Abstract:
The yellow sugarcane aphid, Sipha flava (Homoptera: Aphididae) is a major insect pest of
sugarcane in Eswatini. Insecticides are used to prevent honeydew build up and yield loss before
harvest but they are not preferred due to resistance problems, disruptive effects on natural control
of other sugarcane pests, pesticide residue and high production costs. The use of the
entomopathogenic fungi as a biocontrol agent of sugarcane aphid is an environmentally friendly
management tactic. The current study evaluated the mortality effects of four concentrations
[Control, 1.25 g/L (2.5×106 spores/ml), 2.5 g/L (5×106
spores/ml) and 5g/L (1×107
spores/ml)] of
commercially available Beauveria bassiana (Eco-Bb®
) strain R444 on adult yellow sugarcane
aphids in laboratory and leaf bioassays. The application of 5g/L (1×107
spores/ml) of B. bassiana
resulted in mortality that was not significantly different from 2.5g/L (5×106
spores/ml) but was
significantly (P<0.05) different to 1.25g/L (2.5×106
spores/ml) and the control in the laboratory
bioassay. The application of 5g/L (1×107
spores/ml) of B. bassiana resulted in mortality that was
significantly (P<0.05) higher from all the other concentrations in the leaf bioassay. The higher
concentration of the fungus can be recommended to control S. flava. However, large-scale field
trials and combining B. bassiana with other biocontrol agents is recommended to demonstrate
the potential use of the biocontrol agent within an integrated pest management program.
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