Principal components analyses (PCA) indicating caste differentiation and supporting caste classifications of female Halictus ligatus collected in nests and pan traps. The histograms are scree plots indicating the significance of the first three prinicipal components for each analysis. The scatterplots indicate the relationship between the first two principal components for each analysis. PCA for nest bees was based on head width, total wear, and ovarian development, while that for pan trap bees was based on head width, wing wear, and ovarian development. Note the greater separation among queens (Q), workers (W), and gynes (G) in the nest sample.