Introduction into Italy of Gryon pennsylvanicum (Ashmead), an egg parasitoid of the alien invasive bug Leptoglossus occidentalis Heidemann

Leptoglossus occidentalis (Heteroptera, Coreidae), a Nearctic species, was accidentally introduced into Northern Italy in the late 1990s, from where it has spread throughout Europe. The bug causes abortion of immature cones of Pinus pinea L., with economic impact on the pine-nut industry. As part of a pest control research program, the egg parasitoid Gryon pennsylvanicum Ashmead (Hymenoptera, Platygastridae) was collected from British Columbia, Canada, and legally introduced to a quarantine climatic chamber in Florence, Italy. The egg parasitoid will be tested against native non target heteropterans, an environmental impact assessment will be conducted, and a mass rearing method will be developed if appropriate. The ultimate goal is to release G. pennsylvanicum into Italian P. pinea forests for classical biological control of L. occidentalis

Implementing mass rearing of trissolcus japonicus (Hymenoptera: Scelionidae) on cold-stored host eggs

Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), a pest of Asian origin, has been causing severe damage to Italian agriculture. The application of classical biological control by the release of Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae), an exotic egg parasitoid, appears to be one promising solution. In Italy, releases of T. japonicus in the field were authorized in 2020. In this study, some parameters that could influence the rearing of T. japonicus in insectaries were investigated. A significantly higher production of progeny was observed on host eggs stored at 6◦C (86.5%) compared to −24◦C (48.8%) for up to two months prior to exposure to parasitism. There were no significant differences in progeny production from single females in a vial provided with only one egg mass (83.2%) or 10 females inside a cage with 6 egg masses (83.9%). The exposure of parasitoids to refrigerated (6◦C) egg masses of H. halys for 72 h led to a significantly higher production of progeny (62.1%) compared to shorter exposures for 48 (44.0%) or 24 h (37.1%). A decline in production of progeny by the same female was detected between the first (62.1%) and the second parasitization (41.3%). Adult parasitoids stored at 16◦C for up to 90 days had an 87.1% survival rate, but a significant decrease in progeny production was detected. These parameters could be adjusted when rearing T. japonicus for specific aims such as the production of individuals for field release or colony maintenance

A first assessment of genetic variability in the longhorn beetle Rosalia alpina (Coleoptera: Cerambycidae) from the Italian Apennines

The Rosalia longicorn (Rosalia alpina) is a strictly protected saproxylic beetle, widely distributed in Central and Southern Europe and mainly associated with ancient beech forests. To improve knowledge about the conservation status of R. alpina in Italy, available molecular markers (microsatellites and mitochondrial cytochrome c oxidase I(COI)) were tested for the first time on Italian populations. The study was performed in four sampling sites distributed in two areas placed in Northern (“Foreste Casentinesi” National Park) and Central Apennines (“Abruzzo, Lazio and Molise” National Park) where populational data about Rosalia longicorn were collected in the framework of the European LIFE MIPP Project. The genetic relationship among Apennine and Central/South-eastern European populations was explored by a comparison with mitochondrial DNA (mtDNA) data from literature. Microsatellite markers were only partially informative when applied to R. alpina Italian individuals, although providing some preliminary indication on an extensive gene flow among populations from the Apennines and local ongoing processes of genetic erosion. Genetic data are consistent with previous ecological data suggesting that the maintenance of variability in this species could be related to both habitat continuity and preservation of large senescent or standing dead trees in forests. Finally, a peculiar origin of the Apennine populations of R. alpina from a putative “Glacial Refugium” in Italy was inferred through COI data. The high genetic distance scored among the analysed populations and those from Central and South-eastern Europe indicates that the R. alpina deme from Apennine Mountains might represent a relevant conservation unit in Europe. Further genetic analyses will allow assessing other possible conservation units of R. alpina and, thus, defining large-scale conservation strategies to protect this endangered longhorn beetle in Europe

Assessing the distribution of exotic egg parasitoids of Halyomorpha halys in Europe with a large-scale monitoring program

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

Aggiornamento sul programma nazionale italiano di lotta biologica classica al moscerino asiatico dei piccoli frutti, Drosophila suzukii

Vengono presentate le attività del Tavolo tecnico-scientifico nazionale di coordinamento per la lotta al moscerino asiatico dei piccoli frutti, Drosophila suzukii Matsumura, istituito formalmente su indicazione del Comitato Fitosanitario Nazionale nel gennaio 2021. La principale finalità del Tavolo è quella di definire e condividere le attività di contrasto al fitofago invasivo attraverso la programmazione di un piano triennale di controllo biologico classico che prevede l’impiego del parassitoide esotico Ganaspis brasiliensis Ihering. La prima campagna di lanci del parassitoide, partita nell’agosto del 2021 a seguito dell’autorizzazione da parte dell’ex Ministero della Transizione Ecologica (ora Ministero dell’Ambiente e della Sicurezza Energetica), ha visto la partecipazione delle regioni Campania, Emilia-Romagna, Piemonte, Puglia, Sicilia, Valle d’Aosta e Veneto e delle Province autonome di Trento e Bolzano. Nel 2023 si aggiungeranno le regioni Lombardia e Toscana. I risultati dei monitoraggi delle prime due stagioni, eseguiti sul 100% dei siti di lancio tra maggio e novembre di ogni anno, suggeriscono che G. brasiliensissi stia insediando in varie aree del territorio nazionale e ne confermano la specificità nei confronti di D. suzukii, già osservata negli studi di laboratorio

I programmi di eradicazione di Anoplophora chinensis e A. glabripennis in Italia

Anoplophora chinensis and Anoplophora glabripennis are two longhorn beetles native of the Far East (mainly from China and Japan) and invasive to Europe and North America. They develop in a number of broadleaf plants extremely different in age and size: from potted plants and bonsais to old and monumental plants of forest, urban, fruit and ornamental trees and shrubs. The wood-boring larvae feed in phloem and xylem of infested plants, causing disruption of vascular tissues and structural weakness, and leading to plant death. Both species are considered worldwide as serious pests and they were accidentally introduced in many North American and European countries, including Italy. Severe phytosanitary regulations were disposed to prevent further introductions and insect spread, and eradication protocols were carried out to remove the invading populations. Recent infestations of both species were found in north and central Italy. Chipping or burning infested plants, also including roots in the case of A. chinensis, are set up for the pest eradication. Eradication programs also include a specific survey, phytosanitary restrictions for movements of host-plants from the quarantine areas, and a citizen science program based on citizen\u2019s information and public awareness

A new strategy of environmentally safe control of chestnut tortricid moths

Insect pest damage represents the mean restricting factor for the chestnut (Castanea sativa Mill.) fruit production in Italy and in Europe. Especially tortricid moth species are constantly very noxious because their larvae feed on developing nuts, thus causing important harvest losses. Although the early chestnut moth (Pammene fasciana L.) attack results only in an early drop of fruits at the beginning of the development, more serious damages are produced by the intermediate and the late chestnut moths, Cydia fagiglandana (Zell.) and C. splendana (Hb.), respectively. Larvae penetrate the nuts and develop into them, digging a tunnel and eating the endosperm. Usually damaged fruits fall during the summer, but in some cases they may complete the ripening and can be harvested as part of the crop. The chemical control of C. fagiglandana and C. splendana is not advisable to preserve the naturalness of the final product and the safety of the chestnut grove. Moreover, the endophytic development of the larvae, the large size of the trees and the characteristics of the Italian chestnut orchards make difficult and not economically advantageous the use of pesticides. Previous studies conducted on the use of tortricid sex attractants showed a potential control ability on both species. On this basis a novel, low impact control method can be achieved by combining the classical mating disruption approach to the use of a new kind of dispenser. A canister housed in a plastic cabinet, called “puffer”, repeatedly sprays proper pheromone doses on a 12- or 24- hour schedule. Puffers, produced by Suterra®, are strategically located in the chestnut orchards, hung on tree branches at heights of 6-8m, in number of 2.5 per ha. Besides the low impact for the environment, this approach shows many advantages since it is very easy to apply and, when optimised, also cheap. Therefore, a large scale trial was initiated to test the efficacy of this approach in three Italian regions: Trentino (north-eastern Italy), Tuscany (central Italy) and Campania (southern Italy). In each region, 19 puffers were located in chestnut orchard areas of about 8ha. Traps (pagoda type), baited with specific pheromones, were installed at heights of 2-4m inside and outside the treated area to verify the effectiveness of the puffers. For each species, 3 traps were placed in the central part of the treated area and 3 traps in the untreated plot and used as control. The traps were checked weekly, removing and counting adults. At the harvest time, fruit damage was also evaluated in treated and untreated areas. First data suggest that the “puffer approach” is quite easy to apply and feasible. Even if such methods need pluriannual trials to be evaluated, preliminary results are encouraging and suggest good perspectives to obtain a complete biotechnical control of Cydia spp