Diversity and Seasonal Variation in population of a Phytophagous and Predatory Mites associated with Apple trees in District Kullu (H.P.)

Studies on population dynamics of some mites found associated with apple plants were conducted in orchards located at Nirmand (1450 m) in Kullu area. Panonychus ulmi Koch, a phytophagous mite and Amblyseius (Euseios) pruni Gupta, a predatory mite were investigated during March, 2005 to February, 2006 in the leaf samples collected from Nirmand area of Kullu hills. Studies on seasonal variations in population dynamics of Panonychus ulmi and Amblyseius (Euseius) pruni revealed that both these species appeared in the month of March on apple crop. Thereafter, their population started increasing till it attained a maximum during the month of June (27.83% and 26.93% respectively). Afterwards, there was a considerable decline till the month of August. A minor peak was again observed during the month of September (0.71% and 0.43% respectively) and then there was a constant decline in population of both Panonychus ulmi and Amblyseius (Euseius) pruni till December (0.71% and 0.43% respectively) and afterwards no infestation was observed. These variations in mite populations may be due to the fluctuations in temperature, relative humidity and sunshine hours.