Leaf size selection by four species of leaf-mining insects on their host plant, Quercus emoryi, was studied in central Arizona, USA. Two species (Stigmella sp. and Tischeria sp.) that produced small mines also selected small leaves. One species, Stilbosis juvantis, which has an intermediate-sized mine, did not select larger or smaller leaves than the average leaf size available. Only one species, Cameraria sp. nov., showed a relationship between its survivorship and leaf size; it selected large leaves and experienced greater survivorship on large leaves. Survivorship of the other species was not related to leaf size.