author(s)
Premalatha K, Nelson SJ, Vishnupriya R, Balakrishnan S and Santhana Krishnan VP

abstract
The acaricidal activity of aqueous extract of 20 plant species at 10 percent concentration on red spider mite, Tetranychus urticae Koch was evaluated under laboratory condition by using the leaf disc method. Among the plants, the aqueous extract of Sesbania grandiflora caused highest mortality of 94.43 percent of T. urticae at 72 hours after treatment (HAT) which was statistically superior to all other treatments. Next to S. grandiflora, Tagetes tenuifolia (85.57%), Artemisia pallens (78.90%), Cantharanthus roseus (77.77%), Delonix regia (76.67%), Cassia alata (74.43%), Tephrosia purpurea (74.43%) and Centella asiatica (74.43%) exhibited statistically similar acaricidal activity on T. urticae. Further, the aqueous extract of Jatropha curcas, Leucaena leucocephala, Senna auriculata, Cassia fistula and Anacardium occidentale caused more than 50 percent mortality of T. urticae. Moderate acaricidal action was noticed in S. aspera (46.67%)> A. paniculata (42.23%)> A. squamosa (40.00%)> T. procumbans (36.67%)> A. cantharitica (35.57%).