbanded stink bug. Four concentrations (104, 105, 106, and 107 spores/ml) of both a Mississippi Delta native strain (NI8) and a commercially available formulation (GHA) were tested against field collected adult redbanded stink bugs in the laboratory and evaluated at four time points (3, 5, 10, and 15 days). Application methods simulated field sprays and were similar to those previously used to screen several other pests and beneficial insects. Both isolates of B. bassiana tested were pathogenic to adult redbanded stink bugs. A significant overall difference between strains (regardless of the concentration) was observed at 3 days after treatment, while differences among concentrations were observed at 5, 10, and 15 days after treatment. The lethal concentration (LC50) and lethal sporulation (LS50) were not significantly different between strains at either 10 or 15 days after treatment. However, higher mortality was observed in cohorts sprayed with GHA at lower concentrations than those sprayed with NI8. Unlike other control options, B. bassiana has a short re-entry interval and no harvest interval, making it a potentially attractive and environmentally benign alternative to conventional synthetic insecticides for control of redbanded stink bugs in soybeans. Further testing on juvenile life stages and field testing is needed to evaluate the potential for in field control.