Bark and ambrosia beetles (Coleoptera: Curculionidae: Scolytinae) are major pests of agricultural and forest systems and include some species which attack hazelnut (Corylus avellana L.) as well. Although hazelnut cultivation is increasingly threatened by insect and mite pests, yet little is known about how management practices can reduce infestations. This study investigated bark and ambrosia beetles in hazelnut orchards from two highly productive areas: Viterbo district (central Italy) and Samegrelo-Zemo Svaneti region (Republic of Georgia). Three phytosanitary management strategies were compared across 2023–2024: Integrated Pest Management, organic farming, and renaturalised orchards. Monitoring also evaluated three ethanol-baited trap designs: three designs in Italy (handmade red funnel [BR] and bottle [TT] and commercial multi-funnel [MF]) and only TT in Georgia. Anisandrus dispar, Hypothenemus eruditus, Xyleborinus saxesenii, and Xylosandrus germanus were detected in both countries, while Xyleborus monographus occurred only in Italy. Xyleborinus saxesenii was the dominant species in both regions. Beetle populations differed among management strategies, being lowest in organic orchards and highest in integrated and renaturalised systems. Trap performance also varied, with BR consistently outperforming commercial MF. These findings highlight the influence of management and monitoring tools on scolytine populations, offering practical insights for sustainable hazelnut production.

Taphrorychus hirtellus Eichhoff (Coleoptera, Curculionidae, Scolytinae), a European scolytine beetle previously documented in Central and Southeastern Europe, Turkey (type locality), and Algeria, is recorded for the first time in Italy. Specimens were collected in April and May 2021 in the Circeo National Park (Latium Region, central Italy) in multifunnel traps baited with a blend of quercivorol, α-copaene, ethanol and α-pinene. The species, considered native, is a new addition to the Italian fauna. In addition to the faunistic record, an identification key to the European Taphrorychus species is provided.

Ambrosia beetles are among the most successful invasive insect groups worldwide, and competition advantages over native species are often assumed to underlie the establishment success of non-native species. We tested this assumption by comparing competitive performance at both the beetle and fungal symbiont level between two ubiquitous ambrosia beetles in Europe: the invasive Xylosandrus germanus and the native Xyleborinus saxesenii . In a laboratory rearing experiment, females were assigned to intraspecific pairings (two individuals of the same species) or interspecific pairings (one individual of each species), and offspring production, dispersal timing, gallery crossings, and cannibalism were recorded. In parallel, the respective nutritional fungal symbionts, Ambrosiella grosmanniae and Dryadomyces sulphureus , were grown in direct competition across a range of ethanol concentrations and substrates (malt-yeast agar, beech and oak sawdust), and growth trajectories were modelled with logistic growth curves. Contrary to expectations, interspecific competition reduced reproductive output in X. germanus but not in X. saxesenii , which also dispersed earlier from galleries. At the fungal level, D. sulphureus consistently outperformed A. grosmanniae across substrates and ethanol treatments, suggesting that beetle-level outcomes are consistent with a mediating role of symbiont competitiveness rather than direct behavioural interactions. These results challenge the assumption that invasive ambrosia beetles are inherently superior competitors and indicate that the spread of X. germanus in Europe is more likely driven by ecological flexibility, host breadth, and repeated introduction through international trade than by competitive dominance over X. saxesenii as the most common native ambrosia beetle species.