Discriminant functions useful for sexing Anelaphus villosus (Coleoptera: Cerambycidae) do not work for A. parallelus

Beetles of the genus Anelaphus (Coleoptera: Cerambycidae: Cerambycinae) are commonly dull or dark-colored. Generally, males in this family possess relatively longer antennae, larger heads, narrower elytra, and the abdomen is smaller and less robust. Some species in this genus, however, such as A. villosus and A. parallelus, lack obvious sexual dimorphism. We explored if male and female A. villosus could be separated based on linear combinations of body measurements. We collected 19 body measurements from 42 A. villosus specimens and analyzed the data with a discriminate function analysis. Body length and the length of antennomere 8 were able to separate the sexes 100% of the time with very high accuracy. Brown et al. (2019) also used discriminant functions based on the same variables to separate a closely related species, Anelaphus parallelus (Newman). Because these two species were recently synonymized, we attempted to determine the sex of A. parallelus specimens with discriminant functions for sexing A. villosus, and vice versa. Discriminant functions that worked well for sexing one species did not work on individuals of the other species. These findings are evidence against the recent taxonomic hypothesis that synonymizes A. villosus and A. parallelus.