SUSCEPTIBILITY OF THE PARASITOID CEPHALON DMIA-STEPHENODERIS TO BEAUVARIA-BASSIANA AND METARHIZIUM-ANISOPLATE STRAINS

Laboratory bioassays at 27 +/- 2 degrees C, 90 +/- 5% RH and 12:12 h L :D were used to determine the susceptibility of Cephalonomia stephanod eris Betrem (Hymenoptera: Bethylidae), a parasitoid of the coffee berr y borer Hypothenemus hampei, to 9 strains of the entomopathogenic fung us Beauveria bassiana and 5 strains of Metarhizium anisopliae (Metsch. ) Sorokin. The most virulent strains of B. bassiana were from Ecuador (code named Bb-4) and two from Mexico (Bb-26 and Bb-17) with Cl-50's o f 5.3 x 10(6), 21.9 x 10(6) and 29.3 x 10(6) conidia/ml respectively. Three aggressive strains of M. anisopliae were identified (code named Ma5, Ma23 and Ma4) with CL50 values of 5.4 x 10(7), 7.6 x 10(7) and 10 .6 x 10(7) conidia/ml respectively. Lethal time (LT50) tests with B. b assiana showed a range of values between 3.8 and 6.8 days with a mean of 5.3 days. LT50 values in M. anisopliae ranged from 4.4 to 7.2 days with a mean of 5.8 days. The highest incidence of sporulation of B. ba ssiana on parasitoid cadavers was observed in strains Bb-4 (Ecuador), Bb-17 and Bb26 (Mexico) all with values of 90%. In the case of M. anis opliae, the highest incidence of sporulation on insects was observed i n strains Ma5 (84.3%), Ma4 (71.6%) and Ma23 (62.7%).