Philaenus Spumarius Research Articles

Quantitative Real-Time PCR Based on SYBR Green Technology for the Identification of Philaenus italosignus Drosopoulos & Remane (Hemiptera Aphrophoridae).

The use of molecular tools to identify insect pests is a critical issue, especially when rapid and reliable tests are required. We proposed a protocol based on qPCR with SYBR Green technology to identify Philaenus italosignus (Hemiptera, Aphrophoridae). The species is one of the three spittlebugs able to transmit Xylella fastidiosa subsp. pauca ST53 in Italy, together with Philaenus spumarius and Neophilaenus campestris. Although less common than the other two species, its identification is key to verifying which role it can play when locally abundant. The proposed assay shows analytical specificity being inclusive with different populations of the target species and exclusive with non-target taxa, either taxonomically related or not. Moreover, it shows analytical sensibility, repeatability, and reproducibility, resulting in an excellent candidate for an official diagnostic method. The molecular test can discriminate P. italosignus from all non-target species, including the congeneric P. spumarius.

DC‐EPG assisted comparison of European spittlebugs and sharpshooters feeding behaviour on grapevine

AbstractXylem‐feeding is apparently the only requirement making an insect a competent vector of the bacterium Xylella fastidiosa, an organism responsible for the devastation of the Southern Italian olive forest and nowadays considered one of the most feared threats to agriculture and landscape in Europe, including vineyards. Here, we used the direct current‐electrical penetration graph (DC‐EPG) technique to compare and describe the feeding behaviour on grapevine of four xylem‐feeding species considered candidate vectors of X. fastidiosa widespread in Europe, namely two spittlebugs (the meadow spittlebug Philaenus spumarius and the spittlebug Neophilaenus campestris) and two sharpshooter leafhoppers (the rhododendron leafhopper Graphocephala fennahi and the green leafhopper Cicadella viridis). We created a standard for the analysis of EPG waveforms recorded with a DC‐EPG device, describing feeding activities performed by these insects from stylet insertion into the plant to withdrawal. This standard, along with freely available software, has been developed to harmonize the calculation of feeding behavioural parameters in xylem‐feeders. The most relevant differences between the two vector taxa were the probing frequency and the dynamics of xylem ingestion. Sharpshooters tended to perform significantly more probes than spittlebugs. In contrast, the latter spent longer times in low‐frequency xylem ingestion, characterized by scattered contractions of the cibarial dilator muscle interspersed with periods of pump inactivity. Cicadella viridis was the species displaying the highest frequency of the electrical pattern found to be associated with X. fastidiosa inoculation in spittlebugs (Xe). Feeding behavioural data presented here represent an important step forward for deepening our knowledge of xylem‐sap feeding insects' interaction with both the host plants and the bacterium they transmit.

Potential of fungi of the genus Trichoderma for biocontrol of Philaenus spumarius, the insect vector for the quarantine bacterium Xylella fastidosa.

The meadow spittlebug Philaenus spumarius L. is the vector for the bacterium Xylella fastidiosa subspecies pauca, involved in olive quick decline syndrome (OQDS) in Salento (Italy). Control of P. spumarius is key to limiting transmission of the bacterium, and an innovative approach can be based on effective natural compounds and biocontrol agents. Entomopathogenic fungi are an important source of bioactive natural molecules that play a role in the relationship between microorganisms and insects. Pathogenicity bioassays, performed by dipping adults of P. spumarius in either fungal culture suspension (120 mg mL-1 ) or cell-free culture supernatant of Trichoderma chlorosporum GJS 91-150, showed, respectively, 97% and 87% death within 24 h. The effect was dose-dependent. In laboratory bioassays, the powdered fungal culture of T. chlorosporum GJS 91-150 did not exhibit pathogenic activity when injected into nymph spittle. T. chlorosporum GJS 91-150 affected the survival of P. spumarius adults. The lethal effect was not associated with the development of mycelium on the cuticle, but seems due, at least partly, to fungal metabolites released in the culture medium. The fungus tested here has good potential for the development of effective low-environmental impact control strategies for P. spumarius and suppression of X. fastidiosa. © 2022 Society of Chemical Industry.

The Epidemiology and Control of “Olive Quick Decline Syndrome” in Salento (Apulia, Italy)

Xylella fastidiosa subsp. pauca sequence type 53 was found to be associated with olive trees showing extensive twig and branch dieback and plant death in the Gallipoli area of Salento and the common name of “olive quick decline syndrome” (OQDS) was given to the disease. Repeated interceptions in Europe and Italy of ornamental coffee plants originated from Central America, jointly in phylogenetic analyses of many strains of the pathogen, indicated this origin as the most probable source of its introduction in Salento. Drought events could have been conducive to the initial outbreaks of the disease. Subsequently, the pathogen largely spread over the territory according to a “stratified dispersal” model. The high susceptibility of the local cultivars Ogliarola salentina and Cellina di Nardò, a low soil content of zinc, copper, and manganese, improper pruning, and adverse climatic events could have further contributed to the spread of the pathogen. The polyphagous insect Philaenus spumarius L. is the main vector of the bacterium in the area. The adults were detected X. f. subsp. pauca-positive in early May, and their incidence was higher during spring and early autumn when they efficiently spread the bacterium among the olive trees. Many other host plant species can host the bacterium, and some of them can act as a “reservoir” for the disease spread. The aggressive fungus Neofusicoccum mediterraneum Crous, M.J. Wingf. And A.J.L. Philips, could also be involved in OQDS. A sustainable control strategy for reducing the incidence and severity of X. f. subsp. pauca in the olive groves of Salento that allows the trees to produce is presented and discussed. Resilient trees of Ogliarola salentina and Cellina di Nardò have been observed in the heavily infected areas of Salento.

Investigating dispersal abilities of Aphrophoridae in European temperate regions to assess the threat of potential Xylella fastidiosa-based pathosystems

Modeling the potential spread of Xylella fastidiosa can document contingency plans in northern Europe, so far uncolonized by the bacterium. Through mark–release–recapture (MRR) and flight-mill experiments, the flight capacity of two potential vectors for temperate Europe was studied: Philaenus spumarius, the reported southern European vector, and Aphrophora salicina, a xylem-specialist feeding on potential host plants of X. fastidiosa. Aphrophora salicina displayed significantly better flight performances than P. spumarius. In flight-mills, the average distance flown was, respectively, 623 m vs. 102 m and the maximal distance flown was 6.16 km vs. 1.54 km in 2.5 h. In MRRs, A. salicina travelled more than 30 m in a single flight, with a maximal interception distance of 80 m after two days, highlighting that dispersal is driven by connectivity and host plant quality. Philaenus spumarius mainly jumped, with 1 m movements in length and a maximal interception distance of 32 m in 27 days. Models estimated P. spumarius' daily mean dispersal at 1.5 m and A. salicina's at 3.5 m. Although only a small part of the population moves over very long distances, this pool of efficient insects could already be sufficient to effectively spread an epidemic. As Salicaceae have been reported as host plants of the bacterium, the association of Aphrophoridae and Salicaceae in riparian areas could create bacterium reservoirs in corridors allowing for transportation over medium to long distances.

Wolbachia infection and genetic diversity of Italian populations of Philaenus spumarius, the main vector of Xylella fastidiosa in Europe.

Philaenus spumarius is a cosmopolitan species that has become a major threat to European agriculture being recognized as the main vector of the introduced plant pathogen Xylella fastidiosa, the agent of the “olive quick decline syndrome”, a disease which is devastating olive orchards in southern Italy. Wolbachia are bacterial symbionts of many insects, frequently as reproductive parasites, sometime by establishing mutualistic relationships, able to spread within host populations. Philaenus spumarius harbors Wolbachia, but the role played by this symbiont is unknown and data on the infection prevalence within host populations are limited. Here, the Wolbachia infection rate was analyzed in relation to the geographic distribution and the genetic diversity of the Italian populations of P. spumarius. Analysis of the COI gene sequences revealed a geographically structured distribution of the three main mitochondrial lineages of P. spumarius. Wolbachia was detected in half of the populations sampled in northern Italy where most individuals belonged to the western-Mediterranean lineage. All populations sampled in southern and central Italy, where the individuals of the eastern-Mediterranean lineage were largely prevalent, were uninfected. Individuals of the north-eastern lineage were found only in populations from the Alps in the northernmost part of Italy, at high altitudes. In this area, Wolbachia infection reached the highest prevalence, with no difference between north-eastern and western-Mediterranean lineage. Analysis of molecular diversity of COI sequences suggested no significant effect of Wolbachia on population genetics of P. spumarius. Using the MLST approach, six new Wolbachia sequence types were identified. Using FISH, Wolbachia were observed within the host’s reproductive tissues and salivary glands. Results obtained led us to discuss the role of Wolbachia in P. spumarius, the factors influencing the geographic distribution of the infection, and the exploitation of Wolbachia for the control of the vector insect to reduce the spread of X. fastidiosa.

Feeding behaviour and mortality of Philaenus spumarius exposed to insecticides and their impact on Xylella fastidiosa transmission.

Insecticides are essential, though controversial tools in modern pest management. Insecticides can slow the spread of key vector-borne plant pathogens, but often lead to inconsistent results given that insecticide use is generally focused on acute toxicity under no-choice conditions. Here, we analysed the lethal (survival) and sublethal (feeding behaviour) effects of six commercial products (acetamiprid, deltamethrin, spinosad, sulfoxaflor, pyrethrin and kaolin) on Philaenus spumarius, vector of the bacterium Xylella fastidiosa. Furthermore, we assessed the impact of insecticides displaying different degrees of acute toxicity against spittlebugs (highest to lowest: acetamiprid, pyrethrin and kaolin) on the transmission of X. fastidiosa by P. spumarius under both free-choice and no-choice conditions. Deltamethrin, acetamiprid and to a limited extent pyrethrin significantly altered the feeding behaviour of P. spumarius. Deltamethrin and acetamiprid were highly toxic against P. spumarius, but the mortality induced by exposure to pyrethrin was limited overall. By contrast, spinosad, sulfoxaflor and kaolin did not significantly impact P. spumarius feeding behaviour or survival. Under no-choice conditions, both pyrethrin and acetamiprid reduced the X. fastidiosa inoculation rate compared with kaolin and the control. On the other hand, pyrethrin reduced transmission, but acetamiprid failed to significantly affect bacterial inoculation under free-choice conditions. Pyrethrin was the only compound able to reduce X. fastidiosa transmission under both free-choice and no-choice conditions. Xylella fastidiosa management strategy based exclusively on the evaluation of insecticide acute toxicity under no-choice conditions would most likely fail to prevent, or slow, bacterial spread. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

New insights on “bois noir” epidemiology in the Chianti Classico area (Tuscany, Central Italy)

Bois noir (BN), a disease of the grapevine yellows complex associated with ‘Candidatus Phytoplasma solani’ (CaPsol), represents a great threat in wine growing areas worldwide. Several studies revealed that BN epidemiology is complex, including multiple insect vectors and plant hosts. In the present work, a survey on putative CaPsol insect vectors along with molecular typing of CaPsol strains was conducted in a BN-affected vineyard in the Chianti Classico area (Tuscany region). No Hyalesthes obsoletus specimens were captured, while Neoaliturus fenestratus and Reptalus artemisiae were found infected by CaPsol strains. Molecular typing evidenced that Reptalus artemisiae and N. fenestratus were infected by CaPsol strains carrying mainly the stamp sequence variant St10 and St5, respectively. Other insects (Philaenus spumarius, Dictyophara europaea, Psammotettix spp.), were found less frequently infected by CaPsol strains carrying mainly the stamp sequence variant St5. Results obtained in the present study are in accordance with previous evidences reporting the prevalence of R. artemisiae in a vineyard located in the same geographical area and allowed to identify the possible active role of other insect species in the spreading of genetically different ‘CaPsol’ strains. Further studies are necessary to investigate the role of weeds in CaPsol transmission routes to grapevine, clarify if grapevine could act as reservoir plant for CaPsol acquisition for these putative vectors.

Landscape and Vegetation Patterns Zoning Is a Methodological Tool for Management Costs Implications Due to Xylella fastidiosa Invasion

Philaenus spumarius (Linnaeus 1758, hereafter Ps) is considered one of the main insect vectors responsible for the spread of an alien biota, Xylella fastidiosa (Wells 1987, hereafter Xf), in the Salento area, Apulia region (Southern Italy). Effective management of this biological invader depends on the continuous surveillance and monitoring of its insect vector. As such, this research elicits the invasion drivers (i.e., landscape and vegetation indicators) that influence the abundance and the dynamics of this vector and, consequently, the spatial spread of this bacterium in this Italian region. For this purpose, a spatial pattern clustering methodological approach is considered. The results reveal that spatial variation and territorial differentiation may differ from zone to zone in the same invaded area, for which effective management and monitoring planning should be addressed. Further, six agro-ecosystems zones have been identified with respect to five indicators: (i) vegetation index, (ii) intensity of cultivation, (iii) cultural diversity, (iv) density of agricultural landscape elements, and (v) altitude. This paper has public implications and contributes to an understanding of how zoning of an infected area, by an alien biota, into homogenous zones may impact its effective management costs. This approach could also be applied in other countries affected or potentially affected by the phenomenon of Xf invasion.

Thidiazuron: New Trends and Future Perspectives to Fight Xylella fastidiosa in Olive Trees.

These days, most of our attention has been focused on the COVID-19 pandemic, and we have often neglected what is happening in the environment. For instance, the bacterium Xylella fastidiosa re-emerged as a plant pathogen of global importance in 2013 when it was first associated with an olive tree disease epidemic in Italy, called Olive Quick Decline Syndrome (OQDS), specifically caused by X. fastidiosa subspecies pauca ST53, which affects the Salento olive trees (Apulia, South-East Italy). This bacterium, transmitted by the insect Philaenus spumarius, is negatively reshaping the Salento landscape and has had a very high impact in the production of olives, leading to an increase of olive oil prices, thus new studies to curb this bacterium are urgently needed. Thidiazuron (TDZ), a diphenylurea (N-phenyl-1,2,3-thiadiazol-5-yl urea), has gained considerable attention in recent decades due to its efficient role in plant cell and tissue culture, being the most suitable growth regulator for rapid and effective plant production in vitro. Its biological activity against bacteria, fungi and biofilms has also been described, and the use of this low-cost compound to fight OQDS may be an intriguing idea.

Habitat manipulation for sustainable management of Philaenus spumarius, the main vector of Xylella fastidiosa in Europe.

The unexpected Xylella fastidiosa (Xf) outbreak in Europe has led to aggressive management of the disease in recent years. As there is no cure for infected plants, management of vector populations is mandatory to contain the spread of Xf in infected areas. We aimed to assess the suitability of plant species commonly used as cover crops for the population growth of Philaenus spumarius L. (Aphrophoridae). Thus, we conducted a series of no-choice and multiple-choice assays to assess the oviposition preference of P. spumarius adults as well as the development and mortality rate of nymphs on 10 candidate plant species under laboratory and semi-field conditions. Our results will help to design ecological infrastructures, including a pull-push strategy for effective management of Xf vectors in olive groves. Results showed that Anthriscus cerefolium is a suitable plant to enhance oviposition but has a lethal effect on the first nymphal instars of P. spumarius. Moreover, Diplotaxis tenuifolia is not suitable for oviposition or nymphal development. Sinapis alba does not enhance oviposition but is suitable for nymphal development with a medium-high cumulative mortality of the nymphs. Conversely, adults and nymphs had a high preference and low mortality on Taraxacum officinale, and nymphs showed a medium-high preference on Lavandula angustifolia, suggesting that these two species should be avoided as ground cover plants on Xf-susceptible crops. The results obtained in our study open new ways to manage the vectors of Xf by using specific plant species as ground cover, which in turn will reduce the spread and prevalence of Xf. © 2022 Society of Chemical Industry.

Application of vibrational signals to study and manipulate an insect vector: the case of Philaenus spumarius (Hemiptera: Aphrophoridae).

Vibrational stimuli can support pest management as they provide environmentally friendly methods to manipulate insect pest behaviors. Different vibrational stimuli were used to study and influence the behavior of the meadow spittlebug, Philaenus spumarius, the European vector of Xylella fastidiosa. In playback experiments, we tested the reactions of the spittlebug toward the male calling signals (test 1) and the male-male signal (test 2). In test 3, we evaluated the use of conspecific signals and noises to repel insects/disrupt mating. Test 1 provided new insights regarding the role of the male calling signal in intraspecific communication, in particular that this signal likely does not underlie aggregation or aggression toward conspecifics. Test 2 demonstrated that the male-male signal is used by males to express distress when physically interacting, whilst, when played back into a host plant, it has not any repellent effect on the spittlebug. Test 3A suggested that males exploit short silence gaps to localize the signaling partner, while test 3B showed that a continuous noise with a specific frequency range successfully disrupt mating, as only one male out of 20 localized the female on the plant. Playbacks obtained from prerecorded P. spumarius' signals were successfully used to accomplish ethological studies; even so, this approach did not show a real potential to be used as a control strategy. However, noises designed to mask the spittlebug signals significantly disrupted species mating and could integrate other techniques aimed at reducing the spread of X. fastidiosa after appropriate implementation. © 2022 Society of Chemical Industry.

Behavioural and electrophysiological responses of Philaenus spumarius to odours from conspecifics

The meadow spittlebug, Philaenus spumarius L. (Hemiptera: Auchenorrhyncha: Aphrophoridae), is the main vector of Xylella fastidiosa subsp. pauca strain ST53, the causal agent of the Olive Quick Decline Syndrome. Philaenus spumarius and other Auchenorrhyncha are known to communicate via vibrations, whereas the possible occurrence of semiochemical communication has been poorly investigated so far. Through a chemical ecology approach, we provide evidence of intraspecific chemical communication in P. spumarius. In Y-tube olfactometer bioassays, males were attracted to unmated females as well as toward the headspace volatile extracts collected from unmated females. Conversely, females did not respond to unmated male volatiles or their extracts, nor did males and females respond to volatiles from individuals of the same sex. Electroantennography assays of unmated male and female headspace extracts elicited measurable responses in the antennae of both sexes. Male responses to body wash extracts from both sexes were stronger compared to female responses. Thus, suggesting the presence of compounds that are highly detected by the male’s olfactory system. The female head seemed to be the source of such compounds. This is the first record of intraspecific chemical communication in P. spumarius and one of the very few records in Auchenorrhyncha. Possible biological roles are under investigation.

Low Temperature Plasma Strategies for Xylella fastidiosa Inactivation

The quarantine bacterium Xylella fastidiosa was first detected in Salento (Apulia, Italy) in 2013 and caused severe symptoms in olives, leading to plant death. The disease, named Olive Quick Decline Syndrome (OQDS), is caused by the strain “De Donno” ST53 of the subspecies pauca of this bacterium (XfDD), which is spread by the insect Philaenus spumarius. The epidemic poses a serious threat to the agricultural economy and the landscape, as X. fastidiosa infects several plant species and there is yet no recognized solution. Research on OQDS is focused on finding strategies to control its spread or mitigate its symptoms. As a perspective solution, we investigated the efficacy of the low-temperature plasma and plasma-activated water to kill bacterial cells. Experiments were conducted in vitro to test the biocidal effect of the direct application of a Surface Dielectric Barrier Discharge (SDBD) plasma on bacteria cells and Plasma Activated Water (PAW). PAW activity was tested as a possible biocidal agent that can move freely in the xylem network paving the way to test the strategy on infected plants. The results showed a high decontamination rate even for cells of XfDD embedded in biofilms grown on solid media and complete inactivation in liquid culture medium.

Interaction networks between spittlebugs and vegetation types in and around olive and clementine groves of Corsica; implications for the spread of Xylella fastidiosa

The bacterium Xylella fastidiosa (Xf) is a major threat to European agriculture and notably to the olive and Citrus industry. It is transmitted by xylem-feeding insects, whose plant-feeding preferences still require investigation in European agroecosystems. Here we studied olive and clementine groves of the oriental plain of Corsica. Insect-vegetation type interaction networks for nymphs and adults of xylem-feeding insects were investigated three times a year during two years in and around crops. Networks were dominated by the Philaenus spumarius – Cistus monspeliensis interaction and were similar for olive and clementine groves, despite differences in plant communities of the ground vegetation and agricultural practices. To a lesser extent, Dittrichia viscosa was also a suitable feeding plant for P. spumarius, the main vector of Xf in Europe. Neophilaenus campestris was associated with grove ground vegetation, whereas Lepyronia coleoptrata and Aphrophora alni exhibited no or weak association with any of the target vegetation types. All species occurred on olive and clementine foliage in similar low abundance. Our results suggest that soil tillage in spring would be less efficient than in Italy to control P. spumarius. Instead, removing C. monspeliensis bushes from the close vicinity of groves could reduce risk of spread of Xf to crops. Finally, conserving D. viscosa in olive groves as a biological control strategy against the olive fruit fly is rather counter-productive as it maintains populations of P. spumarius under susceptible crops. Overall, our study shows that management strategies should be designed in relation to local insect-plant interaction networks that should be investigated in both cultivated areas and their immediate environment.

Composition of landscape impacts the distribution of the main vectors of Xylella fastidiosa in southern Spain

AbstractThe bacterium Xylella fastidiosa (Xf) is a harmful insect‐borne plant pathogen that causes severe diseases to major agricultural crops and many forest, ornamental and uncultivated plants. The pathogen, native to the Americas, has recently been detected in Europe, where it causes huge agricultural losses. The effect of landscape composition on the distribution of the vectors of the bacterium in Europe remains little explored. The present study aims at identifying how landscape composition impacts the distribution of the spittlebugs Philaenus spumarius and Neophilaenus campestris, which can carry and transmit the pathogen to plants and are considered to be the main vectors of Xf in the Mediterranean region. During the period 2015–2018, we thoroughly sampled the distribution of both species in the southwest of Iberian Peninsula. We characterized landscape composition in the sampling area by computing landscape metrics and fitted multivariate analyses and species distribution models (SDMs) to investigate spittlebugs’ response to climate and landscape structure. High densities of Mediterranean agro‐forestry systems (named “dehesas” in Spanish), sclerophyllous vegetation and broad‐leaved forests in the landscape, were positively associated with the presence of P. spumarius. Conversely, the high density of coniferous vegetation in the landscape was positively associated with the occurrence of N. campestris. For P. spumarius, SDMs accounting for ecologically relevant landscape descriptors yielded better predictive accuracy than models relying on climate only. These results highlight the importance of considering landscape information when modelling pests’ distributions and provide practical information to design landscape‐informed monitoring plans to prevent the spread of Xf in Europe.

Prevention and control of OQDS (olive quick decline syndrome) outbreaks caused by Xylella fastidiosa.

In Southern Italy, since 2013, there has been an ongoing Olive Quick Decline Syndrome (OQDS) outbreak, due to the bacterium Xylella fastidiosa, which has caused a dramatic impact from both socio-economic and environmental points of view. The main players involved in OQDS are represented by the insect vector, Philaenus spumarius, its host plants (olive trees and weeds) and the bacterium, X. fastidiosa. Current agronomic practices are mainly based on uprooting the sick olive trees and their surrounding ones, with later installment of olive cultivars more resistant to the bacterium infection. Unfortunately, both of these practices are having an undesirable impact on the environment (most of these olive trees were monumental ones) and on the economy. Based on a mathematical model expressed in terms of a nontrivial system of ordinary differential equations, our analysis has provided a clear picture of all possible steady states (feasible equilibria) and their stability properties, corresponding to a variety of different parameter scenarios; all of this has been illustrated by a set of computational experiments.A significant original contribution of this paper is the proof of the global asymptotic stability of each of the feasible equilibria under its existence assumptions, a fact that excludes multiple equilibria under the given conditions.It has emerged that the removal of a suitable amount of weed biomass (host plants of the juvenile stages of the insect vector of X. fastidiosa) from olive orchards and surrounding areas leads to the eradication of the epidemic, without requiring neither the removal nor the substitution of the existing olive trees.

Large abdominal mechanoreceptive sense organs in small plant-dwelling insects

The Hemiptera, with approximately 98 000 species, is one of the largest insect orders. Most species feed by sucking sap from plant tissues and are thus often vectors for economically important phytopathogens. Well known within this group are the large cicadas (Cicadomorpha: Cicadoidea: Cicadidae) because they produce extremely loud airborne sounds. Less well known are their mostly tiny relatives, the leafhoppers, spittlebugs, treehoppers and planthoppers that communicate by silent vibrational signals. While the generation of these signals has been extensively investigated, the mechanisms of their perception are poorly understood. This study provides a complete description and three-dimensional reconstruction of a large and complex array of mechanoreceptors in the first abdominal segments of the Rhododendron leafhopper Graphocephala fennahi (Cicadomorpha: Membracoidea: Cicadellidae). Further, we identify homologous organs in the spittlebug Philaenus spumarius (Cicadomorpha: Cercopoidea: Aphrophoridae) and the planthopper Issus coleoptratus (Fulgoromorpha: Fulgoroidea: Issidae). Such large abdominal sensory arrays have not been found in any other insect orders studied so far. This indicates that these sense organs, together with the signal-producing tymbal organ, constitute a synapomorphy of the Tymbalia (Hemiptera excl. Sternorrhyncha). Our results contribute to the understanding of the evolution from substrate-borne to airborne communication in insects.

Visceral Ecologies in the Borderland: Soils and Care from Olive Trees’ Hecatomb in Salento

This contribution focuses on Soils and Care as fundamental matters of inquiry in order to retrace the processes determining the resurging possibilities of Salento’s landscape. The South-East Italian territory is plagued by the epidemic of bacteria Xylella Fastidiosa, cause for hundreds of thousands of olive-trees’ deaths. We embark on the untangling of the ecology of the olive trees’ depletion, taking into consideration the most recent scientific research on the main vector of the bacteria, the little spittlebug Philaenus spumarius. We refer to Visceral Ecology as the quality of relationships that entangles multispecies assemblies. With this effort we interlace the vector’s ecology and the dying of olive trees with a local oil miller’s intestinal disease. Framing the soil of Salento as an “open air intestine” allows us to merge materialistic views and practices of care with the ecosystem’s transformations. In conclusion, we argue the interconnectedness of Materialism and Care in shaping both the imaginary and the conditions for futurable local human-landscape relations.

Olfactory responses to volatile organic compounds and movement parameters of Philaenus spumarius and Cicadella viridis

AbstractXylella fastidiosa, the causal agent of several diseases in crops of economic interest, could be rapidly transmitted and spread throughout the agroecosystem landscape by xylem sap‐feeding insects. Chemical signals in the environment drive the behaviour of insects. Attractive or repulsive responses to signals may affect insects’ fitness, survival and reproduction, and elicit different movement patterns. Specific movement patterns derived from olfactory cues towards the selection of plants for feeding may trigger the transmission of the pathogen by the insect. Thus, understanding vectors’ olfactory response and movement parameters are of utmost importance. This work aimed to assess the olfactory response of Philaenus spumarius and Cicadella viridis adults to two Volatile Organic Compounds (VOCs) (cis‐3‐hexenyl acetate and cis‐3‐hexen‐1‐ol) present in almond, olive and vine leaves. Insects’ behavioural responses were conducted in a four‐arm olfactometer, and the two aforementioned VOCs were tested at different concentrations (5, 10, 20 and 30 µg/µl). At the lowest concentration, females of P. spumarius were significantly attracted by the two VOCs. At the highest concentrations, no significant differences were detected among treatments. Cicadella viridis individuals showed no significant differences in their choice at any concentration. Additionally, the walking movement of these insects was also studied in the absence of food. Females of P. spumarius and C. viridis can walk significantly more at a significantly higher velocity than males. Knowledge of the olfactory response of X. fastidiosa vectors and their movement parameters can be essential to develop new tools to limit the spread of this phytopathogen.