The European red mite, Panonychus ulmi (Koch), has assumed the status of major pest in recent years in Himachal Pradesh, India. It is essential that a fresh approach to mite control be undertaken especially by studying its population fluctuation in relation to host plant nutrition. The effect of three levels of N, P, and K, each at the recommended dose (N1, P1, K1), 25% above (N2, P2, K2) and 25% below the recommended dose (N3, P3, K3), plus the untreated control (N0P0K0) was studied on the build-up of P. ulmi populations on potted apple cultivars `Delicious΄ at RHRS, Mashobra, Shimla (2,286 m above sea level). Among ten combinations of NxPxKx, the lowest mite population was recorded at N3P2K2 (i.e., 25% less than recommended N and 25% more than recommended P and K), with 21.9 adults, 29.2 immatures, and 103.2 eggs/leaf. In the control treatment (N0P0K0), 40.0 adults, 44.3 immatures, and 166.3 eggs were obtained. Treatment combination N2P3K3 supported the largest population of 74.8 adults, 91.8 immatures, and 320.9 eggs/Fleaf, significantly different from the other treatments. These results suggested that slight manipulation in the recommended doses of NPK fertilizers can contribute substantially to controlling the abundance of P. ulmi population on apple trees. [ABSTRACT FROM AUTHOR]