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The coffee berry borer Hipothenemus hampei (Ferrari) is the most serious insect pest of the coffee plantations. Among the biological con­trol methods the fungus Beauveria bassiana (Bals.) Vuill. may play an important role in borer population reduction. In this research, a bioassay method was standardized to test the pathoge­nicity of B. bassiana on H. hampel. Adults of the borer were obtained from a laboratory mass rearing using parchment coffee at 45% R.H. The borers were disinfected with sodium hy­pochlorite at 0,5% for 10 minutes and rinsing the excess in three washes with sterile distilled water. The experiment was organized in a complete randomized design using three treatments formed by isolate Cenicafe Bb-9205 from Diatraea saccharalis (Bb-9205 DS), the same isolate passed through the borer (Bb­9205 BFC) and a control. Thirty adults of the borer were used per replication. These insects were exposed to the fungus using a concentra­tion of 1 x 107 conidia/ml for two minutes and then transferred individually in glass vials (4 ccs of capacity) with a piece of wet paper inside and capped with absorbent cotton. Twenty-four hours later a berry of waxed-parchment coffee with 45% of humidity was added as a substrate. Infected insects showed reduced activity, loss of legs and antennae, and therefore inability to bore the coffee grain. Treated insects with the fungus resulted in lower grain attack (14.44%) compared with control insects (44.44%). There were significant differences (130.05) among treatments, average mortality was 88.88% for isolate Bb-9205 DS and 100% for Bb-9205 BFC. Mean lethal time (TL50) was 92.4 hours with isolate Bb-9205 DS and 54.72 hours with Bb-9205 BFC. Five stages of development of B. bassiana on H. hampei were recognized: inoculation to death, death to initial mycelial growth, death to mycelial c3verage, death to conidiogenesis, and death to discharge of conidia. These stages lasted 20.16; 31.92; 56.40; 83.28 and 198 hours for Bb-9205 DS and 20.88; 44.40: 66.88; 116 and 182 hours for Bb-920r BFC. This bioassay can be used as a model to evaluate different entomopathogens to be tested against H. hampei.

GONZÁLEZ-G., M. T., POSADA-F., F. J., & BUSTILLO-P., A. E. (1993). BIOESSAY TO TEST THE PATHOGENICITY OF Beauveria bassiana (Bals.) Vuill. ON THE COFFEE BERRY BORER Hypothenemus hampei (Ferrari). Revista Colombiana De Entomología, 19(4), 123–130. https://doi.org/10.25100/socolen.v19i4.10068
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