Abstract
The predatory mite, N. longispinosus preys up on red spider mite, O. coffeae infesting tea in south India. An attempt has been made to determine the predatory potential, prey stage preference and optimum predator–prey ratio of N. longispinosus under laboratory and green house conditions. When 50 adult female O. coffeae were given, the number of adults reduced by eight days along with an increase in the number of predators. The larvae hatched from the eggs laid by O. coffeae were fed by predatory mite. N. longispinosus preyed up on all life stages with a preference to larvae and nymphs of red spider mite. Predator–prey ratios of 1:33 and 1:50 were effective in lab, and 1:25 was found to be effective in green house. These results revealed that N. longispinosus could be used as a successful biocontrol candidate of O. coffeae in tea through augmentation or mass rearing and field release.
Acknowledgements
The authors thank Dr. K. Ramaraju, Tamil Nadu Agricultural University, Coimbatore and Dr. Mary Anithalatha Sadanandan, Malabar Christian College, Calicut for confirming the identity of the predatory mite. The authors are grateful to Dr. P. Mohan Kumar, Director, UPASI Tea Research Foundation for his incessant encouragement. The financial support for this work was provided by Tea Board, Ministry of Commerce, Govt. of India under XI five year plan.