Laboratory evaluation of the impact of entomopathogenic fungi on Prorops nasuta (Hymenoptera : Bethylidae), a parasitoid of the coffee berry borer

The entomopathogenic fungi Metarhizium anisopliae (Metschnikoff) Sorokin an d Beauveria bassiana (Balsamo) Vuillemin and the bethylid parasitoid Prorop s nasuta Waterston are natural enemies of the coffee berry borer, Hypothene mus hampei (Ferrari), and are considered valuable biocontrol agents in the coffee-growing regions of Central and South America. Laboratory evaluations were made on the impact of three isolates of each fungus on adult P, nasut a. These isolates were selected because of their high virulence toward H, h ampei in previous studies. B, bassiana isolate Bb25 and M. anisopliae isola te Ma4 caused the lowest infection levels in P. nasuta with LC50 values of 8.31 x 10(6) and 4.08 X 10(6) spores per milliliter, respectively, Ly direc t inoculation. Spore suspensions of each of these isolates were applied to coffee berry borer infested coffee berries. P. nasuta adult females were al lowed to search and parasitize hosts within the treated berries. Despite th e high virulence of these fungi to P. nasuta, neither pathogen significantl y affected the predatory or parasitic capacity of P, nasuta, indicating tha t these isolates may he compatible with the action of the parasitoid under field conditions provided that pathogen applications and parasitoid liberat ions are timed not to coincide.