The Experts below are selected from a list of 172551 Experts worldwide ranked by ideXlab platform
Charles H J Godfray - One of the best experts on this subject based on the ideXlab platform.
-
Host Plant determines the population size of an obligate symbiont buchnera aphidicola in aphids
Applied and Environmental Microbiology, 2016Co-Authors: Yuanchen Zhang, Wenjie Cao, Lerong Zhong, Charles H J Godfray, Xiangdong LiuAbstract:ABSTRACT Buchnera aphidicola is an obligate endosymbiont that provides aphids with several essential nutrients. Though much is known about aphid-Buchnera interactions, the effect of the Host Plant on Buchnera population size remains unclear. Here we used quantitative PCR (qPCR) techniques to explore the effects of the Host Plant on Buchnera densities in the cotton-melon aphid, Aphis gossypii. Buchnera titers were significantly higher in populations that had been reared on cucumber for over 10 years than in populations maintained on cotton for a similar length of time. Aphids collected in the wild from hibiscus and zucchini harbored more Buchnera symbionts than those collected from cucumber and cotton. The effect of aphid genotype on the population size of Buchnera depended on the Host Plant upon which they fed. When aphids from populations maintained on cucumber or cotton were transferred to novel Host Plants, Host survival and Buchnera population size fluctuated markedly for the first two generations before becoming relatively stable in the third and later generations. Host Plant extracts from cucumber, pumpkin, zucchini, and cowpea added to artificial diets led to a significant increase in Buchnera titers in the aphids from the population reared on cotton, while Plant extracts from cotton and zucchini led to a decrease in Buchnera titers in the aphids reared on cucumber. Gossypol, a secondary metabolite from cotton, suppressed Buchnera populations in populations from both cotton and cucumber, while cucurbitacin from cucurbit Plants led to higher densities. Together, the results suggest that Host Plants influence Buchnera population processes and that this may provide phenotypic plasticity in Host Plant use for clonal aphids.
-
population differentiation and genetic variation in Host choice among pea aphids from eight Host Plant genera
Evolution, 2006Co-Authors: Julia Ferrari, Charles H J Godfray, Adam Faulconbridge, Kim Prior, Sara ViaAbstract:Habitat choice plays a critical role in the processes of Host range evolution, specialization, and ecological speciation. Pea aphid, Acyrthosiphon pisum, populations from alfalfa and red clover in eastern North America are known to be genetically differentiated and show genetic preferences for the appropriate Host Plant. This species feeds on many more Hosts, and here we report a study of the genetic variation in Host Plant preference within and between pea aphid populations collected from eight genera of Host Plants in southeastern England. Most Host-associated populations show a strong, genetically based preference for the Host Plant from which they were collected. Only in one case (populations from Vicia and Trifolium) was there little difference in the Plant preference spectrum between populations. All populations showed a significant secondary preference for the Plant on which all the aphid lines were reared: broad bean, Vicia faba, previously suggested to be a “universal Host” for pea aphids. Of the total genetic variance in Host preference within our sample, 61% could be attributed to preference for the collection Host Plant and a further 9% to systematic differences in secondary preferences with the residual representing within-population genetic variation between clones. We discuss how a combination of Host Plant preference and mating on the Host Plant may promote local adaptation and possibly ecological speciation, and whether a widely accepted Host could oppose speciation by mediating gene flow between different populations.
Niklas Wahlberg - One of the best experts on this subject based on the ideXlab platform.
-
Dynamics of Host Plant use and species diversity in Polygonia butterflies (Nymphalidae)
Journal of Evolutionary Biology, 2006Co-Authors: Elisabet Weingartner, Niklas Wahlberg, Sören NylinAbstract:The ability of insects to utilize different Host Plants has been suggested to be a dynamic and transient phase. During or after this phase, species can shift to novel Host Plants or respecialize on ancestral ones. Expanding the range of Host Plants might also be a factor leading to higher levels of net speciation rates. In this paper, we have studied the possible importance of Host Plant range for diversification in the genus Polygonia (Nymphalidae, Nymphalini). We have compared species richness between sistergroups in order to find out if there are any differences in number of species between clades including species that utilize only the ancestral Host Plants (‘urticalean rosids’) and their sisterclades with a broader (or in some cases potentially broader) Host Plant repertoire. Four comparisons could be made, and although these are not all phylogenetically or statistically independent, all showed clades including butterfly species using other or additional Host Plants than the urticalean rosids to be more species-rich than their sisterclade restricted to the ancestral Host Plants. These results are consistent with the theory that expansions in Host Plant range are involved in the process of diversification in butterflies and other phytophagous insects, in line with the general theory that plasticity may drive speciation.
-
THE PHYLOGENETICS AND BIOCHEMISTRY OF Host-Plant SPECIALIZATION IN MELITAEINE BUTTERFLIES (LEPIDOPTERA: NYMPHALIDAE)
Evolution, 2001Co-Authors: Niklas WahlbergAbstract:Butterflies in the tribe Melitaeini (Lepidoptera: Nymphalidae) are known to utilize Host Plants belonging to 16 families, although most Host-Plant records are from four families. Of the 16 Host-Plant families, 12 produce secondary Plant metabolites called iridoids. Earlier studies have shown that larvae of several melitaeine species use iridoids as feeding stimulants and sequester these compounds for larval defense. I investigate the evolutionary history of Host-Plant use in the tribe Melitaeini by testing a recent phylogenetic hypothesis of 65 species representing the four major species groups of the tribe. By simple character optimization of Host-Plant families and presence/absence of iridoids in the Host Plants, I find that Plant chemistry is a more conservative trait than Plant taxonomy. The ancestral Host Plant(s) of the entire tribe most likely contained iridoids and were likely to be in the Plant family Plantaginaceae. A major Host shift from Plants containing iridoids to Plants not containing iridoids has happened three times inde- pendently. The results show that the evolution of Host-Plant use in melitaeines has been (and still is) a dynamic process when considering Plant taxonomy, but is relatively stable when considering Host-Plant chemistry.
Julia Ferrari - One of the best experts on this subject based on the ideXlab platform.
-
effects of bacterial secondary symbionts on Host Plant use in pea aphids
Proceedings of The Royal Society B: Biological Sciences, 2011Co-Authors: Ailsa H C Mclean, Julia Ferrari, M Van Asch, H C J GodfrayAbstract:Aphids possess several facultative bacterial symbionts that have important effects on their Hosts' biology. These have been most closely studied in the pea aphid (Acyrthosiphon pisum), a species that feeds on multiple Host Plants. Whether secondary symbionts influence Host Plant utilization is unclear. We report the fitness consequences of introducing different strains of the symbiont Hamiltonella defensa into three aphid clones collected on Lathyrus pratensis that naturally lack symbionts, and of removing symbionts from 20 natural aphid-bacterial associations. Infection decreased fitness on Lathyrus but not on Vicia faba, a Plant on which most pea aphids readily feed. This may explain the unusually low prevalence of symbionts in aphids collected on Lathyrus. There was no effect of presence of symbiont on performance of the aphids on the Host Plants of the clones from which the H. defensa strains were isolated. Removing the symbiont from natural aphid-bacterial associations led to an average approximate 20 per cent reduction in fecundity, both on the natural Host Plant and on V. faba, suggesting general rather than Plant-species-specific effects of the symbiont. Throughout, we find significant genetic variation among aphid clones. The results provide no evidence that secondary symbionts have a major direct role in facilitating aphid utilization of particular Host Plant species.
-
effects of the maternal and pre adult Host Plant on adult performance and preference in the pea aphid acyrthosiphon pisum
Ecological Entomology, 2009Co-Authors: Ailsa H C Mclean, Julia Ferrari, H C J GodfrayAbstract:Abstract 1. The taxon known as the pea aphid, Acyrthosiphon pisum, is composed of a series of Host Plant associated populations and is widely used as a model system to explore ecological speciation and the evolution of specialisation. It is thus important to know how maternal and pre-adult experience influences Host Plant utilisation in this species. 2. The relative importance of the maternal and pre-adult Host Plant for adult fecundity and Host preference was investigated using three aphid clones collected from Lathyrus pratensis and maintained on Lathyrus or Vicia faba. 3. No significant effects of the maternal Host Plant on offspring fecundity were detected. 4. The Host Plant on which the aphid grew up influenced adult fecundity, although in a complex way that depended on both the adult Host Plant species and when after transfer to the test Plant fecundity was assessed. 5. All three clones preferred to colonise Lathyrus over Vicia, and this preference was stronger for aphids raised on Lathyrus. 6. The significance of the results for studies of the evolution of specialisation and speciation that employ A. pisum is discussed.
-
population differentiation and genetic variation in Host choice among pea aphids from eight Host Plant genera
Evolution, 2006Co-Authors: Julia Ferrari, Charles H J Godfray, Adam Faulconbridge, Kim Prior, Sara ViaAbstract:Habitat choice plays a critical role in the processes of Host range evolution, specialization, and ecological speciation. Pea aphid, Acyrthosiphon pisum, populations from alfalfa and red clover in eastern North America are known to be genetically differentiated and show genetic preferences for the appropriate Host Plant. This species feeds on many more Hosts, and here we report a study of the genetic variation in Host Plant preference within and between pea aphid populations collected from eight genera of Host Plants in southeastern England. Most Host-associated populations show a strong, genetically based preference for the Host Plant from which they were collected. Only in one case (populations from Vicia and Trifolium) was there little difference in the Plant preference spectrum between populations. All populations showed a significant secondary preference for the Plant on which all the aphid lines were reared: broad bean, Vicia faba, previously suggested to be a “universal Host” for pea aphids. Of the total genetic variance in Host preference within our sample, 61% could be attributed to preference for the collection Host Plant and a further 9% to systematic differences in secondary preferences with the residual representing within-population genetic variation between clones. We discuss how a combination of Host Plant preference and mating on the Host Plant may promote local adaptation and possibly ecological speciation, and whether a widely accepted Host could oppose speciation by mediating gene flow between different populations.
Micky D Eubanks - One of the best experts on this subject based on the ideXlab platform.
-
effects of virus infection of mimulus guttatus phrymaceae on Host Plant quality for meadow spittlebugs philaenus spumarius hemiptera cercopidae
Environmental Entomology, 2005Co-Authors: Micky D Eubanks, David E Carr, John F MurphyAbstract:Herbivorous insects often feed on pathogen-infected Plants in nature, and it is likely that pathogen infection alters Host Plant quality. We documented the effects of Plant infection by a widespread Plant virus on Host Plant quality for a generalist insect herbivore and tested the hypothesis that these effects vary among Plant genotypes. We found that infection by Cucumber mosaic virus (CMV) altered the Host Plant quality of Mimulus guttatus (Phrymaceae) for meadow spittlebugs, Philaenus spumarius (Hemiptera: Cercopidae). The effects of CMV infection on Host Plant quality, however, varied among full-sib M. guttatus families, suggesting that these effects vary among Plant genotypes. In most full-sib families, CMV infection either had no effect on Host Plant quality or increased Host Plant quality as measured by spittlebug size and development time. In a few M. guttatus families, however, CMV infection decreased Host Plant quality. There was no relationship between the effect of CMV infection on Plant growth and the subsequent effect of CMV infection on spittlebug performance, suggesting that broad changes in Host Plant performance (e.g., growth rate) were not responsible for the effects of CMV infection on Host Plant quality for spittlebugs. We suggest that future studies of the effects of pathogen infection of Plants on insect herbivores consider variation among Plant genotypes in the mechanisms and ecological consequences associated with these effects.
-
inbreeding alters resistance to insect herbivory and Host Plant quality in mimulus guttatus scrophulariaceae
Evolution, 2002Co-Authors: David E Carr, Micky D EubanksAbstract:Previous studies have demonstrated genetic variation for resistance to insect herbivores and Host Plant quality. The effect of Plant mating system, an important determinant of the distribution of genetic variation, on Host Plant characteristics has received almost no attention. This study used a controlled greenhouse experiment to examine the effect of self- and cross-pollination in Mimulus guttatus (Scrophulariaceae) on resistance to and Host Plant quality for the xylem-feeding spittlebug Philaenus spumarius (Homoptera: Cercopidae). Spittlebugs were found to have a negative effect on two important fitness components in M. guttatus, flower production and above ground biomass. One of two M. guttatus populations examined showed a significant interaction between the pollination and herbivore treatments. In this case, the detrimental effects of herbivores on biomass and flower production were much more pronounced in inbred (self) Plants. The presence of spittlebug nymphs increased inbreeding depression by as much as three times. Pollination treatments also had significant effects on important components of herbivore fitness, but these effects were in opposite directions in our two Host Plant populations. Spittlebug nymphs maturing on self Plants emerged as significantly larger adults in one of our Host Plant populations, indicating that inbreeding increased Host Plant quality. In our second Host Plant population, spittlebug nymphs took significantly longer to develop to adulthood on self Plants, indicating that inbreeding decreased Host Plant quality. Taken together these results suggest that the degree of inbreeding in Host Plant populations can have important and perhaps complex effects on the dynamics of Plant-herbivore interactions and on mating-system evolution in the Host.
May R Berenbaum - One of the best experts on this subject based on the ideXlab platform.
-
Host Plant records of antherina suraka boisduval 1833 saturniidae in madagascar
Journal of The Lepidopterists Society, 2014Co-Authors: Maminirina Randrianandrasana, Herisolo Andrianiaina Razafindraleva, May R BerenbaumAbstract:ABSTRACT. The larval stage of Antherina suraka (Boisduval) (Saturniidae) consumes leaves of Plant species from 23 families. These Host Plant species belong mainly to families in the subclass Rosidae, although those in the family Oleaceae and Apocynaceae from another subclass (Asteridae) are nearly as numerous as those in the family Rosaceae. Documentation and field surveys from 2008 to 2011 in different regions of Madagascar enabled an update of the list of the Host Plants of A. suraka. As few records of Host Plants exist and no immature stages were found in the dry areas, in contrast with other regions of Madagascar, further studies of A. suraka in these special ecosystems will provide interesting ecological data. The discovery of several Host Plant species endemic to Madagascar showed that, although A. suraka has adapted to feed on non-native species in disturbed sites throughout its range, it remains reliant on native forests. Determination of its Host availability in each region constitutes an importa...
-
Host Plant, Host Plant chemistry and the polyembryonic parasitoid Copidosoma sosares: indirect effects in a tritrophic interaction
Oikos, 2004Co-Authors: May R Berenbaum, Arthur R. Zangerl, Ian C.w. HardyAbstract:Host Plant identity and Host Plant chemistry have often been shown to influence Host finding and acceptance by natural enemies but comparatively less attention has been paid to the tritrophic effects of Host Plant and Host Plant chemistry on other natural enemy fitness correlates, such as survivorship, clutch size, body size, and sex ratio. Such studies are central to understanding both the selective impact of Plants on natural enemies as well as the potential for reciprocal selective impact of natural enemies on Plant traits. We examined the effects of Host Plant and Host Plant chemistry in a tritrophic system consisting of three apiaceous Plants (Pastinaca sativa, Heracleum sphondylium and H. mantegazzianum), the parsnip webworm (Depressaria pastinacella) and the polyembryonic parasitic wasp Copidosoma sosares. All of these Plants produce furanocoumarins, known resistance factors for parsnip webworms. Furanocoumarin concentrations were correlated neither with the presence nor the number of webworms on a given Plant. Concentrations of two furanocoumarins were negatively associated with C. sosares fitness correlates: isopimpinellin with the likelihood that a given webworm would be parasitized and xanthotoxin with both within-brood survivorship (of all-male and mixed-sex broods) and clutch size. Brood sex ratio and body sizes of individual wasps were not correlated with furanocoumarin chemistry. Because additive genetic variation exists in P. sativa for furanocoumarin chemical traits, these are subject to selection by webworms through herbivory. Third trophic level selective impacts on furanocoumarin traits may include selection for reduced production of those chemicals that affect parasitoid survivorship yet do not influence Host Plant choice by the herbivore. That such might be the case is suggested by patterns of furanocoumarin production in populations of P. sativa with different histories of infestation; in the Netherlands, where parasitism rates of webworms by C. sosares are high, Plants produce lower levels of all linear furanocoumarins and proportionately less isopimpinellin than do midwestern U.S. populations of P. sativa, where natural enemies of the webworm are effectively absent.
-
behavioral responses of the parsnip webworm to Host Plant volatiles
Journal of Chemical Ecology, 2002Co-Authors: Mark J. Carroll, May R BerenbaumAbstract:Sixth instars of the parsnip webworm, Depressaria pastinacella, orient by olfaction to bud, male flowers, and female flowers of their primary Host Plant, Pastinaca sativa. Because octyl acetate and octyl butyrate are characteristic of tissues consumed by the sixth instar, we investigated the influence of these esters on webworm feeding behavior and chemo-orientation. Although octyl acetate and octyl butyrate are feeding deterrents, and octyl butyrate is an olfactory repellent, octyl acetate serves as an olfactory attractant. In olfactometers, webworms do not show a preference when given a choice between octyl acetate and Host Plant tissues. These findings suggest that octyl acetate is a sufficient cue for olfactory orientation. Such behavior may explain differences in the relative abundance of these esters observed among populations of wild parsnip under differential selection pressure from these insects.
