Apple cultivars investigated as new hosts for two-spotted spider mite, Tetranychus urticae Koch appeared to provide good environment for its development and reproduction. The best conditions for two-spotted spider mite development were on leaves of cultivars Novamac and Freedom with a net reproduction (R_o) 22.6 and 20.3 respectively, while the worst on cultivars Pioner and Primula with R_o 8.9 and 10.2 ,respectively.

Evaluation offruits and leaves ofseventeen apple cultivars in respect of their attraction as food for caterpillars of leafroller species occurring in an experimental apple orchard was carried out over 1995 to 1998 in the Institute of Pomology and Floriculture at Skierniewice. The highest levels ofinjuries were observed on two cultivars: ‘Ligol’ and ‘Elstar’. High number ofinjured fruits was noted on the following cultivars: ‘Gala’, ‘Jonagold’, ‘Cortland’, ‘Idared’, ‘Lodel’ and ‘Szampion’. By far the number of injured fruits was lower on ‘Lobo’ and ‘Jonathan’, and the least on ‘Rubinette’, ‘Starkrimson’ and ‘Gloster’. Significant differences in the number of caterpillars settled down in leaf/flower clusters ofparticular cultivars during the vernal period were also confirmed. In each season the highest number ofcaterpillars of Pandemis heparana and Archips rosana were observed on leaves of‘Alwa’. To cultivars whose leaves were also readily settled down by the two aforementioned species were: ‘Jonathan’, ‘Cortland’, ‘Ligol’, ‘Lobo’, ‘Jonagold’ and ‘Elstar’. Relatively less caterpillars were observed on leaves of‘Arlet’, ‘Gloster’, ‘Szampion’, ‘Starkrimson’, ‘Pilot’, ‘Pinowa’ and ‘Rubinette’.