Marco Valerio Rossi Stacconi

Addressing the challenges posed by Non-Indigenous Species (NIS) demands coordinated efforts across terrestrial, freshwater and marine ecosystems. In this study, we engaged a diverse group of 90 Italian researchers operating within these three domains to identify and assess strategies for advancing NIS research, using a structured, interactive and expert-driven methodology. The process began with a comprehensive evaluation of ongoing activities, research methodologies and specific needs. This assessment provided information for the development of an initial set of suggestions to ameliorate NIS research, which were collectively discussed and refined, leading to the identification of six good practices identified by the acronym TRACKS and described as: i ) Tracking NIS in biodiversity data collection; ii ) Reference protocols for NIS data collection; iii ) Active participation; iv ) Collaboration and FAIR principles; v ) Knowledge hub for NIS data; vi ) Strategic communication. A SWOT framework was then applied to analyse the internal and external factors influencing the Strengths, Weaknesses, Opportunities and Threats associated with each good practice. Consensus-building techniques were used throughout the evaluation process to ensure the robustness of outcomes. Finally, a quantitative assessment of the SWOT analysis revealed a strong consensus amongst experts regarding the various strengths, weaknesses, opportunities and threats of the different good practices, along with a general optimism about the opportunities and strengths associated with their implementation. Developed within the Italian research community, this approach offered valuable insights to researchers worldwide working on NIS and enabled the expert assessment of six best practices that may serve as a benchmark for advancing the science of biological invasions.

The spotted‐wing drosophila, Drosophila suzukii , is one of the most damaging invasive fruit pests in the world. It infests a wide range of wild and crop host plants, impacting natural habitats and causing significant economic losses. Leptopilina japonica , a predominant larval parasitoid of D. suzukii in the native areas of the fly, is now spontaneously expanding into non‐native areas of its fly host. This study documents the presence and genetic structure of L. japonica collected from various wild and cultivated fruits across 11 sites in France in 2023. Leptopilina japonica emerged from 15% of fruit samples and was strongly positively associated with D. suzukii , showing parasitism rates of up to 38.5%, notably in Lonicera fruits. Despite this, D. suzukii remained dominant, indicating a limited current biocontrol effect, while native parasitoids were nearly absent from samples. Molecular analyses using COI markers revealed 10 distinct haplotypes of the L. j. japonica subspecies in France that clustered into three groups, suggesting multiple introductions and/or migration routes into France from Asia, North America and neighbouring European countries. The lack of nuclear diversity measured from ITS2 markers suggests that the colonization is recent and that the populations experienced a bottleneck process. Nevertheless, a more extensive sampling combined with the use of additional genetic markers would be needed to better understand the origin and spread of L. japonica and its consequences on the equilibrium of Drosophila communities.

The meadow spittlebug, Philaenus spumarius (Hemiptera: Aphrophoridae) (L.), is the primary vector of the bacterium Xylella fastidiosa (Xanthomonadales: Xanthomonadaceae) (Wells et al.), which causes a severe vascular disease leading to significant economic losses in olive production in southern Italy. In this study, we investigated the deterrent effect of ant scent on the behavior and activity of P. spumarius on olive twigs. Using binary choice experiments, we found that the compounds released by Crematogaster scutellaris (Hymenoptera: Formicidae) (Olivier) ants significantly reduced the time spent by spittlebugs on the olive twigs. Chemical analysis of ant cuticular composition, and of ant-scented and control olive leaves identified a mixture of specific compounds, which include octadecanal, triacontane, nepetalactol, and pelargonic acid, presumably involved in this interaction. Our findings contribute to the understanding of trait-mediated indirect interactions in agroecosystems and suggest further studies focused on behavioral bioassay-based experiments to evaluate the potential role of ants’ chemical cues in P. spumarius control to preserve olive groves.

The management of the invasive fruit fly Drosophila suzukii (Diptera: Drosophilidae) still relies on chemical control, despite concerns about pesticide resistance and environmental impact. Integrated pest management strategies are being explored, but current options remain limited and often insufficient. In invaded regions, local natural enemies are mostly generalist pupal parasitoids, which have proven inadequate for controlling this rapidly spreading pest. Conversely, in its native range, D. suzukii is host to more specialized larval parasitoids that may mitigate its impact on fruit crops. Extensive foreign exploration and risk assessments identified the larval endoparasitoid Ganaspis kimorum (Hymenoptera: Figitidae) as the most suitable candidate for classical biological control. In 2021, Italy launched a propagative biocontrol program utilizing a Japanese population of G. kimorum. Here, we present the results from the first 4 yr of releases conducted in Northeast Italy, where the parasitoid was released at 20 different locations. We provide an overview of the monitoring activities at these sites to determine whether G. kimorum has successfully established and to assess its parasitism levels on both the target pest and nontarget species. Results confirmed that G. kimorum is a specialist on D. suzukii and likely does not compete with local parasitoids for reproductive resources. Collected data also suggest that the parasitoid has become established in several locations, and it is gradually expanding its range from the initial release sites. Four years after the initial release of G. kimorum, the data gathered offers valuable insights into the efficacy and ecological implications of this biocontrol strategy.

The invasive spotted-wing drosophila, Drosophila suzukii , has emerged as a significant global pest over the past decade, threatening fruit production worldwide. The parasitoid Leptopilina japonica , presumed native to East Asia, has established adventive populations in Europe and North America and is increasingly recognized for its ability to parasitize substantial proportions of D. suzukii larvae across diverse habitats. Here, we provide a broad review of the biology, establishment, distribution, and potential impacts of L. japonica . Using field data from international monitoring programs, we document the seasonal dynamics of plant–host–parasitoid associations and assess evidence for L. japonica ’s impact on D. suzukii and non-target organisms. Findings indicate that L. japonica has successfully established in several areas where D. suzukii is present in Europe and North America, showing promise as a biological control agent to support sustainable pest management. Current data suggest it provides some suppression of D. suzukii populations with minimal non-target effects. However, long-term studies are necessary to clarify its food web interactions and efficacy as a biological control agent. In areas where L. japonica has been established, we propose its use in augmentative biological control programs to enhance its impacts in specific agricultural settings. Case-specific evaluations of its ecological effects and role in integrated pest management, supported by continued monitoring, are essential. The case of L. japonica illustrates the need for clear, research-informed policies to guide the use of adventively established non-indigenous natural enemies in pest management.

Background: G1 strain Ganaspis brasiliensis (Ihering) has been recently released in both Europe and America as a biological control agent of the spotted wing drosophila, Drosophila suzukii (Matsumura). In initial phases of classical biological control programs, it becomes imperative to evaluate the susceptibility of parasitoids to insecticides, to identify the best alternatives to adopt in an integrated pest management and organic perspective. In this study, we evaluated lethal and sublethal effects of topical application of five different insecticides classes: neonicotinoids, diamides, pyrethroids, organophosphates and spinosyns. Additionally, we tested residual toxicity in field trials in vineyards and sweet cherry orchards.Results: Adult wasps' susceptibility to different insecticides' classes were consistent between laboratory and field. Spinosad exhibited the highest toxicity, with a median lethal concentration (LC₅₀) of 0.00372 of the maximum field dose, and the highest knock‐down effect in field trials, causing 92.5 ± 5% of mortality at T₀. λ‐cyhalothrin showed sublethal effects on both male and female insects' longevity when applied at LC₃₀. In field trials, deltamethrin showed the highest persistence, causing significant parasitoid mortality up to 14 days after treatment. Conversely, cyantraniliprole was the least toxic active ingredient according to both topical and residual bioassays, even though its residues caused mortality up to 7 days after the treatment in the field.Conclusion: Our results indicate that spinosad and λ‐cyhalothrin are highly toxic to G. brasiliensis, making them incompatible with classical biological control programs. Cyantraniliprole exhibited lower toxicity, and may be considered a selective pesticide for the integrated management of D. suzukii. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The spotted-wing drosophila (SWD), Drosophila suzukii (Matsumura), is an invasive species native to East Asia and now widespread worldwide. Major economic damage is caused by the larvae developing within ripening soft-skin fruit. Currently, larval detection in fruit is limited to destructive methods and post-harvest control strategies heavily rely on the use of chemicals or cold to inhibit egg eclosion and larval growth. Feeding larvae are likely to induce substrate-borne vibrations in the berry that could be exploited as cues by predators or to develop a non-invasive pest detection method, an approach previously applied on leaves and wooden structures, but never on fresh fruit. We used a laser vibrometer to detect and characterize the incidental vibrations produced by D. suzukii larvae within fresh blueberries at five different pest age (48, 96, 168, 216 and 264 h). An innovative statistical analysis was performed to assess if infestation level (number of pupae) and pest age (hours after exposure) affect the spectrum and the amplitude of vibrations. The recordings of infested berries were characterized by the presence of a series of broad-band pulses (frequency range 0.1–2 kHz) without a regular temporal pattern, in an amplitude range between 12.1 and 946 µm/s. Furthermore, the analysis revealed the possibility to distinguish between different pest ages and infestation levels. By a spectral analysis of the recordings, the pest ages can be distinguished among each other, but for the age groups at 168 and 216 h after infestation. The vibration amplitude trend gradually increased up to 168–216 h after infestation, and then decreased until fly emergence. Low-infested blueberries showed a faster D. suzukii development time compared to high-infested blueberries. This was reflected into vibrational recordings, as low-infested blueberries exhibited peak amplitude at earlier stage compared to high-infested ones. Results suggest that D. suzukii larvae induce detectable vibrations by feeding within berries that are dependent on infestation level and pest age. We discuss the possible ecological role of such vibrations as cues for unintended receivers, such as predators and parasitoids, and their potential for innovative infestation detection methods.

The spotted-wing drosophila (SWD), Drosophila suzukii(Matsumura), is an invasive species native to East Asia and now widespread worldwide. Major economic damage is caused by the larvae developing within ripening soft-skin fruit. Currently, larval detection in fruit is limited to destructive methods and post-harvest control strategies heavily rely on the use of chemicals or cold to inhibit egg eclosion and larval growth. Feeding larvae are likely to induce substrate-borne vibrations in the berry that could be exploited as cues by predators or to develop a non-invasive pest detection method, an approach previously applied on leaves and wooden structures, but never on fresh fruit. We used a laser vibrometer to detect and characterize the incidental vibrations produced by D.suzukii larvae within fresh blueberries at five different pest age (48, 96, 168, 216 and 264 hours). An innovative statistical analysis was performed to assess if infestation level (number of pupae) and pest age (hours after exposure) affect the spectrum and the amplitude of vibrations. The recordings of infested berries were characterized by the presence of a series of broad-band pulses (frequency range 0.1 - 2 kHz) without a regular temporal pattern, in an amplitude range between 12.1 and 946 µm/s. Furthermore, the analysis revealed the possibility to distinguish between different pest ages and infestation levels. By a spectral analysis of the recordings, the pest ages can be distinguished among each other, but for the age groups at 168 and 216 hours after infestation. The vibration amplitude trend gradually increased up to 168-216 hours after infestation, and then decreased until fly emergence. Low-infested blueberries showed a faster D. suzukii development time compared to high-infested blueberries. This was reflected into vibrational recordings, as low-infested blueberries exhibited peak amplitude at earlier stage compared to high-infested ones. Results suggest that D. suzukii larvae induce detectable vibrations by feeding within berries that are dependent on infestation level and pest age. We discuss the possible ecological role of such vibrations as cues for unintended receivers, such as predators and parasitoids, and their potential for innovative infestation detection methods.

The brown marmorated stink bug, Halyomorpha halys, is a pentatomid bug of Eastern Asian origin that became an economically relevant pest in the Eurasian and American continents. Management of this species is limited to use of chemical insecticides: an inefficient method due to the strong adaptability of the target pest. The sterile insect technique (SIT) is potentially a valid tactic in the search for nontoxic alternatives. In this work, we investigated the suitability of mass-trapped overwintering males, collected during the aggregation phase before the winter diapause, for their release as competitive sterile males in an SIT programme. Differently from previous studies, irradiation was applied with a linear accelerator device that produced high-energy photons. Following a similar scientific protocol with newly emerged irradiated males, the effects of X-ray irradiation on physiological parameters (longevity, fecundity and fertility) were assessed. In addition, behavioural bioassays were carried out in no-choice conditions to evaluate if irradiation interferes with mating processes. The results are very encouraging; the effects of the irradiation at 32 Gy did not differ from the controls in the longevity or fecundity of the exposed overwintering adults. The hatching rate of the eggs laid by the fertile females that had mated with the irradiated males was less than 5%. The results of behavioural bioassays showed that the irradiation did not cause a significant impact on the quality of the sterile males. More research is warranted to evaluate the mating competitiveness of sterile males in semi-field and field conditions.

Current management strategy of the invasive fruit fly Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) exploits different tools but relies mainly on chemical control. In the invaded areas, the local natural enemy community mostly consists of generalist pupal parasitoids unable to control the pest efficiently. Conversely, in the pest native area, there are more specialized sympatric larval parasitoids attacking D. suzukii. Following foreign explorations and quarantine risk assessments, the larval endoparasitoid Ganaspis brasiliensis (Ihering) (Hymenoptera: Figitidae) was selected as the best candidate for classical biological control programs. In 2021, the first ever propagative biocontrol program using a Japanese G1 lineage of G. brasiliensis started in Italy. Here we report the results of the first year of releases in the province of Trento (Northeast Italy), wherein G. brasiliensis was released in 12 locations. Pre- and post-release samplings on fresh and fallen fruits were performed around the release points to assess the recapture rate, the impact of the exotic parasitoid on D. suzukii and its potential interactions with local non-target species. After releases, G. brasiliensis was recovered at 50% of the locations. The exotic parasitoid only emerged from D. suzukii, mostly from fresh fruit still on the plant. Post-overwintering monitoring revealed the presence of a four G. brasiliensis individuals at two release locations.