Scolytus schevyrewi

Adults are morphologically similar to Scolytus multistriatus (smaller European elm bark beetle) and cannot be reliably distinguished by external characters alone. Aedeagus morphology provides definitive species identification. RAPD-PCR analysis with specific oligonucleotide primers yields distinct DNA banding patterns and can identify both adults and larvae. External morphology is highly variable within species, making identification based on adult appearance problematic.

Urban and forested areas with elm trees; primarily colonizes weakened, water-stressed, or wilting trees rather than healthy hosts. In China, found in fruit tree ecosystems causing damage to apricot orchards. Laboratory rearing successful at 26.5°C with 14:10 light:dark cycle and 65% relative humidity.

Native to Asia: China (Hebei, Heilongjiang, Henan, Ningxia, Qinghai, Shaanxi, Xinjiang), Kazakhstan, Korea, Kyrgyzstan, Mongolia, Tajikistan, Turkmenistan, Uzbekistan, and eastern Siberia/Russian Far East. Introduced to North America: Canada (Alberta, Manitoba, Ontario, Saskatchewan) and USA (Arizona, California, Colorado, Connecticut, Idaho, Illinois, Indiana, Kansas, Maryland, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, New Jersey, New Mexico, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, South Dakota, Texas, Utah, Virginia, Washington, Wyoming). First detected in Canada in 2007.

Flight activity observed from May to October in Saskatchewan and Manitoba, Canada.

Xylem-feeding; larvae develop in phloem and outer xylem of host tree branches and stems. Adults feed on xylem of host trees.

• Ulmus pumila - primary hoststrongly attracted to water-stressed trees; successfully colonized for breeding
• Ulmus americana - spore sourceadults acquire fungal spores but not colonized for breeding in Saskatchewan/Manitoba study
• Ulmus - host genuspoor attraction to healthy trees
• Armeniaca vulgaris - laboratory hostused for rearing in Chinese studies
• Armeniaca spp. - hostcauses serious damage to apricot trees in Xinjiang Province, China
• Caragana korshinskii - hostKorshinsk pea shrub
• Elaeagnus spp. - hostoleaster
• Prunus spp. - hostplum
• Pyrus bretschneideri - hostyali pear
• Salix babylonica - hostweeping willow

Eggs deposited in galleries constructed in phloem of host trees. Larvae feed and develop in phloem and outer xylem, creating characteristic gallery patterns. Pupation occurs within host material. Adults emerge from brood galleries; emerging adults from diseased trees frequently carry fungal spores. Adults can be collected daily upon emergence in laboratory settings.

Exhibits aggregation behavior mediated by male-produced pheromones. Strongly attracted to volatiles from stressed or freshly cut host material, particularly Ulmus pumila and apricot logs. Antennal response to host volatiles includes detection of (1S)-(−)-α-pinene, (±)-limonene, (1S)-(+)-3-carene, and 1-hexanol. Repelled by octanal, nonanal, decanal, linalool, and N,N-diethylformamide at tested concentrations. Adults acquire Dutch elm disease fungal spores when developing in infected trees and transmit pathogens when contacting xylem of healthy trees during feeding.

Vector of Dutch elm disease pathogens Ophiostoma ulmi and Ophiostoma novo-ulmi. Invasive competitor displacing native Scolytus species and earlier-introduced S. multistriatus in North America. Significant pest of fruit industry in China, particularly apricot production in Xinjiang Province. Primary association with Ulmus pumila in North America, which rarely exhibits Dutch elm disease symptoms in Saskatchewan and Manitoba, potentially limiting disease impact in that region.

Economic pest of fruit orchards in China. Threat to urban and forest elm populations in North America as vector of Dutch elm disease. Subject of monitoring and management efforts using semiochemical-based traps. Displacement of earlier bark beetle invaders alters forest pest community composition.

• Scolytus multistriatusSmaller European elm bark beetle; morphologically similar adults with overlapping size range and external character variability; distinguished reliably by aedeagus morphology or RAPD-PCR markers; displaced by S. schevyrewi in North America
• Native Scolytus elm bark beetlesNative North American species; being displaced by invasive S. schevyrewi throughout its expanding range

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

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Scolytus schevyrewi . [Distribution map].
• Identification of Candidate Olfactory Genes in Scolytus schevyrewi Based on Transcriptomic Analysis
• Bionomics ofScolytus schevyrewi(Coleoptera: Curculionidae) in Saskatchewan and Manitoba, Canada
• Characterization of two non-native invasive bark beetles, Scolytus schevyrewi and Scolytus multistriatus (Coleoptera: Curculionidae: Scolytinae)
• Behavioral Responses of Scolytus schevyrewi (Coleoptera: Curculionidae: Scolytinae) to Volatiles From Apricot Tree (Rosales: Rosaceae)
• Breeding behaviour of the bark beetle Scolytus schevyrewi Semenov (Col., Scolytidae) in Ulmus pumila
• Host Acceptance and Larval Competition in the Banded and European Elm Bark Beetles, Scolytus schevyrewi and S. multistriatus (Coleoptera: Scolytidae): Potential Mechanisms for Competitive Displacement between Invasive Species