Experiments on development of Amblyseius longispinosus Evans (Acari:Phytoseiidae) as influenced by castor pollen as an alternate food and its interaction with sorghum mite, Oligonychus indicus Hirst (Acari:Tetranychidae) were conducted under laboratory conditions. A. longispinosus showed poor growth on castor pollen. Female and male developmental periods were 2.6 +/- 0.30 and 2.42 +/- 0.21 days on spider mites, 2.70 +/- 0.89 and 2.68 +/- 0.39 days on spider mites + castor pollen and 5.12 +/- 2.03 and 3.89 +/- 1.80 days on castor pollen alone, respectively. At interaction A. longispinosus suppressed populations of O. indicus at 1:10, 1:20, 1:30, 1:40 and 1:50. Prey elimination was on 12th day in 1:10, 18th day in 1:20, 20th day in 1:30, 24th day in 1:40 and on 30th day in 1:50 ratio.
