SRINIVASA, N.POOJA2020-05-142020-05-142019-08-16Th-12363http://krishikosh.egranth.ac.in/handle/1/5810146029DNA barcode data generated for Tetranychus okinawanus, T.truncatus and T.udaipurensis are complimentary to conventional morphological identification. Development and demography of three emerging spider mite pests were studied on host plants, Amaranth, Maize, Ridge gourd and French bean at four different constant temperature (22º-34ºC) and humidity conditions (67-80%). Development of T.okinawanus, T.truncatus and T.udaipurensis female was faster (6.16 days on Amaranth and 6.56 on Ridge gourd; 6.67 days on Amaranth and 6.91 on Maize; 7.31 days on French bean and 7.42 days on Ridge gourd, respectively) at the higher temperature of 34ºC. Effective Temperature Threshold and Thermal Constant for the corresponding mite species on their more preferred host plant were, 13.92ºC; 122.22 degree days, 14.39ºC; 116.67 dd and 10.28ºC; 155.65 dd. For reproduction (female longevity, fecundity & sex ratio) and demography of mite species, the favourable temperature range was 26º-30ºC. Chief demographic parameters viz., Mean Generation Time, Doubling Time, Net Reproduction Rate and Intrinsic rate of Natural Increase of different mite species on the preferred host plant were: T.okinawanus ex. Amaranth -19 to 25 days, 3.14 to 3.94 days, 63 to 84 females and 0.180 to 0.229 females/day; T.truncatus ex. Amaranth–15 to 27 days, 2.9 to 4.5 days, 42 to 64 females and 0.160 to 0.268 females/day; T.udaipurensis ex. French bean-16 to 20 days, 2.98 to 3.80 days, 42 to 48 days and 0.200 to 0.248 females/day, respectively. In the event of changing climatic conditions, T.okinawanus & T.truncatus on Amaranth and T.udaipurensis on French bean might emerge as potential pests.enThesis