Non−larch hosts of Ips cembrae (Coleoptera: Curculionidae): Review and field observations

Ips cembrae, the large larch bark beetle, is primarily associated with Larix spp., yet scattered reports suggest occasional colonization of other conifers. To clarify the reliability and ecological meaning of these records, we combined a critical review of published host data with field observations on non−larch hosts. Literature data showed that non−larch hosts are reported only rarely and often without biological detail. Field surveys of 2,720 Norway spruce trees conducted from 2006 to 2009 yielded only two confirmed cases of colonization by I. cembrae. A single−tree field observation on Douglas fir showed that I. cembrae was able to complete development to the callow adult stage under observed conditions in 2025. Although the species was originally described from material collected under the bark of Pinus cembra, occurrences on this host are similarly rare and geographically isolated, and no consistent evidence exists for regular development on non−larch hosts. Taken together, these findings suggest that non−larch conifers may occasionally permit colonization by I. cembrae, but the available evidence remains too limited to infer their role in sustaining populations.