A Locally Isolated Entomopathogenic Fungus to Control Tea Red Spider Mites (Oligonychus coffeae Acarina -Tetranychidae)

PGDS Amarasena, KM Mohotti, D Ahangama
2011 Tropical Agricultural Research  
Mites are considered as seasonal pests in tea. They cause significant damage to the crop during dry weather. However, the restrictions imposed by tea importers on pesticide residues in made tea pose an immediate need to identify alternative control methods for Propargite (a synthetic acaricide) and sulphur which are the current recommendations. The alternative methods should be effective, biological, safe and acceptable to the importers. Previous attempts have been made to screen predatory
more » ... reen predatory mites and entomopathogenic fungi against tea mites; however, local sources have not yet been investigated. The present study was conducted to explore the possibilities in biological control methods with specific objectives of isolating and preliminary screening of local entomopathogenic fungi against tea mites under laboratory conditions. In this study, naturally occurring fungal species from six different tea ecosystems reducing populations of tea red spider mites (Oligonychus coffeae) were isolated. The laboratory experiments conducted on mite-infested excised-leaves confirmed that the unidentified fungus coded as HF1 was significantly (p<0.05) effective in reducing mite populations. The Fungal isolate gave 65% mortality while the highest mortality of 75% was achieved by the TRI recommended acaricide, Propargite. Comparatively, H. thompsonii and neem seed extract exhibited lower mortality. This is the first record of isolation of entomopathogenic fungi from tea mites in Sri Lanka. The preliminary results foresee the potential of harnessing local entomopathogenic fungi in managing tea mites as an environmentally safe and effective treatment.
doi:10.4038/tar.v22i4.3789 fatcat:42a7h3lnrfajfkp4ah4x3ejkai