Biology and Demographic Parameters of European Red Mite, Panonychus ulmi Koch (Acari: Tetranychidae) on Mulberry in Kashmir Valley, India

Life history traits of Panonychus ulmi on mulberry (Morus multicaulis) determined under ambient conditions; the temperature and relative humidity were same as that in natural conditions in three seasons of 2012. Developmental time from egg to adult for female and male varied from 12.66-23.24 and 10.62-18.65 days, respectively. Total and daily egg production was highest during summer (34.00 and 4.68 eggs, respectively) followed by spring (27.33 and 3.60 eggs) and lowest during autumn (17.80 and 1.87 eggs). Panonychus ulmi completed its life span in 19.07 and 21.76 days for male and female, respectively during summer and took more than one and half times during autumn. All parameters were intermediate during spring compared to highest during summer and least during winter. Intrinsic rate of natural increase (rm) were 0.091, 0.147 and 0.051 dayG1 during spring, summer and autumn seasons, respectively. Mean generation time (To) of the population ranged from 18.01 days during summer to 30.80 days during autumn. Based on the observed demographic parameters during three seasons, it is concluded that the summer season with average temperature of 25.72°C is highly favorable for development of P. ulmi.