NC State Extension Publications

Description and Biology

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The smaller European elm bark beetle, Scolytus multistriatus, is dark reddish brown, shiny, and about 1/8 inch long. The underside of the rear is concave, with a noticeable projection or spine. Larvae are small, white grubs found under the bark of dying or dead elms. The egg galleries are straight and parallel with the grain of the wood and the larvae feed across the grain in the cambium just under the bark. Larvae develop through the summer months and also overwinter as grubs in “brood” trees. (Brood trees are dying or dead elms usually infected with Dutch elm disease.) Development from egg to adult beetle takes six or seven weeks in warm weather. New beetles fly to healthy elms to feed and then fly to dying or dead elms to breed. They can not breed in healthy trees although they can infect healthy elms with the Dutch elm disease pathogen as they feed. Smaller European elm bark beetles produce an aggregating pheromone, and host plant odors also play an important role in attracting the beetles to susceptible host trees. They have two to three generations per year here in North Carolina. Due to overlapping of generations, adults may be present almost continuously from April to October. The smaller European elm bark beetle is a serious pest of native and introduced elms because it is an important vector of the Dutch elm disease.

Smaller European elm bark beetle top view

Smaller European elm bark beetles and small and dark.

J.R. Baker

Smaller European elm bark beetle side view

Smaller European elm bark beetles have a peculiar rear end.

J.R. Baker

Egg galleries and larval galleries of the smaller European elm bark beetle

Egg galleries (with the grain) and larval galleries (across grain) occur in the cambium layer under the bark.

J.R. Baker

Emergence holes of the smaller European elm bark beetle from the bark of a dying elm.

Smaller European elm bark beetles that emerge from brood trees usually carry Dutch elm disease.

J.R. Baker

Elm twig showing feeding hole in the crotch by a smaller European elm bark beetle

New smaller European elm bark beetles feed on healthy twigs.

J.R. Baker, NC State University

Elm twig crotch showing feeding site of a smaller European elm bark beetle and the staining from Dutch elm disease starting down the twig

Feeding sites may become infected with Dutch elm disease.

J.R. Baker

Host Plants

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Smaller European elm bark beetles infest all of our native elm trees as well as Siberian elm and Japanese zelkova. Drought stress predisposes exotic elm species to infestation. Dutch elm disease is primarily a problem in American elm.

A twig from a "resistant" cultivar of elm stained with the dutch elm disease fungus.

The Dutch elm disease pathogen travels from twigs to trunk to roots.

R. K. Jones

Residential Recommendations

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It is possible to spray elms with a pyrethroid to prevent further bark beetle infestation. When used as directed, pyrethroids are very toxic to insects but are not particularly hazardous to humans and pets (other than fish-avoid using pyrethroids around pools, ponds, and streams). Because smaller European elm bark beetles infect elms by feeding in twig crotches, the whole canopy must be sprayed in spring before bud break and again after the new growth has emerged. Once a tree contracts Dutch elm disease but before the trunk and larger branches are infested, try to control the disease by pruning out dead and dying branches and paint the wounds with tree wound dressing. In urban settings, rapid removal of beetle infested, Dutch-elm-disease-infected American elms followed by destruction of the host material may slow the progress of Dutch elm disease. The wood from infected elms should be destroyed or debarked and the bark destroyed to prevent smaller European elm bark beetles from emerging successfully from such wood for months afterward.

Ronald K. Jones, former plant pathologist, and Chuck Hodges, plant pathologist, examine a so-called 'resistant' elm cultivar recently felled to control the spread of Dutch elm dise

A practical control for Dutch elm disease.

J.R. Baker


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For assistance with a specific problem, contact your local N.C. Cooperative Extension Center.

This Factsheet has not been peer reviewed.


Extension Entomologist

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Publication date: March 18, 2014
Revised: Oct. 3, 2023

Recommendations for the use of agricultural chemicals are included in this publication as a convenience to the reader. The use of brand names and any mention or listing of commercial products or services in this publication does not imply endorsement by NC State University or N.C. A&T State University nor discrimination against similar products or services not mentioned. Individuals who use agricultural chemicals are responsible for ensuring that the intended use complies with current regulations and conforms to the product label. Be sure to obtain current information about usage regulations and examine a current product label before applying any chemical. For assistance, contact your local N.C. Cooperative Extension county center.

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