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Jeffrey L Feder - One of the best experts on this subject based on the ideXlab platform.
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Distinct Adult Eclosion Traits of Sibling Species Rhagoletis pomonella and Rhagoletis zephyria (Diptera: Tephritidae) Under Laboratory Conditions
Environmental entomology, 2020Co-Authors: Wee L. Yee, Robert B. Goughnour, Jeffrey L FederAbstract:Closely related phytophagous insects that specialize on different host plants may have divergent responses to environmental factors. Rhagoletis pomonella (Walsh) and Rhagoletis zephyria Snow (Diptera: Tephritidae) are sibling, sympatric fly species found in western North America that attack and mate on plants of Rosaceae (~60 taxa) and Caprifoliaceae (three taxa), respectively, likely contributing to partial reproductive isolation. Rhagoletis zephyria evolved from R. pomonella and is native to western North America, whereas R. pomonella was introduced there. Given that key features of the flies' ecology, breeding compatibility, and evolution differ, we predicted that adult eclosion patterns of the two flies from Washington State, USA are also distinct. When puparia were chilled, eclosion of apple- and black hawthorn-origin R. pomonella was significantly more dispersed, with less pronounced peaks, than of snowberry-origin R. zephyria within sympatric and nonsympatric site comparisons. Percentages of chilled puparia that produced adults were ≥67% for both species. However, when puparia were not chilled, from 13.5 to 21.9% of apple-origin R. pomonella versus only 1.2% to 1.9% of R. zephyria eclosed. The distinct differences in eclosion traits of R. pomonella and R. zephyria could be due to greater genetic variation in R. pomonella, associated with its use of a wider range of host plants than R. zephyria.
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Can the genomics of ecological speciation be predicted across the divergence continuum from host races to species? A case study in Rhagoletis.
Philosophical transactions of the Royal Society of London. Series B Biological sciences, 2020Co-Authors: Peter J. Meyers, Scott P. Egan, Glen R. Hood, Thomas H. Q. Powell, Meredith M. Doellman, Gregory J. Ragland, Patrik Nosil, Jeffrey L FederAbstract:Studies assessing the predictability of evolution typically focus on short-term adaptation within populations or the repeatability of change among lineages. A missing consideration in speciation research is to determine whether natural selection predictably transforms standing genetic variation within populations into differences between species. Here, we test whether and how host-related selection on diapause timing associates with genome-wide differentiation during ecological speciation by comparing ancestral hawthorn and newly formed apple-infesting host races of Rhagoletis pomonella to their sibling species Rhagoletis mendax that attacks blueberries. The associations of 57 857 single nucleotide polymorphisms in a diapause genome-wide-association study (GWAS) on the hawthorn race strongly predicted the direction and magnitude of genomic divergence among the three fly populations at a field site in Fennville, MI, USA. The apple race and R. mendax show parallel changes in the frequencies of putative inversions on three chromosomes associated with the earlier fruiting times of apples and blueberries compared to hawthorns. A diapause GWAS on R. mendax revealed compensatory changes throughout the genome accounting for the earlier eclosion of blueberry, but not apple flies. Thus, a degree of predictability, although not complete, exists in the genomics of diapause across the ecological speciation continuum in Rhagoletis. The generality of this result is placed in the context of other similar systems. This article is part of the theme issue 'Towards the completion of speciation: the evolution of reproductive isolation beyond the first barriers'.
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Comparative Responses of Rhagoletis zephyria and Rhagoletis pomonella (Diptera: Tephritidae) to Commercial and Experimental Sticky Traps and Odors in Washington State.
Environmental entomology, 2017Co-Authors: Wee L. Yee, Robert B. Goughnour, Jeffrey L Feder, Charles E Linn, Dong H. ChaAbstract:Rhagoletis zephyria Snow and Rhagoletis pomonella (Walsh) (Diptera: Tephritidae) are morphologically similar flies that attack white-colored snowberry fruit (Symphoricarpos spp.) and yellow/red or dark-colored apple/hawthorn fruit (Malus/Crataegus spp.), respectively. The two flies are caught together on traps in R. pomonella surveys in the western United States, increasing labor needed to process catches. Comparing responses of the two species with different traps could help identify best practices for reducing R. zephyria captures in these surveys and could contribute to understanding population divergence in Rhagoletis flies. In Washington State, United States, we found that R. zephyria responded most to yellow rectangles and more to white than red spheres (RSs) baited with ammonium carbonate (AC), whereas R. pomonella responded most to RSs with AC. Yellow plastic rectangles with AC were more effective in capturing R. zephyria than cardboard rectangles, as has been found for R. pomonella. R. zephyria did not respond to apple fruit volatiles associated with RSs that were attractive to R. pomonella. In contrast, R. zephyria responded more to yellow rectangles with snowberry than apple volatiles. Both species responded to AC. Our results suggest that RSs are better than yellow rectangles for surveying R. pomonella when snowberries are abundant. However, if discrimination from R. zephyria is paramount, RSs with apple volatiles should be used. Differences in the species' responses to traps appear related to odor/color cues of the flies' host fruit, while commonalties appear related to visual/olfactory stimuli associated with protein feeding, for which AC is a general attractant.
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Sensory specificity and speciation: a potential neuronal pathway for host fruit odour discrimination in Rhagoletis pomonella.
Proceedings. Biological sciences, 2016Co-Authors: Cheyenne Tait, Jeffrey L Feder, Srishti Batra, Sree Subha Ramaswamy, Shannon B. OlssonAbstract:Behavioural changes in habitat or mate choice can trigger population divergence, leading to speciation. However, little is known about the neurological bases for such changes. Rhagoletis pomonella (Diptera: Tephritidae) is a model for ecological speciation via host plant shifts. Within the past 180 years, Rhagoletis flies infesting hawthorn (Crataegus spp.) shifted to attack domesticated apple (Malus pumila). The two populations differ in their olfactory preferences for apple versus hawthorn fruit. Here, we looked for patterns of sensory organization that may have contributed to this shift by characterizing the morphology, specificity and distribution of olfactory sensory neurons (OSNs) on the antennae of Rhagoletis responding to host fruit and non-host volatiles. Of 28 OSN classes identified, two colocalized OSN pairs were found that specifically responded to the major behavioural attractant and antagonist volatiles for each fly population. A reversal in the response of these OSNs to fruit volatiles, either through a switch in receptor expression between these paired neurons or changes in neuronal projections in the brain, could therefore account for the behavioural difference between apple and hawthorn flies. The finding supports the hypothesis that relatively minor changes in olfactory sensory pathways may contribute to rapid host shifting and divergence in Rhagoletis.
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new records of Rhagoletis loew 1862 diptera tephritidae and their host plants in western montana u s a
Pan-pacific Entomologist, 2015Co-Authors: Wee L. Yee, Glen R. Hood, Tom W Lawrence, Jeffrey L FederAbstract:Little information exists concerning the distribution of fruit flies in the genus Rhagoletis Loew, 1862 (Diptera: Tephritidae) in Montana, western U.S.A. Here, the presence of and host plant use by Rhagoletis spp. are documented in northwestern Montana. The western cherry fruit fly, Rhagoletis indifferens Curran, 1932, was abundant in the state and infested sweet cherry, Prunus avium (L.) L.; mahaleb cherry, P. mahaleb L.; tart cherry, P. cerasus L.; and bitter cherry, P. emarginata (Douglas ex Hook.) D. Dietr. (Rosaceae). Black cherry fruit fly, R. fausta (Osten-Sacken, 1877), was rare and detected only in bitter cherry. Rhagoletis berberis Curran, 1932, R. basiola (Osten-Sacken, 1873), R. tabellaria (Fitch, 1855), and apple maggot, R. pomonella (Walsh, 1867), were all recorded for the first time in Montana. Flies in Montana were mainly reared from previously reported species of host plants, but new host records also documented include, R. indifferens from black hawthorn, Crataegus douglasii Lindl. (Rosaceae), a new Montana record; R. berberis from sweet cherry; R. basiola from baldhip rose, Rosa gymnocarpa Nutt. (Rosaceae); and R. tabellaria from Hooker's fairy bells, Prosartes hookeri Torr. (Liliaceae). Rhagoletis pomonella, likely introduced into the western U.S., was reared from C. douglasii but not from the relatively few domesticated apple trees, Malus domestica Borkh., (Rosaceae) sampled. The findings extend the known geographic ranges of four Rhagoletis species and indicate that some flies in northwestern Montana have the ability to survive and develop in alternative and novel hosts, consistent with findings for populations in other areas of the western U.S.
Wee L. Yee - One of the best experts on this subject based on the ideXlab platform.
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Distinct Adult Eclosion Traits of Sibling Species Rhagoletis pomonella and Rhagoletis zephyria (Diptera: Tephritidae) Under Laboratory Conditions
Environmental entomology, 2020Co-Authors: Wee L. Yee, Robert B. Goughnour, Jeffrey L FederAbstract:Closely related phytophagous insects that specialize on different host plants may have divergent responses to environmental factors. Rhagoletis pomonella (Walsh) and Rhagoletis zephyria Snow (Diptera: Tephritidae) are sibling, sympatric fly species found in western North America that attack and mate on plants of Rosaceae (~60 taxa) and Caprifoliaceae (three taxa), respectively, likely contributing to partial reproductive isolation. Rhagoletis zephyria evolved from R. pomonella and is native to western North America, whereas R. pomonella was introduced there. Given that key features of the flies' ecology, breeding compatibility, and evolution differ, we predicted that adult eclosion patterns of the two flies from Washington State, USA are also distinct. When puparia were chilled, eclosion of apple- and black hawthorn-origin R. pomonella was significantly more dispersed, with less pronounced peaks, than of snowberry-origin R. zephyria within sympatric and nonsympatric site comparisons. Percentages of chilled puparia that produced adults were ≥67% for both species. However, when puparia were not chilled, from 13.5 to 21.9% of apple-origin R. pomonella versus only 1.2% to 1.9% of R. zephyria eclosed. The distinct differences in eclosion traits of R. pomonella and R. zephyria could be due to greater genetic variation in R. pomonella, associated with its use of a wider range of host plants than R. zephyria.
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eclosion and adult longevity traits of Rhagoletis tabellaria diptera tephritidae and utetes tabellariae hymenoptera braconidae in the laboratory
Canadian Entomologist, 2020Co-Authors: Wee L. Yee, A A Forbes, J L FederAbstract:Eclosion times and rates of Rhagoletis tabellaria (Fitch) (Diptera: Tephritidae) and its parasitoid wasp Utetes tabellariae (Fischer) (Hymenoptera: Braconidae) held at different chilling durations were determined in the laboratory. Adult fly and wasp longevity were also determined. Adult female and male flies from R. tabellaria puparia chilled for 195 days at 4.8 °C and then held at 23.2 °C eclosed on average earlier than U. tabellariae reared from R. tabellaria puparia. Rhagoletis tabellaria also eclosed significantly earlier from puparia chilled for 150 days than 120 days at 2.7 °C, but U. tabellariae eclosion from the two treatments did not differ significantly. Rhagoletis tabellaria eclosion rates were greater with longer chill durations, but U. tabellariae eclosion rates per R. tabellaria puparium did not differ among chill durations. No R. tabellaria eclosed from nonchilled puparia held at 20–22 °C, but at least 18.8% of nonchilled U. tabellariae eclosed. Female and male R. tabellaria on average survived 52.1 and 83.3 days, respectively, while female and male U. tabellariae survived 37.7 and 28.7 days, respectively. Results indicate diapause and developmental traits of R. tabellaria may be more dependent on chilling durations and less flexible than those of U. tabellariae, a wasp that appears adapted to flies in the R. tabellaria species complex.
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Modeling the abundance of two Rhagoletis fly (Diptera: Tephritidae) pests in Washington State, U.S.A.
PloS one, 2019Co-Authors: Tewodros T. Wakie, Wee L. Yee, Lisa G. Neven, Sunil KumarAbstract:Well-adapted and abundant insect pests can negatively affect agricultural production. We modeled the abundance of two Rhagoletis fly (Diptera: Tephritidae) pests, apple maggot fly, Rhagoletis pomonella (Walsh), and western cherry fruit fly, Rhagoletis indifferens Curran, in Washington State (WA), U.S.A. using biologically relevant environmental variables. We tested the hypothesis that abundance of the two species is influenced by different environmental variables, based on the fact that these two species evolved in different environments, have different host plants, and that R. pomonella is an introduced pest in WA while R. indifferens is native. We collected data on fly and host plant abundance at 61 randomly selected sites across WA in 2015 and 2016. We obtained land-cover, climate, and elevation data from online sources and used these data to derive relevant landscape variables and modeled fly abundance using generalized linear models. For R. pomonella, relatively high winter mean minimum temperature, low elevation, and developed land-cover were the top variables positively related to fly abundance. In contrast, for R. indifferens, the top variables related to greater fly abundance were high Hargreaves climatic moisture and annual heat-moisture deficits (indication of drier habitats), high host plant abundance, and developed land-cover. Our results identify key environmental variables driving Rhagoletis fly abundance in WA and can be used for understanding adaptation of insects to non-native and native habitats and for assisting fly quarantine and management decisions.
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Genetic Evidence for the Introduction of Rhagoletis pomonella (Diptera: Tephritidae) into the Northwestern United States.
Journal of economic entomology, 2017Co-Authors: Sheina B. Sim, Robert B. Goughnour, Gilbert St. Jean, Scott P. Egan, Wee L. Yee, Glen R. Hood, Thomas H. Q. Powell, Meredith M. Doellman, Dietmar Schwarz, James J. SmithAbstract:The apple maggot fly, Rhagoletis pomonella Walsh (Diptera: Tephritidae), is a serious quarantine pest in the apple-growing regions of central Washington and Oregon. The fly is believed to have been introduced into the Pacific Northwest via the transport of larval-infested apples near Portland, Oregon, within the last 40 yr. However, R. pomonella also attacks native black hawthorn, Crataegus douglasii Lindley (Rosales: Rosaceae), and introduced ornamental hawthorn, Crataegus monogyna Jacquin, in the region. It is, therefore, possible that R. pomonella was not introduced but has always been present on black hawthorn. If true, then the fly may have independently shifted from hawthorn onto apple in the Pacific Northwest within the last 40 yr after apples were introduced. Here, we test the introduction hypothesis through a microsatellite genetic survey of 10 R. pomonella sites in Washington and 5 in the eastern United States, as well as a comparison to patterns of genetic variation between populations of Rhagoletis cingulata Loew and Rhagoletis indifferens Curran, two sister species of cherry-infesting flies known to be native to the eastern and western United States, respectively. We report results based on genetic distance networks, patterns of allelic variation, and estimated times of population divergence that are consistent with the introduction hypothesis for R. pomonella. The results have important implications for R. pomonella management, suggesting that black hawthorn-infesting flies near commercial apple-growing regions of central Washington may harbor sufficient variation to utilize apple as an alternate host, urging careful monitoring, and possible removal of hawthorn trees near orchards.
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Comparative Responses of Rhagoletis zephyria and Rhagoletis pomonella (Diptera: Tephritidae) to Commercial and Experimental Sticky Traps and Odors in Washington State.
Environmental entomology, 2017Co-Authors: Wee L. Yee, Robert B. Goughnour, Jeffrey L Feder, Charles E Linn, Dong H. ChaAbstract:Rhagoletis zephyria Snow and Rhagoletis pomonella (Walsh) (Diptera: Tephritidae) are morphologically similar flies that attack white-colored snowberry fruit (Symphoricarpos spp.) and yellow/red or dark-colored apple/hawthorn fruit (Malus/Crataegus spp.), respectively. The two flies are caught together on traps in R. pomonella surveys in the western United States, increasing labor needed to process catches. Comparing responses of the two species with different traps could help identify best practices for reducing R. zephyria captures in these surveys and could contribute to understanding population divergence in Rhagoletis flies. In Washington State, United States, we found that R. zephyria responded most to yellow rectangles and more to white than red spheres (RSs) baited with ammonium carbonate (AC), whereas R. pomonella responded most to RSs with AC. Yellow plastic rectangles with AC were more effective in capturing R. zephyria than cardboard rectangles, as has been found for R. pomonella. R. zephyria did not respond to apple fruit volatiles associated with RSs that were attractive to R. pomonella. In contrast, R. zephyria responded more to yellow rectangles with snowberry than apple volatiles. Both species responded to AC. Our results suggest that RSs are better than yellow rectangles for surveying R. pomonella when snowberries are abundant. However, if discrimination from R. zephyria is paramount, RSs with apple volatiles should be used. Differences in the species' responses to traps appear related to odor/color cues of the flies' host fruit, while commonalties appear related to visual/olfactory stimuli associated with protein feeding, for which AC is a general attractant.
Juan Rull - One of the best experts on this subject based on the ideXlab platform.
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Life History and Mating Behavior of Rhagoletis solanophaga (Diptera: Tephritidae), a Non-Diapausing Species with Highly Variable Mating Duration
Journal of Insect Behavior, 2016Co-Authors: Juan Rull, Eduardo Tadeo, Solana Abraham, Christian RodríguezAbstract:As an initial contribution to understanding the adaptive value of behavioral and life-history strategies, the life cycle and mating behavior of an unstudied species of tephritid fruit fly in the genus Rhagoletis are characterized for the first time. Over a 9-month fruiting period, a small proportion of Solanum appendiculatum Dunal (< 10 %) was found to be infested with a single larva of Rhagoletis solanophaga (Hernandez & Frias). The average duration of R. solanophaga lifecycle (c.a. 140 days from egg laying to death of adults) exceeded the three month fruitless period. Additionally, R. solanophaga is capable of exploiting Solanaceous plants in at least two genera. These features could have selected for a non-diapausing species of Rhagoletis, a genus where most species are univoltine. Nevertheless, some individuals in the population became dormant. As other members of the genus, R. solanophaga exhibited a resource defense mating system with forced copulations and multiple mating. Both males and females could be highly promiscuous and individual mating success exhibited a wide range of outcomes. Regardless of mating success, mated females stored similar amounts of sperm in two spherical spermathecae. Long copulations were observed, perhaps functioning as a form of mate guarding with probable disadvantages for females. We outline hypotheses and opportunities for future comparative studies examining sperm competition and mate guarding.
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The effect of winter length on survival and duration of dormancy of four sympatric species of Rhagoletis exploiting plants with different fruiting phenology.
Bulletin of entomological research, 2016Co-Authors: Juan Rull, Eduardo Tadeo, Rodrigo Lasa, Martín AlujaAbstract:Dormancy has been thoroughly studied for several species of economic importance in the genus Rhagoletis in temperate areas of North America and Europe. Much less is known on life history regulation for species inhabiting high-elevation areas in the subtropics at the southern extreme of their geographical range. Host plant phenology has been found to play a key role in generating allochronic isolation among sibling species and host races of Rhagoletis in the course of sympatric speciation, and has important implications for pest management. We compare the effect of winter length on survival to adult eclosion and dormancy duration among four species of Rhagoletis (three of them sympatric) exploiting hosts with different fruiting phenology in subtropical isolated highlands. Survival and duration of dormancy was found to be different among the four species. At 24°C, a very small proportion (
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the effect of winter length on survival and duration of dormancy of four sympatric species of Rhagoletis exploiting plants with different fruiting phenology
Bulletin of Entomological Research, 2016Co-Authors: Juan Rull, Eduardo Tadeo, Rodrigo Lasa, Martín AlujaAbstract:Dormancy has been thoroughly studied for several species of economic importance in the genus Rhagoletis in temperate areas of North America and Europe. Much less is known on life history regulation for species inhabiting high-elevation areas in the subtropics at the southern extreme of their geographical range. Host plant phenology has been found to play a key role in generating allochronic isolation among sibling species and host races of Rhagoletis in the course of sympatric speciation, and has important implications for pest management. We compare the effect of winter length on survival to adult eclosion and dormancy duration among four species of Rhagoletis (three of them sympatric) exploiting hosts with different fruiting phenology in subtropical isolated highlands. Survival and duration of dormancy was found to be different among the four species. At 24°C, a very small proportion (<1%) of R. pomonella, R. turpiniae and R. zoqui completed development without becoming dormant, while in the case of R. solanophaga the majority of the population emerged after development within 40 days of pupation. Also, a large proportion of braconid parasitoids infesting Rhagoletis eggs and larvae emerged as adults without becoming dormant. Greatest survival after artificial winter was obtained for R. pomonella (50-60%) and R. zoqui (30%) after only four weeks at 5°C (a third of the time reported for studies on northern R. pomonella), while R. turpiniae, under identical environmental conditions experienced low adult emergence, and highest survival (11%) was recorded for flies exposed to 5°C during 10 and 12 weeks. For R. pomonella, there was a strong positive relationship between winter length and time to post-winter adult eclosion that was not observed for R. zoqui. In sum, for R. pomonella, mild winters in highland subtropical areas appear to select for flies better able to withstand longer periods of warm temperature before winter than flies exploiting late fruiting hosts and inhabiting northern latitudes. In the case of R. turpiniae and R. zoqui environmental cues such as fluctuations in humidity and/or different temperature thresholds (5°C) may play a more important role than winter length in life history regulation. Continuous host availability for R. solanophaga appears to have selected for non-diapausing flies. From an applied perspective our results are useful for handling flies in the laboratory to conduct research and suggest that non-diapausing strains of flies and parasitoids may be selected for SIT and innundative biological control programs.
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Divergence and evolution of reproductive barriers among three allopatric populations of Rhagoletis cingulata across eastern North America and Mexico
Entomologia Experimentalis et Applicata, 2015Co-Authors: Eduardo Tadeo, Scott P. Egan, Martín Aluja, Jeffery L. Feder, Hannes Schuler, Juan RullAbstract:Geography is often a key factor facilitating population divergence and speciation. In this regard, the geographic distributions of flies in the genus Rhagoletis (Diptera: Tephritidae) in temperate North America have been affected by cycles of Pleistocene glaciation and interglacial periods. Fluctuations in climatic conditions may have had their most dramatic effects on geographically isolating Rhagoletis flies in the central highland region of Mexico. During past periods of allopatry, a degree of post-zygotic reproductive isolation appears to have evolved between hawthorn-infesting populations of Rhagoletis pomonella (Walsh) in the central Eje Volcanico Trans Mexicano (EVTM) and those from the Sierra Madre Oriental Mountains (SMO) of Mexico, as well as hawthorn flies from the eastern USA. Here, we investigate the generality of this finding in the genus Rhagoletis by testing for reproductive isolation among populations of Rhagoletis cingulata (Loew) (Diptera: Tephritidae) collected from infested domesticated sweet cherry (Prunus avium L.) in the USA and black cherry [Prunus serotina Ehrh. (both Rosaceae)] from the SMO and EVTM. We report evidence for marked post-mating reproductive isolation among certain R. cingulata populations. The high levels of reproductive isolation were observed between R. cingulata flies from populations in the USA and SMO differed from the pattern seen for R. pomonella, primarily involving the EVTM. In addition, egg hatch was significantly reduced for crosses between SMO males and EVTM females, but not greatly in the opposite direction. We discuss potential causes for the different patterns of post-mating reproductive isolation among Rhagoletis flies.
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Status of Rhagoletis (Diptera: Tephritidae) Pests in the NAPPO Countries
Journal of economic entomology, 2014Co-Authors: Wee L. Yee, Juan Rull, Vicente Hernández-ortiz, Bradley J. Sinclair, Lisa G. NevenAbstract:The North American Plant Protection Organization (NAPPO) is an organization comprising plant protection regulatory officials of the three signatory countries: the United States, Canada, and Mexico. NAPPO develops Regional Standards for Phytosanitary Measures (RSPMs) as well as discussion papers on important issues related to plant protection. The Fruit Panel of NAPPO organized a Technical Assistance Group (TAG) to develop a discussion paper on the status of pest species of Rhagoletis (Diptera: Tephritidae) within the NAPPO countries. As regulations are developed to prevent the spread of these pests both within and outside of the NAPPO countries, it was important to understand the pest status of these species. This article reviews the basic biology, host range, distribution, potential to spread, management, and regulatory status of pest species of Rhagoletis within the NAPPO countries.
Scott P. Egan - One of the best experts on this subject based on the ideXlab platform.
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Can the genomics of ecological speciation be predicted across the divergence continuum from host races to species? A case study in Rhagoletis.
Philosophical transactions of the Royal Society of London. Series B Biological sciences, 2020Co-Authors: Peter J. Meyers, Scott P. Egan, Glen R. Hood, Thomas H. Q. Powell, Meredith M. Doellman, Gregory J. Ragland, Patrik Nosil, Jeffrey L FederAbstract:Studies assessing the predictability of evolution typically focus on short-term adaptation within populations or the repeatability of change among lineages. A missing consideration in speciation research is to determine whether natural selection predictably transforms standing genetic variation within populations into differences between species. Here, we test whether and how host-related selection on diapause timing associates with genome-wide differentiation during ecological speciation by comparing ancestral hawthorn and newly formed apple-infesting host races of Rhagoletis pomonella to their sibling species Rhagoletis mendax that attacks blueberries. The associations of 57 857 single nucleotide polymorphisms in a diapause genome-wide-association study (GWAS) on the hawthorn race strongly predicted the direction and magnitude of genomic divergence among the three fly populations at a field site in Fennville, MI, USA. The apple race and R. mendax show parallel changes in the frequencies of putative inversions on three chromosomes associated with the earlier fruiting times of apples and blueberries compared to hawthorns. A diapause GWAS on R. mendax revealed compensatory changes throughout the genome accounting for the earlier eclosion of blueberry, but not apple flies. Thus, a degree of predictability, although not complete, exists in the genomics of diapause across the ecological speciation continuum in Rhagoletis. The generality of this result is placed in the context of other similar systems. This article is part of the theme issue 'Towards the completion of speciation: the evolution of reproductive isolation beyond the first barriers'.
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Genetic Evidence for the Introduction of Rhagoletis pomonella (Diptera: Tephritidae) into the Northwestern United States.
Journal of economic entomology, 2017Co-Authors: Sheina B. Sim, Robert B. Goughnour, Gilbert St. Jean, Scott P. Egan, Wee L. Yee, Glen R. Hood, Thomas H. Q. Powell, Meredith M. Doellman, Dietmar Schwarz, James J. SmithAbstract:The apple maggot fly, Rhagoletis pomonella Walsh (Diptera: Tephritidae), is a serious quarantine pest in the apple-growing regions of central Washington and Oregon. The fly is believed to have been introduced into the Pacific Northwest via the transport of larval-infested apples near Portland, Oregon, within the last 40 yr. However, R. pomonella also attacks native black hawthorn, Crataegus douglasii Lindley (Rosales: Rosaceae), and introduced ornamental hawthorn, Crataegus monogyna Jacquin, in the region. It is, therefore, possible that R. pomonella was not introduced but has always been present on black hawthorn. If true, then the fly may have independently shifted from hawthorn onto apple in the Pacific Northwest within the last 40 yr after apples were introduced. Here, we test the introduction hypothesis through a microsatellite genetic survey of 10 R. pomonella sites in Washington and 5 in the eastern United States, as well as a comparison to patterns of genetic variation between populations of Rhagoletis cingulata Loew and Rhagoletis indifferens Curran, two sister species of cherry-infesting flies known to be native to the eastern and western United States, respectively. We report results based on genetic distance networks, patterns of allelic variation, and estimated times of population divergence that are consistent with the introduction hypothesis for R. pomonella. The results have important implications for R. pomonella management, suggesting that black hawthorn-infesting flies near commercial apple-growing regions of central Washington may harbor sufficient variation to utilize apple as an alternate host, urging careful monitoring, and possible removal of hawthorn trees near orchards.
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Divergence and evolution of reproductive barriers among three allopatric populations of Rhagoletis cingulata across eastern North America and Mexico
Entomologia Experimentalis et Applicata, 2015Co-Authors: Eduardo Tadeo, Scott P. Egan, Martín Aluja, Jeffery L. Feder, Hannes Schuler, Juan RullAbstract:Geography is often a key factor facilitating population divergence and speciation. In this regard, the geographic distributions of flies in the genus Rhagoletis (Diptera: Tephritidae) in temperate North America have been affected by cycles of Pleistocene glaciation and interglacial periods. Fluctuations in climatic conditions may have had their most dramatic effects on geographically isolating Rhagoletis flies in the central highland region of Mexico. During past periods of allopatry, a degree of post-zygotic reproductive isolation appears to have evolved between hawthorn-infesting populations of Rhagoletis pomonella (Walsh) in the central Eje Volcanico Trans Mexicano (EVTM) and those from the Sierra Madre Oriental Mountains (SMO) of Mexico, as well as hawthorn flies from the eastern USA. Here, we investigate the generality of this finding in the genus Rhagoletis by testing for reproductive isolation among populations of Rhagoletis cingulata (Loew) (Diptera: Tephritidae) collected from infested domesticated sweet cherry (Prunus avium L.) in the USA and black cherry [Prunus serotina Ehrh. (both Rosaceae)] from the SMO and EVTM. We report evidence for marked post-mating reproductive isolation among certain R. cingulata populations. The high levels of reproductive isolation were observed between R. cingulata flies from populations in the USA and SMO differed from the pattern seen for R. pomonella, primarily involving the EVTM. In addition, egg hatch was significantly reduced for crosses between SMO males and EVTM females, but not greatly in the opposite direction. We discuss potential causes for the different patterns of post-mating reproductive isolation among Rhagoletis flies.
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distribution host plant affiliation phenology and phylogeny of walnut infesting Rhagoletis flies diptera tephritidae in mexico
Biological Journal of The Linnean Society, 2013Co-Authors: Juan Rull, Scott P. Egan, Martín Aluja, Eduardo Tadeo, Larissa Guillén, Mary M. Glover, Jeffrey L FederAbstract:Many taxa of Nearctic origin have diversified in the subtropical highlands of Mexico. In particular, flies in the genus Rhagoletis have undergone episodes of isolation and gene flow during Pleistocene glaciations and post-glacial times that have produced lineage differentiation and reproductive isolation. To reach a better understanding of the phylogeography of the genus Rhagoletis, a host plant survey of the walnut-infesting Rhagoletis suavis species group was conducted across sixteen states comprising 34 different collecting sites in Mexico over a 9-year period. Five species of Juglans were found to be infested by three species of walnut-attacking Rhagoletis flies. Several species of parasitoids were also recovered from collections, but in contrast to their walnut fly hosts, they revealed little evidence for host or geographic subdivision. There was no consistent difference in mean eclosion time between walnut fly species or populations associated with different host walnuts in Mexico, unlike the case for other Rhagoletis species, in which allochronic isolation arising from variation in diapause timing is a major ecological adaptation, reproductively isolating flies. We compare the distribution of R. suavis flies in Mexico with those of other Rhagoletis species attacking hawthorns and cherries, and discuss its implications for population divergence and speciation. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110, 765–779.
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Distribution, host plant affiliation, phenology, and phylogeny of walnut‐infesting Rhagoletis flies (Diptera: Tephritidae) in Mexico
Biological Journal of the Linnean Society, 2013Co-Authors: Juan Rull, Scott P. Egan, Martín Aluja, Eduardo Tadeo, Larissa Guillén, Mary M. Glover, Jeffrey L FederAbstract:Many taxa of Nearctic origin have diversified in the subtropical highlands of Mexico. In particular, flies in the genus Rhagoletis have undergone episodes of isolation and gene flow during Pleistocene glaciations and post-glacial times that have produced lineage differentiation and reproductive isolation. To reach a better understanding of the phylogeography of the genus Rhagoletis, a host plant survey of the walnut-infesting Rhagoletis suavis species group was conducted across sixteen states comprising 34 different collecting sites in Mexico over a 9-year period. Five species of Juglans were found to be infested by three species of walnut-attacking Rhagoletis flies. Several species of parasitoids were also recovered from collections, but in contrast to their walnut fly hosts, they revealed little evidence for host or geographic subdivision. There was no consistent difference in mean eclosion time between walnut fly species or populations associated with different host walnuts in Mexico, unlike the case for other Rhagoletis species, in which allochronic isolation arising from variation in diapause timing is a major ecological adaptation, reproductively isolating flies. We compare the distribution of R. suavis flies in Mexico with those of other Rhagoletis species attacking hawthorns and cherries, and discuss its implications for population divergence and speciation. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110, 765–779.
Martín Aluja - One of the best experts on this subject based on the ideXlab platform.
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the effect of winter length on survival and duration of dormancy of four sympatric species of Rhagoletis exploiting plants with different fruiting phenology
Bulletin of Entomological Research, 2016Co-Authors: Juan Rull, Eduardo Tadeo, Rodrigo Lasa, Martín AlujaAbstract:Dormancy has been thoroughly studied for several species of economic importance in the genus Rhagoletis in temperate areas of North America and Europe. Much less is known on life history regulation for species inhabiting high-elevation areas in the subtropics at the southern extreme of their geographical range. Host plant phenology has been found to play a key role in generating allochronic isolation among sibling species and host races of Rhagoletis in the course of sympatric speciation, and has important implications for pest management. We compare the effect of winter length on survival to adult eclosion and dormancy duration among four species of Rhagoletis (three of them sympatric) exploiting hosts with different fruiting phenology in subtropical isolated highlands. Survival and duration of dormancy was found to be different among the four species. At 24°C, a very small proportion (<1%) of R. pomonella, R. turpiniae and R. zoqui completed development without becoming dormant, while in the case of R. solanophaga the majority of the population emerged after development within 40 days of pupation. Also, a large proportion of braconid parasitoids infesting Rhagoletis eggs and larvae emerged as adults without becoming dormant. Greatest survival after artificial winter was obtained for R. pomonella (50-60%) and R. zoqui (30%) after only four weeks at 5°C (a third of the time reported for studies on northern R. pomonella), while R. turpiniae, under identical environmental conditions experienced low adult emergence, and highest survival (11%) was recorded for flies exposed to 5°C during 10 and 12 weeks. For R. pomonella, there was a strong positive relationship between winter length and time to post-winter adult eclosion that was not observed for R. zoqui. In sum, for R. pomonella, mild winters in highland subtropical areas appear to select for flies better able to withstand longer periods of warm temperature before winter than flies exploiting late fruiting hosts and inhabiting northern latitudes. In the case of R. turpiniae and R. zoqui environmental cues such as fluctuations in humidity and/or different temperature thresholds (5°C) may play a more important role than winter length in life history regulation. Continuous host availability for R. solanophaga appears to have selected for non-diapausing flies. From an applied perspective our results are useful for handling flies in the laboratory to conduct research and suggest that non-diapausing strains of flies and parasitoids may be selected for SIT and innundative biological control programs.
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The effect of winter length on survival and duration of dormancy of four sympatric species of Rhagoletis exploiting plants with different fruiting phenology.
Bulletin of entomological research, 2016Co-Authors: Juan Rull, Eduardo Tadeo, Rodrigo Lasa, Martín AlujaAbstract:Dormancy has been thoroughly studied for several species of economic importance in the genus Rhagoletis in temperate areas of North America and Europe. Much less is known on life history regulation for species inhabiting high-elevation areas in the subtropics at the southern extreme of their geographical range. Host plant phenology has been found to play a key role in generating allochronic isolation among sibling species and host races of Rhagoletis in the course of sympatric speciation, and has important implications for pest management. We compare the effect of winter length on survival to adult eclosion and dormancy duration among four species of Rhagoletis (three of them sympatric) exploiting hosts with different fruiting phenology in subtropical isolated highlands. Survival and duration of dormancy was found to be different among the four species. At 24°C, a very small proportion (
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Divergence and evolution of reproductive barriers among three allopatric populations of Rhagoletis cingulata across eastern North America and Mexico
Entomologia Experimentalis et Applicata, 2015Co-Authors: Eduardo Tadeo, Scott P. Egan, Martín Aluja, Jeffery L. Feder, Hannes Schuler, Juan RullAbstract:Geography is often a key factor facilitating population divergence and speciation. In this regard, the geographic distributions of flies in the genus Rhagoletis (Diptera: Tephritidae) in temperate North America have been affected by cycles of Pleistocene glaciation and interglacial periods. Fluctuations in climatic conditions may have had their most dramatic effects on geographically isolating Rhagoletis flies in the central highland region of Mexico. During past periods of allopatry, a degree of post-zygotic reproductive isolation appears to have evolved between hawthorn-infesting populations of Rhagoletis pomonella (Walsh) in the central Eje Volcanico Trans Mexicano (EVTM) and those from the Sierra Madre Oriental Mountains (SMO) of Mexico, as well as hawthorn flies from the eastern USA. Here, we investigate the generality of this finding in the genus Rhagoletis by testing for reproductive isolation among populations of Rhagoletis cingulata (Loew) (Diptera: Tephritidae) collected from infested domesticated sweet cherry (Prunus avium L.) in the USA and black cherry [Prunus serotina Ehrh. (both Rosaceae)] from the SMO and EVTM. We report evidence for marked post-mating reproductive isolation among certain R. cingulata populations. The high levels of reproductive isolation were observed between R. cingulata flies from populations in the USA and SMO differed from the pattern seen for R. pomonella, primarily involving the EVTM. In addition, egg hatch was significantly reduced for crosses between SMO males and EVTM females, but not greatly in the opposite direction. We discuss potential causes for the different patterns of post-mating reproductive isolation among Rhagoletis flies.
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distribution host plant affiliation phenology and phylogeny of walnut infesting Rhagoletis flies diptera tephritidae in mexico
Biological Journal of The Linnean Society, 2013Co-Authors: Juan Rull, Scott P. Egan, Martín Aluja, Eduardo Tadeo, Larissa Guillén, Mary M. Glover, Jeffrey L FederAbstract:Many taxa of Nearctic origin have diversified in the subtropical highlands of Mexico. In particular, flies in the genus Rhagoletis have undergone episodes of isolation and gene flow during Pleistocene glaciations and post-glacial times that have produced lineage differentiation and reproductive isolation. To reach a better understanding of the phylogeography of the genus Rhagoletis, a host plant survey of the walnut-infesting Rhagoletis suavis species group was conducted across sixteen states comprising 34 different collecting sites in Mexico over a 9-year period. Five species of Juglans were found to be infested by three species of walnut-attacking Rhagoletis flies. Several species of parasitoids were also recovered from collections, but in contrast to their walnut fly hosts, they revealed little evidence for host or geographic subdivision. There was no consistent difference in mean eclosion time between walnut fly species or populations associated with different host walnuts in Mexico, unlike the case for other Rhagoletis species, in which allochronic isolation arising from variation in diapause timing is a major ecological adaptation, reproductively isolating flies. We compare the distribution of R. suavis flies in Mexico with those of other Rhagoletis species attacking hawthorns and cherries, and discuss its implications for population divergence and speciation. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110, 765–779.
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Distribution, host plant affiliation, phenology, and phylogeny of walnut‐infesting Rhagoletis flies (Diptera: Tephritidae) in Mexico
Biological Journal of the Linnean Society, 2013Co-Authors: Juan Rull, Scott P. Egan, Martín Aluja, Eduardo Tadeo, Larissa Guillén, Mary M. Glover, Jeffrey L FederAbstract:Many taxa of Nearctic origin have diversified in the subtropical highlands of Mexico. In particular, flies in the genus Rhagoletis have undergone episodes of isolation and gene flow during Pleistocene glaciations and post-glacial times that have produced lineage differentiation and reproductive isolation. To reach a better understanding of the phylogeography of the genus Rhagoletis, a host plant survey of the walnut-infesting Rhagoletis suavis species group was conducted across sixteen states comprising 34 different collecting sites in Mexico over a 9-year period. Five species of Juglans were found to be infested by three species of walnut-attacking Rhagoletis flies. Several species of parasitoids were also recovered from collections, but in contrast to their walnut fly hosts, they revealed little evidence for host or geographic subdivision. There was no consistent difference in mean eclosion time between walnut fly species or populations associated with different host walnuts in Mexico, unlike the case for other Rhagoletis species, in which allochronic isolation arising from variation in diapause timing is a major ecological adaptation, reproductively isolating flies. We compare the distribution of R. suavis flies in Mexico with those of other Rhagoletis species attacking hawthorns and cherries, and discuss its implications for population divergence and speciation. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110, 765–779.
