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influence of substrate type and temperature on the developmental morphology of pandora neoaphidis (zygomycetes: entomophthorales), a pathogen of the tobacco aphid (homoptera: aphididae).developmental morphology of pandora neoaphidis was observed on the surfaces of the tobacco aphid, myzus nicotianae, tobacco leaves (nicotiana tabacum), and glass coverslips at 13 and 20 degrees c for 12 and 24 h postinoculation. pandora neoaphidis responded similarly on the two living substrates, but differed on the inert coverslips. the proportions of ellipsoid conidia (primary and secondary) were similar on all substrates. higher proportions of appressoria and lower proportions of round second ...19989709010
effects of fungal infection on the alarm response of pea aphidspea aphids (acyrthosiphon pisum, homoptera: aphididae) infected with the fungal pathogen erynia neoaphidis (zygomycetes: entomophthorales) were less sensitive to the aphid alarm pheromone (e)-beta-farnesene than uninfected aphids. approximately 83% of the healthy aphids and 45% of the infected aphids (2 and 3 days post-inoculation) responded to the alarm pheromone. the percentage of nonresponding aphids increased as the disease progressed. when squeezed (simulated attack) healthy aphids and aphi ...199910388549
[biomass, sporulation and aphid-infecting virulence of pandora neoaphidis mycelia produced in repeated liquid culture].repeated culture of entomophthoraceous isolates is a suspectable factor leading to their virulence decline of biological variation. in the present study, an isolate of pandora neoaphidis, f98028, was repeatedly cultured six times at the regime of 20 degrees c and 80 r/min in sabouraud dextrose broth(sdb) at three inoculation ratio of 1/20, 2/20, and 4/20 (seed culture over fresh sdb). mycelial biomass(mb), sporulation capacity(sc), and virulence to the green peach aphid, myzus persicae, were ass ...200112549095
direct and indirect estimates of pandora neoaphidis conidia in laboratory bioassays with aphids. 200314615224
wide dispersal of aphid-pathogenic entomophthorales among aphids relies upon migratory alates.entomophthoralean mycoses are of general importance in the natural control of aphids, but mechanisms involved in their dissemination are poorly understood. despite several possible means of fungal survival, the dispersal of the mycoses in aphids has never been related to the flight of their migratory alates that are able to locate suitable host plants. in this study, aphid-pathogenic fungi proved to be widely disseminated among various aphids by their alates through migratory flight based on the ...200415049924
issr, eric and rapd techniques to detect genetic diversity in the aphid pathogen pandora neoaphidis.the entomopathogenic fungus pandora neoaphidis is an important natural enemy of aphids. issr, eric (enterobacterial repetitive intergenic consensus) and rapd pcr-based dna fingerprint analyses were undertaken to study intra-specific variation amongst 30 isolates of p. neoaphidis worldwide, together with six closely related species of entomophthorales. all methods yielded scorable binary characters, and distance matrices were constructed from both individual and combined data sets. neighbour-join ...200515912945
epizootiological modeling of pandora neoaphidis mycosis transmission in myzus persicae colonies initiated by primarily infected alates.pandora neoaphidis transmission was monitored within progeny colonies initiated by infected myzus periscae alates individually flown for 1 to 5 h. mycosis progress in the colonies was well fitted (r2= 0.97) to a modified logistic or gompertz model that included their flight distance, postflight survival time, premycosis fecundity, and primary infection rate as influential variables.200516000827
pandora neoaphidis transmission and aphid foraging behaviour.pandora neoaphidis is an aphid-specific entomopathogen that produces infective conidia. as aphid movement increases, so does the likelihood of contact with conidia. volatile distress signals released in response to aphid infestation as an indirect defence against herbivory may affect aphid foraging and, therefore, the fungus-aphid interaction. in this study, two different methods were used to investigate the effect of plant volatiles and p. neoaphidis-sporulating cadavers on (1) the colonisation ...200516039666
effect of fungal infection on the reproductive potential of aphids and their progeny.the effect of infection by pandora neoaphidis and beauveria bassiana on the reproductive potential of the pea aphid, acyrthosiphon pisum, and their progeny was assessed. infection by either p. neoaphidis or b. bassiana reduced the number of nymphs produced within 24 h of inoculation and over the entire infection period compared to uninfected aphids. however, infection by either p. neoaphidis or b. bassiana for 24 or 72 h did not alter the intrinsic rate of increase of the host aphid's progeny. t ...200616410010
ants defend aphids against lethal disease.social insects defend their own colonies and some species also protect their mutualist partners. in mutualisms with aphids, ants typically feed on honeydew produced by aphids and, in turn guard and shelter aphid colonies from insect natural enemies. here we report that formica podzolica ants tending milkweed aphids, aphis asclepiadis, protect aphid colonies from lethal fungal infections caused by an obligate aphid pathogen, pandora neoaphidis. in field experiments, bodies of fungal-killed aphids ...201019923138
intraguild interactions between the entomopathogenic fungus pandora neoaphidis and an aphid predator and parasitoid at the population scale.the interactions that occur between the entomopathogenic fungus pandora neoaphidis and a predator (coccinella septempunctata) and a parasitoid (aphidius ervi) were assessed in microcosm and polytunnel experiments. transmission of p. neoaphidis to the pea aphid, acyrthosiphon pisum, was enhanced in the presence of both c. septempunctata and a. ervi in microcosm experiments done under fixed abiotic conditions. in contrast, the reproductive success of a. ervi was reduced in the presence of p. neoap ...200919682460
pathogenic fungi and parasitoids of aphids present in air captures of migratory alates in the low-latitude plateau of yunnan, china.to survey fungal pathogens and parasitoids of aphids in the low-latitude plateau of yunnan, southwest china, 3,553 migratory alates of brevicoryne brassicae, lipaphis erysimi, and myzus persicae were attracted to a yellow-plus-plant trap from air during a full-year period and individually reared on cabbage leaves for 7-14 d at 18-22 degrees c and l:d 12:12. among the trapped alates, 19.2% were killed by 10 species of aphid-pathogenic fungi after survival of 2.3 d (range, 1-7 d). another 2.8% wer ...200819036206
impacts of thiamethoxam seed treatment and host plant resistance on the soybean aphid fungal pathogen, pandora neoaphidis.since the introduction of soybean aphid, aphis glycines matsumura, from asia, insecticide use in soybean has increased substantially in the north central united states. insecticide seed treatments and aphid resistant soybean varieties are management tactics that may reduce reliance on foliar applications of broad-spectrum insecticides. exploring potential nontarget impacts of these technologies will be an important step in incorporating them into aphid management programs. we investigated impact ...201122299341
transmission of pandora neoaphidis in the presence of co-occurring arthropods.transmission of the entomopathogenic fungus pandora neoaphidis to the nettle aphid microlophium carnosum was assessed in the presence of arthropods that co-exist with the fungus within the habitat but do not compete for aphid hosts. the presence of a parasitoid significantly enhanced transmission, and transmission rates were similar for both enemy and non-enemy parasitoids. although herbivory of nettle leaves by peacock butterfly (inchis io) caterpillars indirectly reduced the number of m. carno ...200818343401
the endosymbiont arsenophonus is widespread in soybean aphid, aphis glycines, but does not provide protection from parasitoids or a fungal pathogen.aphids commonly harbor bacterial facultative symbionts that have a variety of effects upon their aphid hosts, including defense against hymenopteran parasitoids and fungal pathogens. the soybean aphid, aphis glycines matsumura (hemiptera: aphididae), is infected with the symbiont arsenophonus sp., which has an unknown role in its aphid host. our research goals were to document the infection frequency and diversity of the symbiont in field-collected soybean aphids, and to determine whether arseno ...201323614027
experimental simulation of transmission of an obligate aphid pathogen with aphid flight dispersal.the wide dispersal of entomophthorales-caused mycoses that usually regulate aphid populations is most likely to be associated with the flight of infected alates. this hypothesis was examined via simulated flight and postflight colonization of myzus periscae alates exposed to spore showers of pandora neoaphidis, a common obligate aphid pathogen prevalent world wide. a total number of 407 alates were showered in different batches, then individually flown in a computer-monitoring flight mill system ...200616343323
wheat containing snowdrop lectin (gna) does not affect infection of the cereal aphid metopolophium dirhodum by the fungal natural enemy pandora neoaphidis.studies were carried out to determine if susceptibility of the cereal aphid metopolophium dirhodum to the fungus pandora neoaphidis was affected by wheat expressing snowdrop lectin (gna). aphid infection did not differ significantly between the transgenic gna and non-transformed lines (91 and 82%, respectively). fecundity also did not differ between aphids on the two lines, and was ca. 18 nymphs adult(-1). time to infection was ca. 5 days for m. dirhodum on both lines in two of three assays. our ...200516201413
response of the entomopathogenic fungus pandora neoaphidis to aphid-induced plant volatiles.we used a model plant-aphid system to investigate whether the aphid-specific entomopathogenic fungus pandora neoaphidis responds to aphid-induced defence by the broad-bean plant, vicia faba. laboratory experiments indicated that neither in vivo sporulation, conidia size nor the in vitro growth of p. neoaphidis was affected by acyrthosiphon pisum-induced v. faba volatiles. the proportion of conidia germinating on a. pisum feeding on previously damaged plants was significantly greater than on aphi ...200516005016
factors affecting the sporulation capacity during long-term storage of the aphid-pathogenic fungus pandora neoaphidis grown on broomcorn millet.aphid-pathogenic fungus, pandora neoaphidis, grown on broomcorn millet possesses greater sporulation capacity (c(s)) than aphid cadavers. the most sporulating cultures (32.0x10(4) spores millet(-1) grain) with water content (c(w)) of 48.7% were prepared by incubation at 20 degrees c for 15 days and used to study the effect of temperature and humidity on c(s) during long-term storage. cultures were sealed with paper to retain ambient humidity, with parafilm for saturated humidity, or kept in 85% ...200515837374
sitobion avenae alatae infected by pandora neoaphidis: their flight ability, post-flight colonization, and mycosis transmission to progeny colonies.epizootics caused by the obligate entomophthorales pathogen pandora neoaphidis may result from more than one possible means of fungal dissemination among host aphids, but we hypothesize that wide dispersal of the fungus is most likely to be associated with the flight behavior of migratory alates. we tested this hypothesis in a simulation experiment by assessing the flight capability of sitobion avenae alates infected with p. neoaphidis and the potential of their post-flight survival, colonizatio ...200415261776
plant waxy bloom on peas affects infection of pea aphids by pandora neoaphidis.this study examined the effects of the surface wax bloom of pea plants, pisum sativum, on infection of pea aphids, acyrthosiphon pisum, by the fungal pathogen pandora neoaphidis. in prior field surveys, a higher proportion of p. neoaphidis-killed pea aphids (cadavers) had been observed on a pea line with reduced wax bloom, as compared with a sister line with normal surface wax bloom. laboratory bioassays were conducted in order to examine the mechanisms. after plants of each line infested with a ...200314726238
new use of broomcorn millets for production of granular cultures of aphid-pathogenic fungus pandora neoaphidis for high sporulation potential and infectivity to myzus persicae.glutinous broomcorn millets from the crop panicum miliaceum were first used as substrate to produce granular cultures of pandora neoaphidis, an obligate fungal pathogen specific to aphids. carrying a water content of 36.5% after being steamed in a regular autoclaving procedure, millet grains of each 15 g (dry weight) in a 100-ml flask were mixed with 3 ml modified sabouraud dextrose broth containing half a mashed colony of p. neoaphidis grown on egg yolk milk agar and then incubated at 20 degree ...200314592724
a novel computerised image analysis method for the measurement of production of conidia from the aphid pathogenic fungus erynia neoaphidis.a semi-automated method has been developed for the quantification and measurement of conidia discharged by the aphid pathogen erynia neoaphidis. this was used to compare conidiation by e. neoaphidis-mycosed pea aphid cadavers, mycelial plugs cut from agar plates, mycelial pellets from shake flasks and by mycelial pellets from different phases of liquid batch fermenter culture. aphid cadavers discharged significantly more and significantly smaller conidia than plugs or pellets. the volume of coni ...200312644230
effect of spatial heterogeneity on the role of coccinella septempunctata as an intra-guild predator of the aphid pathogen pandora neoaphidis.the foraging behavior of starved and non-starved adult and larval coccinella septempunctata on groups of plants in the presence of pandora neoaphidis-infected acyrthosiphon pisum, uninfected aphids or a mixture of these two prey types was compared. in general results of these studies confirmed the results of previous work comparing foraging behavior on a smaller spatial scale in petri dishes. however, behaviors were modified in response to spatial complexity, prey quality, and the host plant. st ...200312623308
effect of erynia neoaphidis infection and coccinellid foraging on the spatial distribution of aphids on plants. 200212445797
influence of temperature on pea aphid acyrthosiphon pisum (hemiptera: aphididae) resistance to natural enemy attack.the ability to resist or avoid natural enemy attack is a critically important insect life history trait, yet little is understood of how these traits may be affected by temperature. this study investigated how different genotypes of the pea aphid acyrthosiphon pisum harris, a pest of leguminous crops, varied in resistance to three different natural enemies (a fungal pathogen, two species of parasitoid wasp and a coccinellid beetle), and whether expression of resistance was influenced by temperat ...200212191444
geographical distribution and host range of entomophthorales infecting the green spruce aphid elatobium abietinum walker in iceland.entomophthora planchoniana and neozygites fresenii caused infection in populations of the green spruce aphid, elatobium abietinum, in iceland. on this aphid species en. planchoniana was exclusively found in the western part of iceland, while n. fresenii was exclusively found in the eastern part of iceland. this discrete and nearly nonoverlapping geographical distribution correlates with the distribution of two different populations of el. abietinum found in iceland. on other aphid species n. fre ...200111812109
clonal variation and covariation in aphid resistance to parasitoids and a pathogen.the potential rate of evolution of resistance to natural enemies depends on the genetic variation present in the population and any trade-offs between resistance and other components of fitness. we measured clonal variation and covariation in pea aphids (acyrthosiphon pisum) for resistance to two parasitoid species (aphidius ervi and a. eadyi) and a fungal pathogen (erynia neoaphidis). we found significant clonal variation in resistance to all three natural enemies. we tested the hypothesis that ...200111681735
method to immobilize the aphid-pathogenic fungus erynia neoaphidis in an alginate matrix for biocontrolerynia neoaphidis is an important fungal pathogen of aphid pests worldwide. there have been few reported attempts to formulate this natural agent for use in biocontrol. in the current study, factors involved in the immobilization of e. neoaphidis hyphae in an alginate matrix were investigated. hyphae of two isolates cultured in liquid medium were 220 to 620 &mgr;m in length and 7 to 19 &mgr;m in diameter with a 74 to 83% cytoplasmic content. the optimal concentration of low-viscosity sodium algi ...19989797274
implications of predator foraging on aphid pathogen dynamics.the foraging behavior of starved and nonstarved second and fourth instar coccinella septempunctata larvae on dead acyrthosiphon pisum aphids, either infected with the entomopathogenic fungus erynia neoaphidis (sporulating) or uninfected, was examined. larvae searched for longer and fed less when presented with infected rather than uninfected a. pisum. although no sporulating infected aphids were completely consumed, both adult and larval ladybirds can still be considered as intraguild predators. ...19989538028
immunological separation of entomophthorales genera.exoantigens from erynia neoaphidis, conidiobolus major, c. thromboides, c. obscurus, zoophthora radicans, and basidiobolus ranarum were obtained from culture filtrates of fungal material grown in a yeast extract, peptone dialysate, dextrose medium and were tested against specific hyperimmune antisera prepared from e. neoaphidis, c. major, c. thromboides, and b. ranarum by the immunodiffusion technique. specific precipitins were observed for e. neoaphidis and b. ranarum, while cross-reactions wer ...19892498433
a pcr-based tool for the cultivation-independent monitoring of pandora neoaphidis.pandora neoaphidis is one of the most important fungal pathogens of aphids and has a great potential for use in biocontrol. little is known on how this fungus persists in an area and in particular on its overwintering strategies. it is hypothesized that natural areas play an important role for survival and that soil may serve as a source of inoculum for new aphid populations in spring. to test these hypotheses, a cultivation-independent pcr-based diagnostic tool was developed, that allows the de ...200818455181
effect of seasonal abiotic conditions and field margin habitat on the activity of pandora neoaphidis inoculum on soil.the ability of the aphid pathogenic fungus pandora neoaphidis to remain active in the absence of a resting stage through a combination of continuous infection and as conidia deposited on soil was assessed alongside the potential for planted field margins to act as a refuge for the fungus. p. neoaphidis was able to infect the pea aphid, acyrthosiphon pisum, when maintained under controlled conditions that simulated those that occur seasonally in the uk. although there was a significant inverse re ...200817964597
observation on the initial inoculum source and dissemination of entomophthorales-caused epizootics in populations of cereal aphids.a total number of 1092 migratory alates were trapped from air in wheat grown area of yuanyang county, henan province from early april through may 2002 in order to confirm the source and dissemination of entomophthoralean inocula to cause epizootics of cereal aphids. those included 415 sitobion avenae, 642 rhopalosiphum padi, 22 metopolophium dirhodum, and 13 schizaphis graminum. the trapped alates were daily collected and individually reared for 7 days on wheat plants in laboratory. of those 341 ...200415382675
pcr-based molecular discrimination of pandora neoaphidis isolates from related entomopathogenic fungi and development of species-specific diagnostic primers.studies were performed to assess the genetic variation amongst isolates of the aphid-pathogenic fungus pandora neoaphidis (syn. erynia neoaphidis). 37 isolates were examined, from a range of pest and non-pest aphid species, as well as 21 from eight other entomophthoralean species. universal primers were used to amplify the its rdna regions and all of the species tested produced discrete its groups, with the exception of conidiobolus spp. neighbour-joining analysis of the its2 regions from p. neo ...200415209282
non-target impacts of soybean rust fungicides on the fungal entomopathogens of soybean aphid.soybean aphid, aphis glycines, has caused serious economic damage to soybean across the north central us since its introduction to north america in 2000. the management of another invasive soybean pest, asian soybean rust, phakopsora pachyrhizi, using foliar fungicide applications has the potential to impact soybean aphid populations by suppressing beneficial fungal entomopathogens. in 2005 and 2006, we applied recommended soybean rust fungicide treatments, consisting of strobilurin and triazole ...201020025884
prevalence of entomophthoralean fungi (entomophthoromycota) of aphids in relation to developmental stages.transmission of fungal pathogens of aphids may be affected by the host developmental stage. brassica and lactuca sativa l. crops were sampled in santa fe, argentina, to determine the prevalence of fungal-diseased aphids and investigate the differences between developmental stages of aphids.201626577724
prevalence of entomophthoralean fungi (entomophthoromycota) of aphids (hemiptera: aphididae) on solanaceous crops in argentina.solanum melongena l. and capsicum annuum l. were sampled in argentina to determine the prevalence of fungal diseased aphids. the pathogens identified were pandora neoaphidis (remaudière & hennebert) humber and zoophthora radicans (brefeld) batko (entomophthorales: entomophthoraceae) on aphids from eggplants; and p. neoaphidis and entomophthora planchoniana cornu (entomophthorales: entomophthoraceae) on aphids from peppers. the highest fungal prevalence was 45.5% (n=2296) and 98.1% (n=3212) from ...201424956128
natural occurrence of entomophthoroid fungi of aphid pests on medicago sativa l. in argentina.four species of entomophthoroid fungi, pandora neoaphidis (entomophthorales: entomophthoraceae), zoophthora radicans (entomophthorales: entomophthoraceae), entomophthora planchoniana (entomophthorales: entomophthoraceae) and neozygites fresenii (neozygitales: neozygitaceae) were found to infect aphis craccivora, therioaphis trifolii, and acyrthosiphon pisum and unidentified species of acyrthosiphon on lucerne in argentina. samples were collected from five sites (ceres, rafaela, sarmiento, monte ...201424721275
the occurrence of two species of entomophthorales (entomophthoromycota), pathogens of sitobion avenae and myzus persicae (hemiptera: aphididae), in tunisia.the natural occurrence of entomophthoralean fungi pathogenic towards aphids on cereal and potato crops was investigated in the years 2009, 2010, and 2011. infected aphids were sampled in three bioclimatic zones in tunisia (beja, cap bon, and kairouan) and fungal species were determined based on morphological characters such as shape, size, and number of nuclei in the primary conidia. polymerase chain reaction (pcr) on the internal transcribed spacer 1 region (its1) was used to verify morphologic ...201323862158
development of a single-nucleotide polymorphism (snp) assay for genotyping of pandora neoaphidis.pandora neoaphidis (entomophthoromycotina, entomophthorales) is one of the most important fungal pathogens of aphids with great potential as a biological control agent. development of tools that allow high-resolution monitoring of p. neoaphidis in the environment is a prerequisite for the successful implementation of biological control strategies. in this study, a single-nucleotide polymorphism (snp) assay was developed. the assay targets 13 snps identified in 6 genomic regions including the lar ...201020943161
first report of pandora neoaphidis resting spore formation in vivo in aphid hosts.the entomopathogenic fungus pandora neoaphidis is a recognized pathogen of aphids, causes natural epizootics in aphid populations, and interacts and competes with aphid predators and parasitoids. survival of entomophthoralean fungi in periods of unsuitable weather conditions or lack of appropriate host insects is accomplished mainly by thick-walled resting spores (zygospores or azygospores). however, resting spores are not known for some entomophthoralean species such as p. neoaphidis. several h ...201122289765
exposure to natural pathogens reveals costly aphid response to fungi but not bacteria.immune responses are costly, causing trade-offs between defense and other host life history traits. aphids present a special system to explore the costs associated with immune activation since they are missing several humoral and cellular mechanisms thought important for microbial resistance, and it is unknown whether they have alternative, novel immune responses to deal with microbial threat. here we expose pea aphids to an array of heat-killed natural pathogens, which should stimulate immune r ...201424634732
effects of hydrophilic and hydrophobic kaolin-based particle films on pea aphid (homoptera: aphididae) and its entomopathogen pandora neoaphidis (entomophthorales: entomophthoraceae).hydrophobic and hydrophilic kaolin-based particle films are effective for control of insect pests in certain agricultural crops. how these products interact with potential biological control agents is not well documented. this study was conducted to evaluate the effects of the hydrophobic (m96-018) and hydrophilic (surround wp) kaolin-based particle films (engelhard corporation, iselin, nj) on pea aphid, acyrthosiphon pisum (harris), on peas (pisum spp.), and on the fungal aphid pathogen pandora ...200616573319
a facultative endosymbiont in aphids can provide diverse ecological benefits.ecologically important traits of insects are often affected by facultative bacterial endosymbionts. this is best studied in the pea aphid acyrthosiphon pisum, which is frequently infected by one or more of eight facultative symbiont species. many of these symbiont species have been shown to provide one ecological benefit, but we have little understanding of the range of effects that a single strain can have. here, we describe the phenotypes conferred by three strains of the recently discovered b ...201526206380
computer-assisted image processing to detect spores from the fungus pandora neoaphidis.this contribution demonstrates an example of experimental automatic image analysis to detect spores prepared on microscope slides derived from trapping. the application is to monitor aerial spore counts of the entomopathogenic fungus pandora neoaphidis which may serve as a biological control agent for aphids. automatic detection of such spores can therefore play a role in plant protection. the present approach for such detection is a modification of traditional manual microscopy of prepared slid ...201627073786
selection of reference genes for expression analysis in the entomophthoralean fungus pandora neoaphidis.the selection of suitable reference genes is crucial for accurate quantification of gene expression and can add to our understanding of host-pathogen interactions. to identify suitable reference genes in pandora neoaphidis, an obligate aphid pathogenic fungus, the expression of three traditional candidate genes including 18s rrna(18s), 28s rrna(28s) and elongation factor 1 alpha-like protein (ef1), were measured by quantitative polymerase chain reaction at different developmental stages (conidia ...201726887253
horizontal transfer of facultative endosymbionts is limited by host relatedness.heritable microbial symbionts can have important effects on many aspects of their hosts' biology. acquisition of a novel symbiont strain can provide fitness benefits to the host, with significant ecological and evolutionary consequences. we measured barriers to horizontal transmission by artificially transferring facultative symbionts from the grain aphid, sitobion avenae, and five other aphid species into two clonal genotypes of s. avenae. we found the symbiont hamiltonella defensa establishes ...201526332792
patterns, causes and consequences of defensive microbiome dynamics across multiple scales.the microbiome can significantly impact host phenotypes and serve as an additional source of heritable genetic variation. while patterns across eukaryotes are consistent with a role for symbiotic microbes in host macroevolution, few studies have examined symbiont-driven host evolution or the ecological implications of a dynamic microbiome across temporal, spatial or ecological scales. the pea aphid, acyrthosiphon pisum, and its eight heritable bacterial endosymbionts have served as a model for s ...201525683348
genetic variation in resistance and fecundity tolerance in a natural host-pathogen interaction.individuals vary in their ability to defend against pathogens. determining how natural selection maintains this variation is often difficult, in part because there are multiple ways that organisms defend themselves against pathogens. one important distinction is between mechanisms of resistance that fight off infection, and mechanisms of tolerance that limit the impact of infection on host fitness without influencing pathogen growth. theory predicts variation among genotypes in resistance, but n ...201424689981
protection against a fungal pathogen conferred by the aphid facultative endosymbionts rickettsia and spiroplasma is expressed in multiple host genotypes and species and is not influenced by co-infection with another symbiont.many insects harbour facultative endosymbiotic bacteria, often more than one type at a time. these symbionts can have major effects on their hosts' biology, which may be modulated by the presence of other symbiont species and by the host's genetic background. we investigated these effects by transferring two sets of facultative endosymbionts (one hamiltonella and rickettsia, the other hamiltonella and spiroplasma) from naturally double-infected pea aphid hosts into five novel host genotypes of t ...201324118386
unrelated facultative endosymbionts protect aphids against a fungal pathogen.the importance of microbial facultative endosymbionts to insects is increasingly being recognized, but our understanding of how the fitness effects of infection are distributed across symbiont taxa is limited. in the pea aphid, some of the seven known species of facultative symbionts influence their host's resistance to natural enemies, including parasitoid wasps and a pathogenic fungus. here we show that protection against this entomopathogen, pandora neoaphidis, can be conferred by strains of ...201323137173
mesocosm experiments to assess the transmission of pandora neoaphidis within simple and mixed field margins and over the crop-margin interface.although considerable research on the development of agri-environment schemes has focussed on the value of managed field margins as reservoirs for arthropod natural enemies, their potential as reservoirs of entomopathogenic fungi has received less attention. whether field margins that are most beneficial for arthropod natural enemies are the same as those for entomopathogenic fungi is unknown. here, within glasshouse mesocosms, we assessed the reproductive success of the aphid-specific entomopat ...201222405936
winter prevalence of obligate aphid pathogen pandora neoaphidis mycosis in the host myzus persicae populations in southern china: modeling description and biocontrol implication.pandora neoaphidis overwintering had been investigated by monitoring its prevalence in myzus persicae populations in open fields. cabbage plants in field plots were weekly taken after mycosis initiation, to count and examine the living and dead aphids infected by p. neoaphidis . based on the field data, infection levels ( i) varied with field temperature (t), relative humidity (rh) and aphid count (numbers of living aphids per plant, n) over days ( d), fitting well to the modified logistic equat ...201224031835
influence of plant resistance at the third trophic level: interactions between parasitoids and entomopathogenic fungi of cereal aphids.host-plant resistance can affect herbivorous insects and their natural enemies such as parasitoids and entomopathogenic fungi. this tritrophic effect acts on interspecific interactions between the two groups of natural enemies distantly related in phylogenetic terms. the intra- and extra-host aspects of the interaction between the cereal aphid parasitoid aphidius rhopalosiphi and the entomopathogenic fungus erynia neoaphidis developing on the grain aphid, sitobion avenae, on resistant and suscep ...199828307923
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