Really? Butterlies?

Pine butterflyYou have got to be kidding me! Beetles are one thing, but c’mon butterflies, everyone loves butterflies. Below is an article posted from the Missoulian a few days ago.

HAMILTON, MT – Anyone strolling through western Montana’s ponderosa pine forests this summer likely noticed a plethora of white-winged pine butterflies flittering about.

“We’ve certainly received a lot of phone calls about them this summer,” said Beverly Yelczyn, a Bitterroot National Forest staff officer.

No one knows for sure just what caused the butterflies to multiply in such great numbers, but their arrival may not bode well for the forests.

The last outbreak of pine butterflies in the Bitterroot started in 1969. By the time the infestation ran its course four years later, some 45,000 acres of pine forest had suffered some defoliation.

The butterflies lay eggs on the foliage of pine trees, which eventually become inch-long caterpillars with a voracious appetite for needles.

Gregg DeNitto, the Forest Service’s Region 1 group leader for forest health protection, said there are always some butterflies in the forest, but usually their numbers are much lower.

“If this outbreak follows the pattern we’ve seen in the past, we will start to see some defoliation from the ground this next year,” he said. “In the next year or two, we’ll be able to detect it from the air.”

The caterpillars normally feed on older foliage first. If the number of caterpillars is high enough, the bugs can completely strip a pine tree.

“You could get up to 100 percent defoliation in some trees,” DeNitto said.

Severe defoliation on a conifer can be debilitating. The resulting stress on a tree could make it more susceptible to an attack from pine beetles, DeNitto said.

On the positive side, DeNitto said pine butterfly outbreaks normally run their course in a couple of years. Most trees have enough reserves to survive through that period of time.

So far, the Bitterroot forest has not been hit as hard as other places in Montana by the pine beetle.

“Right now the Bitterroot is in a rather unique position with the Montana pine beetle,” Yelczyn said. “They are here on the forest, but still in relatively low population numbers.”

DeNitto hopes to have someone spend time this fall to take some pine butterfly egg samples in an effort to determine the extent of the outbreak.

“It was a procedure identified in earlier infestations that could give us an idea what the population will do next year,” he said. “By now, they have pretty much laid their eggs and completed their life cycle.”

From here on, nature will decide if the outbreak will continue into next year.

“It was pretty amazing to see them this summer,” DeNitto said. “In some places, it seemed like they were everywhere.”

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