Each summer, the USDA Forest Service flies the forests of the West and sketches areas where trees show damage. This page keeps only the insects and only the seven counties we work in. It tells you which beetles and scale insects have mattered here and when, which is useful context if a pine or fir on your property is turning red or thin. It does not tell you what is wrong with your tree.
How to read the table
Each row is one damage agent as the surveyors recorded it. The second column adds the mapped acres of every year. The peak year is the year with the most mapped acres, and the next column gives that year's acres. The last columns show the span of years recorded and how many of them had any damage mapped.
The unit is mapped acres, which means the area where damage was seen from the air, not acres of trees killed. The same ground can be mapped in several years and by several agents, so the rows overlap and should not be added into one total.
What stands out
Two outbreaks account for most of the mapped acres, and the bark beetle story has shifted to newer agents.
- Pinyon ips: 684,088 acres, peaking at 325,255 in 2004 after 185,907 in 2003 and 36,055 in 2002. A second pulse of 70,403 acres came in 2009.
- Pinyon needle scale: 443,025 acres, mapped from 2009 to 2024, with a peak of 133,859 acres in 2010 and 112,790 in 2012.
- Fir engraver: 105,970 acres over 29 recorded years, peaking at 22,623 in 2023, after 20,078 in 2022 and 17,677 in 2017.
- Mountain pine beetle: 71,543 acres, with the largest year in 2022 (19,705 acres) and more than 7,800 acres each in 2023, 2024 and 2025.
- Jeffrey pine beetle: 10,080 acres, almost half of it, 4,929 acres, in 2016.
What it means for trees near you
The agents are named for the trees they attack. Pinyon ips and pinyon needle scale are named for the pinyon pines, the Jeffrey, mountain and western pine beetles for the pines they attack, and the fir engraver for firs. Our bark beetles in pines, fir engraver and pinyon needle scale pages help with identification.
Our work here is the decision, not a treatment: an arborist looks at the tree and recommends pruning, monitoring or removal. A pine or fir that is dead or declining near a house is a removal question; see removing dead pines and bark beetle trees. Our firewood guide covers moving wood.
Limits of the data
Survey coverage changes every year. The Pacific Southwest region did not fly Nevada in 2020 or 2025, and the flown area in 2020 and 2021 was small, so a low or missing year can mean the ground was not flown rather than that no damage occurred. The yearly numbers are not a trend on their own.
The table includes insect agents only. Drought, disease and fire damage mapped in the same survey are left out, and the counties are clipped from larger polygons, so edges are approximate.