Evaluation of Insecticides for a Leaffooted Bug in Pomegranates, 2018

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New insights into the distribution and spreading of the Asian walnut moth, Garella musculana (Erschov, 1874) (Lepidoptera, Nolidae) in Europe with a focus on the Italian range

The Asian walnut moth, Garella musculana (Erschov, 1874) (Lepidoptera, Nolidae) is an alien pest originating from Central Asia and is now spreading in Europe, attacking walnut trees. In this study, we updated the current distribution of G. musculana, focusing on the Italian range, where it was reported for the first time in 2021. Field surveys showed an extensive distribution of G. musculana in northern Italy, particularly in the Veneto Region. In this area, the Asian walnut moth developed on English and black walnut, attacking almost exclusively tree shoots. Based on current distribution data, further investigations are required in the nearby regions as well as in those that were less surveyed. Lastly, it is imperative to conduct more studies on insect biology and the impact on walnut production

Co-haplotyping symbiont and host to unravel invasion pathways of the exotic pest Halyomorpha halys in Italy

The brown marmorated stink bug Halyomorpha halys (Stål) is a globally invasive species that harbors a primary bacterial symbiont ‘Candidatus Pantoea carbekii’. In this work, P. carbekii was used here as another genetic marker to investigate the biodiversity and biogeographical patterns of this important pest, in native and newly invaded areas, especially in Italy. The correlation between the genetic structure of the symbiont and that of its host was studied through the analyses of one bacterial and one host marker, the putative pseudogene ΔybgF and the mitochondrial gene COI, respectively. As a result, five new P. carbekii haplotypes were identified, and an association pattern between host-symbiont haplotypes was observed. Host species showed higher haplotype diversity than symbiont, which can be expected in a long term host-symbiont association. Populations from the north-eastern Italy showed the highest values of genetic diversity for both markers, highlighting that this particular Italian area could be the result of multiple ongoing introductions. Moreover, some of the symbiont-host haplotypes observed were shared only by populations from north-eastern Italy and native areas, especially Japan, suggesting further introductions from this native country to Italy. Overall, our findings improve the understanding of the potential origin of multiple accidental introductions of H. halys in Italy

An Insight into the Role of Trissolcus mitsukurii as Biological Control Agent of Halyomorpha halys in Northeastern Italy

Sustainable strategies such as classical or augmentative biological control are currently being evaluated for the long-term management of the alien invasive pest Halyomorpha halys (Stål) (Hemiptera: Pentatomidae). A three-year study carried out in northeastern Italy was performed to investigate the distribution and field performance of the H. halys egg parasitoid Trissolcus mitsukurii (Ashmead) (Hymenoptera: Scelionidae), in comparison with other parasitoid species. In the study area, adventive populations of T. mitsukurii were present since 2016, representing the earliest detection of this species in Europe. Trissolcus mitsukurii was the most abundant parasitoid and showed a higher “parasitoid impact” (i.e., number of parasitized eggs over the total number of field-collected eggs) compared to the other species, i.e., Anastatus bifasciatus (Geoffroy) (Hymenoptera: Eupelmidae), Trissolcus basalis (Wollaston) and Trissolcus kozlovi Rjachovskij (Hymenoptera: Scelionidae). The hyperparasitoid Acroclisoides sinicus (Huang and Liao) (Hymenoptera: Pteromalidae) was also recorded. Phylogenetic analysis of T. mitsukurii population distinguished two clades, one covering samples from Italy, Japan and China, the other from South Korea. The present study provides promising results for the biological control of a pest that is having a dramatic impact on a wide range of crops worldwide

Invasive brown marmorated stink bug (Hemiptera: Pentatomidae) facilitates feeding of European wasps and ants (Hymenoptera: Vespidae, Formicidae) on plant exudates

The brown marmorated stink bug, Halyomorpha halys, is a polyphagous species from eastern Asia, which has spread to America and Europe where it damages many crops. In recently colonized areas, facilitative interactions between H. halys and native insects are poorly investigated. In this study, we report for the first time facilitation of native wasp and ant feeding by H. halys in Europe. The facilitation was related to the outflow of plant exudates caused by H. halys feeding on manna ash trees, where they have aggregated in response to an aggregation pheromone, which then attracted species of Hymenoptera to the infested trees. Trees other than manna ash were not involved in the facilitation between these two taxa. The species that frequently visited infested manna ash were Polistes dominula, Vespa crabro, Formica (Serviformica) cunicularia and Lasius emarginatus, while Polistes cf. nimpha, Vespula germanica, Crematogaster scutellaris and Tapinoma subboreale were occasional visitors. The numbers of wasps and ants feeding on plant exudates differed at different times in a day, with more Hymenoptera foraging in the afternoon, when more H. halys individuals were actively feeding. Facilitative interactions, such as those recorded in this study, are important for furthering our understanding of the ecology of invasive species in terms of creating sources of food for native organisms

Lethal Effects of High Temperatures on Brown Marmorated Stink Bug Adults before and after Overwintering

The invasive brown marmorated stink bug, Halyomorpha halys, is causing economic and ecological damage in invaded areas. Its overwintering behavior warrants mitigation practices in warehouses and shipping operations. The aim of this study was to characterize the mortality response curves of H. halys adults to short high-temperature exposure. Here we compared field-collected individuals entering (ENA) and exiting diapause (EXA). EXA adults displayed increased susceptibility to high temperatures compared to ENA individuals. Complete mortality of all tested individuals was obtained after 10 min exposure at 50.0 \ub0C, and after 15 (EXA) or 20 min (ENA) at 47.5 \ub0C. The nutritional status of these insects had no effect on high-temperature tolerance. The mortality curves obtained here may be used for the definition of cost-effective heat treatments aimed at the H. halys control