In pest insect biology, the resource concentration hypothesis considers how suitability and availability of host plants are involved in pest population dynamics. Limiting the spread and buildup of pest species using resistant host plants can be an important pest management strategy. Incidence of frosted and grapevine scales at regional and vineyard scales may vary as a result of grapevine variety effect. Two main effects can be distinguished. First, grapevine varieties provide a habitat of variable quality for pests and beneficial organisms. Second, grapevine varieties respond differently to insect feeding depending on pest population. Using field and glasshouse studies the effect of grapevine varieties on scale population was investigated. My work demonstrated that grapevines affected scale population growth differently and that environment played a role in scale responses.