Bombus sylvestris, commonly known as the forest cuckoo bumblebee, is a parasitic bee found in Europe and parts of Asia. It primarily inhabits woodlands and forest edges. Unlike typical bees, it doesn't build its own nests but instead overtakes those of other bumblebee species. The species is known for its distinctive yellow banding and black body, as well as its role in controlling host bee populations.

Bombus sylvestris, also known as the forest cuckoo bumblebee, is native to the Palearctic region. This includes parts of Europe, Asia, and North Africa. It is found across a wide range of countries such as the United Kingdom, France, Germany, and Russia, extending into parts of Mongolia and China.

Bombus sylvestris typically inhabits temperate climates with a preference for woodlands, forest edges, and heathlands. These environments provide the necessary floral resources and nesting sites. The species is adapted to regions with moderate temperatures and seasonal variations.

As a cuckoo bumblebee, Bombus sylvestris does not build its own nests. Instead, it parasitizes the nests of other bumblebee species, primarily those in the Bombus pratorum group. This behavior impacts its ecological niche, as it relies on the presence of host species for reproduction. The species' presence in diverse floral environments supports its foraging activities during its active seasons.