| identification of phytoplasmas in eggs, nymphs and adults of scaphoideus titanus ball reared on healthy plants. | a survey for the presence of aster yellows-related phytoplasmas in the different life stages of scaphoideus titanus was carried out by means of pcr and nested-pcr assays. using a phytoplasma 16srl group-specific primer pair followed by rflp analysis of amplified products, we were able to detect and identify phytoplasmas from eggs, newly hatched nymphs, fourth and fifth instar nymphs and adults reared on ten phytoplasma-free vicia faba seedlings. two of these broad beans became infected, whereas ... | 1997 | 9099575 |
| a novel bacteroidetes symbiont is localized in scaphoideus titanus, the insect vector of flavescence dorée in vitis vinifera. | flavescence dorée (fd) is a grapevine disease that afflicts several wine production areas in europe, from portugal to serbia. fd is caused by a bacterium, "candidatus phytoplasma vitis," which is spread throughout the vineyards by a leafhopper, scaphoideus titanus (cicadellidae). after collection of s. titanus specimens from fd-contaminated vineyards in three different areas in the piedmont region of italy, we performed a survey to characterize the bacterial microflora associated with this insec ... | 2006 | 16461701 |
| spatial distribution of nymphs of scaphoideus titanus (homoptera: cicadellidae) in grapes, and evaluation of sequential sampling plans. | the spatial distribution of the nymphs of scaphoideus titanus ball (homoptera cicadellidae), the vector of grapevine flavescence dorée (candidatus phytoplasma vitis, 16sr-v), was studied by applying taylor's power law. studies were conducted from 2002 to 2005, in organic and conventional vineyards of piedmont, northern italy. minimum sample size and fixed precision level stop lines were calculated to develop appropriate sampling plans. model validation was performed, using independent field data ... | 2006 | 16686162 |
| ultrastructure of a novel cardinium sp. symbiont in scaphoideus titanus (hemiptera: cicadellidae). | an ultrastructural study of the novel symbiont cardinium sp. was performed with particular attention to the description of the structure and organization of highly elaborated cytoplasmic complexes containing microtubule-like elements (mlc). three major components were observed. the first was a system of microtubule-like elements (ml) arranged in parallel array extending from the plasma membrane into the cytosol of the bacterium. the second, an fibrous electrondense plaque (fep), approximately 8 ... | 2006 | 16876837 |
| diffusion of the nearctic leafhopper scaphoideus titanus ball in europe: a consequence of human trading activity. | scaphoideus titanus ball is a nearctic leafhopper that was introduced for the first time in europe probably at the beginning of the 20th century. in europe, this species is a specialist on cultivated grapevines and is of great economic importance as the vector of flavescence dorée (fd), a grapevine yellows disease caused by candidatus phytoplasma vitis. the random amplified polymorphic dna (rapd) technique was employed to obtain genetic information about the diffusion and the structure of s. tit ... | 2007 | 17242963 |
| multilocus sequence typing confirms the close genetic interrelatedness of three distinct flavescence dorée phytoplasma strain clusters and group 16srv phytoplasmas infecting grapevine and alder in europe. | vineyards of southern france and northern italy are affected by the flavescence dorée (fd) phytoplasma, a quarantine pathogen transmitted by the leafhopper of nearctic origin scaphoideus titanus. to better trace propagation of fd strains and identify possible passage between the vineyard and wild plant compartments, molecular typing of phytoplasma strains was applied. the sequences of the two genetic loci map and uvrb-degv, along with the sequence of the secy gene, were determined among a collec ... | 2007 | 17468266 |
| multiple symbiosis in the leafhopper scaphoideus titanus (hemiptera: cicadellidae): details of transovarial transmission of cardinium sp. and yeast-like endosymbionts. | scaphoideus titanus is the insect vector of flavescence dorée (fd), a yellow disease of grapevines. observations on adult females and nymphs of s. titanus showed that this insect is associated with a complex microbial community. ultrastructural analysis showed that the fat body, salivary glands and ovary of the insect harbour microorganisms showing the brush-like structure typically observed in the genus cardinium. in particular, it has been shown that these symbiotic bacteria are present both i ... | 2008 | 18272191 |
| epidemiology of flavescence dorée in vineyards in northwestern italy. | abstract a serious outbreak of flavescence dorée (fd) was reported in piemonte, northwestern italy, in 1998, and since then, the disease has compromised the economy of this traditional wine-growing area, even following the application of compulsory insecticide treatments to control scaphoideus titanus, the vector of the causal phytoplasma. affected vines show severe symptoms, varying according to the cultivar, and are rogued to reduce disease spread. following winter and pruning, a previously af ... | 2007 | 18943511 |
| seasonal progression of sex ratio and phytoplasma infection in scaphoideus titanus ball (hemiptera: cicadellidae). | the differences between the seasonal occurrence and likelihood of being infected by fd phytoplasmas, of male and female scaphoideus titanus ball, were investigated. sex ratio (male: female) was calculated by counting males and females sampled by means of yellow sticky traps and sweep-nets and from adults derived from hatched eggs in field-collected grapevine wood. pcr essays were performed to test differences in infection between genders. overall, the sex ratio on sticky traps was significantly ... | 2009 | 19063761 |
| cold winter temperatures condition the egg-hatching dynamics of a grape disease vector. | the leafhopper scaphoideus titanus is the vector of a major phytoplasma grapevine disease, flavescence dorée. the vector's distribution is in eastern and northern europe, and its population dynamics varies as a function of vineyard latitude. we tested the hypothesis that hatching dynamics are cued by cold temperatures observed in winter. we exposed eggs from a natural population to simulated "cold" and "mild" winters and varied the exposure time at 5 degrees c from 0 to 63 days. we show that tem ... | 2009 | 19401803 |
| comparing the spatial genetic structures of the flavescence dorée phytoplasma and its leafhopper vector scaphoideus titanus. | the nearctic leafhopper scaphoideus titanus ball is the vector of "flavescence dorée" phytoplasma (fdp) in european vineyards. we studied the genetic diversity and structure of s. titanus populations in france and of the fdp they carried. a total of 621 s. titanus individuals, sampled in 24 fdp-infected and uninfected vineyards, were genotyped using seven polymorphic microsatellite loci. the mean observed heterozygosity in s. titanus populations was between 0.364 and 0.548. there was evidence of ... | 2009 | 19464388 |
| study on the role of olfaction in host plant detection of scaphoideus titanus (hemiptera: cicadellidae) nymphs. | the american grapevine leafhopper, scaphoideus titanus ball (hemiptera: cicadellidae), is the vector of the phytoplasma that causes flavescence dorée, one of the most threatening grapevine yellows disease. the role of olfaction in host plant detection of this species is still unknown. in this study, the attractiveness of a host plant, the grapevine rootstock vitis riparia x rupestris 101/14, to nymphs was verified through behavioral bioassays in a vertical glass y-olfactometer. furthermore, the ... | 2009 | 19610410 |
| asaia, a versatile acetic acid bacterial symbiont, capable of cross-colonizing insects of phylogenetically distant genera and orders. | bacterial symbionts of insects have been proposed for blocking transmission of vector-borne pathogens. however, in many vector models the ecology of symbionts and their capability of cross-colonizing different hosts, an important feature in the symbiotic control approach, is poorly known. here we show that the acetic acid bacterium asaia, previously found in the malaria mosquito vector anopheles stephensi, is also present in, and capable of cross-colonizing other sugar-feeding insects of phyloge ... | 2009 | 19735280 |
| acetic acid bacteria, newly emerging symbionts of insects. | recent research in microbe-insect symbiosis has shown that acetic acid bacteria (aab) establish symbiotic relationships with several insects of the orders diptera, hymenoptera, hemiptera, and homoptera, all relying on sugar-based diets, such as nectars, fruit sugars, or phloem sap. to date, the fruit flies drosophila melanogaster and bactrocera oleae, mosquitoes of the genera anopheles and aedes, the honey bee apis mellifera, the leafhopper scaphoideus titanus, and the mealybug saccharicoccus sa ... | 2010 | 20851977 |
| Antennal sensory structures in Scaphoideus titanus ball (Hemiptera: Cicadellidae). | Scaphoideus titanus Ball (Hemiptera: Cicadomorpha) is a leafhopper vector of a phytoplasma disease, the Flavescence dorée (FD), belonging to the vine yellows group. A scanning and transmission electron microscope study has been carried out to investigate the antennal sensory structures. The first two segments, the scape and the pedicel, are short, covered by cuticular scales and devoid of sensilla, with exception of some scattered hairs on the pedicel. The flagellum consists of a unique, elongat ... | 2011 | 21956855 |
| horizontal transmission of the symbiotic bacterium asaia sp. in the leafhopper scaphoideus titanus ball (hemiptera: cicadellidae). | bacteria of the genus asaia have been recently recognized as secondary symbionts of different sugar-feeding insects, including the leafhopper scaphoideus titanus, vector of flavescence dorée phytoplasmas. asaia has been shown to be localized in s. titanus gut, salivary glands and gonoducts and to be maternally transmitted to the progeny by an egg smearing mechanism. it is currently not known whether asaia in s. titanus is transmitted by additional routes. we performed a study to evaluate if asai ... | 2012 | 22376056 |
| heterologous expression and processing of the flavescence dorée phytoplasma variable membrane protein vmpa in spiroplasma citri. | flavescence dorée (fd) of grapevine is a phloem bacterial disease that threatens european vineyards. the disease is associated with a non-cultivable mollicute, a phytoplasma that is transmitted by the grapevine leafhopper scaphoideus titanus in a persistent, propagative manner. the specificity of insect transmission is presumably mediated through interactions between the host tissues and phytoplasma surface proteins comprising the so-called variable membrane proteins (vmps). plant spiroplasmas a ... | 2015 | 25879952 |
| tracking the dispersion of scaphoideus titanus ball (hemiptera: cicadellidae) from wild to cultivated grapevine: use of a novel mark-capture technique. | the dispersion of scaphoideus titanus ball adults from wild to cultivated grapevines was studied using a novel mark-capture technique. the crowns of wild grapevines located at a distance from vineyards ranging from 5 to 330 m were sprayed with a water solution of either cow milk (marker: casein) or chicken egg whites (marker: albumin) and insects captured in yellow sticky traps placed on the canopy of grapes were analyzed via an indirect elisa for markers' identification. data were subject to ex ... | 2014 | 24725361 |
| a phloem-feeding insect transfers bacterial endophytic communities between grapevine plants. | bacterial endophytes colonize the inner tissues of host plants through the roots or through discontinuities on the plant surface, including wounds and stomata. little is known regarding a possible role of insects in acquiring and transmitting non-phytopathogenic microorganisms from plant to plant, especially those endophytes that are beneficial symbionts providing plant protection properties and homeostatic stability to the host. to understand the ecological role of insects in the transmission o ... | 2017 | 28555131 |
| acquisition of flavescence dorée phytoplasma by scaphoideus titanus ball from different grapevine varieties. | flavescence dorée (fd) is a threat for wine production in the vineyard landscape of piemonte, langhe-roero and monferrato, italy. spread of the disease is dependent on complex interactions between insect, plant and phytoplasma. in the piemonte region, wine production is based on local cultivars. the role of six local grapevine varieties as a source of inoculum for the vector scaphoideus titanus was investigated. fd phytoplasma (fdp) load was compared among red and white varieties with different ... | 2016 | 27649162 |
| acibenzolar-s-methyl may prevent vector-mediated flavescence dorée phytoplasma transmission, but is ineffective in inducing recovery of infected grapevines. | acibenzolar-s-methyl (bth), a functional analogue of salicylic acid (sa), is known to elicit a systemic resistance across a broad range of plant-pathogen interactions, but so far it has not been tested against flavescence dorée (fdp), one of the most devastating grapevine diseases. the aim of this work was to evaluate the activity of bth in preventing fdp transmission by the insect vector and in inducing recovery of infected grapevines. | 2017 | 27116913 |
| a stage-structured model of scaphoideus titanus in vineyards. | we present a population model of the insect scaphoideus titanus ball, the leafhopper vector of flavescence dorée phytoplasma in vitis vinifera l. the model accounted for the stage-dependent s. titanus life cycle rates and timing, and vineyard settings such as surface area, plant density, and sampling characteristics. the model parameters were estimated against 13 independent cases of population counting in both laboratory and field conditions, and returned a correlation coefficient in the range ... | 2013 | 23575007 |
| microsatellite and mitochondrial data provide evidence for a single major introduction for the neartic leafhopper scaphoideus titanus in europe. | scaphoideus titanus, a leafhopper native to north america and invasive in europe, is the vector of the flavescence dorée phytoplasma, the causal agent of the most important form of grapevine yellows in european vineyards. we studied 10 polymorphic microsatellite loci and a 623 bp fragment of the mitochondrial cytochrome oxidase ii gene in native s. titanus from north-eastern america and introduced european populations, to elucidate the colonization scenario. consistent with their recent history, ... | 2012 | 22629338 |
| space-time point pattern analysis of flavescence dorée epidemic in a grapevine field: disease progression and recovery. | analyses of space-time statistical features of a flavescence dorée (fd) epidemic in vitis vinifera plants are presented. fd spread was surveyed from 2011 to 2015 in a vineyard of 17,500 m2 surface area in the piemonte region, italy; count and position of symptomatic plants were used to test the hypothesis of epidemic complete spatial randomness and isotropicity in the space-time static (year-by-year) point pattern measure. space-time dynamic (year-to-year) point pattern analyses were applied to ... | 2016 | 28111581 |
| contrasting susceptibilities to flavescence dorée in vitis vinifera, rootstocks and wild vitis species. | flavescence dorée (fd) is a quarantine disease of grapevine, involving interactions between the plants, leafhopper vectors, and fd phytoplasma. characterizing the susceptibility of vine varieties could limit disease propagation. after extensive surveys in vineyards, we showed that cabernet sauvignon (cs) is highly susceptible, with a high proportion of symptomatic branches and phytoplasma titers, in contrast to merlot (m). localized insect transmissions and grafting showed that phytoplasma circu ... | 2016 | 27965681 |
| phenological synchrony between scaphoideus titanus (hemiptera: cicadellidae) hatchings and grapevine bud break: could this explain the insect's expansion? | scaphoideus titanus is the invasive vector of the phytoplasma causing the flavescence dorée in european vineyards. this epidemic is a serious threat to viticulture that has been increasing for more than 60 years in europe. we studied the effect of synchrony with the plant phenology and the effect of plant-sap quality on the individual fitness. thus, we conducted laboratory experiments to determine if insect hatchings were synchronized with grapevine bud break. we used two natural populations: on ... | 2015 | 25339543 |
| aquaporin-related proteins in the filter chamber of homopteran insects. | in the homopteran order of insects, the plant xylem feeders exhibit a highly differentiated part of their digestive tract known as the filter chamber. in this tissue, water crosses plasma membranes through a transepithelial osmotic gradient. in previous studies on the filter chamber of cicadella viridis, we purified and characterized from the plasma membranes a 25 kda protein that we demonstrated to be an aquaporin (or water channel, member of the major intrinsic protein family, a group of membr ... | 1997 | 9377634 |
| the reproductive strategy and the vibrational duet of the leafhopper empoasca vitis. | the recent description of a new vibrational mating disruption method to control the leafhopper scaphoideus titanus ball opened questions about its possible application to other leafhopper pests. since the prerequisite for the method's successful application is a deep knowledge of the species mating behavior and the exact role of associated signals, we conducted behavioral assays on the green leafhopper empoasca vitis göthe, a pest of grapevine and other crops in europe and asia. laser vibrometer ... | 2017 | 28296131 |
| spatial distribution and sampling plans for grapevine plant canopy-inhabiting scaphoideus titanus (hemiptera: cicadellidae) nymphs. | the paper deals with the study of the spatial distribution and the design of sampling plans for estimating nymph densities of the grape leafhopper scaphoideus titanus ball in vine plant canopies. in a reference vineyard sampled for model parameterization, leaf samples were repeatedly taken according to a multistage, stratified, random sampling procedure, and data were subjected to an anova. there were no significant differences in density neither among the strata within the vineyard nor between ... | 2016 | 26719593 |
| plant-mediated interspecific horizontal transmission of an intracellular symbiont in insects. | intracellular reproductive manipulators, such as candidatus cardinium and wolbachia are vertically transmitted to progeny but rarely show co-speciation with the host. in sap-feeding insects, plant tissues have been proposed as alternative horizontal routes of interspecific transmission, but experimental evidence is limited. here we report results from experiments that show that cardinium is horizontally transmitted between different phloem sap-feeding insect species through plants. quantitative ... | 2015 | 26563507 |
| molecular diversity of phytoplasmas associated with grapevine yellows disease in north-eastern italy. | a 3-year survey was conducted in northern italy to verify the presence and diversity of phytoplasmas in selected vineyards showing symptoms of severe yellows. symptomatic and asymptomatic grapevines were sampled, and insects were collected using yellow sticky traps. the phytoplasmas detected in grapevine samples were different according to the years: "flavescence dorée" (16srv-c/d) was detected together with other phytoplasmas such as 16srxii-a ('candidatus phytoplasma solani'-related, bois noir ... | 2018 | 28945521 |
| comparative neuroanatomy of the antennal lobes of 2 homopteran species. | we compared the morphology of the primary olfactory center, the antennal lobe (al), in 2 homopteran insects, hyalesthes obsoletus signoret (homoptera: cixiidae) and scaphoideus titanus ball (homoptera: cicadomorpha). the comparison between the als of the 2 species is particularly interesting considering that, although both use volatile cues to locate their host plants, their feeding behavior differs considerably: specifically, h. obsoletus is a highly polyphagous species, whereas s. titanus is s ... | 2014 | 24443423 |
| the johnston's organ of three homopteran species: a comparative ultrastructural study. | a transmission electron-microscopy study has been carried out on the pedicel of three homopteran species, with particular focus on the leafhopper scaphoideus titanus ball. the two other species, the planthoppers hyalesthes obsoletus signoret and metcalfa pruinosa say, were investigated in order to compare the ultrastructure of the johnston's organ (jo) among representatives of the auchenorrhyncha group. the results showed the presence of a well developed jo located within the pedicel. depending ... | 2013 | 23428838 |
| control of scaphoideus titanus with natural products in organic vineyards. | the leafhopper scaphoideus titanus is the vector of 'candidatus phytoplasma vitis', the causal agent of flavescence dorée (fd) a key disease for european viticulture. in organic vineyards, the control of s. titanus relies mostly on the use of pyrethrins that have suboptimal efficacy. during 2016, three field trials were conducted to evaluate the efficacy of kaolin, orange oil, insecticidal soap and spinosad against s. titanus nymphs, in comparison with pyrethrins. the activity of kaolin was eval ... | 2017 | 29258165 |
| first finding of a dual-meaning x wave for phloem and xylem fluid ingestion: characterization of scaphoideus titanus (hemiptera: cicadellidae) epg waveforms. | the leafhopper scaphoideus titanus (hemiptera: cicadomorpha: cicadellidae), an invasive deltocephaline species introduced into europe from north america, is the vector of the most important phytoplasma disease in european viticulture, flavescence dorée. in this first electropenetrography (epg) study of s. titanus, we characterized its feeding waveforms and defined their biological meanings. four typical waveform phases (pathway, x wave, sustained ingestion, and interruption) and four families wi ... | 2017 | 28130146 |
| mixed xylem and phloem sap ingestion in sheath-feeders as normal dietary behavior: evidence from the leafhopper scaphoideus titanus. | in phytophagous piercing-sucking insects, salivary sheath-feeding species are often described as xylem- or phloem-sap feeding specialists. because these two food sources have very different characteristics, two feeding tactics are often associated with this supposed specialization. studying the feeding behavior of insects provides substantial information on their biology, ecology, and evolution. furthermore, study of feeding behavior is of primary importance to elucidate the transmission ability ... | 2017 | 28126373 |
| the process of pair formation mediated by substrate-borne vibrations in a small insect. | the ability to identify and locate conspecifics depends on reliable transfer of information between emitter and receiver. for a majority of plant-dwelling insects communicating with substrate-borne vibrations, localization of a potential partner may be a difficult task due to their small body size and complex transmission properties of plants. in the present study, we used the leafhopper scaphoideus titanus as a model to investigate duetting and mate searching associated with pair formation. stu ... | 2014 | 25101559 |
| egg incubation temperature differently affects female and male hatching dynamics and larval fitness in a leafhopper. | temperature effects on ectotherms are widely studied particularly in insects. however, the life-history effects of temperature experienced during a window of embryonic development, that is egg stage, have rarely been considered. we simulated fluctuating temperatures and examined how this affects the operational sex ratio (osr) of hatching as well as nymph and adult fitness in a leafhopper, scaphoideus titanus. specifically, after a warm or cold incubation we compared males and females hatching d ... | 2012 | 22837822 |
| exploitation of insect vibrational signals reveals a new method of pest management. | food production is considered to be the main source of human impact on the environment and the concerns about detrimental effects of pesticides on biodiversity and human health are likely to lead to an increasingly restricted use of chemicals in agriculture. since the first successful field trial, pheromone based mating disruption enabled sustainable insect control, which resulted in reduced levels of pesticide use. organic farming is one of the fastest growing segments of agriculture and with t ... | 2012 | 22457726 |
| do scaphoideus titanus (hemiptera: cicadellidae) nymphs use vibrational communication? | small auchenorrhyncha use substrate-borne vibrations to communicate. although this behaviour is well known in adult leafhoppers, so far no studies have been published on nymphs. here we checked the occurrence of vibrational communication in scaphoideus titanus (hemiptera: cicadellidae) nymphs as a possible explanation of their aggregative distributions on host plants. we studied possible vibratory emissions of isolated and grouped nymphs, as well as their behavioural responses to vibration stimu ... | 2011 | 21656005 |
| inter-plant vibrational communication in a leafhopper insect. | vibrational communication is one of the least understood channels of communication. most studies have focused on the role of substrate-borne signals in insect mating behavior, where a male and a female establish a stereotyped duet that enables partner recognition and localization. while the effective communication range of substrate-borne signals may be up to several meters, it is generally accepted that insect vibrational communication is limited to a continuous substrate. until now, interplant ... | 2011 | 21573131 |
| towards an improved understanding of the dynamics of vineyard-infesting scaphoideus titanus leafhopper populations for better timing of management activities. | this paper deals with supervised management of scaphoideus titanus (homoptera cicadellidae) and describes a phenology model designed for improving the understanding of the within-vineyard dynamics and the timing of insect growth regulator (igr) applications. | 2011 | 21495157 |
| reproductive strategy of the nearctic leafhopper scaphoideus titanus ball (hemiptera: cicadellidae). | mating behaviour of scaphoideus titanus ball, the vector of the grapevine disease flavescence dorée, was investigated in order to determine the role of substrate-borne vibrational signals in intra-specific communication and pair formation. vibrational signals were recorded from grapevine leaves with a laser vibrometer. signalling activity of single males changed throughout the day and the peak in activity was associated with twilight and early night when 'call and fly' behaviour was observed. pa ... | 2009 | 18947453 |