This bumblebee is ready for its closeup, if you can find it

Bumblebee researchers are asking for help from regular New Brunswickers in their effort to find signs of a critically endangered bee species.

The rusty-patched bumblebee was once commonly found in southern parts of Eastern Canada into the 1970's.

"At one time in southern Ontario, if you saw a hundred bumblebee, odds are 15 would have been rusty-patched bumblebees," said Sheila Colla, an assistant professor of environmental studies at York University.

"They were the fourth most common species here."

But something went wrong in the 1970s, and the species, whose scientific name is bombus affinis, began to disappear dramatically.

In the last two decades or so, only two have been found in Canada, both by Colla herself at Pinery Provincial Park, about 50 kilometres northwest of London, Ont., on the shore of Lake Huron.

The last specimen was found in 2009.

Scientists aren't sure what is killing the bees off, but given the scale of the decline, Colla said the most likely culprit is a pathogen.

Colla said the theory is a disease or parasite was introduced into wild bee populations from the managed bee industry, one the rusty-patched bumblebee had no natural defence against.

In 2010, the Committee on the Status of Endangered Wildlife in Canada, or COSEWIC, declared the species endangered.

Its U.S. counterpart has done the same.

COSEWIC said in 2010 that it estimates populations of the bee species have declined by 99 per cent.

Researchers are now preparing a 10-year update on the status of the rusty-patched bumblebee.

Colla said that was supposed to include field trips across the southern parts of Ontario, Quebec and New Brunswick, the three provinces believed to be within the species' natural range.

"But with COVID, that's not going to be possible."

So researchers are asking citizen scientists to get up close with the bumblebees in their gardens, or those they see on their travels, and take photos.

They can then send those photos off with location information to bumblebeewatch.org

The rusty-patched bumblebee is a larger species, about one to 1½ centimetres long.

It is recognized by a brownish-rusty coloured patch on the top of its abdomen, surrounded by yellow. Other bees have a similar patch but not surrounded by the yellow colour.

But you don't have to be able to identify the species yourself. The researchers will do that.

Colla said researchers want to see as many pictures of bumblebees as possible.

"It's really important to send any pictures you get. It tells us how much effort is being made. Send us all of your photos."

The only verified collection of the species in New Brunswick was in 1949 in the Fredericton area, and that specimen is in the collection of the New Brunswick Museum in Saint John.

It was found by W.E. Cawthray, who is believed to have been studying forestry in Fredericton at the time.

Colla said the photos are easiest to take as the bees are foraging and should be taken from the side or back, where most of the identifying features are.

And the closer, the better.

The photos can be uploaded on the website bumblebeewatch.org, or you can download a phone app that will send the photo with a GPS locator attached.

Rusty-patched bumblebees are active from April until October.