A number of Hawaiian yellow-faced bees (Hylaeus species) endemic to the Hawaiian Islands are threatened with extinction. These bees are important pollinators of native Hawaiian plants many of which are also endangered and the decline of these bees might lead to the loss of native plants. Alternatively, protection of these pollinators could aid the recovery of the endangered plants.
Hawaiian yellow-faced bees are threatened by development (especially in coastal areas), fire, feral ungulates such as pigs, invasive ants, and the loss of native vegetation to invasive plant species. Because remnant populations of many species of Hawaiian yellow-faced bees are small and isolated, they are especially vulnerable to habitat loss, predation, stochastic events, and other changes to their habitat.