“Numerous authors have presented this species as a synonym of basalis. Wilcox (January 1953, p. 51) cited it as a valid species distinct from basalis and presented the characters which serve to distinguish the two. This action, I believe, was correct; however, Pallister (May, 1953, p. 28) resynonymized mucoreus with basalis, but Wilcox's treatment of 1954 (p. 382) amounted to a revalidation of mucoreus” (White, 1968).
“Pronotum: With fine, silvery pubescence; black throughout; punctuation dual, larger punctures moderate, dense. Elytra: With fine, silvery pubescence. Each elytron black, following parts orange to red; basal fourth and side to or (infrequently) past middle; apex; basal marking, rarely almost attaining apical spot; posterior margin of basal marking concave. With nine rows of punctures, sixth and seventh rows sometimes confused, punctures rather small and indistinct, obscured by roughened surface; inner and outer rows generally distinct at apex and usually meeting. Prosternum: Anterior margin in male with a large, sharp, downward and posteriorly directed spine; anterior margin in female simple or with a feeble, longitudinal, median carina. Length: 4.2 to 5.5 mm” (White, 1968: 69).
USA: TX, KS, MO, KY.