For Connecticut's Pine Trees, a New Insect Threat Emerges

Apr 17, 2015

The southern pine beetle bores holes into pine trees, restricting nutrient flow and causing tree death.

Asian Longhorned Beetles, Emerald Ash Borers, Hemlock Woolly Adelgids: all these bugs pose threats to trees in Connecticut. Now, you can add another bug to that list: the southern pine beetle.

"It's certainly kind of disheartening to get another pest, yet again, attacking our forests," said Connecticut state entomologist Kirby Stafford.

Southern pine beetles were first seen in Connecticut last month in Wallingford. Since then, they've also popped up in Litchfield and Hartford counties. Last year, the bugs turned up in surprisingly high numbers in Long Island.

Stafford said the insects bore holes into pine trees, restricting nutrient flow and causing tree death.

When female beetles attack a tree, he said they'll release an attraction pheromone, the smell of which brings in other beetles.

"This beetle has a tendency to build up high populations -- or because of the pheromone, do a mass attack," Stafford said. "If the tree's healthy and the beetle population isn't too large at that point, the tree can awfully successfully pitch out the beetle -- drown it in that resin that the tree produces as it defends. That's what people will see. It looks like popcorn stuck all over the pine tree."

A pine tree housing southern pine beetles. Resin discharges bear similarities to popcorn as they form on the outside of pine bark.
Credit Department of Energy and Environmental Protection / Connecticut Agricultural Experiment Station
Defensive resin looks like popcorn stuck all over a pine tree.

Southern pine beetles have caused millions of dollars in damage to commercial pine trees in the southeastern United States, but here in Connecticut, there aren't a lot of native hard pine trees. That means the economic and ecological risks posed by southern pine beetles are less than those of other pests like the emerald ash borer or the Asian longhorned beetle. 

Still, the DEEP says certain types of pines, like pitch pines, are ecologically important to a number of endangered moths and butterflies in the state.