Has the bumblebee Bombus bellicosus gone extinct in the northern portion of its distribution range in Brazil?

Evidence for the extinction of the bumblebee Bombus bellicosus in Parana state, in Brazil, is presented. The species is found in areas covered with open grass fields and shrub vegetation, originally ranging from northwestern Argentina to Parana, where it reached its northeastern limit. Until the early 1980s, B. bellicosus was relatively abundant in Parana, when the last known specimens were collected. In recent surveys conducted from 2002 to 2005, no specimens were recovered at sites in which the species was previously known to occur. Possible causes for local extinction of this species are discussed, including habitat conversion, pollution and climate change.