Investigations on Sporothrix fungorum De Hoog&de Vries, a Newly Recorded Pathogen of Aceria guerreronis Keifer, the Coconut Eriophyid Mite

Abstract

The hyphomycetous fungus, Sporothrix fungorum de Hoog&de Vries was discovered affecting the coconut eriophyid mite, Aceria gllerreronis Keifer in Karnataka and Tamil Nadu in India during 1999-2000 in up to 15 per cent of coconut samples. At 2xlOs, 2xl0· and 2xl07 conidia per ml the fungus could bring' about 47.03, 92.75 and 98.29 per cent mortalities, respectively, 96h after inoculation. It was able to grow and conidiate profusely on potato dextrose agar (PDA) as well as Sabouraud dextrose agar (SDA). The diameter of the colony increased significantly between 10 and 21 days of inoculation in both the media, reaching up to 35.83 and 36.00 mm on PDA and SDA, respectively. Among three different liquid media, viz., potato dextrose broth (PDB), Sabouraud dextrose broth (SDB) and an enrichment medium (EM), EM was the best in terms of wet and dry weights (per 100 ml) as well as conidia production in both stationary (6450.3 mg, 1602.3 mg and 71.7 x 106 / ml) and shake cultures (13416.7 mg, 3402.7 mg and 83.0 x 107 / mI). The present report gives new details about S. fungorum as well as its association with the coconut mite.