What aspect of the Yellowish Cuckoo Bumblebee coloration shows considerable individual variability?

Amount of black patterning on the abdomen

While the species is generally characterized by a yellowish or orangish-yellow appearance, the extent and presence of black markings on the abdomen exhibit significant variation among individuals within the population. Many specimens possess a visible black band or patch on the abdomen, but the consistency and size of this dark marking are highly unreliable for definitive field identification. Some individuals may present as almost entirely pale yellow, lacking the typical dark segmentation found in related species or even in other members of the same species. This high degree of individual difference in abdominal pigmentation necessitates relying on structural cues, like leg morphology, rather than color alone for accurate confirmation.