Application Frequency of Beauvaria bassiana Isolates Against Antestia Bugs (Antetiopsis intircata: Pentatomidea, Hemimptera) Management

Abstract

The production and productivity of coffee is affected by many insect pests and Ethiopian farmers get below 0.636 tons per hectare. Among insect pests Antestia bug is the major coffee insect pest affecting coffee productions. Therefore, the study was carried out to determine the frequency of promised Entomopathogenic fungi isolates against antestia bug. The experiment was done in Jimma Agricultural Research Center, Entomology and Pathology laboratories. Used entomopathogenic fungi isolates were brought from Ambo Agricultural Research Center. Two isolates of Beauvaria bassiana, PPRC-44BC and PPRC-27J isolates applied at 1x108 conidia ml-1 and three times were used for the experiment. Completely randomized design with three replications and probit analysis were used for data analysis by using SAS software version 9.3. PPRC-44BC and PPRC-27J isolates killed all the tested Antestia bugs in exposure time. The isolates applied three times reduced median lethal time by 42.13 and 38.89%, respectively as compared to with their respective one time application. The correlation result also showed that there was strong negative correlation between application frequency of isolates and median lethal times (LT50 and LT90 were r=-0.811 and r=-0.714, respectively). The study indicated that the more frequently applied isolates the shorter the median lethal time. This showed promising result in the microbials based insect pest management methods and need further investigations under field conditions and the effect of these isolates against natural enemies of the pest.