| effects of total dietary nitrogen and nitrogen form on the development of xylophagous leafhoppers | the influence of primary nutrients on the development of the leafhopper homalodisca coagulata (say) was examined using glycine max (l.) merrill subjected to treatments using different forms of nitrogen fertilization (urea and nitrate) and inoculation with rhizobium bacteria. concentrations of amino acids, organic acids, carbohydrates, and ureides in xylem fluid varied with treatment; differences were most pronounced in young plants (6 weeks after planting), and subsided as plants aged. plants re ... | 1999 | 10467055 |
| effect of selected insecticides on homalodisca coagulata (homoptera: cicadellidae) and transmission of oleander leaf scorch in a greenhouse study. | homalodisca coagulata (say) is a recent introduction to california. it is known to spread a strain of the bacterium xylella fastidiosa wells, raju, hung, weisberg, mandelco-paul & brenner that induces oleander leaf scorch disease in oleander, nerium oleander l. oleander leaf scorch is lethal to oleander and threatens to decimate one of the most important landscape shrubs in california. towards developing a management strategy for h. coagulata-spread oleander leaf scorch, we documented the affect ... | 2001 | 11681662 |
| seasonal flight activity of two homalodisca species (homoptera: cicadellidae) that spread xylella fastidiosa in southern california. | homalodisca coagulata (say) and homalodisca lacerta (fowler) are vectors of a new bacterial disease of oleander in california known as oleander leaf scorch, induced by the bacterium xylella fastidiosa. h. coagulata also has been implicated in the spread of the strain of x. fastidiosa that induces pierce's disease of grapevines in california. we monitored the flight activity of h. coagulata and h. lacerta in oleander and citrus by using yellow sticky cards at three southern california locations w ... | 2001 | 11777056 |
| intracellular symbionts of sharpshooters (insecta: hemiptera: cicadellinae) form a distinct clade with a small genome. | the leafhoppers (insecta: hemiptera: cicadellidae) are the most species-rich group of invertebrates in which intracellular symbionts are usual. here we present the first molecular characterization of bacteriome-associates in the leafhoppers, with focus on the subfamily cicadellinae (sharpshooters). phylogenetic analyses of 16s rdna sequences from intracellular symbionts residing in the bacteriomes of five host species indicate that these symbionts form a well-defined clade within the gamma-3 pro ... | 2003 | 12558594 |
| environmental monitoring of carbaryl applied in urban areas to control the glassy-winged sharpshooter in california. | carbaryl insecticide was applied by ground spray to plants in urban areas to control a serious insect pest the glassy-winged sharpshooter, homalodisca coagulata (say), newly introduced in california. to assure there are no adverse impacts to human health and the environment from the carbaryl applications, carbaryl was monitored in tank mixtures, air, surface water, foliage and backyard fruits and vegetables. results from the five urban areas - porterville, fresno, rancho cordova, brentwood and c ... | 2003 | 12602631 |
| dispersion of homalodisca coagulata (hemiptera: cicadellidae), a vector of xylella fastidiosa, into vineyards in southern california. | recent epidemics of pierce's disease of grapevine in california vectored by homalodisca coagulata (say), an invasive vector species, have characteristics that differ from epidemics involving native vectors. among these differences are the longer distances and greater speed that the disease is spread by h. coagulata. in this investigation, we used yellow sticky traps to study the seasonal dispersion activity of h. coagulata in a southern california grape-growing area in which an epidemic of pierc ... | 2003 | 14650508 |
| the biology of xylem fluid-feeding insect vectors of xylella fastidiosa and their relation to disease epidemiology. | xylophagous leafhopppers are common and abundant insects of tropical and subtropical environments and play important ecological roles in these ecosystems. the feeding biology of these insects is unique in terms of their high feeding rates and a digestive physiology that allows them to assimilate amino acids, organic acids, and sugars at approximately 99% efficiency. for those species well studied, fluctuations in plant xylem chemistry and tension appear to determine the diurnal and seasonal use ... | 2004 | 14651464 |
| transmission of xylella fastidiosa to grapevines by homalodisca coagulata (hemiptera: cicadellidae). | pierce's disease (pd) of grapevines is caused by a xylem-limited bacterium xylella fastidiosa (wells, raju, hung, weisburg, mandelco-paul, and brenner) that is transmitted to plants by xylem sap-feeding insects. the introduction of the sharpshooter leafhopper homalodisca coagulata (say) into california has initiated new pd epidemics in southern california. in laboratory experiments, the major characteristics of h. coagulata's transmission of x. fastidiosa to grapevines were the same as reported ... | 2003 | 14994789 |
| delivery of a genetically marked alcaligenes sp. to the glassy-winged sharpshooter for use in a paratransgenic control strategy. | an artificial feeding system was designed for the glassy-winged sharpshooter (gwss), homalodisca coagulata say (hemiptera: cicadellidae). the system, unlike previous systems, provided enough nutrients to gwss to survive for 48 h. a system like this is a prerequisite to examining the potential use of paratransgenesis to interrupt transmission of xylella fastidiosa, the bacterial pathogen causing pierce's disease of grape, by insect vectors. we developed a system for short-term feeding of gwss tha ... | 2004 | 15060727 |
| evaluation of methods for extracting xylella fastidiosa dna from the glassy-winged sharpshooter. | the recent spread of the plant pathogenic bacterium xylclla fastidiosa wells et al. by an invasive vector species, homalodisca coagulata say, in southern california has resulted in new epidemics of pierce's disease of grapevine. our goal is to develop an efficient method to detect low titers of x. fastidiosa in h. coagulata that is amenable to large sample sizes for epidemiological studies. detection of the plant pathogenic bacterium x. fastidiosa in its insect vector is complicated by low titer ... | 2004 | 15279249 |
| establishment of a genetically marked insect-derived symbiont in multiple host plants. | alcaligenes xylosoxidans subsp. denitrificans, originally isolated from the cibarial region of the foregut of the glassy-winged sharpshooter (homalodisca coagulata), was transformed using the himar1 transposition system to express egfp. seedlings of six potential host plants were inoculated with transformed bacteria and 2 weeks later samples were taken 5 cm away and analyzed by quantitative real-time pcr using primers designed to amplify the gene insert. the largest colony of 3,591,427 cells/2 c ... | 2005 | 15723145 |
| application of competitive enzyme-linked immunosorbent assay for the quantification of imidacloprid titers in xylem fluid extracted from grapevines. | a competitive enzyme-linked immunosorbent assay (elisa) technique was evaluated for quantifying titers of imidacloprid in xylem fluid extracted from vitis vinifera l. grapevines that were treated with systemic applications of the neonicotinoid insecticide admire. evidence of matrix effects, factors that compromise the precision and accuracy of the elisa, was present in assays with undiluted xylem fluid. these effects could be eliminated by dilution of extracts in water, resulting in a lower sens ... | 2005 | 15765681 |
| impact of pymetrozine on glassy-winged sharpshooter feeding behavior and rate of xylella fastidiosa transmission. | pymetrozine is a compound that interferes with insect feeding and interrupts transmission of plant pathogens. the glassy-winged sharpshooter, homalodisca coagulata say (hemiptera, cicadellidae), is a vector of xylella fastidiosa, the foregut-borne, propagative bacterium that causes pierce's disease of grapevine. in this study, we recorded the behavioral response of h. coagulata to plants treated by soil drench with pymetrozine using time-lapse photography, quantified the reduction in liquid excr ... | 2004 | 15861249 |
| a sybr green-based real-time polymerase chain reaction protocol and novel dna extraction technique to detect xylella fastidiosa in homalodisca coagulata. | homalodisca coagulata say (hemiptera: cicadellidae) is a major agronomic pest because it transmits xylella fastidiosa (wells), the bacterium that causes pierce's disease of grapevine. the ability to easily detect x. fastidiosa in populations of h. coagulata facilitates epidemiological studies and development of a monitoring program supporting disease management. such a program depends on a detection protocol that is rapid, reproducible, and amenable to large sample sizes, while remaining sensiti ... | 2005 | 16022291 |
| characterization of cell lines developed from the glassy-winged sharpshooter, homalodisca coagulata (hemiptera: cicadellidae). | four continuous cell lines were established from the embryos of the glassy-winged sharpshooter, homalodisca coagulata (say), an economically important insect vector of bacterial pathogens of grape, almond, citrus, oleander, and other agricultural and ornamental plantings. the cell lines were designated gwss-z10, gwss-z15, gwss-g3, and gwss-lh. the gwss-z10, gwss-z15, and gwss-g3 lines were cultured in ex-cell 401 medium supplemented with 10% fetal bovine serum (fbs), whereas the gwss-lh line was ... | 2005 | 16153147 |
| hypersensitivity to forcipomyia taiwana (biting midge): clinical analysis and identification of major for t 1, for t 2 and for t 3 allergens. | forcipomyia taiwana is a tiny, blood-sucking midge that cause intense pruritus and swelling in sensitive individuals. it is distributed island-wide in rural taiwan and southern china. objective: this study aimed to study the allergic immune responses and identify f. taiwana allergens. | 2005 | 16266384 |
| correlation of stylet activities by the glassy-winged sharpshooter, homalodisca coagulata (say), with electrical penetration graph (epg) waveforms. | glassy-winged sharpshooter, homalodisca coagulata (say), is an efficient vector of xylella fastidiosa (xf), the causal bacterium of pierce's disease, and leaf scorch in almond and oleander. acquisition and inoculation of xf occur sometime during the process of stylet penetration into the plant. that process is most rigorously studied via electrical penetration graph (epg) monitoring of insect feeding. this study provides part of the crucial biological meanings that define the waveforms of each n ... | 2006 | 16427072 |
| metabolic complementarity and genomics of the dual bacterial symbiosis of sharpshooters. | mutualistic intracellular symbiosis between bacteria and insects is a widespread phenomenon that has contributed to the global success of insects. the symbionts, by provisioning nutrients lacking from diets, allow various insects to occupy or dominate ecological niches that might otherwise be unavailable. one such insect is the glassy-winged sharpshooter (homalodisca coagulata), which feeds on xylem fluid, a diet exceptionally poor in organic nutrients. phylogenetic studies based on rrna have sh ... | 2006 | 16729848 |
| detection and differentiation of xylella fastidiosa strains acquired and retained by glassy-winged sharpshooters (hemiptera: cicadellidae) using a mixture of strain-specific primer sets. | xylella fastidiosa wells is a bacterial pathogen that causes a variety of plant diseases, including pierce's disease (pd) of grapevine, almond leaf scorch, alfalfa dwarf, citrus variegated chlorosis, and oleander leaf scorch (ols). numerous strains of this pathogen have been genetically characterized, and several different strains occur in the united states. the dominant vector in southern california is the glassy-winged sharpshooter, homalodisca coagulata (say) (hemiptera: cicadellidae). the hi ... | 2006 | 16937656 |
| spatial and temporal dynamics of overwintering homalodisca coagulata (hemiptera: cicadellidae). | a 4-yr landscape-scale study was conducted to investigate spatial and temporal dynamics of overwintering homalodisca coagulata (say) (hemiptera: cicadellidae) in the lower san joaquin valley, california. spatial structures of h. coagulata distributions were characterized with moran's i index, and spatial associations between h. coagulata and the surrounding environment were investigated with a geographic information system. h. coagulata was caught consistently with sticky traps throughout the wi ... | 2006 | 17195657 |
| effect of host plant xylem fluid on growth, aggregation, and attachment of xylella fastidiosa. | in the temecula valley of california the proximity of citrus groves to vineyards influences the incidence and severity of pierce's disease (pd) in grapes, a disease caused by the gram-negative bacterium, xylella fastidiosa. although the glassy-winged sharpshooter (gwss), the major insect vector of the bacterium, feeds on and moves back and forth between citrus groves and vineyards, there are no visible symptoms of disease caused by x fastidiosa in citrus. previous evidences suggested that while ... | 2007 | 17252211 |
| behavioral responses of homalodisca vitripennis (hemiptera: auchenorrhyncha: cicadellidae) on four vitis genotypes. | pierce's disease is a major threat to the california grape industry. the disease-causing bacterium xylella fastidiosa is vectored by a number of leafhoppers including homalodisca vitripennis (germar) (hemiptera: cicadellidae). experiments were conducted to study h. vitripennis preference, feeding, and survivorship in response to four vitis genotypes. plants of v. vinifera ('chardonnay'), v. girdiana, v. candicans, and a v. rupestris x v. arizonica/candicans hybrid (d8909-17) were grown in pots i ... | 2007 | 17716485 |
| toxicity of seven foliar insecticides to four insect parasitoids attacking citrus and cotton pests. | laboratory studies were carried out to compare the toxicity of seven foliar insecticides to four species of adult beneficial insects representing two families of hymenoptera: aphelinidae (aphytis melinus debach, eretmocerus eremicus rose & zolnerowich, and encarsiaformosa gahan) and mymaridae (gonatocerus ashmeadi girault) that attack california red scale, aonidiella aurantii (maskell); sweetpotato whitefly, bemisia tabaci (gennadius) (both e. eremicus and e. formosa); and glassy-winged sharpsho ... | 2007 | 17849851 |
| initial genetic analysis of xylella fastidiosa in texas. | xylella fastidiosa is the causative agent of pierce's disease of grape. no published record of x. fastidiosa genetics in texas exists despite growing financial risk to the u.s. grape industry, a texas population of the glassy-winged sharpshooter insect vector (homalodisca vitripennis) now spreading in california, and evidence that the bacterium is ubiquitous to southern states. using sequences of conserved gyrb and mopb genes, we have established at least two strains in texas, grape strain and r ... | 2008 | 18172717 |
| effects of citrus and avocado irrigation and nitrogen-form soil amendment on host selection by adult homalodisca vitripennis (hemiptera: cicadellidae). | host plant water status is thought to influence dispersal of the xylophagous leafhopper homalodisca vitripennis germar, especially where plants are grown under high evaporative demand. preference by adult h. vitripennis for plants grown under different water deficit and nitrogen form fertilization regimens was studied under laboratory conditions. leafhopper abundance and ovipositional preference were studied on potted 'washington navel' orange and 'haas' avocado in cage choice tests, and feeding ... | 2008 | 18559186 |
| identifying the predator complex of homalodisca vitripennis (hemiptera: cicadellidae): a comparative study of the efficacy of an elisa and pcr gut content assay. | a growing number of ecologists are using molecular gut content assays to qualitatively measure predation. the two most popular gut content assays are immunoassays employing pest-specific monoclonal antibodies (mab) and polymerase chain reaction (pcr) assays employing pest-specific dna. here, we present results from the first study to simultaneously use both methods to identify predators of the glassy winged sharpshooter (gwss), homalodisca vitripennis (germar) (hemiptera: cicadellidae). a total ... | 2008 | 18618149 |
| impact of duration versus frequency of probing by homalodisca vitripennis (hemiptera: cicadellidae) on inoculation of xylella fastidiosa. | successful infection of the plant pathogenic bacterium xylella fastidiosa (wells) from an infected plant to a new host involves three main steps: 1) acquisition of the bacterium by a vector; 2) inoculation of a noninfected host plant by the vector; and 3) establishment of sufficient titers of x. fastidiosa in the host plant to sustain a chronic infection. understanding the basic biology of the transmission process is a key to limiting the spread of plant diseases induced by x. fasdidiosa and red ... | 2008 | 18767718 |
| quantitative comparison of stylet penetration behaviors of glassy-winged sharpshooter on selected hosts. | new zealand is threatened by invasion of the glassy-winged sharpshooter, homalodisca vitripennis (germar) (hemiptera: cicadellidae), an important vector of xylella fastidiosa, a gram-negative bacterium that causes pierce's disease in grape (vitis spp.) and scorch diseases in many other horticultural crops. therefore, an understanding of the host acceptability, feeding behavior, and potential vector efficiency of glassy-winged sharpshooter on new zealand crops is important. we tested host plant a ... | 2008 | 18767727 |
| seasonal abundance and spatio-temporal distribution of dominant xylem fluid-feeding hemiptera in vineyards of central texas and surrounding habitats. | a survey of xylem fluid-feeding insects (hemiptera) exhibiting potential for transmission of xylella fastidiosa, the bacterium causing pierce's disease of grapevine, was conducted from 2004 to 2006 in the hill country grape growing region of central texas. nineteen insect species were collected from yellow sticky traps. among these, two leafhoppers and one spittlebug comprised 94.57% of the xylem specialists caught in this region. homalodisca vitripennis (germar), graphocephala versuta (say), an ... | 2008 | 18801258 |
| analysis of the spatial patterns of pierce's disease incidence in the lower san joaquin valley in california. | abstract the incidence of pierce's disease (pd), caused by xylella fastidiosa, was monitored in 11 naturally infested commercial vineyards to determine the presence of an x. fastidiosa vector, homalodisca coagulata (glassy-winged sharpshooter [gwss]), to examine the spatial patterns of the disease and elucidate possible influences of surrounding environments. disease incidence ranged from <1 to 65% among vineyards in 2001. our efforts to trap or capture potential disease vectors have indicated t ... | 2004 | 18943803 |
| fate of a genetically modified bacterium in foregut of glassy-winged sharpshooter (hemiptera: cicadellidae). | symbiotic control is a new strategy being investigated to prevent the spread of insect-transmitted pathogens by reducing vector competence. we are developing this strategy to reduce the spread of xylella fastidiosa by homalodisca vitripennis (germar) [formerly homalodisca coagulata (say)] (hemiptera: cicadellidae), the glassy-winged sharpshooter. in this study, the fate of a transformed symbiotic bacterium, alcaligenes xylosoxidans variety denitriicans (s1axd), in the foregut of glassy-winged sh ... | 2008 | 18950032 |
| behavioral model for homalodisca vitripennis (hemiptera: cicadellidae): optimization of host plant utilization and management implications. | the glassy-winged sharpshooter, homalodisca vitripennis (germar), (hemiptera: cicadellidae), is a xylophagous leafhopper native to the southeastern united states and northern mexico, with recent introductions into california, arizona, french polynesia, and hawaii. it is a primary vector of the xylem-limited bacterium, xylella fastidiosa wells et al., the causative agent of pierce's disease of grape, citrus variegated chlorosis, phony peach, and numerous leaf scorch diseases. h. vitripennis uses ... | 2008 | 19036181 |
| egg load dynamics of homalodisca vitripennis. | homalodisca vitripennis, the glassy-winged sharpshooter, poses a serious threat to grape production because of its ability to vector xylella fastidiosa, the causal agent of pierce's disease. the glassy-winged sharpshooter is native to the southeastern united states, and over the last 20 yr has expanded its range into texas and california and more distantly into french polynesia. a better understanding of the reproductive dynamics of h. vitripennis will aid in assessment of the invasiveness of th ... | 2008 | 19036198 |
| a new phytoreovirus infecting the glassy-winged sharpshooter (homalodisca vitripennis). | a new virus species of the genus phytoreovirus was isolated from glassy-winged sharpshooter (gwss), homalodisca vitripennis germar (hemiptera: cicadellidae), in california and designated here as homalodisca vitripennis reovirus (hovrv). extraction of nucleic acid from gwss adults collected from three californian populations revealed an array of double-stranded (ds) rna species that was soluble in 2 m licl and resistant to degradation upon exposure to s1 nuclease and dnase. analysis of nucleic ac ... | 2009 | 19239972 |
| molecular analysis of capsid protein of homalodisca coagulata virus-1, a new leafhopper-infecting virus from the glassy-winged sharpshooter, homalodisca coagulata. | a new virus that infects and causes increased mortality in leafhoppers was isolated from the glassy-winged sharpshooter, homalodisca coagulata (say) (hemiptera: cicadellidae). the virus, named homalodisca coagulata virus -1, hocv-1, was associated with increased mortality of cultured 5(th) instar h. coagulata. to identify the presence of h. coagulata viral pathogens, cdna expression libraries were made from adult and nymphs. analysis using reverse transcriptase pcr demonstrated that the virus wa ... | 2006 | 19537993 |
| dispersal, patch leaving, and distribution of homalodisca vitripennis (hemiptera: cicadellidae). | homalodisca vitripennis (germar) and related species have caused millions of dollars in damage to southern california vineyards in recent years through the vectoring of pierce's disease. however, the effects of surrounding vegetation on the dispersal and distribution of h. vitripennis are poorly understood. therefore, the relationship between dispersal rates and patch quality was tested, as well as the basic predictions of the marginal value theorem. additional experiments were conducted to comp ... | 2009 | 19791613 |
| seasonal increase of xylella fastidiosa in hemiptera collected from central texas vineyards. | yellow sticky traps were placed in six vineyards in central texas from 2003 to 2006 and in locations outside the vineyards in 2004-2006. in total, 72 collections on 55 dates were examined. xylem fluid-feeding insects were removed and identified to species and then analyzed by polymerase chain reaction to determine the presence or absence of xylella fastidiosa wells et al. of the 1318 insects removed, 13 species were found, dominated by homalodisca vitripennis (germar), clastoptera xanthocepahala ... | 2009 | 19886437 |
| medium for development of bee cell cultures (apis mellifera: hymenoptera: apidae). | a media for the production of cell cultures from hymenopteran species such as honey bee, apis mellifera l. (hymenoptera: apidae) was developed. multiple bee cell cultures were produced when using bee larvae and pupae as starting material and modified hert-hunter 70 media. cell culture systems for bees solves an impasse that has hindered efforts to isolate and screen pathogens which may be influencing or causing colony collapse disorder of bees. multiple life stages of maturing larvae to early pu ... | 2010 | 20033792 |
| temporal patterns in homalodisca spp. (hemiptera: cicadellidae) oviposition on southern california citrus and jojoba. | a detailed study of the distribution of egg masses of homalodisca vitripennis (germar) and h. liturata ball was done across a 2-yr period (2001-2003) on six host plants in southern california (marsh grapefruit, lisbon lemon, washington navel, dancy tangerine, rough lemon, and jojoba in riverside; jojoba in desert center). the majority of egg masses in riverside belonged to h. vitripennis (84-100%), whereas in desert center, all homalodisca egg masses were h. liturata. oviposition in riverside oc ... | 2010 | 20146836 |
| detection of the bacterium, xylella fastidiosa, in saliva of glassy-winged sharpshooter, homalodisca vitripennis. | homalodisca vitripennis (germar) (hemiptera: cicadellidae), the glassy-winged sharpshooter, is one of the most important vectors of the bacterium, xylella fastidiosa subsp. piercei (xanthomonadales: xanthomonadaceae) that causes pierce's disease in grapevines in california. in the present study we report a new method for studying pathogen transmission or probing behavior of h. vitripennis. when confined, h. vitripennis attempt to probe the surface of sterile containers 48 hours post-acquisition ... | 2008 | 20233080 |
| rnai effects on actin mrnas in homalodisca vitripennis cells. | the xylem feeding leafhopper homalodisaca vitripennis (h. vitripennis) is an unusually robust and efficient vector of xylella fastidiosa, a gram-negative bacterium which causes several very important plant diseases. here we investigated rna interference (rnai) to target actin, a key component of insect cells and whole bodies, in h. vitripennis cells. rnai effectors were delivered via lipid based transfection and real-time rt-pcr, rna hybridization, and microscopic analyses were employed to verif ... | 2010 | 20628496 |
| population genetics of homalodisca vitripennis reovirus validates timing and limited introduction to california of its invasive insect host, the glassy-winged sharpshooter. | as rna viruses evolve rapidly, we hypothesized that a virus could serve as a surrogate to discriminate recently separated populations of an invasive insect species. homalodisca vitripennis reovirus (hovrv) was used as a surrogate to assess population structure of glassy-winged sharpshooter (gwss), an invasive species detected in california ~20 years ago. hovrv nucleotide sequence polymorphism revealed a bottleneck in the introduced population, yielded population age estimates consistent with tim ... | 2010 | 20739043 |
| graph-based analysis of the metabolic exchanges between two co-resident intracellular symbionts, baumannia cicadellinicola and sulcia muelleri, with their insect host, homalodisca coagulata. | endosymbiotic bacteria from different species can live inside cells of the same eukaryotic organism. metabolic exchanges occur between host and bacteria but also between different endocytobionts. since a complete genome annotation is available for both, we built the metabolic network of two endosymbiotic bacteria, sulcia muelleri and baumannia cicadellinicola, that live inside specific cells of the sharpshooter homalodisca coagulata and studied the metabolic exchanges involving transfers of carb ... | 2010 | 20838465 |
| detection and analysis of the bacterium, xylella fastidiosa, in glassy-winged sharpshooter, homalodisca vitripennis, populations in texas. | the glassy-winged sharpshooter, homalodisca vitripeninis germar (hemiptera: cicadellidae), is a xylophagous insect that is an endemic pest of several economically important plants in texas. h. vitripennis is the main vector of xylella fastidiosa wells (xanthomonadales: xanthomonadaceae), the bacterium that causes pierce's disease of grapevine and can travel long distances putting much of texas grape production at risk. understanding the movement of h. vitripennis populations capable of transmitt ... | 2010 | 21062210 |
| spatiotemporal colonization of xylella fastidiosa in its vector supports the role of egestion in the inoculation mechanism of foregut-borne plant pathogens. | the pathogen that causes pierce's disease of grapevine, xylella fastidiosa, is the only known bacterial, arthropod-transmitted plant pathogen that does not circulate in the vector's hemolymph. instead, bacteria are foregut-borne, persistent in adult vectors but semipersistent in immatures (i.e., bacteria colonize cuticular surfaces of the anterior foregut, are retained for hours to days, but are lost during molting). yet, exactly how a sharpshooter vector inoculates bacteria from foregut acquisi ... | 2011 | 21425930 |
| estimation of feeding threshold for homalodisca vitripennis (hemiptera: cicadellidae) and its application to prediction of overwintering mortality. | the glassy-winged sharpshooter, homalodisca vitripennis (germar), vectors the bacterium xylella fastidiosa that induces pierce's disease of grape. this study determined the effect of temperature on the feeding activity of h. vitripennis adults and the resulting production of excreta. the logan type i model described a nonlinear pattern that showed excreta production increased up to an optimal temperature (33.1°c), followed by an abrupt decline near an estimated upper threshold (36.4°c). a tempe ... | 2010 | 22127177 |
| culture independent survey of the microbiota of the glassy-winged sharpshooter (homalodisca vitripennis) using 454 pyrosequencing. | the glassy-winged sharpshooter, homalodisca vitripennis (germar), is an invasive pest that has spread across the southern and western united states. h. vitripennis is highly polyphagous and voracious, feeding on at least 100 plant species and consuming up to 100 times its weight in xylem fluid daily. the insect is a vector of the phytopathogen xylella fastidiosa (wells), which is the causative agent of pierce's disease in grapevines. to evaluate the microbial flora associated with h. vitripenni ... | 2011 | 22182607 |
| Age determination of the glassy-winged sharpshooter, Homalodisca vitripennis, using wing pigmentation. | A red pigment is contained in the wing veins of the glassy-winged sharpshooter, Homalodisca vitripennis (Hemiptera: Cicadellidae). This insect is the main vector of the plant-pathogenic bacterium Xylella fastidiosa Wells (Xanthomonadales: Xanthomonadaceae), the causal agent of Pierce's disease of grapevines. Over the course of the H. vitripennis lifespan, the red pigment darkens and eventually becomes brown/black in color. These pigments are believed to be pheomelanin and eumelanin, respectively ... | 2011 | 21870964 |
| differential genome evolution between companion symbionts in an insect-bacterial symbiosis. | obligate symbioses with bacteria allow insects to feed on otherwise unsuitable diets. some symbionts have extremely reduced genomes and have lost many genes considered to be essential in other bacteria. to understand how symbiont genome degeneration proceeds, we compared the genomes of symbionts in two leafhopper species, homalodisca vitripennis (glassy-winged sharpshooter [gwss]) and graphocephala atropunctata (blue-green sharpshooter [bgss]) (hemiptera: cicadellidae). each host species is asso ... | 2014 | 25271287 |
| a delivery system for field application of paratransgenic control. | as an alternative to chemical pesticides, paratransgenesis relies on transformation of symbiotic bacteria of an arthropod vector to deliver molecules that disrupt pathogen transmission. for over a decade paratransgenesis has remained a laboratory-based endeavor owing to regulatory concerns regarding introduction of transformed microorganisms into the environment. to facilitate field application of paratransgenic strategies, risk mitigation approaches that address environmental contamination and ... | 2015 | 26099939 |
| sequencing and de novo assembly of the transcriptome of the glassy-winged sharpshooter (homalodisca vitripennis). | the glassy-winged sharpshooter homalodisca vitripennis (hemiptera: cicadellidae), is a xylem-feeding leafhopper and important vector of the bacterium xylella fastidiosa; the causal agent of pierce's disease of grapevines. the functional complexity of the transcriptome of h. vitripennis has not been elucidated thus far. it is a necessary blueprint for an understanding of the development of h. vitripennis and for designing efficient biorational control strategies including those based on rna inter ... | 2013 | 24339955 |
| identification of novel and conserved micrornas in homalodisca vitripennis, the glassy-winged sharpshooter by expression profiling. | the glassy-winged sharpshooter (gwss) homalodisca vitripennis (hemiptera: cicadellidae), is a xylem-feeding leafhopper and an important vector of the bacterium xylella fastidiosa; the causal agent of pierce's disease of grapevines. micrornas are a class of small rnas that play an important role in the functional development of various organisms including insects. in h. vitripennis, we identified micrornas using high-throughput deep sequencing of adults followed by computational and manual annota ... | 2015 | 26440407 |
| ribosome display of combinatorial antibody libraries derived from mice immunized with heat-killed xylella fastidiosa and the selection of mopb-specific single-chain antibodies. | pierce's disease is a devastating lethal disease of vitus vinifera grapevines caused by the bacterium xylella fastidiosa. there is no cure for pierce's disease, and control is achieved predominantly by suppressing transmission of the glassy-winged sharpshooter insect vector. we present a simple robust approach for the generation of panels of recombinant single-chain antibodies against the surface-exposed elements of x. fastidiosa that may have potential use in diagnosis and/or disease transmissi ... | 2012 | 22327580 |
| molecular distinction between populations of gonatocerus morrilli, egg parasitoids of the glassy-winged sharpshooter from texas and california: do cryptic species exist? | two molecular methods were utilized to distinguish geographic populations of gonatocerus morrilli (howard) from texas and california and to test the possibility that this species could exist as a species-complex. inter-simple sequence repeat-polymerase chain reactions (issr-pcr) were performed with a 5'-anchored issr primer. twenty-five markers were generated with four populations (40 individuals) of g. morrilli. twenty-three were polymorphic and the percentage of polymorphic loci was 92%. most ... | 2004 | 15861254 |
| molecular characterization, expression analysis and rnai knock-down of elongation factor 1α and 1γ from nilaparvata lugens and its yeast-like symbiont. | in the present paper, four cdnas encoding the alpha and gamma subunits of elongation factor 1 (ef-1) were cloned and sequenced from nilaparvata lugens, named nlef-1α, nlef-1γ, and its yeast-like symbiont (yls), named ysef-1α and ysef-1γ, respectively. comparisons with sequences from other species indicated a greater conservation for ef-1α than for ef-1γ. nlef-1α has two identical copies. the deduced amino acid sequence homology of nlef-1α and nlef-1γ is 96 and 64%, respectively, compared with ho ... | 2016 | 27809951 |
| effects of xylem-sap composition on glassy-winged sharpshooter (hemiptera: cicadellidae) egg maturation on high- and low-quality host plants. | glassy-winged sharpshooters must feed as adults to produce mature eggs. cowpea and sunflower are both readily accepted by the glassy-winged sharpshooter for feeding, but egg production on sunflower was reported to be lower than egg production on cowpea. to better understand the role of adult diet in egg production, effects of xylem-sap chemistry on glassy-winged sharpshooter egg maturation was compared for females confined to cowpea and sunflower. females confined to cowpea consumed more xylem-s ... | 2017 | 28334386 |
| development and validation of a real-time pcr assay for the glassy-winged sharpshooter homalodisca vitripennis (hemiptera: cicadellidae). | the glassy-winged sharpshooter (homalodisca vitripennis) is an invasive pest organism, which is found throughout central america and has recently invaded a few countries in the pacific islands. as a carrier of the highly virulent plant pathogenic bacterium xylella fastidiosa, it is of great economic significance to horticulture and is estimated to cost californian vineyards over us$100 million per year in control and losses. new zealand is currently free from this pest, but its recent spread thr ... | 2016 | 27819200 |
| transmission of phage by glassy-winged sharpshooters, a vector of xylella fastidiosa. | xylella fastidiosa subsp. fastidiosa (xff) is the causal agent of pierce's disease (pd) of grapevines and is vectored by the glassy-winged sharpshooter (gwss, homalodisca vitripennis). previously we have reported the development of a bacteriophage (phage) based biocontrol system for pd, but no information on insect transmission of phages has been reported. here we communicate that laboratory reared gwsss fed on cowpea plants (vigna unguiculata subsp. unguiculata) harboring the virulent phage paz ... | 2017 | 27738554 |
| effects of glassy-winged sharpshooter (hemiptera: cicadellidae) feeding, size, and lipid content on egg maturation. | the glassy-winged sharpshooter (homalodisca vitripennis) is synovigenic and must feed as an adult to produce eggs. egg maturation rates depend on the host plant species provided to the adult female for feeding and are variable for females provided with the same host plant species. here, the contribution of female size and lipid content to variation in egg maturation rates among females held on the same host plant species was assessed. to assess effects of female size and lipid content on egg mat ... | 2015 | 26470224 |
| is vector control sufficient to limit pathogen spread in vineyards? | vector control is widely viewed as an integral part of disease management. yet epidemiological theory suggests that the effectiveness of control programs at limiting pathogen spread depends on a variety of intrinsic and extrinsic aspects of a pathosystem. moreover, control programs rarely evaluate whether reductions in vector density or activity translate into reduced disease prevalence. in areas of california invaded by the glassy-winged sharpshooter (homalodisca vitripennis germar), pierce's d ... | 2015 | 26313985 |
| direct evidence of egestion and salivation of xylella fastidiosa suggests sharpshooters can be "flying syringes". | xylella fastidiosa is unique among insect-transmitted plant pathogens because it is propagative but noncirculative, adhering to and multiplying on the cuticular lining of the anterior foregut. any inoculation mechanism for x. fastidiosa must explain how bacterial cells exit the vector's stylets via the food canal and directly enter the plant. a combined egestion-salivation mechanism has been proposed to explain these unique features. egestion is the putative outward flow of fluid from the foregu ... | 2015 | 26020829 |
| propagation of homalodisca coagulata virus-01 via homalodisca vitripennis cell culture. | the glassy-winged sharpshooter (homalodisca vitripennis) is a highly vagile and polyphagous insect found throughout the southwestern united states. these insects are the predominant vectors of xylella fastidiosa (x. fastidiosa), a xylem-limited bacterium that is the causal agent of pierce's disease (pd) of grapevine. pierce's disease is economically damaging; thus, h. vitripennis have become a target for pathogen management strategies. a dicistrovirus identified as homalodisca coagulata virus-01 ... | 2014 | 25285687 |
| anterior foregut microbiota of the glassy-winged sharpshooter explored using deep 16s rrna gene sequencing from individual insects. | the glassy-winged sharpshooter (gwss) is an invasive insect species that transmits xylella fastidiosa, the bacterium causing pierce's disease of grapevine and other leaf scorch diseases. x. fastidiosa has been shown to colonize the anterior foregut (cibarium and precibarium) of sharpshooters, where it may interact with other naturally-occurring bacterial species. to evaluate such interactions, a comprehensive list of bacterial species associated with the sharpshooter cibarium and precibarium is ... | 2014 | 25184624 |
| plant water stress effects on stylet probing behaviors of homalodisca vitripennis (hemiptera: cicadellidae) associated with acquisition and inoculation of the bacterium xylella fastidiosa. | abstract the glassy-winged sharpshooter, homalodisca vitripennis (germar) (hemiptera: cicadellidae), is a xylem fluid-ingesting leafhopper that transmits xylella fastidiosa wells et al., a plant-infecting bacterium that causes several plant diseases in the americas. although the role of plant water stress on the population density and dispersal ofh. vitripennis has been studied, nothing is known about the effects of plant water stress on the transmission of x. fastidiosa by h. vitripennis. a lab ... | 2014 | 24665686 |
| feeding and development of the glassy-winged sharpshooter, homalodisca vitripennis, on australian native plant species and implications for australian biosecurity. | in any insect invasion the presence or absence of suitable food and oviposition hosts in the invaded range is a key factor determining establishment success. the glassy-winged sharpshooter, homalodisca vitripennis, is an important insect vector of the xylem-limited bacterial plant pathogen, xylella fastidiosa, which causes disease in numerous host plants including food and feedstock crops, ornamentals and weeds. both the pathogen and the vector are native to the americas and are considered to be ... | 2014 | 24614821 |
| characterization of hovi-meh1, a microsomal epoxide hydrolase from the glassy-winged sharpshooter homalodisca vitripennis. | epoxide hydrolase (eh) is an enzyme in the α/β-hydrolase fold superfamily that uses a water molecule to transform an epoxide to its corresponding diol. in insects, ehs metabolize among other things critical developmental hormones called juvenile hormones (jhs). ehs also play roles in the detoxification of toxic compounds that are found in the insect's diet or environment. in this study, a full-length cdna encoding an epoxide hydrolase, hovi-meh1, was obtained from the xylem-feeding insect homalo ... | 2013 | 23704009 |
| plant water stress effects on the net dispersal rate of the insect vector homalodisca vitripennis (hemiptera: cicadellidae) and movement of its egg parasitoid, gonatocerus ashmeadi (hymenoptera: mymaridae). | homalodisca vitripennis (germar), a vector of xylella fastidiosa, is associated with citrus plantings in california. infested citrus orchards act as a source of vectors to adjacent vineyards where x. fastidiosa causes pierce's disease. an analysis of the pattern and rate of movement of h. vitripennis and its egg parasitoid, gonatocerus ashmeadi girault, was conducted in a citrus orchard by using a protein mark-capture technique to quantify movement and net dispersal rates in the experimental are ... | 2012 | 23321075 |
| pattern of stylet penetration activity by homalodisca vitripennis (hemiptera: cicadellidae) adults in relation to environmental temperature and light conditions. | effects of ambient spring air temperature and light intensity on stylet penetration activities of the glassy-winged sharpshooter, homalodisca vitripennis (germar), were studied under field conditions by using an electrical penetration graph. electrical penetration graph waveforms representing salivary sheath formation and searching (pathway phase), xylem contact (x waves), and ingestion of xylem fluid (waveform c) were analyzed. previous research supported the concept that acquisition of xylella ... | 2012 | 23068180 |
| salivary enzymes are injected into xylem by the glassy-winged sharpshooter, a vector of xylella fastidiosa. | a few phytophagous hemipteran species such as the glassy-winged sharpshooter, homalodisca vitripennis, (germar), subsist entirely on xylem fluid. although poorly understood, aspects of the insect's salivary physiology may facilitate both xylem-feeding and transmission of plant pathogens. xylella fastidiosa is a xylem-limited bacterium that causes pierce's disease of grape and other scorch diseases in many important crops. x. fastidiosa colonizes the anterior foregut (precibarium and cibarium) of ... | 2012 | 22587965 |
| rna interference is induced in the glassy winged sharpshooter homalodisca vitripennis by actin dsrna. | the glassy winged sharpshooter, homalodisca vitripennis, is an unusually robust and efficient leafhopper vector of xylella fastidiosa. x. fastidiosa is the causative agent of pierce's disease, almond scorch, citrus variegated chlorosis and other serious plant diseases. the present study was conducted to establish whether rna interference (rnai) was induced in nymphal h. vitripennis that were injected with actin dsrnas and other dsrnas. | 2012 | 22345053 |
| grapevine genotype susceptibility to xylella fastidiosa does not predict vector transmission success. | for vector-borne diseases, interactions between vector, host, and pathogen can influence patterns of disease spread. in particular, previous studies suggest that host genotype may influence disease dynamics because of differences in susceptibility to the pathogen and, therefore, subsequent vector transmission efficiency from these plants. we tested this hypothesis by using the pathogenic bacterium xylella fastidiosa, the etiological agent of pierce's disease in grapevines, and its leafhopper vec ... | 2011 | 22251730 |
| geographic distribution and relative abundance of the invasive glassy-winged sharpshooter: effects of temperature and egg parasitoids. | the capacity to predict the geographic distribution and relative abundance of invasive species is pivotal to developing policy for eradication or control and management. commonly used methods fall under the ambit of ecological niche models (enms). these methods were reviewed and shortcomings identified. weather-driven physiologically based demographic models (pbdms) are proposed that resolve many of the deficiencies of enms. the pbdm approach is used to analyze the invasiveness of the polyphagou ... | 2011 | 22251675 |
| formation of stylet sheaths in āere (in air) from eight species of phytophagous hemipterans from six families (suborders: auchenorrhyncha and sternorrhyncha). | stylet sheath formation is a common feature among phytophagous hemipterans. these sheaths are considered essential to promote a successful feeding event. stylet sheath compositions are largely unknown and their mode of solidification remains to be elucidated. this report demonstrates the formation and solidification of in āere (in air) produced stylet sheaths by six hemipteran families: diaphorina citri (psyllidae, asian citrus psyllid), aphis nerii (aphididae, oleander/milkweed aphid), toxopter ... | 2013 | 23638086 |
| eradication of invasive species: why the biology matters. | published bi- and tri-trophic physiologically based demographic system models having similar sub components are used to assess prospectively the geographic distributions and relative abundance (a measure of invasiveness) of six invasive herbivorous insect species across the united states and mexico. the plant hosts and insect species included in the study are: 1) cotton/pink bollworm, 2) a fruit tree host/mediterranean fruit fly, 3) olive/olive fly, 4) a perennial host/light brown apple moth, 5) ... | 2013 | 23726048 |
| probabilities for survival of glassy-winged sharpshooter and olive fruit fly pests in urban yard waste piles. | glassy-winged sharpshooter (homolodisca coagulate) and olive fruit fly (bactrocera oleae) were introduced into unturned, chipped yard waste piles to evaluate their survival with time and depth within the piles. in all three trials, no pests lasted more than 14 d, and in no trial did pests survive more than 4d at the 30 and 100 cm depths. no survivors were found after 14 d in any of the treatments at any depth. neither of the pests survived 100 cm after 2d. a mathematical model for describing pes ... | 2008 | 17419052 |
| influences of temperature on homalodisca vitripennis (hemiptera: cicadellidae) survival under various feeding conditions. | survival of the glassy-winged sharpshooter, homalodisca vitripennis (germar) (hemiptera: cicadellidae), was studied under various constant temperatures and feeding conditions. when provided a host plant (citrus limon l. burm. f.) to feed on during a 21-d trial, 100% mortality occurred at 0.1, 3.2, and 40.1 degrees c, whereas an average of 74-76% of adults survived in the 13.2-24.5 degrees c range. when individually confined with moist cotton, adult longevity was greatest (16.3 d) at 13.3 degrees ... | 2009 | 19825304 |
| seasonal population dynamics of homalodisca vitripennis (hemiptera: cicadellidae) in sweet orange trees maintained under continuous deficit irrigation. | a 2-yr study was conducted in a citrus orchard (citrus sinensis l. osbeck cultivar valencia) to determine the influence of plant water stress on the population dynamics of glassy-winged sharpshooter, homalodisca vitripennis (germar). experimental treatments included irrigation at 100% of the crop evapotranspiration rate (et(c)) and continuous deficit-irrigation regimens at 80 and 60% et(c). microclimate and plant conditions monitored included temperature and humidity in the tree canopy, leaf sur ... | 2009 | 19610409 |
| preference-performance linkage of the xylem feeding leafhopper, homalodisca vitripennis (hemiptera cicadellidae). | insect species exhibiting a weak linkage between adult preference and immature performance have frequently been shown to be prone to outbreaks. we used choice and no-choice tests to examine the preference-performance linkage of the xylem fluid-feeding leafhopper, homalodisca vitripennis germar. leafhoppers were offered a choice of hosts common to their native range and also a choice from hosts where they have been recently introduced. behavior (residence preference, oviposition preference, and c ... | 2007 | 18284780 |
| a glassy-winged sharpshooter cell line supports replication of rhopalosiphum padi virus (dicistroviridae). | rhopalosiphum padi virus (rhpv) (family dicistroviridae; genus cripavirus) is an icosahedral aphid virus with a 10kb positive-sense rna genome. to study the molecular biology of rhpv, identification of a cell line that supports replication of the virus is essential. we screened nine cell lines derived from species within the lepidoptera, diptera and hemiptera for susceptibility to rhpv following rna transfection. we observed cytopathic effects (cpe) only in cell lines derived from hemipterans, s ... | 2007 | 17113099 |
| insect nicotinic acetylcholine receptors: neonicotinoid binding site specificity is usually but not always conserved with varied substituents and species. | the diversity of neonicotinoid insecticides acting as insect nicotinic acetylcholine (ach) receptor (nachr) agonists is illustrated by imidacloprid (imi) with chloropyridinylmethyl (cpm) and n-nitroimine substituents, dinotefuran (din) with tetrahydrofurylmethyl (tfm) and n-nitroimine moieties, and acetamiprid (ace) with cpm and n-cyanoimine groups. these three neonicotinoids are used here as radioligands to test the hypothesis that they all bind to the same site in the same way in both fruit fl ... | 2006 | 16637697 |
| the complete mitochondrial genome of tambocerus sp. (hemiptera: cicadellidae). | the complete mitochondrial genome of tambocerus sp. (hemiptera: cicadellidae) from zhejiang and anhui provinces of china was sequenced. the total length of the mitogenome is 15 955 bp (genbank accession no. kt827824) and consists of 22 transfer rnas, 13 protein-coding genes, 2 ribosomal rnas and 1 control region. the base composition of the heavy strand for a, t, c, and g is 41.39, 35.02, 14.00, and 9.59%, respectively. all of the protein-coding genes (pcgs) start with atn. five protein-coding g ... | 2017 | 26710270 |
| egg parasitoids of proconiini (hemiptera: cicadellidae) in northwestern mexico, with description of a new species of gonatocerus (hymenoptera: mymaridae). | nine species of mymaridae and trichogrammatidae parasitic on eggs of proconiini sharpshooters (cicadellidae: cicadellinae) were collected in northwestern mexico in relation to neoclassical biological control efforts against glassy-winged sharpshooter, homalodisca vitripennis (germar), in california. gonatocerus chula triapitsyn and bernal sp. n., which belongs to the ater species group of gonatocerus nees (mymaridae), is described. specimens of g. chula sp. n. were reared from eggs of the smoke- ... | 2009 | 19611244 |
| small rna populations for two unrelated viruses exhibit different biases in strand polarity and proximity to terminal sequences in the insect host homalodisca vitripennis. | next generation sequence analyses were used to assess virus-derived small rna (vsrna) profiles for homalodisca coagulata virus-1 (hocv-1), family dicistroviridae, and homalodisca vitripennis reovirus (hovrv), family reoviridae, from virus-infected h. vitripennis, the glassy-winged sharpshooter. the vsrna reads were mapped against the monopartite genome of hocv-1 and all 12 genome segments of hovrv, and 21nt vsrnas were most common. however, strikingly contrasting patterns for the hocv-1 and hovr ... | 2013 | 23642540 |
| design of a candidate vibrational signal for mating disruption against the glassy-winged sharpshooter, homalodisca vitripennis. | the glassy-winged sharpshooter (gwss), homalodisca vitripennis, is an important pest of grapevines due to its ability to transmit xylella fastidiosa, the causal agent of pierce's disease. gwss mating communication is based on vibrational signals; therefore, vibrational mating disruption could be an alternative to insecticides for suppression of the gwss population. our objectives were to identify spectral features of the female signal that elicit male signaling, design disruptive signals able to ... | 2017 | 28523722 |
| genome-wide transcriptional dynamics in the companion bacterial symbionts of the glassy-winged sharpshooter (cicadellidae: homalodisca vitripennis) reveal differential gene expression in bacteria occupying multiple host organs. | the agricultural pest known as the glassy-winged sharpshooter (gwss) or homalodisca vitripennis (hemiptera: cicadellidae) harbors two bacterial symbionts, "candidatus sulcia muelleri" and "ca baumannia cicadellinicola," which provide the 10 essential amino acids (eaas) that are limited in the host plant-sap diet. although they differ in origin and symbiotic age, both bacteria have experienced extensive genome degradation resulting from their ancient restriction to specialized host organs (bacter ... | 2017 | 28705905 |
| lineage-specific patterns of genome deterioration in obligate symbionts of sharpshooter leafhoppers. | plant sap-feeding insects (hemiptera) rely on obligate bacterial symbionts that provision nutrients. some of these symbionts are ancient and have evolved tiny genomes, whereas others are younger and retain larger, dynamic genomes. baumannia cicadellinicola, an obligate symbiont of sharpshooter leafhoppers, is derived from a relatively recent symbiont replacement. to better understand evolutionary decay of genomes, we compared baumannia from three host species. a newly sequenced genome for bauman ... | 2015 | 26260652 |
| host plant effects on development and reproduction of the glassy-winged sharpshooter, homalodisca vitripennis (homoptera: cicadellidae). | development, survivorship, longevity, reproduction, and life table parameters of the glassy-winged sharpshooter, homalodisca vitripennis (germar), were examined in the laboratory using three host plants, sunflower (helianthus annuus l.), chrysanthemum morifolium l., and euonymus (euonymus japonica thurb.). females deposited similar-sized egg masses on all three plants. hatching was highest with eggs deposited on euonymus and lowest for those deposited on sunflower. embryonic development time amo ... | 2010 | 22546451 |
| molecular profiling of proteolytic and lectin transcripts in homalodisca vitripennis (hemiptera: auchenorrhyncha: cicadellidae) feeding on sunflower and cowpea. | homalodisca vitripennis germar 1821 (hemiptera: cicadellidae) [takiya et al. (2006) ann entomol soc am 99:648-655; syn. h. coagulata (say)] salivary gland and gut est libraries were used to isolate cdna fragments of the gene transcripts encoding for cathepsin l, asparaginyl endopeptidase, cathepsin b, metalloendopeptidase, cathepsin d, multicatalytic endopeptidase, and a sugar-binding c-type lectin. transcript levels were evaluated in immature and adult h. vitripennis feeding on sunflower (helia ... | 2007 | 17879231 |
| distribution of glassy-winged sharpshooter and threecornered alfalfa hopper on plant hosts in the san joaquin valley, california. | homalodisca vitripennis (germar) and spissistilus festinus (say) populations were surveyed bimonthly for 14 mo in kern county, ca, at five agricultural sites made up of a variety of potential host plants. in addition, s. festinus populations were surveyed in four alfalfa, medicago sativa l., fields in kern and tulare counties. insects were collected by beats-sweeps and sticky traps. data on host plant condition and phenology, and ground cover presence and composition were collected at the five a ... | 2010 | 20857711 |
| amino acids as determinants of host preference for the xylem feeding leafhopper, homalodisca coagulata (homoptera: cicadellidae). | homalodisca coagulata is a highly polyphagous xylem feeder with distinct seasonal patterns in it's selection of host plants. these patterns were examined in relation to the amino acid content of the xylem for four common host species; lagerstroemia indica, baccharis halimifolia, prunus persica, and prunus salicina. xylem fluid was collected from each host species at times when numbers of feeding leafhoppers were both low and high. in each case, concentrations of amino acids were greatest when nu ... | 1990 | 28313004 |
| mitochondrial dna variation among populations of the glassy-winged sharpshooter, homalodisca coagulata. | the glassy-winged sharpshooter, homalodisca coagulata (homoptera: cicadellidae), is a highly polyphagous insect species that is distributed throughout most of the southern regions of the united states. in the last 10 years, h. coagualta has become established in california and represents a significant threat to the state's 35 billion dollar wine and table grape industries. dna sequencing analysis was used to characterize a portion of the mitochondrial cytochrome oxidase i gene from a single popu ... | 2005 | 17119623 |
| effects of energy reserves and diet on glassy-winged sharpshooter egg maturation. | the glassy-winged sharpshooter is an invasive insect capable of transmitting the plant pathogen xylella fastidiosa. as rates of pathogen spread are a function of vector abundance, identification of factors contributing to glassy-winged sharpshooter egg production will aid in predicting population growth. here, effects of stored energy reserves and adult diet on glassy-winged sharpshooter egg maturation were evaluated. to estimate energy reserves available to adult females at the beginning of fee ... | 2017 | 29267936 |
| sequence polymorphism in an insect rna virus field population: a snapshot from a single point in space and time reveals stochastic differences among and within individual hosts. | population structure of homalodisca coagulata virus-1 (hocv-1) among and within field-collected insects sampled from a single point in space and time was examined. polymorphism in complete consensus sequences among single-insect isolates was dominated by synonymous substitutions. the mutant spectrum of the c2 helicase region within each single-insect isolate was unique and dominated by nonsynonymous singletons. bootstrapping was used to correct the within-isolate nonsynonymous:synonymous arithme ... | 2016 | 27598532 |
| stability of a positive equilibrium state for a stochastically perturbed mathematical model of glassy-winged sharpshooter population. | the known nonlinear mathematical model of the glassy-winged sharpshooter is considered. it is assumed that this model is influenced by stochastic perturbations of the white noise type and these perturbations are directly proportional to the deviation of the system state from the positive equilibrium point. a necessary and sufficient condition for asymptotic mean square stability of the equilibrium point of the linear part of the considered stochastic differential equation is obtained. this condi ... | 2014 | 25347804 |
| evaluation of a method to quantify glassy-winged sharpshooter (hemiptera: cicadellidae) egg maturation during a feeding assay. | a method to improve an assay relating adult feeding to egg maturation by the glassy-winged sharpshooter (hemiptera: cicadellidae) was evaluated. the assay consisted on confining females to cowpea stems and quantifying feeding and egg maturation. feeding was quantified by measuring excreta production. the number of eggs matured during the assay was estimated by taking the difference between female egg load (number of mature eggs carried by a female) at end of the assay (determined by dissection) ... | 2014 | 24665703 |
| mathematical modeling of glassy-winged sharpshooter population. | pierce's disease (pd) is a fatal disease of grapevines which results from an infection by the plant pathogen xyllela fastidiosa. this bacterium grows in the xylem (water-conducting) vessels of the plant blocking movement of water. pd can kill vines in one year and poses a serious threat to both the california and the expanding texas wine industries. bacteria are vectored from one vine to the next by a number of xylem feeding insect species. of these, the glassy-winged sharpshooter (gwss) is cons ... | 2014 | 24506556 |
| biology of pseudoligosita plebeia (hymenoptera: trichogrammatidae), an egg parasitoid of homalodisca spp. (hemiptera: cicadellidae) collected from northwestern mexico as a potential biocontrol agent of h. vitripennis in california. | pseudoligosita plebeia (perkins) (hymenoptera: trichogrammatidae) is a candidate biological control agent targeting the glassy-winged sharpshooter, homalodisca vitripennis (germar) (hemiptera: cicadellidae), in california. little is known about the biology of p. plebeia. here we report the results of laboratory studies describing the longevity of p. plebeia adults provided alternative food resources, their ability to parasitize h. vitripennis eggs of different ages, lifetime offspring production ... | 2012 | 23156147 |
| nutrient mediation of behavioral plasticity and resource allocation in a xylem-feeding leafhopper. | phenotypic plasticity may be critical for nutrient-limited organisms that allocate ingested nutrients to the competing demands of reproduction and survivorship. leafhoppers that feed on xylem fluid allow assessment of plasticity in response to the constant selective pressure of nutritional inadequacy. we examined feeding behavior (host selection and consumption rates) and nutrient allocation (fecundity, change in body mass and composition) of the xylem fluid-feeding leafhopper homalodisca vitrip ... | 2011 | 20730545 |
| functional response of gonatocerus ashmeadi and the "new association" parasitoid g. tuberculifemur attacking eggs of homalodisca vitripennis. | the functional response of two egg parasitoids, gonatocerus tuberculifemur (ogloblin) and g. ashmeadi girault (hymenoptera: mymaridae), to varying densities of homalodisca vitripennis (germar) (hemiptera: cicadellidae) eggs was studied in the laboratory. g. tuberculifemur showed a type ii functional response where parasitism increased at a decreasing rate as host egg density increased from 5 to 40, reaching an asymptote of an upper limit of 9.3 host eggs within the 1-h exposure period. the insta ... | 2009 | 20021759 |
| cold storage of adult gonatocerus ashmeadi (hymenoptera: mymaridae) and effects on maternal and progeny fitness. | storage of conatocerus ashmeadi girault (hymenoptera: mymaridae) adults at 2, 5, and 10 degrees c showed that these parasitoids do not survive at 2 degrees c for 5 d, and exposure to 5 and 10 degrees c shortens their life span. the lethal time (lt) 50 (i.e., length of storage time for 50% wasp survival) at 5 degrees c was 14 d for males and approximately 29 d for females, whereas at 10 degrees c was 32 and 39 d, respectively. effects of adult storage at 10 degrees c on other factors indicating f ... | 2008 | 19133454 |