Although there are many species of bark beetles that attack a variety of trees, two that are important in Colorado are Ips beetles and Mountain Pine Beetle (MPB).
Knowing the differences between these two can be useful. An easy comparison is:
- Galleries – Ips shaped in a Y, X, or H; MPB’s- egg galleries shaped like a J or I.
- Pitch tubes – Ips have none (Pinyon is an exception); MPB – pitch tubes almost always present.
- Boring dust – Ips have none; MPB packs boring dust in galleries.
- Hind wing cover – Ips has a pronounced cavity with 3-6 pairs of spines; MPB has a gradually curved wing.
- Generations per year – Ips 2 to 4 per year, March through October; MPB one per year from approximately mid-July to early September.
- Tree size attacked – Ips usually infests smaller trees; MPB attacks trees 8″ in diameter or larger.
- Size and color – Ips 1/8″ to 1/4″, color usually brown to reddish brown; MPB a little bigger than Ips, color brown to black.