Scolytus multistriatus

Adults can be distinguished from the similar Scolytus schevyrewi (banded elm bark beetle) by aedeagus morphology; external morphological characters alone are unreliable due to wide within-species variability. DNA markers (RAPD-PCR) produce distinct banding patterns that can identify both adults and larvae. The gallery pattern in elm wood is characteristic: the female creates a mother gallery with eggs laid in notches along the sides, and larval galleries radiate from this central tunnel. The antennal club has sensilla basiconica (long type) as the predominant type across all three fields, unlike S. scolytus where sensilla trichodea type II predominate in field three.

Adults are small, cylindrical bark beetles typical of the genus Scolytus. The antennal club contains sensilla basiconica (long type) as the predominant sensilla, comprising 63–68% of sensilla on the antennal club, with sensilla trichodea type II and III also present. The aedeagus morphology is diagnostic and can be used to distinguish this species from the morphologically similar Scolytus schevyrewi. Larvae are whitish, wrinkled, legless grubs with brown scaly heads, closely resembling other Scolytus larvae.

Associated with elm trees (Ulmus spp.), specifically colonizing the inner bark and sapwood of living, dying, or recently dead elms. In Europe, has been documented on Ulmus glabra (wych elm).

Native to Europe, with documented occurrence in Austria, Belgium, Britain, Bulgaria, Corsica, Czechoslovakia, France, Germany, Greece, Hungary, Italy, Netherlands, Poland, Portugal, Romania, Spain, Switzerland, and Yugoslavia. Also recorded in Iran, Algeria, and Egypt. Introduced to North America (Canada and USA) and Australia, where it is established as a non-native invasive species.

Larvae feed on phloem and sapwood tissue of elm trees. Adults may feed on bark tissue, though specific adult feeding habits are not well documented in available sources.

• Ulmus - hostPrimary host genus; includes Ulmus glabra and other elm species
• Ophiostoma ulmi - vectorTransmits the fungus causing Dutch elm disease; less effective vector than Scolytus scolytus

Females enter host trees to construct egg galleries (mother galleries) in the inner bark, laying eggs in notches along the gallery sides. Larvae develop within the phloem and sapwood, creating characteristic larval galleries that radiate from the mother gallery. Larvae are legless, whitish grubs with brown scaly heads. Pupation occurs within the gallery system. The species overwinters as larvae or adults, though specific overwintering stage varies. Developmental stages (egg, larva, pupa, adult) all occur within the host tree.

Uses olfactory cues for host location: vanillin and syringaldehyde serve as signals to find host trees during oviposition. Females bore into host tree bark to construct galleries for egg-laying. Adults and larvae are confined to the inner bark and sapwood of host trees. Phoretic mites and nematodes are carried on or within adults, including under the elytra and inside the abdomen.

Primary vector of Dutch elm disease fungus Ophiostoma ulmi, contributing to elm tree mortality and forest ecosystem change. Galleries and feeding activity damage wood structure, altering hydrogen bond patterns in cellulose and affecting wood strength. Serves as host for parasitoid wasps (e.g., Dendrosoter protuberans) and associated mites and nematodes. May facilitate fungal colonization of wood through gallery construction and introduction of symbiotic fungi.

Significant forest pest and invasive species in North America and other introduced ranges. Causes economic damage through tree mortality and reduced timber quality. Vector of Dutch elm disease, which has devastated urban and forest elm populations across multiple continents. Subject to quarantine and early detection programs; identification tools including genitalia morphology and DNA markers are used for monitoring. Biological control efforts include parasitoid wasp introductions.

• Scolytus scolytusLarger European elm bark beetle; more effective vector of Dutch elm disease; differs in antennal sensilla distribution (sensilla trichodea type II predominate in field three of antennal club versus sensilla basiconica in S. multistriatus)
• Scolytus schevyrewiBanded elm bark beetle; morphologically similar external appearance; distinguished by aedeagus morphology and DNA markers (RAPD-PCR)
• Scolytus pygmaeusSmaller elm bark beetle with which it shares mite associates and habitat; differs in size and gallery characteristics

• bark beetle
• forest pest
• vector
• invasive species
• Dutch elm disease
• Scolytinae

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Scolytus multistriatus . [Distribution map].
• The change in the structure of hydrogen bonds in elm wood due to damage by European elm bark beetle Scolytus multistriatus (Marsham) (Coleoptera: Curculionidae, Scolytinae)
• A Redescription of Parasitaphelenchus Oldhamirühm, 1956 (Nematoda: Aphelenchoididae) to a Parasite of Two Elm Bark Beetles: Scolytus scolytus and S. multistriatus, Together With Some Notes on Its Biology
• Relative effectiveness of Scolytus scolytus, S. multistriatus and S. kirschi as vectors of Dutch elm disease
• Morphology of the antennal club of Scolytus scolytus (F.) and S. multistriatus (Marsham) (Coleoptera, Scolytidae)
• Survival of Dendrosoter protuberans,1 a Parasitoid of Scolytus multistriatus,2 in Colorado
• The Biology and Forest Importance of Scolytus (Eccoptogaster) multistriatus (Marsh)
• Characterization of two non-native invasive bark beetles, Scolytus schevyrewi and Scolytus multistriatus (Coleoptera: Curculionidae: Scolytinae)
• Phoretic mites and nematode associates of Scolytus multistriatus and Scolytus pygmaeus (Coleoptera: Scolytidae) in Austria