BIOECOLOGY AND MANAGEMENT OF RED SPIDER MITE INFESTING TEA

摘要

The red spider mite (RSM), Oligonychus coffeae (Nietner) (Tetranychidae: Acarina) is an important pest of tea in south India, Studies were carried out on the life history, seasonal abundance, crop loss, natural enemies and on different control strategies, Life stages of red spider mite include egg, six legged larva and eight legged protonymph, deutonymph and adult. The time required for development from egg to adult is 10-14 days. Population density of red spider mite was high during January to May and low during June to December and reached a peak in March/April. Low temperature, high relative humidity and rainfall adversely affected the populations. Attempts were made to assess the loss in crop due to RSM infestation. The study revealed that the mite can cause more than 18 % loss in crop when the infestation is severe. The entomopathogenic fungus, Paecilomyces fumosoroseus was evaluated for its efficacy against the red spider mite in the lab and field with encouraging results. Another pathogen, Bacillus sp. isolated from red spider mite was also evaluated and recorded significant reduction in the mite population, Surveys revealed the presence of four important predators, Oligofa pygmaea, Stethorus gilvifrons, Chrysopa madestes and Mallada boninensis and found that these predators are playing an important role in the natural regulation of red spider mites, Field studies on the new herbal product and paraffinic spray oil showed a significant reduction in the number of RSM. Similarly, lime sulphur was also found very useful in controlling red spider mite population. Spraying of propargite, fenpropathrin, fenazaquin, flufenzine, bifenthrin, fenpyroximate, spiromesifen and hexythiazox have given satisfactory control of red spider mites and found to have prolonged efficacy. An integrated strategy involving biological, agronomic and chemical methods is recommended for the management of red spider mites.