Abstract
The heritability of a trait determines whether selection will lead to a change in that trait. Heritability can be measured through breeding designs where the parents are known and the trait is measured on offspring of known relatedness, such as full siblings and half siblings. During range expansion, individuals at the edge are predicted to evolve higher fecundity and greater dispersal ability than core individuals. In insects, both of these are correlated with larger body size. These data were collected to investigate the genetic variation available for evolution of body size of a beetle introduced to North America for biological control (Diorhabda carinulata). The data consist of measurements of body mass and thorax width of full sibling and half sibling families of D. carinulata from one population at the origin of the range expansion.