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The mosaic leafhopper, Orientus ishidae (Matsumura), is an Asian species widespread in Europe that can cause leaf damage in wild trees and transmit disease phytoplasmas to grapevines. Following an O. ishidae outbreak reported in 2019 in an apple orchard in northern Italy, the biology and damage caused by this species to apples were investigated during 2020 and 2021. Our studies included observations on the O. ishidae life cycle, leaf symptoms associated to its trophic activity, and its capability to acquire “Candidatus Phytoplasma mali,” a causal agent of Apple Proliferation (AP). The results indicate that O. ishidae can complete the life cycle on apple trees. Nymphs emerged between May and June, and adults were present from early July to late October, with the peak of flight between July and early August. Semi-field observations allowed for an accurate description of leaf symptoms that appeared as a distinct yellowing after a one-day exposure. In field experiments, 23% of the leaves were found damaged. In addition, 16–18% of the collected leafhoppers were found carrying AP phytoplasma. We conclude that O. ishidae has the potential to be a new apple tree pest. However, further studies are required to better understand the economic impact of the infestations.

Halyomorpha halys (Stål, 1855), the brown marmorated stink bug (BMSB), is an invasive species that has become a key agricultural pest in its invaded range. Commercial traps available for BMSB monitoring rely on male produced aggregation pheromones as lure, with two possible shortcomings: trap spillover and low detection precision. In this study, we assessed if vibrational signals can increase the attractiveness of pheromone traps by testing the optimized vibration-based lure (Female Song 2, FS2) associated with a specifically designed trap (i.e., the vibrotrap). We evaluated the efficacy of this bimodal trap (i.e., pheromones + vibrations) on females, males and nymphs in controlled conditions (greenhouse) and in the field, in two sites at the margin of two commercial vineyards. In the field, bimodal vibrotraps were compared to three unimodal (i.e., only pheromone) trap types. Both experiments showed that the vibrotrap is highly attractive for BMSB, and the optimized FS2 signal significantly improved its effectiveness. Even though FS2 was selected to target males, the number of trapped females increased as well. Overall, the presented findings show a feasible improvement to future commercial BMSB traps through the synergic use of semiophysicals and semiochemicals. Further research is needed to evaluate the effectiveness of vibrotraps for both early detection and mass trapping.

Trissolcus mitsukurii and Trissolcus japonicus are two Asian egg parasitoids associated with different pentatomids such as Halyomorpha halys. Adventive populations of T. mitsukurii were found in Northern Italy, suggesting its employment as a biological control agent (BCA) against H. halys. Nevertheless, to reduce the latter’s population, T. japonicus was released in Italy. Releasing an exotic parasitoid requires investigating the interaction between the BCA and the environment to avoid negative impacts on the entomofauna of the new habitat. Trissolcus mitsukurii is mainly associated with Nezara viridula in its native area. Therefore, we investigated and compared the ability of female T. mitsukurii and T. japonicus to distinguish between naturally released cues of H. halys and N. viridula. A single parasitoid was exposed to contact kairomones of both pests to evaluate its modifications in orthokinetic and locomotory behaviour. The behaviour of female T. mitsukurii was also tested on synthetic compounds simulating the cues of the two pentatomids. When naturally released cues were used, T. japonicus preferred the traces of H. halys, while T. mitsukurii preferred N. viridula’s cues. Moreover, the attraction of T. mitsukurii to N. viridula’s cues was confirmed with synthetic cues. Additional studies are needed to judge if this parasitoid can be used as a BCA.

Simple Summary The management of invasive alien species is a very challenging task. For the brown marmorated stink bug (Halyomorpha halys), classical biological control has been identified as the most suitable method to sustainably reduce its populations in the long-term. Among its natural enemies, two species were identified as the most promising candidates for biocontrol, Trissolcus japonicus and Trissolcus mitsukurii. Populations of these two species have recently been detected in Europe and to assess their distribution, a large-scale study was performed. Combining several monitoring methods, in four months (May–September 2019), a wide area covering northern Italy and parts of Switzerland was surveyed. The results showed that both species have spread into all types of habitats where H. halys is present and the parasitization of native species was rarely observed. Among native species, Anastatus bifasciatus was the predominant parasitoid of H. halys. This study supported the development of the first release program of Tr. japonicus in Europe. Abstract The brown marmorated stink bug Halyomorpha halys is an invasive agricultural pest with a worldwide distribution. Classical biological control has been identified as the most promising method to reduce the populations of H. halys. Adventive populations of two candidates for releases, Trissolcus japonicus and Trissolcus mitsukurii, have recently been detected in Europe. To assess their distribution and abundance, a large-scale survey was performed. From May to September 2019, a wide area covering northern Italy and parts of Switzerland was surveyed, highlighting the expanding distribution of both Tr. japonicus and Tr. mitsukurii. Within four years after their first detection in Europe, both species have rapidly spread into all types of habitats where H. halys is present, showing a wide distribution and continuous expansion. Both exotic Trissolcus showed high levels of parasitism rate towards H. halys, while parasitization of non-target species was a rare event. The generalist Anastatus bifasciatus was the predominant native parasitoid of H. halys, while the emergence of native scelionids from H. halys eggs was rarely observed. The presence of the hyperparasitoid Acroclisoides sinicus was also recorded. This study provided fundamental data that supported the development of the first inoculative release program of Tr. japonicus in Europe.

Halyomorpha halys (St&aring, l) (Hemiptera: Pentatomidae) is an invasive alien species and a key agricultural pest. Its native parasitoids (Trissolcus japonicus Ashmead and Tr. mitsukurii Ashmead) have been registered in several countries where H. halys brought dramatic economic losses and where biological control is considered to be the most effective long-term solution. By searching for stink bug egg masses and exposing sentinel egg masses, we monitored the distribution of native and exotic egg parasitoids in Trentino-Alto Adige (Italy), an area where both the host and parasitoids are in expansion. We recorded ten pentatomids, seven parasitoid species, with the first report of Tr. japonicus in this area and a hyperparasitoid. In the assemblage, Anastatus bifasciatus (Geoffroy) and Tr. mitsukurii were the dominant parasitoids, with a different distribution in terms of context and host plants. Sycamore was the host plant where the highest number of naturally laid parasitized egg masses (26%) were recorded. Trissolcus mitsukurii showed the highest parasitism rate, and was often found in apple orchards. The emergence of exotic parasitoids showed a temporal delay compared to native ones. Sequence analysis of 823 bp of the CO1 mitochondrial gene revealed that the recovered Tr. japonicus and Tr. mitsukurii harbored one single haplotype each. These haplotypes were previously found in 2018 in Northern Italy. While sentinel egg masses proved to be very effective in tracking the arrival of exotic Trissolcus species, the collection of stink bug egg masses provided fundamental data on the plant host species. The results lend strong support to the adaptation of exotic Trissolcus species to the environmental conditions of the range of introduction, providing new information on plant host-associations, fundamental for the development of biological control programs.

In this study we analyzed the inter-specific relationships in assemblages of syrphids at a site in northern Italy in order to determine whether there are patterns in diurnal co-occurrence. We adopted a null model approach and calculated two co-occurrence metrics, the C-score and variance ratio (V-ratio), both for the total catch and of the morning (8:00-13:00) and afternoon (13:00-18:00) catches separately, and for males and females. We recorded discordant species richness, abundance and co-occurrence patterns in the samples collected. Higher species richness and abundance were recorded in the morning, when the assemblage had an aggregated structure, which agrees with previous findings on communities of invertebrate primary consumers. A segregated pattern of co-occurrence was recorded in the afternoon, when fewer species and individuals were collected. The pattern recorded is likely to be caused by a number of factors, such as a greater availability of food in the morning, prevalence of hot and dry conditions in the early afternoon, which are unfavourable for hoverflies, and possibly competition with other pollinators. Our results indicate that restricting community studies to a particular time of day will result in certain species and/or species interactions not being recorded.

Developing protocols for threatened invertebrates is often challenging, because they are not only rare but also elusive. This is the case with the stag beetle (Lucanus cervus), a protected and flagship species for the saproxylic beetle fauna in Europe. We applied a standard transect walk at a European scale (8 countries, 29 transects) to test its practicability and reliability as survey design. A total of 533 sightings were recorded throughout the sampling period, but detection probability changed as the season progressed. Considering the observed activity pattern, occupancy models showed that a short period of three consecutive weeks, between the middle of June and the first week of July, resulted in a high probability of detection (P > 0.7). As time of the peak of activity varies from year to year and between sites, we propose to extend the sampling period to five weekly surveys. Detailed information on the transect characteristics and the optimal time for surveying were analysed. The data indicate that a weekly transect at dusk provides a reliable method for monitoring this species throughout its distributional range. No correlation was found between latitude, longitude and phenology of sightings, however. However, a standard method such as the one presented, allows broadening the scale of monitoring studies, provinding data to evaluate the efficacy of conservation measures. © 2016 The Royal Entomological Society