Biocontrol potential of a new strain of Isaria fumosorosea

Authors: WU, SHAOBUI - University Of Georgia; TOEWS, MICHAEL - University Of Georgia; Shapiro Ilan, David; Castrillo, Louela; BARMAN, APURBA - University Of Georgia

Submitted to: Entomological Society of America, Southwestern and Southeastern Branch
Publication Type: Abstract Only
Publication Acceptance Date: 3/3/2019
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: A new strain of the entomopathogenic fungus Isaria fumosorosea was found naturally infecting silverleaf whiteflies, Bemisia tabaci (biotype B), in the commercial cotton fields in Georgia. The fungus was isolated, identified, and tested for comparative virulence against three commercial strains of entomopathogenic fungi. In a bioassay against yellow mealworm Tenebrio molitor, the virulence of the new strain was not significantly different from the commercial strain of I. fumosorosea (Apopka strain 97) and had similar LC50 values. Further, the virulence of the new strain was compared with commercial strains of I. fumosorosea, Beauveria bassiana (GHA strain), and Metarhizium brunneum (F52 strain) against 4th instar immatures of B. tabaci in the laboratory. Moreover, the naturally occurring epizootiology of the new fungal strain was monitored in both immature and adult whiteflies in a commercial cotton field over time and space. Soil samples were taken from six sites with the highest occurring incidence to determine the presence of the fungus in soil. Cotton plants from those sites were examined for the fungal presence as endophytes in leaves, stems, and roots. Fungi growing out of the plants were isolated, tested for insect pathogenicity, and identified.