cloning, organization, and expression of the bioluminescence genes of xenorhabdus luminescens.the lux genes of xenorhabdus luminescens, a symbiont of the nematode heterorhabditis bacteriophora, were cloned and expressed in escherichia coli. the expression of these genes in e. coli was qualitatively similar to their expression in x. luminescens. the organization of the genes is similar to that found in the marine luminous bacteria. hybridization studies with the dna that codes for the two subunits of luciferase revealed considerable homology among all of the strains of x. luminescens and ...19902211511
genetic transformation of nematodes using arrays of micromechanical piercing structures.foreign genes were expressed in the nematode heterorhabditis bacteriophora using a new micro-mechanical device to inject dna-coated microprobe through the nematode cuticle. after introduction of a plasmid in which a caenorhabditis elegans 16-kda heat shock promoter was fused to escherichia coli, a beta-galactosidase gene was expressed in the progeny of the injected worms. the tip of the microprobe penetrated through the nematode cuticle without causing injury to the nematode, and about 8% of the ...19958588914
ecology of anti-microbials produced by bacterial associates of steinernema carpocapsae and heterorhabditis bacteriophora.based on the ability of bacterial associates of entomopathogenic nematodes to produce antibiotic compounds on artificial media, it has been commonly accepted that xenorhabdus sp. and photorhabdus sp. inhibit a wide range of invading microorganisms in insects infected with steinernema spp. or heterorhabditis spp. therefore, the question of whether antibiotic compounds produced by the primary form of bacterial symbionts associated mutualistically with s. carpocapsae and h. bacteriophora explain wh ...19968684829
rapid changes in thermal sensitivity of entomopathogenic nematodes in response to selection at temperature extremesentomopathogenic nematodes (rhabditida: heterorhabditidae, steinernematidae) are lethal insect parasites that have a symbiotic association with bacteria in the family enterobacteriaceae. we evaluated the changes in thermal sensitivity of two nematodes heterorhabditis bacteriophora and steinernema anomali. the nematodes were genetically selected, together with their respective symbiotic bacteria, at nematodes' reproductive thermal niche breadth extremes, 15° and 30°c, by repeated passage ...19968812571
effect of cucurbitacin d on in vitro growth of xenorhabdus and photorhabdus spp., symbiotic bacteria of entomopathogenic vitro assays were conducted to determine the effect of cucurbitacin d, an oxygenated tetracyclic triterpenoid found in cucurbits, on the growth of xenorhabdus isolated from steinernema carpocapsae (all, mexican, agriotos strains), steinernema riobravis, steinernema glaseri (nc strain, strain 27), and photorhabdus from heterorhabditis bacteriophora (nc, lewiston strains), and heterorhabditis sp. (fl2122 strain). cucurbitacin d inhibited the growth of four isolates, had no effect on the growth ...19968858910
the laboratory preference of annual legumes by pea weevil sitona lineatus l. (col., curculionidae) and their effect on susceptibility of weevils to entomogenous nematodes.the activity and natural mortality of sitona lineatus weevils during the egg laying period may be connected with host plant preference. preference of s. lineatus adults for early field pea and other pea cultivars influences their low feeding activity and results in lopff average body weight and higher susceptibility to entomogenous nematodes, steinernema carpocapsae, s. feltiae, and heterorhabditis bacteriophora.19989538029
active resistance of entomophagous rhabditid heterorhabditis bacteriophora to insect immunity.a specific extracellular proteinase, degrading selectively the cecropin-based defence system of insects, is secreted into the larval body during parasitism of the greater wax moth by the heterorhabditis bacteriophora/photorhabdus luminescens complex and by phase 1 of p. luminescens. the proteolytic digestion of insect inducible cecropin-like immune molecules was demonstrated by the disappearance of the galleria mellonella cecropins and purified hyalophora cecropin b peptide page bands upon expos ...19989774783
pest status of american plum borer (lepidoptera: pyralidae) and fruit tree borer control with synthetic insecticides and entomopathogenic nematodes in new york state.surveys were conducted in 1994 and 1995 to determine the pest status of the american plum borer, euzophera semifuneralis (walker), in new york state stone fruit crops. these surveys indicate that american plum borer is the most important of the wood-boring insects infesting tart cherries and also is an important pest in peaches suffering from canker diseases. it is not prevalent in plums or in healthy peaches. trials to control american plum borer were conducted in tart cherry and peach by using ...199910036985
host range, specificity, and virulence of steinernema feltiae, steinernema rarum, and heterorhabditis bacteriophora (steinernematidae and heterorhabditidae) from argentina.infections were carried out in the laboratory to determine the host range, specificity, and virulence of steinernema rarum, s. feltiae, and heterorhabditis bacteriophora that were isolated from different regions of argentina. all insect orders showed a remarkable susceptibility to the three nematode species, showing mortality values higher than 66%, except for anoplura. the mortality of the insects of agronomic interest was more than 90%. as for insects of sanitary importance, s. feltiae and s. ...199910222175
polyphasic classification of the genus photorhabdus and proposal of new taxa: p. luminescens subsp. luminescens subsp. nov., p. luminescens subsp. akhurstii subsp. nov., p. luminescens subsp. laumondii subsp. nov., p. temperata sp. nov., p. temperata subsp. temperata subsp. nov. and p. asymbiotica sp. nov.the taxonomic position of photorhabdus strains was examined through the results of dna relatedness (s1 nuclease method) studies associated with the determination of delta tm, 16s rrna phylogenetic inferences and phenotypic characterization, including morphological, auxanographic, biochemical and physiological properties. three genomic species were delineated on a consensus assessment. one of these species corresponded to photorhabdus luminescens, since strains were at least 50% related to the ty ...199910555346
interaction between ticks (acari: ixodidae) and pathogenic nematodes (nematoda): susceptibility of tick species at various developmental stages.the virulence of entomopathogenic nematodes (steinernematidae and heterorhabditidae) to tick species under laboratory conditions is reported. the susceptibility of larval, nymphal, and adult stages of the ticks hyalomma excavatum (koch), rhipicephalus bursa (canestrini & fanz), and r. sanguineus (latereille) to 2 strains of steinernema carpocapsae and 3 strains of heterorhabditis bacteriophora were compared in laboratory assays. preimaginal stages of ticks were found to be more resistant to the ...199910593074
pathogenicity, development, and reproduction of heterorhabditis bacteriophora and steinernema carpocapsae under axenic in vivo conditions.galleria mellonella larvae cultured axenically were treated with axenic dauer juveniles of heterorhabditis bacteriophora and steinernema carpocapsae. after 3 days s. carpocapsae had killed all insects, with 9.4 +/- 4.3 nematodes per larva. h. bacteriophora were unable to kill g. mellonella, although 13.3 +/- 6.4 nematodes per galleria were found in the hemocoel. invading nematodes of both strains recovered from the dauer stage. h. bacteriophora developed into hermaphrodites with eggs and j1 in t ...200010631058
deficiency of current methods in assaying endochitinase activity.since chitin is degraded by a combination of both endo- and exochitinases, it is likely that both enzymes will be present in a crude extract. currently used substrates for detecting endochitinase activity suffer from the fact that they could easily be digested by the contaminating exochitinase, thus giving either a false-positive or an inaccurate reading of the endochitinase activity. using photorhabdus luminescens, a bacterium symbiotically associated with insect-parasitic nematode heterorhabdi ...200010679198
exoproteinases of the type a in pathogenesis of insect bacterial diseases.immune inhibitors produced in infected larvae of galleria mellonella by such entomopathogens as pseudomonas aeruginosa, serratia marcescens and heterorhabditis bacteriophora effectively blocked in vitro bactericidal activity of insect haemolymph against escherichia coli d31, both in galleria mellonella and pieris brassicae pupae previously vaccinated with enterobacter cloacae. even at a trace concentration, the extracellular proteinases, by proteolytic degradation, totally destroyed the activity ...199910754793
environmental factors affecting sexual differentiation in the entomopathogenic nematode heterorhabditis bacteriophora.the present study was aimed at determining the influence of various environmental factors on sex differentiation (sd) in the entomopathogenic nematode heterorhabditis bacteriophora hp88 strain, under in vivo and in vitro culture conditions. injection of individual nematodes into last instars of galleria mellonella resulted in development of a similar number of females and hermaphrodites (35-40%) and 20-25% males. increasing the number of nematodes injected into the insect did not change these pr ...200010900435
mortality rate of adult ticks due to infection by entomopathogenic nematodes.the mortality of boophilus annulatus, hyalomma excavatum, rhipicephalus bursa, and rhipicephalus sanguineus adult ticks was recorded after their exposure in petri dishes to 5 entomopathogenic nematode strains. the strains used were dt and mexican of steinernema carpocapsae, hb hp88 of heterorhabditis bacteriophora, and is-3 and is-5 of heterorhabditis sp. the most rapid killing rates (lt50 and lt90) were observed for b. annulatus ticks (0.8-5.0 days). most unfed males died 0.3-2.8 days after the ...200010958439
virulence of entomopathogenic nematodes to diaprepes abbreviatus (coleoptera: curculionidae) in the laboratory.the diaprepes root weevil, diaprepes abbreviatus (l.) is the most severe weevil pest in florida citrus. entomopathogenic nematodes have effectively suppressed larval populations of d. abbreviatus. our objective was to conduct a broad laboratory comparison of entomopathogenic nematodes for virulence toward larvae of d. abbreviatus. the study was conducted at three temperatures (20, 24, and 29 degrees c) and included nine entomopathogenic species and 17 strains: heterorhabditis bacteriophora poina ...200010985017
a new broad-spectrum protease inhibitor from the entomopathogenic bacterium photorhabdus luminescens.a new protease inhibitor was purified to apparent homogeneity from a culture medium of photorhabdus luminescens by ammonium sulfate precipitation and preparative isoelectric focusing followed by affinity chromatography. ph. luminescens, a bacterium symbiotically associated with the insect-parasitic nematode heterorhabditis bacteriophora, exists in two morphologically distinguishable phases (primary and secondary). it appears that only the secondary-phase bacterium produces this protease inhibito ...200011101672
liquid media development for heterorhabditis bacteriophora: lipid source and concentration.lipids are important entomopathogenic nematode nutritional components because they are energy reserves and serve as indicators of nematode quality. the composition and concentration of the media lipid component determine bacterial and nematode yields. heterorhabditis bacteriophora and its symbiont, photorhabdus luminescens, were cultured in media containing various lipid sources. as lipid concentration increased from 2.5% to 8.0% (w/v), the final yield and productivity [calculated from the numbe ...200011152066
laboratory evaluation of pathogenicity of entomogenous nematodes to african tick species.five strains of entomogenous nematodes, steinernema carpocapsae strains dd, mexican, sr, and heterorhabditis bacteriophora strains 1s5 and hp88, were tested for their pathogenicity to various developmental stages of five african tick species namely; rhipicephalus appendiculatus, r. evertsi, amblyomma variegatum, a. gemma, and boophilus decoloratus. in engorged female r. appendiculatus, all nematodes at a concentration of 1,000 infective juveniles (ij)/dish, except s. carpocapsae mexican strain, ...200011193637
virulence of entomopathogenic nematodes to pecan weevil larvae, curculio caryae (coleoptera: curculionidae), in the laboratory.the pecan weevil, curculio caryae (horn), is a key pest of pecans in the southeast. entomopathogenic nematodes have been shown to be pathogenic toward the larval stage of this pest. before this research, only three species of nematodes had been tested against pecan weevil larvae. in this study, the virulence of the following nine species and 15 strains of nematodes toward fourth-instar pecan weevil was tested: heterorhabditis bacteriophora poinar (baine, hp88, oswego, nj1, and tf strains), h. in ...200111233136
effect of photorhabdus luminescens phase variants on the in vivo and in vitro development and reproduction of the entomopathogenic nematodes heterorhabditis bacteriophora and steinernema carpocapsae.photorhabdus luminescens (enterobacteriaceae) is a symbiont of entomopathogenic nematodes heterorhabditis spp. (nematoda: rhabditida) used for biological control of insect pests. for industrial mass production, the nematodes are produced in liquid media, pre-incubated with their bacterial symbiont, which provides nutrients essential for the nematode's development and reproduction. particularly under in vitro conditions, p. luminescens produces phase variants, which do not allow normal nematode d ...200111311434
a phosphopantetheinyl transferase homolog is essential for photorhabdus luminescens to support growth and reproduction of the entomopathogenic nematode heterorhabditis bacteriophora.the bacterium photorhabdus luminescens is a symbiont of the entomopathogenic nematode heterorhabditis bacteriophora. the nematode requires the bacterium for infection of insect larvae and as a substrate for growth and reproduction. the nematodes do not grow and reproduce in insect hosts or on artificial media in the absence of viable p. luminescens cells. in an effort to identify bacterial factors that are required for nematode growth and reproduction, transposon-induced mutants of p. luminescen ...200111325940
management of early-instar japanese beetle (coleoptera: searabaeidae) in field-grown nursery crops.numerous field studies were conducted in commercial nurseries in tennessee from 1996 through 1999 to evaluate chemical and biological treatments, application timing and rates, and method of application for control of early instars of japanese beetle, popillia japonica newman. insecticide treatments included bifenthrin, bendiocarb, chlorpyrifos, carbaryl, fipronil, halofenozide, imidacloprid, permethrin, tefluthrin, thiamethoxam, and trichlorfon. biological treatments included entomopathogenic ne ...200111681678
differences between the pathogenic processes induced by steinernema and heterorhabditis (nemata: rhabditida) in pseudaletia unipuncta (insecta: lepidoptera).larvae of pseudaletia unipuncta are moderately susceptible to infections caused by entomopathogenic nematodes, being a desirable host to study pathogenic processes caused by heterorhabditis bacteriophora, steinernema carpocapsae, and steinernema glaseri and their associated bacteria. the ability of the infective stage of these nematodes to invade hosts is quite different. s. carpocapsae invades the highest number of insects and presents the highest penetration rate, followed by h. bacteriophora. ...200212234542
response of ants to a deterrent factor(s) produced by the symbiotic bacteria of entomopathogenic nematodes.the production of an ant-deterrent factor(s) (adf) by xenorhabdus nematophila and photorhabdus luminescens, the symbiotic bacteria of the nematodes steinernema carpocapsae and heterorhabditis bacteriophora, respectively, was examined. in addition to an in vivo assay in which bacteria were tested for their ability to produce adf within insect cadavers (m.e. baur, h. k. kaya, and d. r. strong, biol. control 12:231-236, 1998), an in vitro microtiter dish assay was developed to monitor adf activity ...200212450845
effects of the entomopathogenic nematode, heterorhabditis bacteriophora hp 88 and azadirachtin on the immune defence response and prophenoloxidase of parasarcophaga surcoufi larvae (diptera: sarcophagidae).each third larval instar (155-175 mg) of the fleshfly, parasarcophaga surcoufi was injected with 20 and 40 infective juveniles (ijs) of entomopathogenic nematode, heterorhabditis bacteriophora, and with 0.5 and 1 microg of azadirachtin. injection with 20 ijs decreased the total haemocyte count (thc) up to 40 h post-injection, except for its increase at 20 h. on the contrary, injection with 40 ijs increased the thc during the hours post-injection, except for its decrease at 40 h. the injection of ...200112557951
for the insect pathogen photorhabdus luminescens, which end of a nematode is out?the nematode heterorhabditis bacteriophora is the vector for transmitting the entomopathogenic bacterium photorhabdus luminescens between insect larvae. the dauer juvenile (dj) stage nematode selectively retains p. luminescens in its intestine until it releases the bacteria into the hemocoel of an insect host. we report the results of studying the transmission of the bacteria by its nematode vector. cells of p. luminescens labeled with green fluorescent protein preferentially colonized a region ...200312676661
photobactin: a catechol siderophore produced by photorhabdus luminescens, an entomopathogen mutually associated with heterorhabditis bacteriophora nc1 nematodes.the nematode heterorhabditis bacteriophora transmits a monoculture of photorhabdus luminescens bacteria to insect hosts, where it requires the bacteria for efficient insect pathogenicity and as a substrate for growth and reproduction. siderophore production was implicated as being involved in the symbiosis because an ngra mutant inadequate for supporting nematode growth and reproduction was also deficient in producing siderophore activity and ngra is homologous to a siderophore biosynthetic gene ...200312902261
biological control agents for white grubs (coleoptera: scarabaeidae) in anticipation of the establishment of the japanese beetle in california.we tested biological control agents for the control of 3rd-instar scarab turfgrass pests, both for the masked chafer cyclocephala hirta leconte and the japanese beetle, popillia japonica newman. the former species is endemic in california whereas the latter, although not yet established, constitutes a permanent serious threat to agriculture and horticulture in california. we conducted experiments using c. hirta in california and p. japonica in new jersey. a field trial conducted in 2 different c ...200014658514
liquid culture mass production of biocontrol nematodes, heterorhabditis bacteriophora (nematoda: rhabditida): improved timing of dauer juvenile inoculation.heterorhabditis bacteriophora is used in biological control of soil-borne insect pests in horticulture and turf. mass production is carried out in monoxenic liquid cultures pre-incubated with the symbiont of the nematodes, the bacterium photorhabdus luminescens, before nematode dauer juveniles (dj) are inoculated. as a response to bacterial food signals, the dj recover from the developmentally arrested dauer stage, grow to adults and produce dj offspring. variable dj recovery after inoculation i ...200414727090
two new subspecies of photorhabdus luminescens, isolated from heterorhabditis bacteriophora (nematoda: heterorhabditidae): photorhabdus luminescens subsp. kayaii subsp. nov. and photorhabdus luminescens subsp. thracensis subsp. nov.bacterial isolates from nematodes from turkish soil samples were initially characterized by molecular methods and seven members of the genus photorhabdus identified to the species level, using riboprint analyses and metabolic properties. strain 07-5 (dsm 15195) was highly related to the type strain of photorhabdus luminescens subsp. laumondii dsm 15139t, and was regarded a strain of this subspecies. strains 1121t (dsm 15194t), 68-3 (dsm 15198) and 47-10 (dsm 15197) formed one, strain 39-8t (dsm ...200415053319
evaluation of efficacy of entomopathogenic nematodes against larvae of lucilia sericata (meigen, 1826) (diptera: calliphoridae).the blowfly lucilia sericata (meigen, 1826) (diptera: calliphoridae) is the primary agent of cutaneous myiasis of sheep in northern europe, southern africa, australia and new zealand. as the application of chemicals has several disadvantages, alternative control measures of traumatic myiasis of livestock must be developed. in this study, the use of entomopathogenic nematodes (epns) as potential biocontrol agents against second instar larvae of lucilia sericata was considered. the following nemat ...200515782660
seasonal dynamics of entomopathogenic nematodes of the genera steinernema and heterorhabditis as a response to abiotic factors and abundance of insect hosts.the seasonal dynamics of entomopathogenic nematodes (epns) of the genus steinernema and heterorhabditis were studied during one season in meadow and oak wood habitats, in the vicinity of ceské budejovice, czech republic. the influences of soil temperature, moisture, and abundance of suitable hosts on epn dynamics were investigated. the host range of these nematodes, in both habitats was also observed. a total of four epn species were found in both habitats. steinernema affine was the dominant sp ...200515893761
compatibility of entomopathogenic nematodes with fipronil.the survival and infectivity of infective juveniles (ijs) of three species of entomopathogenic nematodes, steinernema carpocapsae weiser, s. arenarium (artyukhovsky) (rhabditida: steinernematidae) and heterorhabditis bacteriophora poinar (rhabditida: heterorhabditidae), were determined after exposure to different concentrations (250, 500, 1000 and 2000 ppm) of fipronil, an insecticide acting on the gaba receptors to block the chloride channel. heterorhabditis bacteriophora was very tolerant to a ...200516336717
whole-genome comparison between photorhabdus strains to identify genomic regions involved in the specificity of nematode interaction.the bacterium photorhabdus establishes a highly specific association with heterorhabditis, its nematode host. photorhabdus strains associated with heterorhabditis bacteriophora or heterorhabditis megidis were compared using a photorhabdus dna microarray. we describe 31 regions belonging to the photorhabdus flexible gene pool. distribution analysis of regions among the photorhabdus genus identified loci possibly involved in nematode specificity.200616385072
both heat-shock and cold-shock influence trehalose metabolism in an entomopathogenic nematode.heat-shock response is highly conserved in animals and microorganisms, and it results in the synthesis of heat-shock proteins. in yeast, heat-shock response has also been reported to induce trehalose accumulation. we explored the relationship between heat- (35 c) or cold-shock (1 and 10 c) and trehalose metabolism in the entomopathogenic nematode, heterorhabditis bacteriophora. because both heat- and cold-shocks may precede desiccation stress in natural soil environments, we hypothesized that ne ...200516419738
evaluation of application technologies of entomopathogenic nematodes for control of the black vine vine weevil, otiorhynchus sulcatus (f.), is a severe pest of small fruit and nursery crops around the world. these studies were conducted to determine the efficacy of three species of entomopathogenic nematodes (heterorhabditis marelatus, heterorhabditis bacteriophora, and steinernema riobrave) applied in infected host cadavers or as aqueous applications for black vine weevil larval control. experiments were conducted in the greenhouse and outdoors. application of three infected host cadav ...200516539109
parasitism of subterranean termites (isoptera: rhinotermitidae: termitidae) by entomopathogenic nematodes (rhabditida: steinernematidae; heterorhabditidae).in laboratory bioassays, steinernema riobrave cabanillas, poinar and raulston (355 strain), steinernema carpocapsae (weiser) (mexican 33 strain), steinernemafeltiae (filipjev) (uk76 strain), and heterorhabditis bacteriophora poinar (hp88 strain) were all capable of infecting and killing three termite species, heterotermes aureus (snyder), gnathamitermes perplexus (banks), and reticulitermes flavipes (kollar) in laboratory sand assays. s. riobrave and s. feltiae caused low levels of reticuliterme ...200616937662
stability of entomopathogenic bacteria, xenorhabdus nematophila and photorhabdus luminescens, during in vitro culture.the entomopathogenic nematode-bacteria complexes heterorhabditis bacteriophora/photorhabdus luminescens and steinernema carpocapsae/xenorhabdus nematophila are mass produced for use as biological insecticides. stability of the bacterial partner in culture is essential for maintaining traits important for both biological control and production. two geographically distinct strains of each bacterial species were isolated from their nematode partners and serially subcultured on in vitro media to ass ...200716941119
relationship between the successful infection by entomopathogenic nematodes and the host immune response.reproduction of entomopathogenic nematodes requires that they escape recognition by a host's immune system or that they have mechanisms to escape encapsulation and melanization. we investigated the immune responses of larvae for the greater wax moth (galleria mellonella), tobacco hornworm (manduca sexta), japanese beetle (popillia japonica), northern masked chafer (cyclocephala borealis), oriental beetle (exomala orientalis) and adult house crickets (acheta domesticus), challenged with infective ...200717275827
nematodes, bacteria, and flies: a tripartite model for nematode parasitism.more than a quarter of the world's population is infected with nematode parasites, and more than a hundred species of nematodes are parasites of humans [1-3]. despite extensive morbidity and mortality caused by nematode parasites, the biological mechanisms of host-parasite interactions are poorly understood, largely because of the lack of genetically tractable model systems. we have demonstrated that the insect parasitic nematode heterorhabditis bacteriophora, its bacterial symbiont photorhabdus ...200717475494
interactions between isolates of the entomopathogenic fungus metarhizium anisopliae and the entomopathogenic nematode heterorhabditis bacteriophora jpm4 during infection of the sugar cane borer diatraea saccharalis (lepidoptera: pyralidae).interactions between the nematode heterorhabditis bacteriophora isolate jpm4 and the fungus metarhizium anisopliae, isolates lpp45 and lpp39, were studied during dual infections of diatraea saccharalis. mortality, production of infective juveniles (ijs) and production of conidia were evaluated. a positive effect was demonstrated for host mortality in duel infections of jpm4 and lpp39, causing 100% mortality with lt(50) and lt(95) values of 1.8 and 2.8 days, respectively. higher values were seen ...200717532003
identification of two down-regulated genes in entomopathogenic nematode heterorhabditis bacteriophora infective juveniles upon contact with insect hemolymph.entomopathogenic nematode heterorhabditis bacteriophora infective juveniles (ijs) employ multiple strategies to combat with insect innate immune system after invasion. we employed suppressive subtractive hybridization (ssh) technique to study the gene expression in the ijs upon contact with the insect hemolymph in vitro. we identified two clones having higher expression levels in the ijs than ijs treated with insect hemolymph. the differential expression levels were confirmed by northern blot hy ...200717767967
postembryonic rnai in heterorhabditis bacteriophora: a nematode insect parasite and host for insect pathogenic symbionts.heterorhabditis bacteriophora is applied throughout the world for the biological control of insects and is an animal model to study interspecies interactions, e.g. mutualism, parasitism and vector-borne disease. h. bacteriophora nematodes are mutually associated with the insect pathogen, photorhabdus luminescens. the developmentally arrested infective juvenile (ij) stage nematode (vector) specifically transmits photorhabdus luminescens bacteria (pathogen) in its gut mucosa to the haemocoel of in ...200717803822
the biology and genome of heterorhabditis bacteriophora.heterorhabditis bacteriophora is an entomopathogenic nematode (epn) mutually associated with the enteric bacterium, photorhabdus luminescens, used globally for the biological control of insects. much of the previous research concerning h. bacteriophora has dealt with applied aspects related to biological control. however, h. bacteriophora is an excellent model to investigate fundamental processes such as parasitism and mutualism in addition to its comparative value to caenorhabditis elegans. in ...200718050499
cell invasion and matricide during photorhabdus luminescens transmission by heterorhabditis bacteriophora nematodes.many animals and plants have symbiotic relationships with beneficial bacteria. experimentally tractable models are necessary to understand the processes involved in the selective transmission of symbiotic bacteria. one such model is the transmission of the insect-pathogenic bacterial symbionts photorhabdus spp. by heterorhabditis bacteriophora infective juvenile (ij)-stage nematodes. by observing egg-laying behavior and ij development, it was determined that ijs develop exclusively via intrauter ...200818281425
expressed sequence tag analysis of gene representation in insect parasitic nematode heterorhabditis bacteriophora.we compared heterorhabditis bacteriophora gps11 expressed sequence tags (ests) to the ests of animal-parasitic, human-parasitic, plant-parasitic, and free-living nematodes. we identified 127 previously nondescribed ests of which 119 had homologs in ests and 8 had homologs in proteins of free-living nematodes. these ests were assigned putative functions in transcription, signal transduction, cell cycle control, metabolism, information processing, and cellular processes, thereby providing better i ...200718314678
pathogenic effect of entomopathogenic nematode-bacterium complexes on terrestrial this study, we evaluated the effect of entomopathogenic nematodes (epns) steinernema carpocapsae, steinernema feltiae and heterorhabditis bacteriophora, symbiotically associated with bacteria of the genera xenorhabdus or photorhabdus, on the survival of eight terrestrial isopod species. the epn species s. carpocapsae and h. bacteriophora reduced the survival of six isopod species while s. feltiae reduced survival for two species. two terrestrial isopod species tested (armadillidium vulgare an ...200818346756
photorhabdus luminescens genes induced upon insect infection.photorhabdus luminescens is a gram-negative luminescent enterobacterium and a symbiote to soil nematodes belonging to the species heterorhabditis bacteriophora. p.luminescens is simultaneously highly pathogenic to insects. this bacterium exhibits a complex life cycle, including one symbiotic stage characterized by colonization of the upper nematode gut, and a pathogenic stage, characterized by release from the nematode into the hemocoel of insect larvae, resulting in rapid insect death caused by ...200818489737
cloning and heterologous expression of insecticidal-protein-encoding genes from photorhabdus luminescens tt01 in enterobacter cloacae for termite control.enterobacter cloacae, one of the indigenous gut bacteria of the formosan subterranean termite (coptotermes formosanus), was genetically modified with a transposon tn5 vector containing genes (tcda1 and tcdb1) encoding orally insecticidal proteins from the entomopathogenic bacterium photorhabdus luminescens subsp. laumondii tt01, a symbiont of the entomopathogenic nematode heterorhabditis bacteriophora, for termite control. in the laboratory, termites were fed filter paper inoculated with the rec ...200818836027
multiple-species natural enemy approach for biological control of alfalfa snout beetle (coleoptera: curculionidae) using entomopathogenic nematodes.multiple-species natural enemy approach for the biological control of the alfalfa snout beetle, otiorhynchus ligustici (l.) (coleoptera: curculionidae), was compared with using single-species of natural enemies in the alfalfa ecosystem by using entomopathogenic nematodes with different dispersal and foraging behaviors. steinernema carpocapsae ny001 (ambush nematode), heterorhabditis bacteriophora oswego (cruiser nematode), and steinernema feltiae valko (intermediate nematode) were applied in sin ...200818950034
potential of two entomopathogenic nematodes for suppression of plum curculio (conotrachelus nenuphar, coleoptera: curculionidae) life stages in northern climates.plum curculio, conotrachelus nenuphar, is a major pest of pome and stone fruits in north america. we evaluated the potential efficacy of two entomopathogenic nematode species for suppression of plum curculio in northern regions, targeting life stages that reside in soil during spring and summer. a strain of heterorhabditis bacteriophora isolated from soil infested with plum curculio in northern utah and a commercially available strain of steinernema feltiae known to tolerate cool temperatures we ...200819036207
non-chemical control of leaf curling midges and sawflies in berries and currants.the susceptibility of larvae of the leaf curling midge, dasineura plicotrix, for entomopathogenic nematodes, predatory mites and rove beetles was studied in the laboratory. the results showed that the leaf curling midge larvae were unaffected by the nematodes heterorhabditis bacteriophora, steinernema carpocapsoe and s. feltiae. the predatory mite (hypoaspis aculeifer) and the rove beetle (atheta coriaria) were very effective in predating the larvae when continuously exposed. however, in a soil ...200819226775
effect of entomopathogenic nematodes on mesocriconema xenoplax populations in peach and pecan.the effect of steinernema riobrave and heterorhabditis bacteriophora on population density of mesocriconema xenoplax in peach was studied in the greenhouse. twenty-one days after adding 112 m. xenoplax adults and juveniles/1,500 cm(3) soil to the soil surface of each pot, 50 infective juveniles/cm(2) soil surface of either s. riobrave or h. bacteriophora were applied. another entomopathogenic nematode application of the same density was administered 3 months later. the experiment was repeated on ...200419262805
susceptibility of the plum curculio, conotrachelus nenuphar, to entomopathogenic nematodes.the plum curculio, conotrachelus nenuphar, is a major pest of pome and stone fruit. our objective was to determine virulence and reproductive potential of six commercially available nematode species in c. nenuphar larvae and adults. nematodes tested were heterorhabditis bacteriophora (hb strain), h. marelatus (point reyes strains), h. megidis (uk211 strain), steinernema riobrave (355 strain), s. carpocapsae (all strain), and s. feltiae (sn strain). survival of c. nenuphar larvae treated with s. ...200219265940
biological control of the pecan weevil, curculio caryae (coleoptera: curculionidae), with entomopathogenic nematodes.steinernema carpocapsae (weiser) strain a11, s. feltiae (filipjev) strain sn, and heterorhabditis bacteriophora poinar strains hp88 and georgia were tested for their efficacy as biological control agents of the pecan weevil, curculio caryae (horn), in pecan orchard soil-profile containers under greenhouse conditions. percentage c. caryae parasitism by s. carpocapsae and h. bacteriophora strain hp88 and georgia was consistently poor when applied either prior to or following c. caryae entry into t ...199319279746
natural occurrence of entomogenous nematodes in tennessee nursery isolate potential insect biocontrol agents, entomogenous nematodes were surveyed in tennessee plant nurseries in 1991. soil samples from 113 nursery sites were baited with greater wax moth (galleria mellonella) larvae, house cricket (acheta domesticus) adults, lesser mealworm (alphitobius diaperings) adults, and house fly (musca domestica) larvae. heterorhabditis bacteriophora and steinernema carpocapsae were each recovered from 17 soil samples. heterorhabditis bacteriophora was more common i ...199319279756
movement of five nematode species through sand subjected to natural temperature gradient fluctuations.temperature gradient fluctuations that occur naturally as a result of heating and cooling of the soil surface were reproduced within 15-cm-d, 15-cm-long acrylic tubes filled with moist sand. sunny and rainy periods during the late summer in eastern texas were simulated. five ecologically different nematode species were adapted to fluctuating temperatures for 20-36 hours at a simulated depth of 12.5 cm before being injected simultaneously into the centers of tubes at that depth. when heat waves w ...199419279868
influence of irrigation and heterorhabditis bacteriophora on plant-parasitic nematodes in turf.daily irrigated, 80% pan replacement, and nonirrigated field plots of kentucky bluegrass (poa pratensis l.) were inoculated with a mixture of steinernema carpocapsae (all strain) and heterorhabditis bacteriophora (hp-88 strain) in 1988. in 1989, daily irrigated and nonirrigated plots were inoculated with hp-88 alone. the turf and associated soil contained populations of tylenchorhynchus dubius, t. nudus, pratylenchus penetrans, paratylenchus projectus, and criconemella rustica. in irrigated plot ...199219283039
identification and characterization of a novel gene involved in the trans-specific nematicidal activity of photorhabdus luminescens ln2.photorhabdus luminescens subsp. akhurstii ln2 from heterorhabditis indica ln2 showed nematicidal activity against axenic heterorhabditis bacteriophora h06 infective juveniles (ijs). transposon mutagenesis identified an ln2 mutant that supports the growth of h06 nematodes. tn5 disrupted the nama gene, encoding a novel 364-residue protein and involving the nematicidal activity. the green fluorescent protein-labeled nama mutant was unable to colonize the intestines of h06 ijs.200919376907
transcriptomic analysis of the entomopathogenic nematode heterorhabditis bacteriophora tto1.the entomopathogenic nematode heterorhabditis bacteriophora and its symbiotic bacterium, photorhabdus luminescens, are important biological control agents of insect pests. this nematode-bacterium-insect association represents an emerging tripartite model for research on mutualistic and parasitic symbioses. elucidation of mechanisms underlying these biological processes may serve as a foundation for improving the biological control potential of the nematode-bacterium complex. this large-scale exp ...200919405965
characterization of immunosuppressive surface coat proteins from steinernema glaseri that selectively kill blood cells in susceptible hosts.surface coat proteins (scps) of entomopathogenic nematodes are implicated in the suppression/evasion of host immune responses, which is required for successful host colonization. steinernema glaseri nc strain scps suppressed immune responses in oriental beetle larvae (exomala orientalis), a susceptible host for s. glaseri, in a dosage-dependent manner, thus protecting heterorhabditis bacteriophora from being killed in the same host. melanization of h. bacteriophora decreased from 92+/-5% in the ...200919428663
efficacy of indigenous entomopathogenic nematodes (rhabditida: heterorhabditidae, steinernematidae), from rio grande do sul brazil, against anastrephafraterculus (wied.) (diptera: tephritidae) in peach orchards.laboratory, greenhouse, and field experiments were performed with the objective of selecting efficient indigenous strains of entomopathogenic nematodes (epns) from rio grande do sul (rs) state, brazil, for controlling the south american fruit fly, anastrepha fraterculus (wied.). laboratory experiments were conducted in 24 well-plates filled with sterile sand and one insect per well. in greenhouse experiments, plastic trays filled with soil collected from the field were used, while in field exper ...200919460384
effects of pink bollworm resistance to bacillus thuringiensis on phenoloxidase activity and susceptibility to entomopathogenic nematodes.widespread planting of crops genetically engineered to produce insecticidal toxins from the bacterium bacillus thuringiensis (bt) imposes selection on many key agricultural pests to evolve resistance to bt. fitness costs can slow the evolution of bt resistance. we examined effects of entomopathogenic nematodes on fitness costs of bt resistance in the pink bollworm, pectinophora gossypiella (saunders) (lepidoptera: gelechiidae), a major pest of cotton, gossypium hirsutum l., in the southwestern u ...200919610442
field efficacy of entomopathogenic fungi and nematodes targeting caged last-instar plum curculio (coleoptera: curculionidae) in michigan cherry and apple orchards.the plum curculio (conotrachelus nenuphar herbst) is a key pest of pome and stone fruit in eastern north america. we tested the efficacy of five pathogens over the course of three seasons in 10 michigan apple and cherry orchards, with introductions of larvae to caged pots containing pathogen-treated soil. the nematode steinernema riobrave was the most effective pathogen in the 2 yr it was tested, but only in soils with the highest sand content (81-88%) and when it was applied 1 h or 5 d after la ...200919689891
identification of genes involved in the mutualistic colonization of the nematode heterorhabditis bacteriophora by the bacterium photorhabdus luminescens.photorhabdus are gram negative entomopathogenic bacteria that also have a mutualistic association with nematodes from the family heterorhabditis. an essential part of this symbiosis is the ability of the bacterium to colonize the gut of the freeliving form of the nematode called the infective juvenile (ij). although the colonization process (also called transmission) has been described phenomonologically very little is known about the underlying molecular mechanisms. therefore, in this study, we ...201020149243
evaluation of the action of heterorhabditis bacteriophora (rhabditida: heterorhabditidae) isolate hp88 on the biology of engorged females of rhipicephalus (boophilus) microplus (acari: ixodidae).the objective of this work was to evaluate the effect of different concentrations of the entomopathogenic nematode (epn) heterorhabditis bacteriophora strain hp88 on the biological parameters of the non-parasite phase of engorged females of the cattle tick rhipicephalus (boophilus) microplus. six groups were formed, each containing 20 engorged females, which were exposed to the following concentrations of infective juveniles of this nematode: 0, 75, 150, 300, 600 and 1200 epns/female, respective ...201020227185
biochemical study and in vitro insect immune suppression by a trypsin-like secreted protease from the nematode steinernema carpocapsae.a trypsin-like serine protease was purified by gel filtration and anion-exchange chromatography from the excretory-secretory products of parasitic phase steinernema carpocapsae. the purified protease exhibited a molecular mass of about 29 kda by sds-page and displayed a pi of 6.3. this protease exhibited high activity with trypsin-specific substrate n-ben-phe-val-arg-p-nitroanilide and was highly sensitive to aprotinin and benzamidine. the purified trypsin protease digested the chromogenic subst ...201020398179
photorhabdus adhesion modification protein (pam) binds extracellular polysaccharide and alters bacterial attachment.photorhabdus are gram-negative nematode-symbiotic and insect-pathogenic bacteria. the species photorhabdus asymbiotica is able to infect humans as well as insects. we investigated the secreted proteome of a clinical isolate of p. asymbiotica at different temperatures in order to identify proteins relevant to the infection of the two different hosts.201020462430
mortality of four stored product pests in stored wheat when exposed to doses of three entomopathogenic nematodes.the insecticidal effect of heterorhabditis bacteriophora poinar (nematoda: heterorhabditidae), steinernema carpocapsae (weiser) (nematoda: steinernematidae), and steinernema feltiae (filipjev) (nematoda: steinernematidae) against mediterranean flour moth, ephestia kuehniella (zeller) (lepidoptera: pyralidae) (larvae), lesser grain borer, rhyzopertha dominica (f.) (coleoptera: bostrychidae) (adults), rice weevil, sitophilus oryzae (l.) (coleoptera: curculionidae) (adults), and confused flour beet ...201020568646
photorhabdus phase variants express a novel fimbrial locus, mad, essential for symbiosis.summary fimbriae are adhesive organelles known to enable pathogens to colonize animal tissue, but little is known of their function in mutualistic symbioses. photorhabdus colonization of heterorhabditis bacteriophora nematodes is essential for the pair's insect pathogenic lifestyle. maternal nematodes acquire photorhabdus symbionts as a persistent intestinal biofilm prior to transmission to infective juvenile (ij) stage offspring developing inside the maternal body. screening 8000 photorhabdus m ...201020572934
imd pathway is involved in the interaction of drosophila melanogaster with the entomopathogenic bacteria, xenorhabdus nematophila and photorhabdus luminescens.xenorhabdus nematophila/steinernema carpocapsae and photorhabdus luminescens/heterorhabditis bacteriophora are nemato-bacterial complexes highly pathogenic for insects. using a syringe as artificial vector, we have analyzed the effects of the two bacteria, x. nematophila and p. luminescens on the genetic tool insect, drosophila melanogaster. both bacteria were found to kill adult flies in a dose dependent manner with x. nematophila being the fastest. on the other hand, when an injection of non-p ...201020627393
in vitro infection of sheep lice (bovicola ovis schrank) by steinernematid and heterorhabditid nematodes.control of sheep lice with conventional pesticides can be compromised by difficulty in contacting lice in the dense water repellent fleeces of sheep, particularly when sheep have not been recently shorn. entomopathogenic nematodes (ens) are motile and are able to actively seek out insect hosts. they have particular advantages for the control of pests in cryptic habitats, such as the fleeces of sheep and avoid many of the problems frequently associated with chemical controls. this study investiga ...201020800970
photorhabdus temperata subsp. stackebrandtii subsp. nov. (enterobacteriales: enterobacteriaceae).the bacterial symbiont of the entomopathogenic nematode heterorhabditis bacteriophora strain gps11 was characterized by 16s rrna gene sequence and physiological traits. the phylogenetic tree built upon 16s rrna gene sequences clustered the gps11 bacterial isolate with photorhabdus temperata strains which have been previously isolated from heterorhabditis species. the phylogenetic tree further identified four subgroups in p. temperata, and the relationships among these subgroups were confirmed by ...201020852981
the first record of entomopathogenic nematodes (rhabiditiae: steinernematidae and heterorhabditidae) in natural ecosystems in lebanon: a biogeographic approach in the mediterranean region.a survey of entomopathogenic nematodes in lebanon was conducted for the first time during 2008-2009. samples were collected on the coastal strip and in nine vegetation types extending from the coastal line to 3088m above sea level. wooded and herbaceous ecosystems were considered for sampling purposes. a total of 570 samples were taken, out of which 1% were positive for entomopathogenic nematodes. approximately, 15.8% out of the 19 sites sampled revealed entomopathogenic nematodes presence (repr ...201121241704
a sensory code for host seeking in parasitic nematodes.parasitic nematode species often display highly specialized host-seeking behaviors that reflect their specific host preferences. many such behaviors are triggered by host odors, but little is known about either the specific olfactory cues that trigger these behaviors or the underlying neural circuits. heterorhabditis bacteriophora and steinernema carpocapsae are phylogenetically distant insect-parasitic nematodes whose host-seeking and host-invasion behavior resembles that of some devastating hu ...201121353558
entomopathogenic nematodes, phoretic paenibacillus spp., and the use of real time quantitative pcr to explore soil food webs in florida citrus groves.quantitative real-time pcr (qpcr) is a powerful tool to detect and quantify species of cryptic organisms such as bacteria, fungi and nematodes from soil samples. as such, qpcr offers new opportunities to study the ecology of soil habitats by providing a single method to characterize communities of diverse organisms from a sample of dna. here we describe molecular tools to detect and quantify two bacteria (paenibacillus nematophilus and paenibacillus sp.) phoretically associated with entomopathog ...201121723288
purl gene expression affects biofilm formation and symbiotic persistence of photorhabdus temperata in the nematode heterorhabditis bacteriophora.extensive studies of the well-known legume and rhizobium symbiosis model system suggest that the purine metabolic pathway plays a key role in microbe-plant interactions, although the exact mechanism is unknown. here, we report the impact of a key purine metabolic gene, purl, on the symbiotic interaction between the bacterium photorhabdus temperata and its nematode partner heterorhabditis bacteriophora. real-time pcr assays showed that the purl gene was upregulated in p. temperata in the nematode ...201121700665
Heterorhabditis bacteriophora (Rhabditida: Heterorhabditidae) HP88 for biological control of Rhipicephalus microplus (Acari: Ixodidae): The effect of different exposure times of engorged females to the nematodes.The aim of this study was to assess the influence of different exposure times of engorged female the Rhipicephalus microplus to infective juveniles of Heterorhabditis bacteriophora isolate HP88. The engorged females were divided into seven groups (six treatments and one control) of 20 ticks each with statistically similar average weights (p>0.05) and exposed to concentrations of 300 nematodes/tick for periods of 3, 6, 12, 24, 48 and 72h. The following biological parameters were monitored: pre-ov ...201122093907
submerged monoxenic culture medium development for heterorhabditis bacteriophora and its symbiotic bacterium photorhabdus luminescens: protein sources.most medium formulations for improving culture of entomopathogenic nematodes (epn) based on protein sources have used enriched media like animal feed such as dried egg yolk, lactalbumin, and liver extract, among other ingredients. most results, however, showed unstable yields and longer production time. many of the results do not show the detailed parameters of fermentation. soy flour, cotton seed flour, corn gluten meal, casein powder, soytone, peptone, casein hydrolysates, and lactalbumin hydr ...201121876379
oral toxicity of photorhabdus culture media on gene expression of the adult sweetpotato whitefly, bemisia tabaci.the oral toxicity of culture media of the symbiotic bacteria, photorhabdus temperata, mutually associated with entomopathogenic nematode heterorhabditis megidis and photorhabdus luminescens ssp. laumondii (tt01) mutually associated with heterorhabditis bacteriophora, were investigated in the adults of bemisia tabaci. the oral ingestion of sucrose diet solutions (20%) containing bacteria-free supernatant of the culture media from symbiotic bacteria gradually increased mortalities and was complete ...201222041203
entomopathogenic nematodes for control of insect pests above and below ground with comments on commercial production.entomopathogenic nematodes (epns) have been utilized in classical, conservation, and augmentative biological control programs. the vast majority of applied research has focused on their potential as inundatively applied augmentative biological control agents. extensive research over the past three decades has demonstrated both their successes and failures for control of insect pests of crops, ornamental plants, trees and lawn and turf. in this paper we present highlights of their development for ...201223482993
involvement of vitamin b6 biosynthesis pathways in the insecticidal activity of photorhabdus luminescens.photorhabdus luminescens is a gram-negative entomopathogenic bacterium which symbiotically associates with the entomopathogenic nematode heterorhabditis bacteriophora p. luminescens is highly virulent to many insects and nonsymbiotic nematodes, including caenorhabditis elegans to understand the virulence mechanisms of p. luminescens, we obtained virulence-deficient and -attenuated mutants against c. elegans through a transposon-mutagenized library. from the genetic screening, we identified the p ...201627060119
comparative analysis of xenorhabdus koppenhoeferi gene expression during symbiotic persistence in the host nematode.species of xenorhabdus and photorhabdus bacteria form mutualistic associations with steinernema and heterorhabditis nematodes, respectively and serve as model systems for studying microbe-animal symbioses. here, we profiled gene expression of xenorhabdus koppenhoeferi during their symbiotic persistence in the newly formed infective juveniles of the host nematode steinernema scarabaei through the selective capture of transcribed sequences (scots). the obtained gene expression profile was then com ...201626745883
antibacterial screening of secreted compounds produced by the phase i variant of photorhabdus this study, antibacterial activity of metabolites secreted by the phase i variant of photorhabdus luminescens was investigated. bioactivity of these metabolites was screened against 28 different bacterial species and strains. bacterial sensitivity was determined by a modified-version of the kirby-bauer disk diffusion susceptibility method, whereas the phase i variant's culture permeate was utilized as the "antibacterial" agent. this investigation demonstrates that 11 of the 28 bacterial speci ...201224293735
transcriptional profiling of trait deterioration in the insect pathogenic nematode heterorhabditis bacteriophora.the success of a biological control agent depends on key traits, particularly reproductive potential, environmental tolerance, and ability to be cultured. these traits can deteriorate rapidly when the biological control agent is reared in culture. trait deterioration under laboratory conditions has been widely documented in the entomopathogenic nematode (epn) heterorhabditis bacteriophora (hb) but the specific mechanisms behind these genetic processes remain unclear. this research investigates t ...200920003534
drosophila anti-nematode and antibacterial immune regulators revealed by rna-seq.drosophila melanogaster activates a variety of immune responses against microbial infections. however, information on the drosophila immune response to entomopathogenic nematode infections is currently limited. the nematode heterorhabditis bacteriophora is an insect parasite that forms a mutualistic relationship with the gram-negative bacteria photorhabdus luminescens. following infection, the nematodes release the bacteria that quickly multiply within the insect and produce several toxins that ...201526162375
transcript abundance of photorhabdus insect-related (pir) toxin in manduca sexta and galleria mellonella this study, we assessed pirab toxin transcription in photorhabdus luminescens laumondii (strain tt01) (enterobacteriaceae) by comparing mrna abundance under in vivo and in vitro conditions. in vivo assays considered both natural and forced infections with two lepidopteran hosts: galleria mellonella and manduca sexta. three portals of entry were utilized for the forced infection assays: (a) integument; (b) the digestive route (via mouth and anus); and (c) the tracheal route (via spiracles). we ...201627690103
a lover and a fighter: the genome sequence of an entomopathogenic nematode heterorhabditis bacteriophora.heterorhabditis bacteriophora are entomopathogenic nematodes that have evolved a mutualism with photorhabdus luminescens bacteria to function as highly virulent insect pathogens. the nematode provides a safe harbor for intestinal symbionts in soil and delivers the symbiotic bacteria into the insect blood. the symbiont provides virulence and toxins, metabolites essential for nematode reproduction, and antibiotic preservation of the insect cadaver. approximately half of the 21,250 putative protein ...201323874975
effects of entomopathogens on mortality of western corn rootworm (coleoptera: chrysomelidae) and fitness costs of resistance to cry3bb1 costs can delay pest resistance to crops that produce insecticidal toxins derived from the bacterium bacillus thuringiensis (bt), and past research has found that entomopathogens impose fitness costs of bt resistance. in addition, entomopathogens can be used for integrated pest management by providing biological control of pests. the western corn rootworm, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), is a major pest of maize and is currently managed by planting of ...201424665720
tri-trophic studies using cry1ac-resistant plutella xylostella demonstrate no adverse effects of cry1ac on the entomopathogenic nematode, heterorhabditis bacteriophora.the potential impacts on natural enemies of crops that produce insecticidal cry proteins from bacillus thuringiensis (bt) are an important part of an environmental risk assessment. entomopathogenic nematodes are important natural enemies of lepidopteran pests, and the effects of bt crops on these nontarget organisms should be investigated to avoid disruption of their biological control function. the objective of this study was to investigate the effects of cry1ac-expressing transgenic bt broccol ...201424665692
adaptation by western corn rootworm (coleoptera: chrysomelidae) to bt maize: inheritance, fitness costs, and feeding preference.we examined inheritance of resistance, feeding behavior, and fitness costs for a laboratory-selected strain of western corn rootworm, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), with resistance to maize (zea maize l.) producing the bacillus thuringiensis berliner (bt) toxin cry3bb1. the resistant strain developed faster and had increased survival on bt maize relative to a susceptible strain. results from reciprocal crosses of the resistant and susceptible strains indicate ...201222928323
in vitro interaction of metarhizium anisopliae ma9236 and beauveria bassiana bb9205 with heterorhabditis bacteriophora hni0100 for the control of plutella xylostella.the diamondback moth (plutella xylostella) is a major pest of broccoli crops in colombia. to control p. xylostella, we evaluated the interaction of beauveria bassiana bb9205 and metarhizium anisopliae ma9236 with heterorhabditis bacteriophora hni0100 and its bacterial symbiont photorhabdus luminescens hni0100. we used antagonism and disk diffusion assays with fungal extracts to test the interaction between symbiotic bacterium and fungi. p. luminescens inhibited the growth of b. bassiana and m. a ...201627995045
the potential for controlling pangaeus bilineatus (heteroptera: cydnidae) using a combination of entomopathogens and an insecticide.the peanut burrower bug, pangaeus bilineatus (say), is an important pest of peanut (arachis hypogaea l.) in the southern united states. current control methods for this pest, which are based on the use of chemical insecticides, have not been successful. our objective was to determine if entomopathogens applied alone or in combination with a standard chemical insecticide would provide superior levels of p. bilineatus mortality compared with the standard chemical applied alone. specifically, we in ...201324224248
association between entomopathogenic nematodes and fungi for control of rhipicephalus microplus (acari: ixodidae).the aim of the study was to assess the effect of the association of entomopathogenic nematodes and fungi on rhipicephalus microplus. the nematodes used were heterorhabditis bacteriophora hp88 and heterorhabditis indica lpp1 and the fungi were metarhizium anisopliae ibcb 116 and beauveria bassiana esalq 986. in the groups treated with the fungi, the females were immersed for 3 min in a conidial suspension, while in the groups treated with the nematodes, the ticks were exposed to infective juvenil ...201323949242
evaluation of entomopathogenic fungi and a nematode against the soil-dwelling stages of the crane fly tipula paludosa.larvae of the crane fly tipula paludosa (diptera: nematocera) are economically important pests of grasslands, nurseries and organically grown crops. this study was conducted to evaluate several entomopathogenic fungal strains, the entomopathogenic nematode heterorhabditis bacteriophora and the organophosphate insecticide dursban wg (75% chlorpyrifos) against larval stages of t. paludosa under laboratory and greenhouse conditions.201222740286
molecular identification and genetic diversity among photorhabdus and xenorhabdus isolates.five bacterial strains were isolated from the hemocoel of the greater wax moth larvae (galleria mellonella) infected with the entomopathogenic nematodes: heterorhabditis bacteriophora hp88, heterorhabditis indicus rm1 and heterorhabditis sp (s1), steinernema abbasi and steinernema sp. (s ii). strains were identified as photorhabdus luminescens hrm1, p. luminescens hs1, p. luminescens hp88, xenorhabdus indica and x. nematophila attc19061 using 16s rdna sequence analysis. to reveal the genetic div ...201728391470
strains of photorhabdus spp. associated with polish heterorhabditis isolates: their molecular and phenotypic characterization and symbiont exchange.the relationships between six bacterial symbionts of the entomopathogenic nematodes heterorhabditis bacteriophora and heterorhabditis megidis from poland to species and subspecies of the genus photorhabdus were evaluated. this study was based on phylogenetic analysis of sequence data of five genes: 16s rrna, gyrb, reca, gltx, and dnan. the bacteria were also characterized phenotypically by biochemical and physiological tests. our results have revealed that the photorhabdus strains isolated from ...201728382473
ethanolic extracts of inula viscosa, salix alba and quercus calliprinos, negatively affect the development of the entomopathogenic nematode, heterorhabditis bacteriophora - a model to compare gastro-intestinal nematodes developmental effect.heterorhabditis bacteriophora can represent a model system for herbal medication against gastro-intestinal strongylid parasites in determining the recovery and development due to their unique parasitic infectious cycle. the fact that plant extracts impair nematode development is known but their differential impact on stages of the life cycle of h. bacteriophora has never been investigated. we examined the developmental stages resumed from eggs, young juveniles (j1-3), infective juveniles (ijs), ...201728300600
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