Tracking the Spread of Sneaking Aliens by Integrating Crowdsourcing and Spatial Modeling: The Italian Invasion of Halyomorpha halys

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.

Section: Introductionmentioning

confidence: 99%

“…In Italy, H. halys was reported in the Emilia Romagna region in 2012, in the Piedmont region in 2013, in the Veneto region and in the Friuli-Venezia Giulia region in 2014, and two years later in the Trentino-Alto Adige region [10][11][12][13][14]. The species is now distributed all over the country [13,15].…”

Section: Introductionmentioning

confidence: 99%

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

Scaccini

Falagiarda

Tortorici

et al. 2020

“…Halyomorpha halys Stål (Hemiptera: Pentatomidae), the brown marmorated stink bug, is a highly polyphagous invasive species. Since its first detection in the United States in 1996 [1], it has been found in several European countries, including Italy [2] and Switzerland [3], in Canada [4] and in South America [5]. Its invasiveness is ensured by high dispersal capabilities [6] and its hitchhiker behavior [7].…”

Section: Introductionmentioning

confidence: 99%

Assemblage of the Egg Parasitoids of the Invasive Stink Bug Halyomorpha halys: Insights on Plant Host Associations

Zapponi

Bon

Fouani

et al. 2020

Halyomorpha halys (Stål) (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.

“…Public engagement in biodiversity monitoring can be very useful to track the spread of exotic species, as already demonstrated in few other cases in Italy [ 98 , 99 , 100 , 101 , 102 , 103 , 104 ]. Current information over the distribution of the probably exotic T. immigrans in Italy remains scarce [ 62 ], but our data suggest that it is very common and widespread in disturbed habitats.…”

Section: Discussionmentioning

confidence: 97%

Public Engagement Provides First Insights on Po Plain Ant Communities and Reveals the Ubiquity of the Cryptic Species Tetramorium immigrans (Hymenoptera, Formicidae)

Castracani

Spotti

Schifani

et al. 2020

Ants are considered a useful model for biodiversity monitoring and several of their characteristics make them promising for citizen science (CS) projects. Involving a wide range of public figures into collecting valuable data on the effect of human impact on ant biodiversity, the School of Ants (SoA) project represents one of the very few attempts to explore the potential of these insects in CS. Through the collaboration with the “BioBlitz Lombardia” project, we tested the SoA protocol on 12 Northern Italy parks, ranging from urban green to subalpine protected sites. As a result, we obtained some of the very first quantitative data characterizing the ants of this region, recording 30 species and highlighting some interesting ecological patterns. These data revealed the ubiquitous presence of the recently taxonomically defined cryptic species Tetramorium immigrans, which appears to be probably introduced in the region. We also discuss advantages and criticisms encountered applying the SoA protocol, originally intended for schools, to new categories of volunteers, from BioBlitz participants to park operators, suggesting best practices based on our experience.