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Mountain Pine Beetle versus Ips

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.

Knowing the differences between these two can be useful. Dave Leatherman, former State Forest Entomologist, developed this easy comparison.

• Galleries - Ips shaped in a Y, X, or H; MPB's- egg galleries shaped like a J or I.
• Pitch tubes - Ips have none (Pinion 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.