Effective October 31, 2016, seven species of Hawaiian yellow-faced bees will be added to the endangered species list: Hylaeus anthracinus, H. assimulans, H. facilis, H. hilaris, H. kuakea, H. longiceps, and H. mana. The Hawaiian Islands are geologically recent volcanic islands that are among the most remote locations from mainland. The Hawaiian Islands have received few colonists compared to other islands. Only one genus of bee, Hylaeus reached the Hawaiian Islands before colonization by humans. After its initial colonization, Hylaeus diverged into 63 species representing about 10 percent of all described species of yellow-faced bees.
Humans have brought many new species to Hawaii that have displaced the native flora and fauna. Many Hylaeus species area associated with plants that are under stress and decline due to invasive competitors. Ants, particularly the yellow crazy ant, Anoplolepis gracilipes, and the Argentine ant, Linepithema humile, have a profound impact both as competitors for nectar and as predators on the pollinating bees. The endangered species designation by the US Fish and Wildlife Service will aid in funding and designating important habitat for the yellow-faced bees.