Susceptibility of five species of thrips to different strains of the entomopathogenic fungus, Beauveria bassiana

Abstract

The susceptibilities of five thrips species, Frankliniella intonsa, E occidentals, Thrips colorants, T. hawaiiensis, and T. tabaci, to three isolates of an entomopathogenic fungus, Beauveria bassiana (isolates AZA38, GOM03, and KOG02), were investigated under laboratory conditions. Among the three fungal isolates, the five thrips species were the most susceptible to isolate KOG02 when inoculated with conidial suspensions at a concentration of 1×10 7 conidia/ml. Females of F. intonsa were more susceptible to the fungi than males, while males of F. occidentalis and T. coloratus were more susceptible than females. Both males and females of T. hawaiiensis were highly susceptible to isolate KOG02. T. tabaci was highly susceptible to isolate KOG02, even by inoculation of the conidial suspension at a concentration of 1 × 106 conidia/ml. Although isolates AZA38 and GOM03 exhibited weaker pathogenicity to the five thrips species than did isolate KOG02, the gross mortality increased significantly with the inoculation of these two isolates as compared with the control.