Occurrence of fungi and other microorganisms in association with the coconut eriophyid mite, Aceria guerreronis, in Kerala.

The occurrence of Hirsutella thompsonii , the mite specific pathogen was confirmed and it was isolated from ten out of the twelve locations surveyed in Thrissur district of Kerala. Apart from the mite-specific pathogen, Hirsutella spp., other fungal pathogens such as Fusarium spp., Acremonium spp. and Paecilomyces spp. were isolated from the eriophyid mite infested coconut samples in the surveys conducted in Thrissur district, Kerala, during the period from July 2003 to June 2004. Natural occurrence of H. thompsonii contributed to 4.93 per cent. Acarifungal pathogens belonging to the genera Hirsutella, Fusarium, Acremonium and Paecilomyces were mostly isolated during the monsoon season and the actinomycetes during summer period in the entire four panchayaths. Pathogenicity to coconut eriophyid mite was proved for two species of Hirsutella, H. thompsonii and H. kirchnerii . The other non-specific fungi found to be pathogenic to mites were Acremonium strictum, A. incoloratum, Fusarium lateritium, F. verticillioides, Paecilomyces fumosoroseus and P. lilacinus . The wide spectrum of fungal pathogens associated with A. guerreronis indicates the significant role played by them in the natural suppression of the pest.