Figure 1: Host preference of individual B. treatae gall wasps expressed for each of three Q. virginiana and three Q. geminata host-associated populations during choice tests that paired each wasp’s native/natal host with the alternative oak species. Illustrated is the mean (±SE) of the proportion of time spent on the native host plant by each sex within each population. The dashed line highlights no preference (defined as 50% of time spent on each host). Note each population differed significantly from 50% ( ). Numbers above the SEs are the number of replicates. Note the reversed left and right -axis.