Bombus auricomus 
Black and Gold Bumble Bee

Bombus auricomus is one of the largest bumble bees in Minnesota.  New queens (gynes) establish a nest aboveground, under wood or logs on the ground, or in cavities aboveground. The gynes emerge from hibernation in early to mid-spring. Workers emerge in late May or early June; males emerge in late June or early July. 

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The thorax has short, even yellow hairs next to the head, has black hairs between the wing bases extending to the rear of the thorax. The rear edge of thorax is bordered by yellow hairs or has prominent or faint scattered intermixed yellow hairs. For females, the first abdominal segment (T1) is either entirely black or is partially covered in yellow hairs. The second and third segment or tergites (T2 and T3) have yellow hairs. The rest of the remaining tergites (T4-T6) have black hairs. Males have yellow hairs on the first through third segments or tergites (T1-T3), and black hairs on remaining tergites (T4-T7). Males and females have yellow hairs on the vertex (back of the head or "neck"). This is one character that separates this species from the similar-looking Bombus pensylvanicus. Females have black hairs on the face and males have yellow hairs on the face. Males have large bulging compound eyes and dark wings; females have black wings.

female