Influence of abiotic stresses on population dynamics of two spotted spider mite (Tetranychus urticae Koch) in Cucumber ecosystem

Population dynamics of Tetranychus urticae, a two spotted spider mite, was studied in cucumber ecosystem (Cucumis sativus) T. urticae showed a peak in population during second week of August, 2011 (3.17, 4.71 and 1.48 mites/cm² leaf and 16.15, 17.80 & 6.86 mites/cm² leaf) and last week of May, 2012 (3.80, 6.21 & 7.17 mites/cm² leaf and 9.36, 16.33 & 11.6 mites/cm² leaf) from adaxial and abaxial surface of tender, grown up and older leaves, respectively. Stage wise, grown up leaves harboured more number of mites followed by tender and older leaves. Among abiotic factors, maximum and minimum temperatures, wind speed and rainfall were significantly positively correlated with the population build up of T. urticae while relative humidity showed a significant negative correlation. Sunshine, however, did not show any significant relationship with the oscillating mite population.