Extending the vibroscape to agroecosystems: investigating the influence of abiotic factors and monitoring insect vibrational signaling

Environmental conditions are crucial factors that influence communication systems and affect animal behavior. Research in the field of biotremology has improved our understanding of insect behavior, ecology, and evolution. However, the interactions between vibrational signaling and environmental factors are less studied, mainly because of technical issues faced in field trials. We therefore developed and tested an approach to investigate the effect of abiotic factors on insect vibrational signaling and explored its implementation as a monitoring tool for insect vibrational signals, using a vineyard as an agroecosystem model. Our results showed a significant decrease in insect signaling activity during unsuitable conditions of high temperature and wind velocity. We determined for the first time, the daily signaling pattern of the two insect pests, Scaphoideus titanus and Halyomorpha halys, in natural conditions. Biotremology techniques could be profitably used to monitor not only the presence of target pest species but also the biodiversity associated with vibrational signaling insects. In particular, the method implemented in this study could be used as a tool to compare the quality of cultivated areas under different management system

Orientus ishidae (Hemiptera: Cicadellidae): biology, direct damage and preliminary studies on apple proliferation infection in apple orchard

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

Vibrational calling signals improve the efficacy of pheromone traps to capture the brown marmorated stink bug

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

Brown marmorated stink bug (Halyomorpha halys) feeding damage determines early drop in olive crops

The brown marmorated stink bug (BMSB), Halyomorpha halys Stål, is an invasive species and a polyphagous pest. BMSB feeding activity was suspected to be responsible for olive damage. To evaluate the effect of feeding damage from adults and nymphs of BMSB, 30 rearing sleeves were positioned in an olive grove, at an early stage of drupe development. The individuals were kept in the rearing sleeves for 48 h, and the number of olives in each sleeve was checked weekly, visually assessing signs of damage and measuring their volume. After the 48-hr exposure, the number of early dropped olives was significantly higher for rearing sleeves containing BMSB adults and nymphs compared with control, with visible signs of damage. The volume of olives still attached was significantly lower for rearing sleeves with adults. These results provide key evidence on BMSB damage in developing olives. If the numbers of BMSB keep increasing in Mediterranean regions (where most of the olive production occurs), actions should be taken to prevent economic losse

Attraction of Egg Parasitoids Trissolcus mitsukurii and Trissolcus japonicus to the Chemical Cues of Halyomorpha halys and Nezara viridula

9openInternationalItalian coauthor/editorTrissolcus 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.openScala, M.; Fouani, J.; Zapponi, L.; Mazzoni, V.; Wells, K.E.; Biondi, A.; Baser, N.; Verrastro, V.; Anfora, GScala, M.; Fouani, J.; Zapponi, L.; Mazzoni, V.; Wells, K.E.; Biondi, A.; Baser, N.; Verrastro, V.; Anfora, G

Factors influencing short-term parasitoid establishment and efficacy for the biological control of Halyomorpha halys with the samurai wasp Trissolcus japonicus

Background: Classical biological control has been identified as the most promising approach to limit the impact of the invasive pest species Halyomorpha halys (Heteroptera: Pentatomidae). This study investigated the parasitism rate at sites where the biocontrol agent Trissolcus japonicus (Hymenoptera: Scelionidae) was released and where its unintentional introduction took place, in the Trentino-South Tyrol region. The effect of land-use composition was studied to understand which factors favor the establishment of hosts and parasitoids, including native and exotic species. Results: The released T. japonicus were detected a year after the start of the program, with a significant parasitoid impact and discovery, compared to control sites. Trissolcus japonicus was the most abundant H. halys parasitoid, and Trissolcus mitsukurii and Anastatus bifasciatus were recorded also. The efficacy of T. mitsukurii was lower in sites where T. japonicus was successfully established, suggesting a possible competitive interaction. Parasitism level by T. japonicus at the release sites was 12.5% in 2020 and 16.4% in 2021. The combined effect of predation and parasitization increased H. halys mortality up to 50% at the release sites. Landscape composition analysis showed that both H. halys and T. japonicus were more likely to be found at sites with lower altitude and with permanent crops, whereas other hosts and parasitoids preferred different conditions. Conclusion: Trissolcus japonicus showed a promising impact on H. halys, at release and adventive sites, with minor nontarget effects, mediated by landscape heterogeneity. The prevalence of T. japonicus in landscapes with permanent crops could support IPM in the future. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry

Combining irradiation and biological control against brown marmorated stink bug: are sterile eggs a suitable substrate for the egg parasitoid Trissolcus Japonicus?

The brown marmorated stink bug (BMSB), Halyomorpha halys, is a phytophagous invasive pest native to south-eastern Asia, and it is now distributed worldwide. This species is considered to be one of the most damaging insect pests in North America and in Europe. In agriculture, the predominant approach to managing BMSB is based on the use of insecticides, specifically pyrethroids and neonicotinoids. Unfortunately, the biology of the species and its facility to develop mechanisms of resistance to available pesticides has induced farmers and scientists to develop different, least-toxic, and more effective strategies of control. In a territorial area-wide approach, the use of a classical biological control program in combination with other least-toxic strategies has been given prominent consideration. Following exploratory surveys in the native range, attention has focused on Trissolcus japonicus, a small scelionid egg parasitoid wasp that is able to oviposit and complete its larval development in a single egg of H. halys. A common method for detecting egg parasitoids in the native range involves the placement of so-called 'sentinel' egg masses of the pest in the environment for a short period, which are then returned to the laboratory to determine if any of them are parasitized. Outside of the area of origin, the use of fertile sentinel eggs of the alien species may lead to the further release of the pest species; an alternative is to use sterile sentinel eggs to record the presence of new indigenous egg parasitoids or to detect the dispersal of alien species (in this case, T. japonicus) released in a new environment to control the target insect pest species. This study evaluated the performance of three types of sterile sentinel eggs as a suitable substrate for the oviposition and larval development of the egg parasitoid T. japonicus in a context of combining classical biological control with a Sterile Insect Technique (SIT) approac

Arthropod communities in fungal fruitbodies are weakly structured by climate and biogeography across European beech forests

Aim The tinder fungus Fomes fomentarius is a pivotal wood decomposer in European beech Fagus sylvatica forests. The fungus, however, has regionally declined due to centuries of logging. To unravel biogeographical drivers of arthropod communities associated with this fungus, we investigated how space, climate and habitat amount structure alpha and beta diversity of arthropod communities in fruitbodies of F. fomentarius. Location Temperate zone of Europe. Taxon Arthropods. Methods We reared arthropods from fruitbodies sampled from 61 sites throughout the range of European beech and identified 13 orders taxonomically or by metabarcoding. We estimated the total number of species occurring in fruitbodies of F. fomentarius in European beech forests using the Chao2 estimator and determined the relative importance of space, climate and habitat amount by hierarchical partitioning for alpha diversity and generalized dissimilarity models for beta diversity. A subset of fungi samples was sequenced for identification of the fungus’ genetic structure. Results The total number of arthropod species occurring in fruitbodies of F. fomentarius across European beech forests was estimated to be 600. Alpha diversity increased with increasing fruitbody biomass; it decreased with increasing longitude, temperature and latitude. Beta diversity was mainly composed by turnover. Patterns of beta diversity were only weakly linked to space and the overall explanatory power was low. We could distinguish two genotypes of F. fomentarius, which showed no spatial structuring. Main conclusion Fomes fomentarius hosts a large number of arthropods in European beech forests. The low biogeographical and climatic structure of the communities suggests that fruitbodies represent a habitat that offers similar conditions across large gradients of climate and space, but are characterized by high local variability in community composition and colonized by species with high dispersal ability. For European beech forests, retention of trees with F. fomentarius and promoting its recolonization where it had declined seems a promising conservation strategy

Indicators of sustainable forest management: application and assessment

Report of the international project Life ManForCBD

Effetto dell’eterogeneità del paesaggio su comunità di vertebrati in frammenti boschivi

Environmental fragmentation leads to the transformation of continuous habitats in several patches, separated from each other by a habitat ifferent from the original that is generally efined matrix. To study its effect on the iodiversity of the residual patches, this process has initially being assimilated to the theories developed on insular fauna dynamics (e.g. acArthur & Wilson). However, the reductionist approach of describing patches as islands, in a sea of non-habitat, does not allow the inclusion of the complexity of real landscapes. The aim of the present study is therefore the investigation of the relationship existing between animal species distribution and landscape heterogeneity, to examine the influence of matrix composition and configuration, and patch structure on the vertebrate assemblages of residual woods. The field part of the study took place in the Marche Region, in an area of 100,000 ha approximately, which encompasses the Chienti and Potenza River catchments. This area was selected since it offered the opportunity of comparing woodland fragments included in landscapes that have suffered a diverse human impact. In the area, 24 sample sites were selected, characterised by the presence of Turkey oak (Quercus cerris) and downy oak (Q. rubescens). In each site, the bird communities composition was described using 66 point counts. The presence and absence of two arboreal mammals was assessed, with 115 hair tubes for the European red squirrel (Sciurus vulgaris), and 132 nestboxes for what concerns the hazel dormouse (Muscardinus avellanarius). Each site spatial structure was also studied, through circular sample plots in which the vertical organization and composition of the herbaceous, shub and arboreal layers was described. Aerial photographs were used to describe and quantify landscape patterns. Four classes of land cover were identified (woodland, cropland, hedges, shrubs, grassland and anthropic areas) and mapped with GIS. Two software were employed to describe the landscape configuration according to the developed map, Patch Analyst and Image Analyzer. The extracted metrics were both structural and functional, and for every land cover class, percentage of occurrence, nearest neighbor, edge density, spatial aggregation and several more parameters were calculated. To avoid multicollinearity a principal components analysis (PCA) was performed on the variables, divided in three subsets describing respectively patch characteristics, landscape composition and landscape configuration. Six factors were extracted from the PCA and used as explanatory variables for the analysis of the target species distributions. The most abundant species present in the bird communities were also the most widespread. The consideration of the existing relationship between single species and environmental variables stressed how the whole community is influenced only by factors describing matrix composition and configuration, and in particular the lack of isolation of the patches, their connectivity and the presence of woods, grasslands and anthropic areas in the landscape. The factors associated to the patch features did not influence the observed pattern. The only feature of the patches that had an effect on the observed abundances was the size of the wood (R2 =0.435, p<0.001). Considering species diversity, the smaller and poorer sites tended to contain subsets of the species present in bigger and richer woods, showing a significant nested pattern that mostly involved generalist species. Using the species’ life history traits, the communities were subdivided in several different guilds, considering their breeding period diet, feeding technique, nest location, average laying date, clutch size and body mass. For each subgroup, the percentage of species and individuals present in each site was calculated, and included in multiple regression models. The fact that patch related factors, as the extent of the canopy cover, the canopy height and the average tree diameter, could not be disregarded in any of the models indicates the importance of the available internal components for species persistence. The contemporaneous consideration of landscape and patch analysis scales led to the emergence of different patterns, highlighting the presence of different driving forces, belonging to the two scales, contemporaneously shaping community structure. The effect of landscape heterogeneity on the two considered mammal species was studied using logistic regressions. The resulting models were ranked using second order Aikaike Information Criterion (AICc and AICc) and the importance of the included parameters was evaluated with Akaike weights (wi). The use of three different sets of variables confirmed the importance of the amount of hedgerows in the landscapes surrounding the patches for the occurrence of both species. The convergence of the two arboreal mammals towards landscapes that offered a higher amount of hedges proved the critical role of this element to ensure species persistence through landscape structural connectivity. The relevance of other elements, as the amount of shrublands and grasslands in the matrix, suggests that since the local forest management impoverished the woods available resources, species occurrence is may be linked to the contemporaneous exploitation of sub-optimal habitats, through a process defined “habitat compensation”. The inclusion of species belonging to different taxa emphasised the matrix essential role, both in terms of composition and configuration, in determining the actual use of residual patches. In a heterogeneous landscape, structure heterogeneity matters in terms of connectivity and lack of isolation, and the presence and position of hedgerows and woods in the landscape were key determinants of species distribution. The contemporaneous consideration of parameters describing landscape and patch features showed how these two elements and their associated scales affect species in a different degree, and their lack of simultaneous consideration may lead to misleading conclusions. The matrix therefore holds the capability to at least mitigate the effects of isolation and habitat loss, if its management, and hence its permeability, allows animal movement