POPULATION TRENDS AND BEHAVIOR OF THE PEAR RUST MITE, EPITRIMERUS-PYRI (PROSTIGMATA, ERIOPHYOIDEA), ON PEARS IN NOVA-SCOTIA

The pear rust mite, Epitrimerus pyri (Nal.), overwinters in a semi-active state in old leaf scar crevices and under bud chips of the leaf clusters. It becomes active within the bud in mid-April, as soon as the weather warms, and passes through three generations in the growing season as indicated by distinct peak egg populations observed in May, June, and July. The first generation eggs are laid within the swelling bud. The mites feed on the ventral surface of the leaves causing bronzing and on the calyx end of the fruit resulting in russeting of the epidermal tissue. Deutogynes of the third generation begin to enter hibernation by mid-August. Occasionally population levels reach economic injury level resulting in the downgrading of fruit. © 1979, Entomological Society of Canada. All rights reserved.