Odors Attracting the Long-Legged Predator Medetera signaticornis Loew to Ips typographus L. Infested Norway Spruce Trees

Maria Sousa, Göran Birgersson, Kristina Karlsson Green, Marc Pollet, Paul G. Becher

Research output: Contribution to journalA1: Web of Science-articlepeer-review


Predatory long-legged flies of the genus Medetera are important, but currently understudied, natural enemies of Scolytinae bark beetles such as Ips typographus. Medetera flies lay eggs on beetle-infested trees, where the developing larvae find their prey, but the chemical cues used by Medetera to locate infested trees are currently unknown. To identify odors attracting Medetera signaticornis, a species in Europe, headspace samples were collected at several time-points through different stages of I. typographus attacks on logs of Norway spruce (Picea abies). The headspace samples were analyzed using combined gas chromatography and mass spectrometry (GC–MS), and gas chromatography coupled with electroantennographic detection (GC-EAD) to determine compounds that stimulate M. signaticornis antennae. Antennae of M. signaticornis males and females were found to detect (–)-cis-verbenol, ( +)-trans-verbenol and myrtenol, which are known to be produced by bark beetles. Antennal responses were also observed for verbenene, isoterpinolene, α-pinene oxide, camphor, pinocamphone, terpinene-4-ol, myrtenal, borneol, α-terpineol, geranyl acetone, and verbenone, which are primarily produced by microorganisms, and α-pinene, α-fenchene, β-pinene, camphene, 3-carene, limonene, γ-terpinene, and terpinolene, known spruce tree compounds. In field experiments testing two synthetic blends containing 18 antennal active and two additional compounds 2-methyl-3-buten-2-ol and ipsdienol we observed significant attraction of M. signaticornis within 24 h. These attractive blends can form the basis for development of Medetera monitoring lures for use in future forest and pest management.
Original languageEnglish
Publication statusPublished - 31-Jan-2023

Thematic List 2020

  • Forest

Thematic list

  • Insects

EWI Biomedical sciences

  • B280-animal-ecology

Taxonomic list

  • true flies (2-winged flies) (Diptera)
  • long-legged flies (Dolichopodidae)


  • woodland protection

Geographic list

  • Northern Europe


  • identification

Free keywords

  • Medetera
  • bark beetle
  • Curculionidae, Scolytinae
  • natural control agent

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