Abstract The olive fruit fly, Bactrocera oleae (Rossi), is a key pest of the olive tree worldwide. This study explores whether the endophytes Alcaligenes faecalis , Aureobasidium pullulans , Bacillus amyloliquefaciens , and Penicillium commune can trigger the emission of repellent volatile organic compounds (VOCs) in olive trees, targeting B. oleae . Accordingly, olive trees were inoculated with each endophyte or with buffer (control), and after 3 months, both fruits and leaves were collected to perform olfactometer assays and to evaluate VOCs by HS-SPME and GC–MS. Alcaligenes faecalis , A. pullulans , and B. amyloliquefaciens were found to significantly repel B. oleae females, with each treatment inducing a distinct VOC profile. Alcaligenes faecalis and B. amyloliquefaciens were characterized by higher levels of alkenes, including o-cymene and d-limonene, while P. commune and A. pullulans induced the emission of alkanes. Six VOCs were found to be negatively correlated with fly entries in the olfactometer assays, with beta-myrcene being the most prominent, followed by d-limonene, o-cymene, and 5-octadecene (E). These repellent VOCs were positively correlated with each other, indicating that their combined emission may produce synergistic effects, potentially enhancing their repellency. In contrast, 1, 4-hexadiene, 5-methyl-3-(1-methyl ethylidene) was identified as an attractant, showing a strong positive correlation with fly entries, and appeared to be produced through different biosynthetic pathways than the repellent VOCs. Overall, this work identifies three endophytes and a combination of repellent VOCs as promising new strategies for sustainable management of the olive fruit fly.

Abstract Psyllids are small (2.5–4 mm), phytophagous, plant sap-feeding insects. Several species, in the genus Cacopsylla , are known as pests of fruit trees in Europe and adjacent countries. Interestingly, some species are multivoltine, such as the pear psyllids Cacopsylla pyri and C. pyricola , while closely related psyllid species of pear, plum, and apple ( C. pyrisuga , C. pruni , and C. picta, resp.) are univoltine and migrate between Rosaceae fruit tree species and evergreen conifers in higher regions. Therefore, the latter species have to cover great distances between their two diverging habitats. To uncover adaptations of the flight behavior and ability to the different life-history strategies, the flight of migrating ( C. pruni ) and non-migrating ( C. pyri and C. pyricola ) psyllids is investigated with a flight mill, showing that the seasonal migration of C. pruni correlates with the motivation to initiate long straight distance flights, indeed. Interestingly, C. pyri and C. pyricola showed great differences in their flight motivation and performance, indicating a greater dispersal propensity of C. pyri than C. pyricola . In addition, the determination of the protein, soluble carbohydrate, and glycogen content of pear psyllids revealed the consumption of carbohydrates during the psyllids’ flight. The content of the energetic resources is discussed in relation to their flight propensity.

Abstract Thrips are important pests of everbearing strawberries worldwide. The emergence of resistance and the ban on several active ingredients mean that alternatives to insecticides need to be developed. Augmentative biological control in many cases has proved successful in controlling thrips; however, in certain cases it fails to keep thrips below the economic damage threshold. Identifying key factors influencing thrips populations is essential. We aimed to assess how thrips population dynamics varied by thrips species, grower practice and location of strawberry plots. In 2022 and 2023, a network of 43 plots in all the main strawberry-growing regions of Switzerland was established. Thrips were counted, adults identified to species level, and the management practices of the growers as well as the crops, topography and temperatures of the plots were recorded. The main species were Frankliniella occidentalis (68% of samples), Thrips tabaci (13%), F. intonsa (12%), and T. fuscipennis (5%) in varying proportions from one plot to another. Only the environmental factors altitude, temperature and distance from a meadow explained a sufficient proportion of thrips population variability. We also observed a link between the distance to the forest and the extent of damage done by thrips to strawberries. No differences were detected between the control strategies used suggesting that the use of insecticides or biocontrol agents is similarly effective. These results underscore the importance of considering the landscape and surrounding host plants in thrips management strategies.