Invasive Ants Threaten Endangered Hawaiian Yellow-Faced Bees

Courtesy of DLNR

Invasive ants are threatening the existence of an already endangered endemic insect, the Hawaiian Yellow-Faced Bee.

the DLNR Division of Forestry and Wildlife (DOFAW) and the U.S. Fish and Wildlife Service’s (USFWS) Pacific Islands Coastal Program have discovered the native bee is being threatened by these invasive ants both directly from predation and indirectly via competition.

Hawaiian yellow-faced bees are one of the very few native insects that survive in lowland areas in the main Hawaiian Islands. Though once abundant in coastal areas, this Hawaiian yellow-faced bee now only persists in healthy populations in a few areas on O‘ahu.

In order to evaluate the effects of invasive ants on nesting, Hawaiian yellow-faced bees DOFAW and USFWS Pacific Islands Coastal Program created artificial nest blocks that allowed researchers to observe and track nest construction and development. These blocks were placed in pairs at 22 points, encompassing three sites on the north and east sides of O‘ahu.

One block in each pair was treated with a sticky barrier (akin to petroleum jelly) to prevent access by ants while the second block remained untreated. It was discovered that 70% of nests in untreated or “control” blocks were invaded by ants. Nests in treated blocks (protected from ants) were more likely to produce at least one adult than nests in untreated blocks (with no barrier).

“Data from this evaluation can go a long way in helping the Hawaiian yellow-faced bee thrive,” according to a DLNR press release Thursday.

While this is a key effort in their survival, there are also ongoing opportunities to help the bees by volunteering with invasive species control programs and coastal restoration projects.

“Hawaiian yellow-faced bees are Hawai‘i’s only native bees and it is important we work together to protect them,” the release stated.