Bombus dahlbomii has not yet been evaluated for the IUCN Red List of Threatened Species. This bumblebee is endemic to the Patagonian Region in southern Argentina and Chile. It is the world’s largest bumblebee and has been affectionately called “flying mouse” and “flying teddy bear” by locals and researchers. The furry, orange queens can get up to 4 cm long!

This species used to be the only bumblebee in Patagonia, and was widely distributed throughout the region. Unfortunately, it began rapidly declining following the introduction of Large Garden Bumblebees (Bombus ruderatus) and Buff-tailed Bumblebees (Bombus terrestris) from Europe. Buff-tailed Bumblebees were introduced to Chile in 1997 for agricultural pollination purposes and reached Patagonia in 2006 which triggered the collapse of the native B. dahlbomii population. The commercially reared Buff-tailed Bumblebees were found to be infested with the parasite Apicystis bombi, which likely played a large role in the decline of B. dahlbomii. B. dahlbomii is a very important pollinator in its temperate forest habitat, assisting in the reproduction of many native plants such as the beautiful Chilean Bellflower (Lapageria rosea) and the Peruvian Lily (Alstoemeria aurea). 

Improved knowledge of the mechanism (e.g. pathogen transmission, competition) leading to the replacement of Bombus dahlbomii with introduced species is required to prevent this species’ further decline. An IUCN Red List assessment will help design suitable and effective conservation measures.