If you’re strolling through the forest this week and see a little black bug on your shirt, check it out.
It could be a pine beetle.
Forest visitors will have a chance in coming weeks to see the bugs that have made such a fuss — and killed ponderosa pines on more than 400,000 acres of the Black Hills National Forest — during the most recent pine-beetle infestation.
Millions — and some say billions — of beetles will be taking to the air in coming weeks in an annual flight that is impressive in numbers and ecological impact but hardly Alfred Hitchcock worthy in a visual sense.
“I don’t want people to think it’s going to be something out of the movie 'The Birds,'” said John Ball of Brookings, a forest health and forestry specialist with the state Agriculture Department and South Dakota State University. “But it’s possible if you’re hiking out in the woods and stand still for a moment to have a mountain pine beetle bump into you.”
It won’t be a jarring collision, however, since the bugs are the size of a grain of rice or the head of a match. They don’t mean much as individuals. But when they gang up on a pine tree, its fate is usually sealed.
And once a tree is hit, it’s typically too late to apply insecticide sprays to save it, Ball said.
“They’re really pushing it at this point for applications,” he said. “All our sprays are designed for before the bugs land on the tree. Once they burrow in, you’re too late.”
Frank Carroll, a retired U.S. Forest Service spokesman now working as a private consultant in Custer, said the “last resort” for people hoping to save pine trees that haven’t yet been infested is to spray with beetle-killing insecticides.
But time is running short for that. And trees should be examined for signs of bug hits before such spraying.
Ball said the signs of infestation show up within a day or two of the first bug attack in pustules of sap called pitch tubes. The tubes, which often resemble wads of gum stuck to the bark, result from the tree’s defense mechanism as it tries to expel the attacking bug.
It can work with a few bugs, but not with a swarm. And swarms are coming, even though they won’t be noticeable like miniature flocks of blackbirds. They will, however, continue an infestation that is changing the forest for generations to come.
“The fight is far from over,” Carroll said in a news release last week, noting that beetles killed trees on 22,000 acres of the Black Hills in 2009, 44,000 acres in 2010 and 67,000 acres in 2011.
Trees infested last year are turning red or rusty brown this year in patches and swaths that can be seen throughout the Black Hills.
Save some last-minute spraying on appropriately selected trees, the battle against the 2012 flights is over, for now. The next move comes in September, when the flight subsides and the marking of infested trees begins. That will be followed by the cutting and removing or chunking of those infested trees to prevent the bugs in them from producing another generation of bugs that will spread next year.
“We will be encouraging people to start looking for those trees that were attacked this year and marking them, and to begin removal,” Ball said. “We’d prefer they get started on that as early as October, but certainly, get it done before March 1.”
Meanwhile, this year’s flight has begun with the first mature bugs called “pioneer” beetles already having taken flight. The big movement is coming soon.
Most won’t fly more than 300 feet to find a new tree. But a few can be carried up above the tree canopy and have been known to travel 15 to 100 miles in unusual cases, Ball said.
The beetles like calm, relatively cool conditions to fly in. So they typically move in the evening, generally flying at about 1.5 miles per hour, with a top speed of 6 mph. They don’t fly as often in the morning, Ball said.
“They don’t seem to be early risers,” he said.