The mountain pine beetle is the number one invasive insect priority – Park Rapids Enterprise

For decades, the mountain pine beetle has caused unprecedented forest mortality in western North America, ripping through pine stands from the Pacific Coast to the Black Hills of South Dakota.

Now, researchers at the Minnesota Invasive Terrestrial Plants and Pests Center (MITPPC) are preparing for the imminent arrival of one of Minnesota’s top tree threats.

Brian Aukema answers questions about the species and explains why it poses a threat to Minnesota’s pine forests.

Question: What is a mountain pine beetle?

The mountain pine beetle is a small bark beetle native to forests in western North America. Adult beetles gnaw the bark of pine trees and lay eggs. The developing larvae tunnel under the bark to feed, destroying the water-conducting tissues. A tree can withstand a few beetles, but large beetle infestations will overwhelm a tree, and sustained outbreaks can cover large areas that turn pine forests from green to red very quickly.

Question: Do researchers expect the mountain pine beetle to come to Minnesota?

The Black Hills pine forests of South Dakota are home to the nearest populations of mountain pine beetles, which are only 500 miles from the nearest mature pine forests in Minnesota.

A warming climate, an unprecedented beetle population, and the transportation of firewood and timber could help this destructive forest pest fight its way through the prairie divide. That’s why, even though researchers have yet to find the mountain pine beetle in the state, MITPPC has listed it as the top priority invasive insect for research funding.

Question: Has the research to date indicated that we should continue to be vigilant?

The mountain pine beetle can be a difficult insect to control, as it flies only once a year and prefers to attack living trees. These nuances make laboratory studies difficult, combined with the fact that we cannot risk accidentally introducing the species to Minnesota with live tree studies here.

Therefore, we took pine logs of species found in Minnesota that the mountain pine beetle had never seen before and brought them to areas of mountain pine beetle activity in the west. There, we discovered that mountain pine beetles can tunnel, attract mates, and reproduce successfully in our pines. We don’t know if these patterns would hold in living trees, but it underscores an ongoing cause for concern.

Question: What are the researchers currently working on?

We are working on several different fronts. For example, if the mountain pine beetle were to arrive, it should assimilate to pine forests whose flora and fauna are very different from the region from which it comes.

We investigated whether competing insect and predator species would recognize the mountain pine beetle, if it arrived, to get an idea of ​​how they might interact.

We also worked on the probability of pioneer beetles blowing. We know that beetles can fly or be blown long distances when looking for mates or a new tree. We investigated whether beetles captured away from infested forest land have lower lipid concentrations. Lipids help indicate how much “fuel” an insect has after exertion, just like in humans. If the insects survive a marathon, would they be able to colonize the trees?

Question: How do you hope this research will better prepare the state for the imminent arrival of the species?

This research has immediate application to help protect Minnesota’s forests. Our findings can help inform quarantine regulations, which are key to keeping this insect out of our beloved state.

Forest monitoring for the mountain pine beetle is also essential to demonstrate that these quarantine regulations are working. It’s not every day that a funding body has the ability to fund proactive research rather than reacting to proven threats, as we so often have to do with invasive species. We greatly appreciate the support from MITPPC and the Albert Victor Ravenholt Fund to invest in this work, as the data continues to show that this is a persistent problem that we need to take seriously.

Brian Aukema, Ph.D., is a professor in the College of Food, Agriculture, and Natural Resource Sciences and a researcher at the Minnesota Invasive Terrestrial Plants and Pests Center. His areas of expertise are forest entomology, invasive species and climate change, and ecological statistics.