Alberto Fereres

Spanish National Research Council | CSIC · Department of Crop Protection (ICA)

The vector-borne bacterium Xylella fastidiosa is responsible for Pierce’s disease (PD), a lethal grapevine disease that originated in the Americas. The international plant trade is expanding the geographic range of this pathogen, posing a new threat to viticulture worldwide. To assess the potential incidence of PD, we have built a dynamic epidemiol...

Introduction Huanglonbing (HLB) is the most serious disease of citrus in the world, associated with three non-cultivable phloem-restricted bacteria Candidatus Liberibacter asiaticus ( C Las), Ca L. africanus ( C Laf) and Ca L. americanus ( C Lam). C Las is transmitted by the Asian citrus psyllid Diaphorina citri , and has spread to several countrie...

Xylem-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 curren...

The software “XylFeed” is designed as MS Excel macro, developed to analyse essential DC-EPG (Direct Current-Electrical Penetration Graph) waveform variables for European xylem sap-feeding insects (spittlebugs and sharpshooters). DC-EPG waveforms must be manually marked in ‘Stylet+a’ (EPG Systems, Wageningen, Netherlands) or comparable software prev...

Philaenus spumarius L., the main vector of Xylella fastidiosa (Wells) in Europe, is a univoltine species that overwinters in the egg stage, and its nymphs emerge in late winter or spring. Predicting the time of egg hatching is essential for determining the precise times for deploying control strategies against insect pests. Here, we monitored P. sp...

En España el melón se produce bajo estrategias de Gestión Integrada de Plagas combinando el control biológico (CB) con plaguicidas. El pulgón, Aphis gossypii Glover (Hemiptera: Aphididae), es el principal vector de cucumber mosaic virus (CMV, Cucumovirus), transmitido de manera no persistente, y el cucurbit aphid-borne virus (CABYV, Polerovirus), t...

Sulfoxaflor (Isoclast™ active) is a sulfoximine insecticide that is active on a broad range of sap-feeding insects, including species that exhibit reduced susceptibility to currently available insecticides. Colonies of Myzus persicae (green peach aphid) were established from aphids collected in the field from peach (Prunus persica) and nectarine (P...

Background: The citrus greening disease or Huanglongbing (HLB) is the most devastating disease of citrus crops. Trioza erytreae is a vector of HLB. Since its introduction in Europe, the insect reached the northern region of Spain and the southern region of Portugal, threatening relevant citrus production areas. Limiting the spread of HLB vectors i...

Background: Insecticides are essential, although controversial tools in modern pest management. However, 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) an...

Barley yellow dwarf has been described as one of the most devastating viral diseases in cereals worldwide resulting in yield losses ranging from 5% to 80% (1, 2). The disease is caused by the barley/cereal yellow dwarf viruses (YDVs) which are luteoviruses transmitted by aphid vectors in a persistent circulative manner. In some European countries s...

Hemipterans cause major economic losses in vegetable and field crops worldwide, not only because of the direct damage they cause, but also because their alimentary habits involve transmission of hundreds of plant viruses. Owing to the ban of their use and the development of resistances to some extensively used pesticides for control of sap feeding...

Background: The unexpected Xylella fastidiosa (Xf) outbreak in Europe has led to an 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 cr...

The vector-borne bacterium Xylella fastidiosa is responsible for Pierce’s disease (PD), a lethal grapevine illness that originated in the Americas. The international plant trade is expanding the geographic range of this pathogen, posing a new threat to viticulture worldwide. To assess the potential incidence of PD, we have built a dynamic epidemiol...

The bacterium Xylella fastidiosa ( Xf ) is an invasive insect-borne pathogen, which causes lethal diseases to important crops including olives, citrus, almonds and grapes as well as numerous forest, ornamental, and uncultivated plants. Outbreaks of Xf -related plant diseases are currently occurring in the Mediterranean region, causing substantial l...

Scaphoideus titanus (Ball) is a grapevine-feeder leafhopper, and the most important vector of Flavescence dorée of grapevine (FD), a disease associated with phytoplasmas belonging to ribosomal subgroups 16Sr-V–C and –D. FD is a major constraint to viticulture in several European countries and, so far, its control has relied on roguing of infected p...

Philaenus spumarius is a vector of Xylella fastidiosa, one of the most dangerous plants pathogenic bacteria worldwide. There is currently no control measure against this pathogen. Thus, the development of vector control strategies, like generalist predators, such as spiders, could be essential to limit the spread of this vector-borne pathogen. In t...

Scaphoideus titanus (Ball) is a grapevine-feeder leafhopper, and the most important vector of Flavescence dorée of grapevine (FD), a disease associated with phytoplasmas belonging to ribosomal subgroups 16Sr-V–C and –D. FD is a major constraint to viticulture in several European countries and, so far, its control has relied on roguing of infected p...

Trioza erytreae , the African citrus psyllid, is a vector of Candidatus Liberibacter spp., the causal agent of the citrus greening disease or Huanglongbing (HLB). The spread of the vector throughout the Iberian Peninsula has been continuous since its introduction in mainland Spain in 2014. The patterns of host preference and feeding behaviour large...

Trioza erytreae is one natural psyllid vector of Candidatus liberibacter, the causal agent of the citrus greening disease (HLB). Since its introduction in 2014 into the Iberian Peninsula, T. erytreae was able to spread continuously toward southern coastal regions of Portugal and northern coastal regions of the Cantabric sea in Spain. Identifying ke...

The recent emergence of Xylella fastidiosa in Europe is a major threat to agriculture, including olive, almond and grape. Philaenus spumarius is the predominant vector of X. fastidiosa in Europe. Understanding vector movement is critical for developing effective control measures against bacterial spread. In this study, our goal was to set up a flig...

The recent history of Xylella fastidiosa Wells et al. introduction in Europe illustrates how the lack of knowledge about the bacterium‐vector‐host interactions hinders the application of effective containment strategies, with the bacterial spread that currently appears relentless. Vector behavior is a key component in plant pathogen transmission; t...

The development of an efficient indoor rearing protocol of Philaenus spumarius is a key step for research on the meadow spittlebug, as it could reduce researchers' dependency on the availability and collection of univoltine individuals in the field. Here, we implemented the rearing protocol previously described by inducing females' parapause breaka...

Climate change could increase pest pressure, due to changes in insect distribution and phenology, affecting herbivore-parasitoids interactions and consequently, the efficacy of biological control of crop pests. Elevated carbon dioxide (eCO2) concentration directly affects plant growth, physiology and biochemistry, subsequently influencing herbivore...

Interactions between plants and herbivores are key drivers of evolution and ecosystem complexity. We investigated the role of plant labile carbohydrates and nitrogen on wheat-aphid relations in a 22 factorial combining [CO2] and nitrogen supply. We measured life history traits (assay 1) and feeding behaviour (assay 2) of bird-cherry oat aphid (Rhop...

Neophilaenus campestris is one of the spittlebugs (Hemiptera: Cercopoidea) able to transmit Xylella fastidiosa to olive trees. Considering its vector ability and the wide distribution of this species in Spain, N. campestris should be considered a serious threat to key crops such as olive, almonds and grapevines. Migration and dispersal abilities of...

Developing efficient sampling protocols is essential to monitor crop pests. One vector of the citrus disease HLB, the African citrus psyllid Trioza erytreae Del Guercio, 1918 (Hemiptera: Triozidae), currently threatens the lemon industry throughout the Mediterranean region. In this work, a pool of sampling methods devoted to monitoring the populati...

Elevated CO 2 (eCO 2 ) modifies plant primary and secondary metabolism that subsequently impacts herbivore insect performance due to changes in its nutritional requirements. This laboratory study evaluated interactions between Aphis gossypii Glover (Hemiptera: Aphididae) and melon ( Cucumis melo L., Cucurbitaceae), previously acclimated two or six...

The green peach aphid Myzus persicae Sulzer is the main vector of the semipersistently transmitted and phloem-limited Beet yellows virus (BYV, Closterovirus). Studies monitoring the M. persicae probing behavior by using the Electrical penetration graphs (EPG) technique revealed that inoculation of BYV occurs during unique brief intracellular punctu...

Atmospheric concentration of carbon dioxide (CO2) is predicted to double by late twenty-first century, likely increasing global temperature by 2.2 °C. Elevated CO2 (eCO2) and temperature (eT) affect agricultural crops as well as pests and their natural enemies. Changes in any part of multitrophic systems due to environmental factors can affect pest...

Plant viruses produce important economic losses in crops worldwide. The study of their transmission by insects has been key in order to develop new strategies to interfere with their spread. Studies on the monitoring of aphid probing behavior by using the electrical penetration graph (EPG) technique allowed to study the different aphid stylet activ...

The “citrus greening disease” or huanglongbing is caused by the Gram-negative bacterium Candidatus liberibacter spp. One vector of HLB, the African citrus psyllid Trioza erytreae (del Guercio, 1918), was recorded for the first time in 2014 in mainland Spain and since then it has spread throughout the Iberian Peninsula. Measures against T. erytreae...

The salicylic acid analog BTH (benzo-(1,2,3)-thiadiazole-7-carbothioic-acid S-methyl ester) induces systemic acquired resistance by promoting plant resistance against numerous plant pathogens and some insect pests. The objective of the research was to evaluate the activation of plant defenses with BTH on melon (Cucumis melo L., Cucurbitaceae) and i...

Citrus exports to Europe are regulated enforcing that fruits shall be free from peduncles and leaves, as they represent an important pathway for the entrance of non-European (non-EU) Citrus tristeza virus (CTV) isolates into the European Community. Aphids, are the vectors of CTV and could potentially feed on peduncles of imported fruits and thus sp...

The Aphrophoridae family contains important vectors of Xylella fastidiosa, a serious bacterial plant disease. In olive orchards, nymphs usually feed on the ground-cover vegetation. However, detailed information about their populations and host/non-host plants in some regions threatened by Xylella, such as the northeast of Portugal, is very limited....

The Orange Spiny Whitefly (OSW) Aleurocanthus spiniferus (Hemiptera: Aleyrodidae) represents a new serious threat to Citrus spp., grapevine and ornamental plants in the whole Mediterranean area. Such threat urgently calls for the development of a sustainable control strategy, including insecticides compatible with biological control, and applicable...

Here, we provide the first insights into the transmission dynamics of the bacterium Xylella fastidiosa by the meadow spittlebug Philaenus spumarius, gathered through DC EPG (electrical penetration graph)-assisted transmission tests and comparative observations of the probing and feeding behavior of infective versus non-infective vectors on healthy...

The development of herbivore insects is influenced by the quality of their host plants. Elevated CO2 alters plant metabolism, which may change the nutritional quality of the plant, modifying the life history and feeding behaviour of herbivore insects. Understanding how insect pests respond to increasing CO2 concentration is essential for predicting...

Assessing the potential of spread of an introduced crop pest in a new country is crucial to anticipating its effects on crop production and deriving phytosanitary management toward reducing potential negative effects. Citrus production represents a key agricultural activity throughout the Mediterranean basin. The African citrus psyllid Trioza erytr...

Bacteria belonging to ‘Candidatus Liberibacter spp.’ are associated with various severe diseases in the five continents. The African citrus psyllid Trioza erytreae (Hemiptera: Triozidae) is an efficient vector of citrus huanglongbing-HLB disease, absent in the Mediterranean basin. This psyllid is currently present in the islands and mainland Portug...

Zoophytophagous predators play an important, though sometimes controversial, role in pest management programs in different crops. In tomato crops, damage caused by phytophagy of the mirid Nesidiocoris tenuis has mainly been reported at high predator population levels or when prey is scarce. Previous research has focused on predator/prey ratios, sty...

Climate change impacts crop production, pest and disease pressure, yield stability, and, therefore, food security. In order to understand how climate and atmospheric change factors affect trophic interactions in agriculture, we evaluated the combined effect of elevated carbon dioxide (CO2) and temperature on the interactions among wheat (Triticum a...

The bacterium Xylella fastidiosa (Xf) is a worldwide distributed invasive insect-borne plant pathogen, which causes lethal diseases to many economically-important crops including olives, citrus, almonds and grapes as well as numerous forest, ornamental, and uncultivated plants. The Mediterranean basin is the top supplier of olive oil with 93% of th...

The majority of plant viruses depend on Hemipteran vectors for their survival and spread. Effective management of these insect vectors is crucial to minimize the spread of vector-borne diseases, and to reduce crop damage. The aim of the present study was to evaluate the effect of various systemic insecticides on the feeding behavior of Bemisiatabac...

Nonstructural carbohydrates in cereals have been widely investigated from physiological, genetic, and breeding perspectives. Nonstructural carbohydrates may contribute to grain filling, but correlations with yield are inconsistent and sometimes negative. Here we ask if there are hidden functions of nonstructural carbohydrates, advance an ecological...

Candidatus Liberibacter asiaticus (CLas) is a phloem-limited bacterium that is associated with the Huanglongbing (HLB) disease of citrus and transmitted by the psyllid, Diaphorina citri. There are no curative methods to control HLB and the prevention of new infections is essential for HLB management. Therefore, the objective of our study was to det...

En este trabajo se evaluó la eficacia de la malla impregnada con insecticida PA2001-01060/ como método de control físico-químico contra insectos plaga y sus virus asociados en cultivo de repollo. El ensayo se realizó en Villa del Prado (Madrid) en el otoño de 2002, empleando un diseño de bloques al azar con 4 repeticiones y 2 tratamientos (con y si...

Neophilaenus campestris is one of the recently identified spittlebugs (Hemiptera: Cercopoidea) able to transmit Xylella fastidiosa to olive trees. Considering its vector ability and the wide distribution of this species in Spain, N. campestris should be considered a serious threat to key crops that are vital for Spanish agriculture such as olive, a...

Photoselective nets have proven to be effective for aphid pest control as they limit their dispersal ability. However, little is known on the impact of such nets on natural enemies of aphids. In this work, we study the effect of UV-absorbing nets on the syrphid fly Sphaerophoria rueppellii Wiedemann (Diptera: Syrphidae), a commercially available ap...

A recent electrical penetration graph (EPG) study identified a unique intracellular puncture that is associated with inoculation of the semipersistently transmitted, phloem-limited Beet yellows virus (BYV, Closterovirus) by the aphid Myzus persicae. This new aphid EPG pattern (named phloem-pd) always occurs shortly before phloem sieve element phase...

Planting flower strips adjacent to crops is among the habitat-management practices employed to offer alternative floral resources to pollinators. However, more information is needed to understand their potential spill-over of pollinators on nearby insect-pollinated crops. Over the course of two consecutive years, the suitability of a flower mixture...

Cicadas are prominent insects in the Mediterranean basin environments, including in olive orchards. The bacterium Xylella fastidiosa is a xylem-limited vector-borne plant pathogen that was introduced into southern Italy, causing significant losses of olive trees. Cicadas are xylem-sap feeders and potential vectors of X. fastidiosa; however, knowled...

A psila-africana-dos-citrinos, Trioza erytreae (Del Guercio), foi recentemente detetada na Península Ibérica (norte de Portugal e Galiza, Espanha). A sua importância reside não apenas nos estragos diretos que ocasiona, mas sobretudo na sua capacidade em transmitir a bactéria Candidatus Liberibacter spp., agente causal da doença huanglongbing (HLB)...

Spiders are generalist predators and potential natural enemies of different pests. In Europe, the spittlebug Philaenus spumarius is the main vector of Xylella fastidiosa, a xylem-limited bacterium, that affects olive plants causing the olive tree quick decline syndrome. The objective of this work was to identify species of spiders among different f...

Xylella fastidiosa (-Proteobacteria: Xanthomonadaceae) es uno de los patógenos de plantas más importantes a nivel mundial, transmitido exclusivamente por insectos que se alimentan del xilema. El principal vector de esta enfermedad en Europa es Philaenus spumarius (Hemiptera: Aphrophoridae). Su control químico es aún limitado y apenas se conocen ag...

The distinguished intracellular stylet puncture termed 'phloem-pd' ('pd': potential drop) produced by Myzus persicae has been associated with the transmission of the semipersistently transmitted, phloem-limited Beet yellows virus (BYV, Closterovirus). However, the production of intracellular punctures in phloem cells (phloem-pd) by other aphid spec...

Mixed viral infections in plants are common, and can result in synergistic or antagonistic interactions. Except in complex diseases with severe symptoms, mixed infections frequently remain unnoticed, and their impact on insect vector transmission is largely unknown. In this study, we considered mixed infections of two unrelated viruses commonly fou...

Psyllids (Hemiptera: Psylloidea) can transmit the phloem restricted bacterium 'Candidatus Liberibacter solanacearum' (Lso). In Europe, Lso causes severe losses to carrot and represents a threat to the potato industry. A rising concern is Lso transmission from carrot to potato and within potato, and this has driven the need for monitoring population...

The threat imposed by the bacterial pathogen Xylella fastidiosa to crops of utter importance to European agriculture such as olive, stone fruit and grapevine calls for immediate research against the meadow spittlebug, Philaenus spumarius (L.), the main European vector. Management tools should consider reducing juveniles of vector populations growin...

The most likely scenarios for Xylella fastidiosa introduction in Central Europe is through infected ornamental plants, with a successive spillover from gardens and parks to cultivated orchards. Given its polyphagy and wide distribution, the meadow spittlebug Philaenus spumarius, the only ascertained vector of X. fastidiosa in Europe so far, might p...

The Gram-negative bacterium Xylella fastidiosa causes disease in a number of important crops and plants within natural ecosystems. Most notable among these diseases are Pierce's disease of grapevine, Citrus Variegated Chlorosis, Almond Leaf Scorch, Oleander Leaf Scorch and Olive Quick Decline Syndrome. In response to substantial economic losses, ex...

The main objective of this Thesis was to study several aspects concerning non-circulative plant virus transmission by aphids and generate basic knowledge to develop new strategies to interfere with virus transmission and spread. More precisely, the following specific objectives were covered in the present PhD Thesis: 1. To evaluate the effect of t...

Psyllids (Hemiptera: Psylloidea) can transmit the phloem restricted bacterium ‘Candidatus Liberibacter solanacearum’ (Lso). In Europe, Lso causes severe losses to carrot and represents a threat to the potato industry. A rising concern of Lso transmission from carrot to potato and within potato has driven the need for monitoring populations of psyll...

Ultraviolet (UV) radiation that reaches the earth surface has increased substantially in the past decades, altering insect–plant interactions by directly affecting herbivores behavior or indirectly by modifying plant chemistry and morphogenesis. We evaluated the indirect effect of supplementary UV radiation under glasshouse conditions on Bemisia ta...