Reduced growth and deterrence from feeding of the insect pest Helicoverpa armigera associated with fungal endophytes from cotton

More than 13 morphospecies of fungal endophyte were isolated from leaves of cotton collected from eastern New South Wales, Australia. Of the fungi tested, methanol extracts of 4 morphospecies offered with a food source reduced the larval growth rate of the insect pest Helicoverpa armigera. Extracts of different isolates of 1 common morphospecies had varying effects on growth rates of H. armigera and H. punctigera. The impact of the endophytes after inoculation to leaves of cotton also differed. Five of 10 selected isolates were associated with reduced feeding from leaf discs in a feeding-choice experiment with H. armigera. The data are consistent with the view that some fungal endophytes benefit their host through reduced herbivory of the plant.