Invasive ants are threatening Hawaii’s endangered Hawaiian yellow-faced bees (Hylaeus anthracinus). This insect, endemic to the Hawaiian Islands, is now fighting for its existence.

Hawaiian ecosystems and wildlife, which includes native insects like the Hawaiian yellow-faced bees, can be greatly harmed by invasive species like these ants which have adverse and even catastrophic impacts. This happens by way of direct predation and indirectly via competition.

Both the US Fish and Wildlife Service (USFWS) Pacific Islands Coastal Program and the DLNR Division of Forestry and Wildlife (DOFAW) are collaborating on understanding the diverse factors that contribute to the decline of species so that solutions can be developed to stabilize and recover these unique species.

They recently discovered that the nature of the assault posed by the invasive ants is twofold: they are predatory to the bees and they are competition. These findings will be in a paper being published in the open-access journal, NeoBiota.

This 0:32-second video by KHON2 News shows the Hawaiian yellow-faced bees in their natural habitats:



There are very few native insects that can survive in lowland areas on the main Hawaiian Islands, and the Hawaiian yellow-faced bee is one of them. Significant declines in range and population has been experienced by the majority of the known 63 species of Hawaiian yellow-faced bees and many of these have not been seen at all in recent years. Saving these bees is crucial since less than 5% of insects in Hawaiian coastal areas are native to this island chain. Over time the population of these bees has been reduced, and now they are only found in a few areas on Oahu whereas previously they were abundant in coastal areas too. Seven species of this bee received federal protection in 2016, under the Endangered Species Act of 1973.

To perform their study, DOFAW and USFWS Pacific Islands Coastal Program created artificial nest blocks that allowed researchers to observe and track nest construction and development, to evaluate the effects invasive ants posed to nesting Hawaiian yellow-faced bees.

The wooden blocks were 2’x4’ in shape with holes drilled into them in dimensions that the bees are known to use. They were placed in pairs at 22 points that encompassed three sites on the north and east sides of O’ahu. In each pair, one block was treated with a sticky barrier like petroleum jelly to prevent access by ants, and the second block was left untreated. It was found that 70% of untreated ‘control’ block nests were invaded by ants. Nests in treated blocks which were protected from ants were more likely to produce at least one adult than nests in untreated blocks without a barrier.

If you have time to watch this 12:21-minute video by VICE News, it shows the ants, the bee and the people who are trying to turn this massive invasion around: 



According to DOFAW’s State Entomologist Cynthia King, invasive ants are suspected of causing population declines and range reductions in addition to habitat loss, especially in coastal areas where ants are more abundant. Some far-reaching consequences are the loss of unique native plant species that would disappear due to the loss of native pollinators, confirming that the negative impacts of invasive ants unfolds and amplifies across native ecosystems.

USFWS Pacific Islands Coastal Program Coordinator Sheldon Plentovich says that invasive ants are just one of many threats this species faces. If you live in Hawaii, you can help protect the native bees by protecting coastal vegetation. Remain on the trails, keep motorized vehicles off the vegetation. Do not use coastal vegetation and coral rubble for fires or pit fires, because they may contain yellow-faced bee nests. There are ongoing opportunities to help to save the bees by volunteering with invasive species control programs and coastal restoration projects. Get involved if you can, it’s a really unique way to do your part for bees of the world.

A press release issued by DLNR states that the data from this evaluation, which is a key effort in their survival, can go a long way in helping the Hawaiian yellow-faced bee to thrive.

The Hawaiian yellow-faced bees are Hawaii’s only native bees, so it is important that we all work together to protect them.