Spittlebugs of Mediterranean Olive Groves: Host-Plant Exploitation throughout the Year

Spittlebugs are the vectors of the bacterium Xylella fastidiosa Wells in Europe, the causal agent of olive dieback epidemic in Apulia, Italy. Selection and distribution of dierent spittlebug species on host-plants were investigated during field surveys in 2016–2018 in four olive orchards of Apulia and Liguria Regions of Italy. The nymphal population in the herbaceous cover was estimated using quadrat samplings. Adults were collected by sweeping net on three dierent vegetational components: herbaceous cover, olive canopy, and wild woody plants. Three species of spittlebugs were collected: Philaenus spumarius L., Neophilaenus campestris (Fallén), and Aphrophora alni (L.) (Hemiptera: Aphrophoridae). Philaenus spumarius was the predominant species both in Apulia and Liguria olive groves. Nymphal stages are highly polyphagous, selecting preferentially Asteraceae Fabaceae plant families, in particular some genera, e.g., Picris, Crepis, Sonchus, Bellis, Cichorium, and Medicago. Host-plant preference of nymphs varies according to the Region and through time and nymphal instar. In the monitored sites, adults peak on olive trees earlier in Apulia (i.e., during inflorescence emergence) than in Liguria (i.e., during flowering and beginning of fruit development). Principal alternative woody hosts are Quercus spp. and Pistacia spp. Knowledge concerning plant selection and ecological traits of spittlebugs in dierent Mediterranean olive production areas is needed to design eective and precise control strategies against X. fastidiosa vectors in olive groves, such as ground cover modifications to reduce populations of spittlebug vectors

Phenology, seasonal abundance and stage-structure of spittlebug (Hemiptera: Aphrophoridae) populations in olive groves in Italy

Spittlebugs (Hemiptera: Aphrophoridae) are the dominant xylem-sap feeders in the Mediterranean area and the only proven vectors of Xylella fastidiosa ST53, the causal agent of the olive dieback epidemic in Apulia, Italy. We have investigated the structured population phenology, abundance and seasonal movement between crops and wild plant species of both the nymphal and adult stages of different spittlebug species in olive groves. Field surveys were conducted during the 2016–2018 period in four olive orchards located in coastal and inland areas in the Apulia and Liguria regions in Italy. The nymphal population in the herbaceous cover was estimated using quadrat samplings. Adults were collected through sweep nets on three different vegetational components: herbaceous cover, olive canopy and wild woody plants. Philaenus spumarius was the most abundant species; its nymphs were collected from early March and reached a peak around mid-April, when the 4th instar was prevalent. Spittlebug adults were collected from late April until late autumn. P. spumarius adults were abundant on the herbaceous cover and olive trees in late spring, and they then dispersed to wild woody hosts during the summer and returned to the olive groves in autumn when searching for oviposition sites in the herbaceous cover. A relatively high abundance of P. spumarius was observed on olive trees during summer in the Liguria Region. The present work provides a large amount of data on the life cycle of spittlebugs within an olive agroecosystem that can be used to design effective control programmes against these vectors in infected areas and to assess the risk of the establishment and spread of X. fastidiosa to Xylella-free areas

Tracking the spread of Halyomorpha halys in Italy combining citizen science and spatial modelling

Native to Asia, the Brown Marmorated Stink Bug (BMSB) Halyomorpha halys (Heteroptera: Pentatomidae) is currently one of the most invasive pests in the world. Extremely polyphagous, once introduced in a new territory, BMSB rapidly becomes a key pest of fruit orchards and other crops. The first detection of BMSB in Italy was in Emilia Romagna in 2012, and now is rapidly dispersing in Northern Italy and in the rest of the country. The detection timely activated a survey that combined active search with citizen science using multimedia channels. Data concerning time and location of the findings and population abundance were collected. The spread of BMSB in Italy was tracked obtaining the current distribution map. To investigate the spatial pattern of dispersal in the early stage of spread, a 116 x 134 km area contain the location of the first detection was considered and divided in 2 x 2 km cells. Rules are specified to define the occupancy of each cell and follow the spread dynamics in a discrete-space and derive a first estimation of the spread rate. Aspects of the temporal population dynamics were investigated estimating the transition probability among different classes of abundance in the cells. Predicting population growth is important since field data in the Northern Italian show that as pest abundance increases the pest becomes a serious threat in fruit orchards. Our findings confirm the potential fast spread of BMSB that could rapidly invade wide areas facilitated by passive transportation at long distance. These preliminary results together with data on phenology, host plants and behaviour collected in the same area could be considered to build more accurate model on the spatial-temporal population dynamics. This model could be used as a tool supporting the design of spread management strategies and guiding crop protection measures

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

Polyphagous phytophagous organisms that shelter in man-made objects have a higher chance of becoming invasive fast-spreading pests, going undetected during phytosanitary checks and travelling with any type of goods. However, if the same organisms are also a household nuisance, they could be used in crowdsourcing surveys aimed at their early detection and to track their spread in real time. By participating in these surveys, people can be educated on the destructive potential of invasive species and on sustainable management options. However, in order to obtain good-quality data, useful to plant protection stakeholders, a one-to-one approach with people is crucial. The case study is the Italian invasion of Halyomorpha halys, among the most dangerous global crop-threatening pests. A 4-year survey that combined active search and a crowdsourcing approach made the tracking of its spread and investigation of its spatiotemporal dynamics possible, showing the functionality of coordinated multiactor approach in data collection

Phenology, Seasonal Abundance, and Host-Plant Association of Spittlebugs (Hemiptera: Aphrophoridae) in Vineyards of Northwestern Italy

Spittlebugs (Hemiptera: Aphrophoridae) are the vectors of the bacterium Xylella fastidiosa (Xf) in Europe. Xf may cause severe epidemics in cultivated plants, including grapevines. To assess the threat represented by the bacterium to grapevines, detailed information on the vectors’ phenology, density, and ecology in vineyards is needed. The aim of the present work was to describe spittlebug diversity, phenology, and host-plant association in the vineyard agroecosystem. Two separate field surveys of nymphal and adult spittlebug populations, i.e., a two-year survey of a single site and a one-year survey of three sites, were performed in vineyards of northwestern Italy in three consecutive years. Philaenus spumarius was the most common species, reaching average nymph densities on herbaceous cover up to 60–130 nymphs/m2. Adults were sampled on grapevines from May to September, with a peak in June (up to 0.43 insects/sweep). Herbaceous cover was colonized after egg hatching and in late summer for oviposition, while wild woody hosts represented a refuge during summer. The results show that spittlebugs can reach high population levels in vineyards, at least in the areas where the ground is covered by herbaceous plants for the whole season and the use of insecticides is moderate. The extended presence of P. spumarius adults on grapevines represents a serious risk factor for the spread of Xf. The scenarios of Xf establishment in vineyards in northwestern Italy and Europe are discussed in relation to the abundance, phenology, and plant association of spittlebugs

Collection of data and information on biology and control of vectors of Xylella fastidiosa

The scope of this project was the collection of data and information on biology, phenology and control of vectors and potential vectors of Xylella fastidiosa (referred to, from now on, as Xf vectors). Systematic literature searches covering the different topics were conducted on authoritative databases indexing peer-reviewed scientific publications as well as on grey literature repositories. An extraction table on the ecology and phenology of Xf vectors was generated, together with a draft protocol for field data collection targeted to Philaenus spumarius. Efficacy tables on different control methods were also produced and crosschecked with data on plant protection products currently applied in the EU with effect on Xf vectors, producing a good agricultural practices table. With the help of questionnaires, we inventoried: i) the ongoing integrated pest management programmes on stone fruits, citrus, grapevine and olive crops in the Mediterranean Member States (MedMSs), and the monitoring activity on Xylella vectors currently conducted in all the EU MSs. Finally, we collected new experimental data on phenology and ecology of P. spumarius and other spittlebug species for three consecutive years (2016-2018). The data have been collected via field surveys in olive orchards, vineyards and insect rearing at the macrocosm (field), mesocosm (screenhouse) and microcosm (small rearing cage) level. All observations in olive groves were conducted in parallel in the Apulia and Liguria regions, while those in vineyard were carried out in the Piedmont region (Italy). The results are provided in the body of the report as metanalysis and in Excel tables as supporting material and concern i) phenology, host-plant associations and population dynamics of nymphs and adults of P. spumarius and other spittlebugs under different environmental conditions, ii) fecundity and reproductive biology from microcosms and field-collected females. Field and mesocosm data are supported by agronomic and meteorological data

Recovery in environmental risk assessments at EFSA

EFSA performs environmental risk assessments (ERAs) for single potential stressors such as plant protection products, genetically modified organisms and feed additives and for invasive alien species that are harmful for plant health. In this risk assessment domain, the EFSA Scientific Committee recognises the importance of more integrated ERAs considering both the local and landscape scales, as well as the possible co-occurrence of multiple potential stressors that fall under the remit of EFSA, which are important when addressing ecological recovery. In this scientific opinion, the Scientific Committee gathered scientific knowledge on the potential for the recovery of non-target organisms for the further development of ERA. Current EFSA guidance documents and opinions were reviewed on how ecological recovery is addressed in ERA schemes. In addition, this scientific opinion is based on expert knowledge and data retrieved from the literature. Finally, the information presented in this opinion was reviewed by experts from the relevant EFSA Panels, European risk assessment bodies and through an open consultation requesting input from stakeholders. A conceptual framework was developed to address ecological recovery for any assessed products, and invasive alien species that are harmful for plant health. This framework proposes an integrative approach based on well-definedspecific protection goals, scientific knowledge derived by means of experimentation, modelling and monitoring, and the selection of focal taxa, communities, processes and landscapes to develop environmental scenarios to allow the assessment of recovery of organisms and ecological processes atrelevant spatial and temporal scales