MIAMI (AFP) - US officials for the first time have placed a bee found in the continental United States on the endangered species list.

Authorities said on Wednesday (Jan 11) the move was taken after a precipitous decline in the rusty patched bumble bee population, due to pesticides, disease and climate change.

These once common bumble bees are now "balancing precariously on the brink of extinction", said a statement from the US Fish and Wildlife Service (FWS).

"Abundance of the rusty patched bumble bee has plummeted by 87 per cent, leaving small, scattered populations in 13 states and one province," down from 28 states in the 1990s.

The final rule listing the rusty patched bumble bee as endangered appeared in the Jan 11 edition of the Federal Register and takes effect on Feb 10.

Experts say the bees are important because they pollinate economically important crops such as tomatoes, cranberries and peppers across the central and northern United States, as well as parts of Canada.

Their decline is likely due to a combination of factors: loss of habitat, disease and parasites, use of pesticides, climate change and extremely small population size.

Their endangered status signifies that they "are in danger of becoming extinct throughout all or a portion of their range", said a statement from FWS.

"Our top priority is to act quickly to prevent extinction of the rusty patched bumble bee," said FWS Midwest regional director Tom Melius.

"Listing the bee as endangered will help us mobilize partners and focus resources on finding ways right now to stop the decline."

Late last year, seven types of bees found in Hawaii became the first to be placed on the US federal list of endangered and threatened species.

The yellow faced or yellow masked bees have become endangered because of a loss of habitat in Hawaii, among other factors, wildlife experts said.