Extracted from: Grigarick A.A., & Stange L.A., (1968). The Pollen Collecting Bees of the Anthidiini of California (Hymenoptera: Megachilidae) Bulletin of the California Insect Survey Volume 9.|
The females of mormonum have a distinctivee tegum VI which consists of a prominent truncate posterior marginal band that is posterior to, and widely separated from, the dorsolateral border (fig 80.). There is no single character for identifying the males but the combination of a reddish setal brush and the pronounced lateral lobe of sternum VI (fig. 44) and tergum VII (fig. 43), which has the mean width of the lateral lobe subequal to the distance separating it from the center spine, will serve to distinguish this sex.
Although many varieties have been described as "species" on the basis of coloration within mormonum, the variation that exists is not extreme within Cali- fornia. The females usually have more yellow than the males. In extreme northern California, mor- monum individuals are noticeably darker with less yellow on the thorax, abdomen, and pronotal lobe. This color pattern decreases even more in Washington and Montana. The darkest specimen was from northwestern Montana; it had a completely dark elypeus and mandible.