Effect of the Fungus Isaria fumosorosea Wize on Herbivory by Adult Yellowmargined Leaf Beetles, Microtheca ochroloma Stal (Coleoptera: Chrysomelidae)

Abstract

The yellowmargined leaf beetle, Microtheca ochroloma Stål (Coleoptera: Chrysomelidae), is a pest that causes economic losses in the production of crucifers (Brassicaceae) in Argentina and the southeastern USA. Biological control using the entomopathogenic fungus Isaria fumosorosea Wize (Hypocreales: Cordycipitaceae) is an option for suppressing pest populations. This study evaluated the effect of this fungus on herbivory by adult beetles when they were fed leaves treated with I. fumosorosea. Four concentrations (0.1, 0.5, 1.0, and 2.0 g) of the formulation PFR-97 20% WDG Apopka strain 97 per 100 ml of distilled water and a distilled water only control were evaluated. Two trials each with 10 bok choy plants per treatment were performed, and each plant was infested with six adult beetles. On the seventh day, leaf area consumed by the beetles was measured. In the first trial, plants applied with 1.0 and 2.0 g/100 ml suffered significantly less damage than the control. In the second trial, there was a significant difference between the control and concentration of 2.0 g/100 ml. The control had 3.7 and 2.0% more damage compared to the other treatments in the first and second trials, respectively.

Ceiba, 2016. Volumen 54(2):118-126