Published online by Cambridge University Press: 27 October 2014
The tea (Camellia sinensis (L.) Kuntze) industry is the backbone of the agroeconomy of the North Bengal region located at the foothills of the Himalayas in North-East (NE) India. This region accounts for about 25% of the total tea production in India. The tea mosquito bug, Helopeltis theivora Waterhouse, is one of the most devastating sucking pests of tea in this region. Various kinds of synthetic insecticides are continuously sprayed to control this bug. The lynx spider Oxyopes javanus Thorell has been found to remain associated with tea plants and feed on H. theivora. The present study investigated the predation potential and efficacy of the O. javanus spider against one of its most common prey species, H. theivora. In the laboratory, with an increase in H. theivora density, the predation rate of both male and female O. javanus increased. Per capita predation rates exhibited by male and female O. javanus per day against adult H. theivora were 3.67 ± 1.52 and 11.67 ± 1.53 (mean ± standard deviation), respectively. At a reasonably small prey density, the prey consumption rate was highest, reaching up to 100%, indicating that the spider predator has the potential to eliminate smaller populations of the pest. The predation effectiveness calculated using Holling's disc equation was 6.08 and 356.58 for male and female O. javanus, respectively. The prey handling time was 0.138 day for male O. javanus and 0.012 day for female O. javanus. Female O. javanus exhibited about fivefold higher searching efficacy than male O. javanus. It appears that the conservation or augmentation of O. javanus in the tea ecosystem can provide effective biological management of the major tea pest, H. theivora, in sub-Himalayan foothills and plains of NE India.