an insect of engraver beetle group (family Scolytidae); two species carry fungus of Dutch elm disease, the native Hylurgopinus rufipes and the European Scolytus multistriatus, which is more prevalent; adults feed in twig crotches of healthy trees, then fly to recently cut, dead, or dying elms, tunnel under bark and lay eggs; larvae tunnel as they feed; fungus grows in tunnels; adults emerging from tunnels carry fungus spores on their bodies and thus transfer spores to healthy trees. see also in index Dutch elm disease; Elm-leaf beetle.