Christmas trees have the potential to spread unwanted critters
CBC
Our planet is changing. So is our journalism. This weekly newsletter is part of a CBC News initiative entitled "Our Changing Planet" to show and explain the effects of climate change. Keep up with the latest news on our Climate and Environment page.
Sign up here to get this newsletter in your inbox every Thursday.
This week:
Three years ago, an owl made headlines after being found in a Christmas tree that was about to be put up at 30 Rockefeller Plaza in New York City.
Trees provide habitat for wildlife, and that's a good thing. But it also means that Christmas trees can carry a variety of live cargo with them when they travel — and many aren't as harmless as "Rockefeller" the owl.
The Centre for Agricultural Biosciences International, a non-profit organization focused on science-based solutions for agriculture and the environment, lists the 12 pests of Christmas trees on its invasive species blog. The list includes the Western yellowjacket, a wasp native to western North America whose young queens spend the winter in species often exported as Christmas trees.
This has caused a huge problem in Hawaii, which imports about 90,000 Christmas trees a year, mostly from Oregon. At least two strains of the invasive Western yellowjacket are thought to have been introduced from imported live Christmas trees in the 20th century.
The wasps are voracious predators that have eaten their way through local insect populations, competing with native birds and insects.
In order to reduce the importation of wasps and other critters, including garter snakes and slugs carrying the rat lungworm parasite, a certain proportion of trees imported to Hawaii are shaken, either mechanically or by hand, before shipping and after arrival. Infested trees may be sent back to the shipper, or "treated" with more shaking or hot water (to remove slugs).
Hawaii isn't the only place that imports Christmas trees and is concerned about hitchhikers.
Canada is a net Christmas tree exporter, but also imports some. In 2022, Canada exported 2.4 million trees worth $98 million, Agriculture Canada reports, mostly from Quebec, Nova Scotia and New Brunswick.
More than 95 per cent went to the U.S., but some also went to Panama, many Caribbean countries, Venezuela and the United Arab Emirates.
One pest of concern that can move between Canada and the U.S. via Christmas trees is the LDD or spongy moth, formerly called the gypsy moth. It can also be a concern with trees moving between different parts of Canada; it caused the shutdown of at least two Christmas tree lots in Thunder Bay, Ont., last year.
According to the Canadian Food Inspection Agency, trees moving from "regulated" Canadian areas infested with the moth to non-infested U.S. areas need a "phytosanitary certificate" saying they've been inspected and have either been found free of moths or have been treated for it.
Health Canada has authorized a new drug to treat postpartum depression.
A website selling moccasins with what looks like Haudenosaunee-style beadwork but with no attribution to an artist or community has sparked conversation online about how to identify authentic Indigenous crafts.
More Canadians have a family doctor or nurse practitioner compared with three years ago, but satisfaction remains low, a comprehensive new survey suggests.
This could be an unusually good year to spot snowy owls in southern Canada.
Over five dozen items belonging to First Nations, Inuit, and Métis are one step closer to returning home.
After Canada announced Tuesday it wouldn’t list the American eel under the Species at Risk Act (SARA) some First Nations people with cultural and spiritual ties to the species are questioning the decision.
The B.C. government is issuing new guidance for physicians when it comes to treating youth with overlapping cases of mental health and substance use challenges, clarifying the use of involuntary care in the process.
Former Assembly of First Nations national chief RoseAnne Archibald says her lawsuit against the national advocacy organization is moving forward, after settlement talks “were stalled and stonewalled” for 18 months.
An early start to Canada’s flu season is hitting children hard, sending a flood of young patients into multiple pediatric hospitals as medical teams warn that emergency visits and admissions could keep climbing in the weeks ahead.
Energy efficient homes are key to improving some health issues and solving the housing crisis in Indigenous communities, according to a new report on Indigenous housing.
Satellite constellations, networks of multiple satellites that can number from a few dozen to tens of thousands, are interfering with scientific research using ground-based telescopes, but now a new study looks at how they might affect space-bound telescopes like Hubble.
A surge in the rate of incurable prostate cancer cases could be a sign to rethink Canada’s stance on screening for one of the most common diseases for men, according to new research.
The Royal Canadian Mounted Police is limiting the use of its 973 Chinese-made drones to non-sensitive operations, stating the devices present "high security risks, primarily due to their country of origin."