Effect of two strains of Beauveria bassiana on the fecundity of the southern green stink bug

Two control (water and Tween-80) and four concentrations (nx10⁴, 10⁵, 10⁶, and 10⁷) of two isolates of Beauveria bassiana 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. Both isolates of B. bassianawith the highest concentrations were pathogenic to the SGSB. However, females were much more susceptible to both strains than males. The measure lethal concentration (LC₅₀) of the native strain NI8 was 1.4-fold lower (236 spores / mm²) than the commercial strain GHA (326 spores/mm²) for female scored 20-D after exposure. Much higher concentrations (11134963 spores/mm², 5206971 spores/mm²) were required to kill males with both strains NI8 and GHA, respectively. High statistically significant differences were found in fecundity on couples sprayed with the highest concentration of GHA strain (nx10⁷), while couple sprayed with the native NI8 (nx10⁶and 10⁷) were significantly higher compared with both controls and the lower concentrations. 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 nx10⁶and 10⁷, respectively and 386 eggs/10 couples sprayed with GHA nx10⁷. Further field testing is needed to evaluate the potential for in-field control.