Engraver Beetles

Ips spp.

From: Field Guide to Diseases and Insect Pests of Idaho and Montana Forests, USDA Forest Service Northern Region, Publication Number R1-89-54

Hosts. – Ponderosa and lodgepole pines. Can attack all species of pines. A few species attack spruce.

Distribution. – Wherever host species are found in Idaho and Montana.

Damage. – Adults and larvae feed in phloem layer of inner bark. Blue stain fungi are introduced. Tops may be killed in larger trees. Entire trees are killed when populations are high.

Identification. – Look for mounds of red-orange boring dust on the bark of slash, logs, or trees (fig. 49). Trees often are killed in groups (fig. 50). On standing trees , the dust is most noticeable in bark crevices and around their bases. Removing the bark reveals a Y-, H-, or star-shaped gallery pattern (fig. 51) usually running with the grain of the wood. These galleries are free of frass. Adult beetles are cylindrical, dark red-brown to black, and typically one-eighth to three-sixteenths inch long. Some species may be as long as one-quarter inch. They have a dish-shaped depression on the end of their abdomens with spines along each side (fig. 52). There may be two or more generations of beetles each year depending on species. Overwintering adults emerge early in the spring and infest slash or winter-damaged trees. This brood develops into adults after 40-55 days, and they attack slash and standing trees by August.

Similar damages. – Other secondary bark beetles may be mistaken for lps beetles. Gallery patterns and distinct shape of adults distinguish these species.

Link to Images in Forestry Images

References.

Anonymous. 1982. For. Insect & disease identification and management. USDA For. Serv., Northern Region; Idaho Dept. of Lands, Insect and Disease Control; Montana Dept. of State Lands, Division of Forestry. 192 p.

Furniss, R. L., and V. M. Carolin. 1977.  Western For. Insects. USDA Forest Serv., Misc. pub. 1339, 654 p., illus.

Livingston, R. L. 1979. The pine engraver, Ips pini (Say), in Idaho--Life history, habits and management recommendations.  Idaho Dept. of Lands, For. Ins. & Dis. Con. Rept. 79-3. 7 p. illus.

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