STUDIES ON INSECT PEST COMPLEX OF WATERMELON Citrullus lanatus (Thunb.) AND THEIR MANAGEMENT
Loading...
Date
19-08-08
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of Agricultural Sciences, Bangalore
Abstract
The present investigation on insect pests of watermelon, Citrullus lanatus (T.) and their management carried out under field conditions revealed that the major insect pests observed during cropping period were leaf miner, Liriomyza trifolii (Burgess); thrips, Thrips palmi (Karny); whitefly, Bemisia tabaci (Gennadius) and fruit fly, Zeugodacus cucurbitae (Coquillett) with mean populations of 3.89±1.88, 9.71±6.25, 3.67±2.77 and 4.91±5.92 respectively. These insect pests prevailed throughout the cropping period, while, red pumpkin beetle, Raphidopalpa foveicollis (Lucas) and leaf eating caterpillar, Diaphania indica (Saunders) were recorded as minor defoliators with mean populations of 0.29±0.34 and 0.27±0.31, respectively. Management of major insect pests with insecticides showed that cyantraniliprole 10.26 % OD was found to be superior over other insecticides against L. trifolii and B. cucurbitae with 79.78 and 48.68 per cent reduction over control respectively. Thiamethoxam 25 % WG was effective against B. tabaci with 87.07 per cent reduction over control. While, two sprays of fipronil 5 % SC was most effective against T. palmi with 76.18 and 76.89 per cent reduction over control during first and second sprays, respectively. Influence of usage of insecticides on natural enemies (spiders, coccinellids) and pollinators (Honey bees) were recorded. The results revealed that Spinosad 45 % SC
was the safest insecticide to natural enemies and pollinators compared to all the other insecticidal treatments. Crop sprayed with cyantraniliprole 10.26 % OD recorded highest fruit yield among different insecticidal treatments with 51.83 t/ha. Whereas, the highest B:C ratio was found in fipronil 5 % SC with 3.39.