Pyrobombus


Pyrobombus is a subgenus of bumblebees, with centres of diversity in Central Asia and North America. Nearly a fifth of all Bombus species fall within Pyrobombus. Pyrobombus bees face issues such as climate change, habitat loss, urbanization, and industrial agriculture. They can be used for beekeeping as they are pollinators, and can be used for wax, honey, venom, and combs.

Morphology

Pyrobombus bees are fairly small. The subgenus is the largest by number of species in Bombus and the most diverse in morphology. Species vary in characteristics such as tongue length, head shape, mouth parts, and wingspan. The coat colour is similar to bees in other subgenera, with black, yellow, and orange patterns; some species can have white patches or stripes. Like all bees, Pyrobombus have translucent wings that can be clear or tinted black, brown, or amber.

Phylogeny

Studies have disagreed on whether Pyrobombus is monophyletic. Hines, Cameron, and Williams concluded that Pyrobombus was monophyletic based on an analysis of 36 of the 43 recognized species. Other studies have supported that Pyrobombus is paraphyletic and suggest the Pyrobombus belong in two different phyletic lines. Plowright and Stephen examined 18 different enzymes and found the taxon sample had close relationships with B. jonellus and B. frigidus. Their study aligned with other independent researchers.

Habitat and nesting

Pyrobombus commonly nest underground. Nest entrances are not elaborate. Generally, plant material is collected and accumulated around and in the nest canal for camouflage. This camouflage of its nest is also known as a pseudo-nest. They use this camouflage to avoid predators and protect against bad weather. These colonies will often be small with some species being flexible in their site preference. European Pyrobombus species tend to be more selective in site preference.

Pollination

Pyrobombus collect pollen from a variety of flora by using their hind legs to trap pollen between body hairs. By vibrating at high frequencies, pollen can be expelled from the bee's body to transport back to the colony and to other plants for fertilization. This act of buzz pollination is typical of Bombus species.

Ecology

Pyrobombus are commonly found in open environments such as meadows, grass fields, and forests. At these locations, bees can face predators such as bears, birds, badgers, and hornets.

Ecology in Europe

''Pyrobombus brodmannicus''

P. brodmannicus is found in higher altitudes like the French Alps. Although it forages on a variety of plants, P. brodmannicus bees in Caucasia specialise in the Boraginaceae.

Distribution

Pyrobombus bees are widespread in the Northern Hemisphere. Most Pyrobombus species are experiencing habitat loss, with a few endangered in certain locations.

Species list

The subgenus contains the following species: