Location: Southern Insect Management ResearchTitle: Effect of Two Strains of Beauveria bassiana on the Fecundity of Nezara viridula L. (Heteroptera: Pentatomidae)
Submitted to: Microbiology Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/31/2022
Publication Date: 8/4/2022
Citation: Portilla, M., Reddy, G.V., Terluliano, M. 2022. Effect of Two Strains of Beauveria bassiana on the Fecundity of Nezara viridula L. (Heteroptera: Pentatomidae). Journal of Microbiology Research. 13(3):514-522. https://doi.org/10.3390/microbiolres13030035.
Interpretive Summary: Beauveria bassiana is a saprophytic fungus that infects and consumes insects and other arthropods and seems to be an appropriate alternative for the control of N. viridula as its effectiveness has been reported by previous studies. Although, several studies have been conducted to determine the potential impact of B. basianna against N. viridula, there is no published information on the sub-lethal effect of this entomopathogenic fungi on N. viridula. Therefore, the current study was carried out to investigate the effect of B. bassianna on the fecundity of this pest and determine the lethal concentration for females and males of N. viridula. It is important to mentioned that there are not entomopathogenic fungi available that have been commercially developed for pentatomids as a primary target; therefore, the commercially GHA strain (BotaniGard 22WP) and the Mississippi Delta native NI8 strains isolated from Lygus lineolaris Palisot de Beauvois (Hemiptera: Miridae) were used for this study.
Technical Abstract: The southern green stink bug, SGSB Nezara viridula (L.) (Heteroptera: Pentatomidae), is one of the most important agricultural pests of soybean and cotton in North and South America. Two con-trols (water and Tween-80) and four concentrations (nx104, 105, 106, and 107) of two isolates of Beauveria bassiana Vuillemin (Hypocreales: Cordycipitaceae) including the commercial strain GHA and the Mississippi Delta native NI8 strain were evaluated in the laboratory to determine the effect on the fecundity of a laboratory colony of SGSB. Both isolates of B. bassiana with the highest concentrations were pathogenic to the SGSB. However, females were much more suscepti-ble to both strains than males. Lethal concentration (LC50) of the native strain NI8 was 1.4-fold lower (236 spores / mm2) than the strain GHA (326 spores/mm2) for females scored 20-D after exposure. Higher concentrations (11134963 spores/mm2, 5206971 spores/mm2) were required to kill males with both strains NI8 and GHA, respectively. Cumulative fecundity for controls and lower concentrations ranged from 1178 to 2082 eggs/10 couples/life reproduction, compared with 597 and 673 eggs/10 couples sprayed with NI8 nx106 and 107, respectively and 386 eggs/10 couples sprayed with GHA nx107. Further field testing is needed to evaluate the potential for in-field control.