How does the typical abdominal marking of the Yellowish Cuckoo Bumblebee differ from Bombus impatiens?

The Cuckoo often blurs lines; its black marking is a variable patch, not a solid band.

A helpful comparison for field identification involves contrasting the Yellowish Cuckoo with common non-parasitic species like Bombus impatiens (Common Eastern Bumblebee). The latter typically displays a highly defined and consistent segmentation, often exhibiting a pattern of black-yellow-black. In contrast, the Yellowish Cuckoo Bumblebee often fails to exhibit such crisp delineation. Its black abdominal marking tends to manifest as an inconsistent, variable patch rather than forming a solid, distinct band that cleanly separates two large, uniform yellow sections. This lack of sharp segmentation in the black area is a key differentiator when comparing it to clearly striped relatives.