Pandian Kumar¹ , Chandran Sundaravadivelan¹ , Duraikkannu Vasantha Kumar¹ , Azariah Babu²

1 Entomology Division, UPASI Tea Research Foundation, Tea Research Institute, Nirar Dam BPO, Valparai 642 127, Tamil Nadu, India
2 Tea Research Association, North Bengal Regional R&D Centre, Nagrakata 735 225, West Bengal, India
Author    Correspondence author
Journal of Tea Science Research, 2016, Vol. 6, No. 10   doi: 10.5376/jtsr.2016.06.0010
Received: 29 Nov., 2016    Accepted: 29 Nov., 2016    Published: 27 Dec., 2016

Kumar P., Sundaravadivelan C., Vasantha Kumar D., and Babu A., 2016, Enhanced acaricidal activity of Senna auriculata and Ocimum tenuiflorum extracts with the addition of adjuvant against red spider mite, Oligonychus coffeae nietner (Acarina : Tetranychidae) infesting tea, Journal of Tea Science Research, 6(10): 1-10 (doi: 10.5376/jtsr.2016.06.0010)

Tea (Camellia sinensis) is one of the most consumed non-alcoholic beverages in the world and has been affected by many pests which damage its quality and production globally. In this paper an attempt has been made to evaluate the aqueous leaf extracts of Senna auriculata and Ocimum tenuiflorum with and without adjuvant for their effect on red spider mite (RSM), Oligonychus coffeae (Nietner) infesting tea. Resulting, Senna auriculata, leaf extracts with adjuvant caused 90 % (LC₅₀:1.21 and LC₉₀:2.33 %) mortality which was greater compared to Ocimum tenuiflorum whereas 73 % (LC₅₀:1.40 and LC₉₀:2.81 %) was observed at 5 % concentration after 24 h exposure and very lowest mortality percent were observed both extracts without adjuvant. Ocimum tenuiflorum leaf extracts with adjuvant (0.05 %) showed highest ovicidal activity and effective ovipositional deterrence compared with S. auriculata treatment. The evaluated plant extracts with adjuvant are effective for controlling RSM and it could be an alternative, easily accessible, and eco-friendly approach for control of mite infesting tea.

Senna auriculata; Ocimum tenuiflorum; Plant extracts; Adjuvant; Red spider mite