The Efficacy of Entomopathogenic Fungi for Antestia Bugs (<i>Antetiopsis intircata</i>: Pentatomidea, Hemimptera) Control

Abstract

Antestia bug (<i>Antestiopsis intricata</i>) is the major coffee insect pest affecting coffee productions in Ethiopia. Therefore, the study was carried out to evaluate entomopathogenic fungi based management options for antestia bug control. The efficacy test of entomopathogenic fungi was done under laboratory condition in Jimma Agricultural Research Center, Entomology and Pathology laboratories. The entomopathogenic fungi isolates were brought from Haramaya University and Ambo Agricultural Research Center. Seven isolates of <i>Beauvaria bassiana</i> (DLCO-12, APPRC-0247, DLCO-90, DLCO-56, DLCO-76, PPRC-44BC, and PPRC-27J) and four isolates of <i>Metarhizium ansopliae</i> (PPRC-51, DLCO23A, DLCO-91 and PPRC-02BC) species were tested for germination. Completely Randomized Design with three replications and probit analysis were used for data analysis by using SAS, GenStat and Microsoft excel. Eight isolates: APPRC 0247, DLCO 90, DLCO 56, DLCO 76, PPRC-44BC, PPRC-27J, PPRC-51 and PPRC-02BC which recorded higher germination were used for pathogenicity test against antestia bugs. All the tested isolates killed antestia bugs but their levels of efficacy differ across exposure time. Among tested isolates, PPRC-44BC and PPRC-27J registered complete mortality against antestia bugs and lower median lethal time, LT₅₀ (9.98 and 10.98 days, respectively). As a result these were taken as promising isolates and used for further isolates rate test. PPRC-44BC and PPRC-27J isolates applied at 1x10⁸ conidia ml^-1 killed all the tested antestia bugs in shorter exposure time. Even though PPRC-44BC and PPRC-27J isolates showed promising results under laboratory conditions, it needs further investigations on its formulation and under field conditions. Isolations of biocontrols from natural coffee growing areas and the effect of biocontrols against natural enemies should be studied.