2025-range-expansion

Guides

• Euwallacea similis

  ambrosia beetle

  Euwallacea similis is a small ambrosia beetle (2.2–2.7 mm) native to South and Southeast Asia and Australia, now globally distributed through human trade in timber and wood commodities. It colonizes stressed, cut, or recently dead host trees rather than healthy living trees, distinguishing it from related invasive species like E. fornicatus. The species exhibits haplodiploid sex determination and inbreeding polygyny, with females farming symbiotic Fusarium fungi in wood galleries. First recorded in the Iberian Peninsula in 2025, it is considered a high-risk quarantine pest due to its polyphagous habits and potential to vector pathogenic fungi.

  ambrosia-beetleinvasive-specieshaplodiploidfungal-symbiosisforest-pestxyleboriniquarantine-pestwood-boring-beetleglobal-trade-vectorcryptic-species-complexsecondary-borercrepuscularlight-attractedfusarium-symbiontparthenogenesisinbreeding-polygynygenome-sequencedchromosome-fissioniberian-peninsula-introduction2025-range-expansion