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

Tracing the dispersal route of the invasive Japanese beetle Popillia japonica

The Japanese beetle, Popillia japonica, is a highly polyphagous Scarabaeidae native to Japan that colonized North America and Azores in the last century and has recently invaded Italy and Switzerland. Considering its economic impact on the horticulture and turfgrass industries, this species was ranked within the EU priority pests list in 2019. According to the EU Convention on Biological Diversity, the identification of invasion routes is a pivotal aspect in an effective management program aimed at controlling invasive alien species. To reconstruct the source of introductions of this pest, we investigated the genetic variability of P. japonica in its native and invaded areas worldwide by analyzing 9 microsatellite loci and two mitochondrial genes, COX I and CytB. In its native area, P. japonica is structured into two populations: one in the southern and another in the northern-central region of Japan. A limited area within central Japan was identified as the putative source of the North American outbreak. Moreover, the ABC inference and phylogeographic reconstruction suggest that two European populations originated from two independent introductions. The Azores Islands outbreak occurred approximately 50 years ago and originated from the southeastern region of North America (For simplicity, in this paper North America refers to Canada and the USA), while the second introduction, more recently, occurred in Italy and Switzerland and originated from northeastern region of North America

Oscheius tipulae in Italy: Evidence of an Alien Isolate in the Integral Natural Reserve of Montecristo Island (Tuscany)

Montecristo Island is an integral natural reserve of the Tuscan Archipelago National Park (Central Italy), characterized by a peculiar assemblage of flora and fauna, with several endemic taxa, and also with a high number of alien species. During a soil survey, we found an alien Oscheius tipulae Lam & Webster, 1971 isolate, phylogenetically close to others from South America. In this article, we examined the possible pathways of introduction of this nematode. Because of the high number of alien plants in this protected area and the low desiccation survival ability of O. tipulae, we hypothesized that the presence of this alien nematode isolate may be related to the soil of introduced plants, although historical association with plant-associated invertebrates is also possible. Further studies with more populations and marker molecules are necessary to investigate the distribution of O. tipulae and the possible impact on this natural reserve

Molecular detection assay of the bud mite Trisetacus juniperinus on Cupressus sempervirens in nurseries of central Italy

Trisetacus juniperinus (Nalepa) sensu Keifer (Acari: Eriophyoidea: Phytoptidae) causes irregular development of buds, shoot deformations and stunted growth of trees, resulting in a serious threat to nurseries and young stands of Cupressus sempervirens L. (Mediterranean cypress). Recently, some cypress clones selected for their resistance to the fungal canker agent Seiridium cardinale (Wag.) have shown high susceptibility to the mite. Considering its tiny body, its hidden lifestyle inside the buds and the probable occurrence of other species (the vagrant Epitrimerus cupressi (Keifer) is common on the Mediterranean cypress in Italy), detection and monitoring of T. juniperinus require taxonomic expertise and are often time-consuming and challenging before serious damage is discernible. In the present study, a rapid, cost-effective PCR-based method was developed and validated to detect T. juniperinus on cypresses. The cytochrome c oxidase subunit I (COI) gene was amplified with degenerate and specific primers, but the latter were the only ones able to discriminate between T. juniperinus and E. cupressi. PCR products distinguished the two species both in a pool of individuals in a mixed population of both species and in single individuals, indicating the sensitivity of the detection method. PCR-RFLP (restriction fragment length polymorphism) by means of XmnI and XbaI endonucleases separated the two species. Furthermore, a washing-sieving protocol was used to make mite collection from the tree sample faster and simpler; this procedure did not interfere with the molecular detection of the species. The possibility of the routine use of this assay to monitor quarantine eriophyoids infesting plant material is discussed

I parassitoidi di Leptoglossus occidentalis in Sicilia e nel suo areale di origine nordamericano

Sul coreide Leptoglossus occidentalis, cimice delle conifere di origine nordamericana, che in Italia ha fatto registrare un calo della produzione di pinoli di Pinus pinea, si sono finora registrati parassitoidi di ninfe e adulti, e parassitoidi oofagi. Al primo gruppo appartengono i Diptera Tachinidae: negli USA e in Canada è stata riscontrata Trichopoda pennipes, mentre nell’Italia centro-settentrionale pochi adulti sono stati parassitizzati da Ectophasia crassipennis e da tachinidi ancora non identificati. Tra i parassitoidi oofagi in Canada erano stati finora segnalati il Platygastridae Gryon pennsylvanicum, l’Eupelmidae Anastatus pearsalli e l'Encyrtidae Ooencyrtus sp.; nell’Italia centro-settentrionale, seppur con minime percentuali, sono già stati segnalati Anastatus bifasciatus, Ooencyrtus pityocampae, e l’eulofide Baryscapus servadeii. Lo scopo del presente lavoro era individuare i parassitoidi in Sicilia e in Nord America. In Sicilia, dopo due anni di rilievi in campo ed esposizioni di ovature sentinella, nessun parassitoide è sfarfallato dalle uova di L. occidentalis; un solo adulto dell'eterottero è stato trovato con un uovo di tachinide. Durante le ricerche svolte in Nord America nel 2010, dalle uova del coreide liberamente deposte in campo G. pennsylvanicum è stato l’unico parassitoide ottenuto in 6 località del British Columbia e in 3 della California; per quest'ultima area risulta il primo e l'unico parassitoide noto. Invece, esponendo coppie di L. occidentalis con femmine ovideponenti all’interno di sacchetti di rete nel British Columbia, su Pinus monticola le uova sono state parassitizzate, oltre che da G. pennsylvanicum (23%), anche da Ooencyrtus johnsoni (4%), per la prima volta segnalato su quest'ospite, e da Anastatus sp. (4%); il platigastridae è stato l'unico parassitoide sfarfallato da uova deposte su Picea engelmannii (60%) e su Pinus contorta (29%). La parassitizzazione del Gryon nelle prove con i sacchetti è stata maggiore (46%) rispetto a quella delle uova deposte fuori dai sacchetti (4%). La maggiore attività di G. pennsylvanicum è stata registrata nel mese di luglio. G. pennsylvanicum appare un efficace antagonista naturale di L. occidentalis, ragion per cui è stato recentemente introdotto in laboratorio in Italia, e sono in corso prove di ovideposizione su eterotteri italiani, in vista di un suo futuro rilascio in pieno campo

Pre-release risk assessment of the egg-parasitoid Gryon pennsylvanicum for classical biological control of Leptoglossus occidentalis.

Leptoglossus occidentalis Heidemann (Heteroptera: Coreidae) is a North American conifer seed pest that was accidentally introduced to Europe. In the Mediterranean area, it threatens the production of Pinus pinea Linna- eus seeds. The egg-parasitoid Gryon pennsylvanicum (Ashmead) (Hymenop- tera: Platygastridae), the main natural enemy in the native range of L. occidentalis, was imported from British Columbia to Italy. Pre-release risk assessments were made under quarantine conditions by no-choice tests conducted with na€ıve and experienced G. pennsylvanicum offering single eggs of target and non-target species for varying exposure times (1, 4, 48 h). G. pennsylvanicum successfully parasitized from 75% to 100% of the target host eggs. Only one female specimen of the egg-parasitoid emerged from a non-target egg (Gonocerus juniperi Herrich-Schaeffer, He- teroptera: Coreidae). Two dead female specimens were found, one inside an egg of Coreus marginatus (Linnaeus) (Heteroptera: Coreidae) and one in an egg of Camptopus lateralis (Germar) (Heteroptera: Alydidae). All three cases occurred at the longest oviposition exposure time. Results obtained with this conservative approach suggest that the risk to non-target species of releasing G. pennsylvanicum in Italy is low

Preliminary studies on the cryopreservation of silkworm (Bombyx mori)

Developing a technique for the cryopreservation of Bombyx mori L. germplasm may provide significant benefits for supplying good strains to farmers and facilitate the conservation of living material in genetic banks. Producing species-specific protocols for the selection of the most apt embryonic stage, dechorionation/permeabilization of eggshells, and the acclimation at low temperature before the treatment of eggs at cryogenic temperature is a prerequisite for cryopreservation of B. mori embryos. In this research, non-diapausing eggs of B. mori Nistari strain were used to study cold hardiness; the final aim was to select the most apt embryonic development stages, and in addition, reliable permeabilization, and vitrification treatments. Polyhybrid B. mori eggs of a diapausing strain were also used for comparison in experiments of embryogenesis, permeability, and acclimation under low temperature before cryopreservation. The Nistari eggs in the stage of 24 hours post-oviposition (h PO) showed a scarce survival rate (0.1%) after their submersion in liquid nitrogen (LN), while the highest survival in loading and dehydration with cryoprotective agents was assessed in 40h PO eggs. Overwintering diapausing eggs preserved for three months at 5 degrees C and then treated with various vitrification solutions gave rise to good hatching rates. The achieved results show that it is possible to improve the method of cryopreservation of B. mori eggs by obtaining a good permeability with cryoprotectants at loading/dehydration steps and by decreasing the toxicity, reducing the treatment time