Worried about moth eggs in your Christmas tree? What to do after they were detected on some in Thunder Bay

A Christmas tree seller in Thunder Bay described a chaotic scene last week as businesses were forced to halt tree sales due to federal investigations, raising some questions about this classic holiday tradition. 

At least two Christmas tree lots were temporarily shut down by the Canadian Food Inspection Agency due to the detection of the LDD moth egg masses.

The LDD moth, which is also known as the spongy moth, is a regulated pest in Canada — and they're certainly not a desired Christmas tree ornament. 

"The Christmas trees were shipped from a nursery located in a regulated area of Ontario. Trees were shipped to several areas across Canada in November, including areas that are non-infested," according to a statement from the federal agency.

These inspections are standard protocol for Christmas trees, which are often shipped from areas regulated for pests to areas outside of their regulated areas.

"These pests can be very harmful to the Canadian forestry industry and impact Canada's ability to export forest products if pests such as the spongy moth become established in a non-regulated area," said the agency spokesperson.

The agency said the concern is around controlling any infested material, adding that inspectors are following up with retailers and nurseries in Thunder Bay and across Canada who have received shipment of trees to determine the extent of the issue and next steps.

The presence of these egg masses on Christmas trees is upsetting but not surprising, explained David Dutkiewicz, an entomology technician at the Invasive Species Centre in Sault Ste. Marie, Ont.

"LDD moths will lay their egg masses really on anything they can they can sort of crawl to," Dutkiewicz said. "There have been some reports down in southern Ontario of people finding egg masses on their Christmas trees, but this is the first time that I've heard of it being brought to Thunder Bay, but thankfully it was detected early." 

This species of moths do have a presence in parts of northern Ontario, but have not migrated much further than Sault Ste. Marie and Wawa, which is still over 330 kilometres from Thunder Bay.

The spongy moth is native to Europe and is currently established in northeastern United States and eastern Canada, including portions of Ontario, Quebec, New Brunswick, Prince Edward Island and Nova Scotia.

The caterpillars feed on crown foliage of a wide range of hardwood and some softwood trees, which makes it a defoliating forest pest of concern, according to the Invasive Species Centre.

Dutkiewicz said while the moth can wreak havoc on hundreds of tree species, they are not really a concern for people when it comes to their Christmas trees.

"I think it is unlikely that you'd find spongy moth egg masses on a Christmas tree. However, you should always be vigilant of anything that you bring into your house and always sort of take a check to see ... whether there are any sort of egg masses or any type of insects that might be on the Christmas tree," he said.