PROSPECTS OF BIOLOGICAL CONTROL OF THE COCOA MIRID, SAHLBERGELLA SINGULARIS Sahl (HETEROPTERA) IN GHANA: FIELD SURVEYS FOR ENTOMOPATHOGENS AND LABORATORY BIOASSAYS WITH BEAUVERIA BASSIANA ISOLATES.

摘要

Distantiella theobroma (Dist) is the most important species of minds attacking cocoa in Ghana. Its control has mainly relied on the application of synthetic insecticides. Because of the hazards, cost and the resultant low adoption rate of research recommendations associated with such chemicals, the Cocoa Research Institute of Ghana continues to search for more cost effective and environmentally benign alternative means of managing the mirid menace in Ghana. Surveys were conducted for two mirid seasons; in all the six cocoa growing regions of Ghana for pathogens of S. singularis and species of Fusarium, Aspergillus, Nomuraea and Ascheinrsonia were isolated. Then followed four bioassays with five isolates of Beauvaria bassiana to assess their biological effect on S. singularis. The results indicated great potentials for the fungus as a biological control agent. Isolate 197 1035 was the most promising, followed by 197 1036, I Ml 335249, 100 1183 and 197 1037. Details of the results are discussed.