Carson National Forest sees uptick in some insect infestations

Carson National Forest shares some of the same insect infestations experienced in the Santa Fe National Forest, said Andrew Graves, an entomologist with the U.S. Forest Service.

Ecologically, the two forests are similar, with shared borders and forests, Graves noted.

The Carson, like Santa Fe, also is experiencing spruce budworm infestations among trees on the northwestern edge of the Tres Piedras Ranger District from along the Colorado border south to Hopewell Lake. Spruce budworm also are defoliating the southeast end of the Camino Real along the Pecos Wilderness. The insect doesn’t kill the trees outright, but are an additional stress on trees already under stress from drought.

The Carson also has Douglas-fir beetle outbreaks that turn the trees a deep red.

But Graves said entomologists haven’t yet seen the Janet’s looper caterpillars in the Carson as they have in the adjacent Santa Fe National Forest.

“The only other place we’ve seen the Janet’s looper was the Lincoln National Forest,” said Graves.

One insect invasion that Carson has had recently is the pine needle miner, a moth that burrows into needles to lay its larvae. The pine needle miner has been active near Vermejo Park west of Raton.

“A lot of what we are seeing could be related to the dry winter we had followed by a warm summer,” Graves said. “Insects tend to do better on stressed trees.”

Graves said it’s important to remember that “all these are native insects on native trees. This is sort of the cycle of some of these forests.”

Because of Carson National Forest’s remoteness, he said, “We can have large outbreaks that occur without much notice.”

Below are results of the annual Carson National Forest Insect and Disease survey:

• Douglas fir mortality from Douglas-fir beetle was recorded on 1,630 acres, a small decrease from 2,100 acres in 2017.

• White fir mortality by the fir engraver beetle decreased from 1,760 acres in 2017 to 620 acres in 2018, mostly on the Questa ranger district.

• Ponderosa pine mortality from bark beetles increased from 270 acres in 2017 to 320 acres in

2018. Most damage was mapped on the Camino Real ranger district .

• Corkbark fir mortality attributed to western balsam bark beetle increased slightly from 50 acres in

2017 to 60 acres in 2018, primarily on the Camino Real ranger district.

• Aspen decline increased from 370 acres in 2017 to 1,020 acres in 2018, primarily on the Canjilon ranger district.

Other Damage

• Western spruce budworm defoliation has declined from 51,950 acres in 2017 to 41,230 in 2018.

• Aspen defoliation, likely from western tent caterpillar, decreased significantly from 18,450 acres in 2017 to 9,200 acres in

2018, primarily on the Tres Piedras ranger district.