Ambrosia beetles exhibit broad host ranges but a narrow preference based on the condition of the host. Tissues infected by pathogens or containing ethanol can facilitate attacks by ambrosia beetles, although it still remains unclear how these factors interact. The present study aimed to examine how (i) chestnut logs infected with the fungal pathogen Cryphonectria parasitica and treated with ethanol (i.e. baited with ethanol lure, soaked in ethanol or untreated) and (ii) hornbeam logs soaked in different ethanol concentrations (3–12.5%) affect host selection and colonization success of ambrosia beetles. Ethanol‐soaked logs were more attractive to Anisandrus dispar than ethanol‐baited logs or untreated logs, although this difference was more evident in uninfected than infected logs. Increasing ethanol concentration in host tissues was differentially attractive to Xyleborinus saxesenii and Xylosandrus germanus. A nonlinear relationship was also documented between ethanol concentration and emergence of X. germanus adults. Overall, the results obtained suggest that the presence of C. parasitica in chestnut logs can affect host selection in ambrosia beetles. In addition, the ethanol concentration in tree tissues affects host selection and colonization success, although the effect varies depending on the beetle species. This contrasting response could be a niche‐partitioning mechanism based on ethanol within host tissues.

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The Spotted Wing Drosophila (SWD), Drosophila suzukii (Matsumura), is a harmful insect pest for soft fruit cultivations. Even though its main hosts belong to the genera Prunus and Rubus, its high polyphagy and adaptability to new environments makes it a serious problem for farmers worldwide, who have reported several economic losses because of this pest. A wide series of proposals to control SWD are available and operate in line with the mechanisms of integrated pest management, demonstrating their high efficiency when applied at the opportune moment. This work aims to apply and validate a physiologically based model which summarises all the available information about D. suzukii biology, such as the relationship between environmental temperature and its development, fertility and mortality rates. The model provided, as a result, a description of a population of SWD females taking into consideration the multiple generations that occurred during the year. Simulations were then compared with field data collected in a three-year survey in two experimental fields located in the Sabina Romana area (Lazio, Italy). More specifically, D. suzukii males were monitored with traps in fields cultivated with mixed varieties of cherries and they were selected because of their clearer identification in comparison to females. Results showed a high level of reliability of simulations in representing the field data, highlighting at the same time that there is no discrepancy in simulating D. suzukii females in order to represent male populations.

No abstract

In the Circeo National Park (Italy), a survey assessed the occurrence of the ambrosia beetle Xylosandrus germanus in addition to the conspecifics X. compactus and X. crassiusculus. This is the first report in Europe of the co‐presence of three Xylosandrus species, in an evergreen Mediterranean maquis dominated by holm oaks (Quercus ilex L.). Although no damage caused by X. germanus has been observed, the richness of plant species in the Circeo National Park may allow the establishment of this highly polyphagous ambrosia beetle, possibly endangering this native ecosystem. The dominance in the associated fungal community of Ambrosiella grosmanniae and Fusarium spp. reflects a stable symbiotic relationship of these taxa with X. germanus.