Half-black Bumble Bee

Bombus vagans

Classification

Phylum: Arthropoda
Subphylum: Hexapoda
Class: Insecta
Order: Hymenoptera
Family: Apidae
Subfamily: Apinae
Tribe: Bombini
Genus: Bombus
Species: vagans

Pronunciation

How to pronounce Bombus vagans: /ˈbɔmbus ˈvaːɡans/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Images

Bombus (Pyrobombus) vagans vagans by the Smithsonian. Used under a CC0 license.

Summary

The half-black bumblebee (Bombus vagans) is a small, distinct bumblebee with a notable yellow and black coloration, widely distributed in North America, particularly in shady forest habitats where it forages from early May through August.

Physical Characteristics

Bombus vagans has the head, thorax, and first two segments of the abdomen that are yellow, while the posterior half of the abdomen is black. The face features a mix of yellow and black hairs, with the thorax densely covered in shaggy yellow hair, except for a smooth central portion which is bare and shiny. The first two abdominal segments have yellow hairs, while the remaining segments are covered in black hairs, with a black underside and legs.

Identification Tips

The half-black bumblebee can be confused with Bombus sandersoni, which is slightly smaller, as well as Bombus perplexus, Bombus impatiens, and Bombus affinis. It can be distinguished by its specific coloration and length of malar space compared to similar species.

Habitat

Bombus vagans forages in shady forest habitats, favoring areas where it can find specific flowers such as apple and plum blossoms.

Distribution

Found from Ontario to Nova Scotia, and southward to Georgia.

Diet

The queen forages on apple and plum blossoms, while workers prefer red clover, Penstemon, Asclepias (milkweed), Cirsium (thistle), Eupatorium, and Spiraea (meadowsweet).

Life Cycle

This bumblebee species emerges from hibernation late in the year, with queens typically initiating activity in early May in Maine, while workers appear from June to August. In southern locations, they may be seen a month earlier.

Reproduction

Nests are usually on the surface of the ground or in holes in the ground, with colonies peaking around seventy workers. Queens lay eggs in the spring after emerging from hibernation.

Predators

The nest may be parasitized by the cuckoo bumblebee Bombus citrinus. Additionally, the protozoon Apicystis bombi may also parasitize Bombus vagans.

Ecosystem Role

As a pollinator, Bombus vagans plays a crucial role in the pollination of various flowering plants, particularly in forest habitats.