Journal of Pest Science (2010) 83, 371-377

Somnath Roy, Ananda Mukhopadhyay and Guruswami Gurusubramanian (2010)
Field efficacy of a biopesticide prepared from Clerodendrum viscosum Vent. (Verbenaceae) against two major tea pests in the sub Himalayan tea plantation of North Bengal, India
Journal of Pest Science 83 (4), 371-377
Abstract: The toxicity of four concentrations (1, 5, 10 and 20% w/v) of an aqueous extract from the weed, Clerodendrum viscosum Ventenat (Verbenaceae) was investigated under field conditions of the North Bengal University, Darjeeling, West Bengal, India for managing two major pests of tea, Camellia sinensis (L), namely the tea mosquito bug, Helopeltis theivora Waterhouse, (Heteroptera: Miridae) and the tea red spider mite, Oligonychus coffeae Nietner, (Acarina: Tetranychidae). Four field trials, two for red spider mite and two for tea mosquito bug, were conducted during April-May 2008 and October-November 2009 following a Randomized Block design. The aqueous extract of C. viscosum effectively and significantly reduced the mite population as well as infestation of tea mosquito bug by 68-95% and 73-86%, respectively, and their bioefficacy is comparable to synthetic and neem pesticides. No phytotoxic effect (score 0-5% and grade 1) was observed in the tea bushes sprayed with different doses of aqueous extract of C. viscosum in the field. Made tea samples were taint free. Organoleptic test revealed leaf-infusions and liquor strength as good, scoring 6.5-7.0 on a 10 point scale. Availability and distribution of this weed (C. viscosum) in and around tea-growing areas of sub Himalayan region, along with its processing for the feasibility of including C. visosum extracts in the current IPM programme is discussed.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website

Research topic(s) for pests/diseases/weeds:
control - general

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Oligonychus coffeae	Tea (Camellia sinensis)	India
	Helopeltis theivora	Tea (Camellia sinensis)	India