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Denis Bourguet - One of the best experts on this subject based on the ideXlab platform.
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Genetic Isolation between two sympatric host plant races of the European corn borer, Ostrinia nubilalis Hubner. II: assortative mating and host-plant preferences for oviposition
Heredity, 2005Co-Authors: Marietherese Bethenod, Yan Thomas, Laurent Pelozuelo, Brigitte Frerot, Francois Rousset, G. Genestier, Denis BourguetAbstract:The European corn borer, Ostrinia nubilalis Hubner, colonized maize ( Zea mays L.) after its introduction into Europe about 500 years ago and is now considered one of the main pests of this crop. In northern France, two sympatric host races have been described: one feeding on maize and the other on mugwort ( Artemisia vulgaris L.) and hop ( Humulus lupulus L.). In a previous study, we showed that mating between the two races may be impeded by differences in the timing of moth emergence and in the composition of the sex pheromone produced by the females. In this study, we further investigated the Genetic Isolation of these two races using strains from the maize (Z strain) and mugwort ( E strain) races selected for diagnostic alleles at two allozyme loci. In a cage containing maize and mugwort plants and located in natural conditions, mating between individuals of the same strain occurred more often than mating between males and females of the E and Z strains. In particular, we obtained no evidence for crosses between Z females and E males. We also found that females of the Z strain laid their eggs almost exclusively on maize, whereas females of the E strain laid their eggs preferentially, but not exclusively, on mugwort. These results suggest that the Genetic differentiation between the two host races may also be favored by host-plant preference, one of the first steps toward sympatric speciation.
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Genetic Isolation between two sympatric host plant races of the european corn borer ostrinia nubilalis hubner i sex pheromone moth emergence timing and parasitism
Evolution, 2003Co-Authors: Yan Thomas, Marietherese Bethenod, Laurent Pelozuelo, Brigitte Frerot, Denis BourguetAbstract:Abstract Adaptation to different environments may be a powerful source of Genetic differentiation between populations. The biological traits selected in each environment can pleiotropically induce assortative mating between individuals of these Genetically differentiated populations. This situation may facilitate sympatric speciation. Successful host shifts in phytophagous insects provide some of the best evidence for the ecological speciation that occurs, or has occurred, in sympatry. The European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), colonized maize after its introduction into Europe by humans about 500 years ago. In northern France, two sympatric host races feed on maize (Zea mays) and mugwort (Artemisia vulgaris), respectively. We investigated the factors involved in the Genetic Isolation of these two races at a field site near Paris, France. We identified two biological differences that might make a significant contribution to the Genetic divergence between sympatric populations fe...
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Genetic Isolation between two sympatric host plant races of the european corn borer ostrinia nubilalis hubner i sex pheromone moth emergence timing and parasitism
Evolution, 2003Co-Authors: Yan Thomas, Marietherese Bethenod, Laurent Pelozuelo, Brigitte Frerot, Denis BourguetAbstract:Abstract Adaptation to different environments may be a powerful source of Genetic differentiation between populations. The biological traits selected in each environment can pleiotropically induce assortative mating between individuals of these Genetically differentiated populations. This situation may facilitate sympatric speciation. Successful host shifts in phytophagous insects provide some of the best evidence for the ecological speciation that occurs, or has occurred, in sympatry. The European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), colonized maize after its introduction into Europe by humans about 500 years ago. In northern France, two sympatric host races feed on maize (Zea mays) and mugwort (Artemisia vulgaris), respectively. We investigated the factors involved in the Genetic Isolation of these two races at a field site near Paris, France. We identified two biological differences that might make a significant contribution to the Genetic divergence between sympatric populations fe...
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Genetic Isolation between two sympatric host-plant races of the European corn borer, Ostrinia nubilalis Hubner. I. Sex pheromone, moth emergence timing, and parasitism
Evolution - International Journal of Organic Evolution, 2003Co-Authors: Yan Thomas, Marietherese Bethenod, Laurent Pelozuelo, Brigitte Frerot, Denis BourguetAbstract:Adaptation to different environments may be a powerful source of Genetic differentiation between populations. The biological traits selected in each environment can pleiotropically induce assortative mating between individuals of these Genetically differentiated populations. This situation may facilitate sympatric speciation. Successful host shifts in phytophagous insects provide some of the best evidence for the ecological speciation that occurs, or has occurred, in sympatry. The European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), colonized maize after its introduction into Europe by humans about 500 years ago. In northern France, two sympatric host races feed on maize (Zea mays) and mugwort (Artemisia vulgaris), respectively. We investigated the factors involved in the Genetic Isolation of these two races at a field site near Paris, France. We identified two biological differences that might make a significant contribution to the Genetic divergence between sympatric populations feeding on the two host plants. First, assortative mating may be due to differences in the moth emergence pattern between the two races: mugwort-race moths emerged on average 10 days earlier than maize-race moths. In addition, the males emerged earlier than females in both races. Hence, the likelihood of mating between maize-race males and mugwort-race females was higher than that of mating between mugwort-race males and maize-race females. Second, the females feeding on mugwort and maize produced sex pheromones with different E/Z isomeric ratios of ⌬-11-tetradecenyl acetate. This difference in mate recognition systems reinforces the potential for assortative mating in the two races. During the experiment, overwintering mortality was much lower on maize than on mugwort. This difference was due to a braconid parasitoid wasp, Macrocentrus cingulum, that killed more than 50% of the larvae overwintering on mugwort but did not infest larvae diapausing on maize. Hence, by colonizing maize, European corn borer populations probably escaped from numerous predators, competitors, and parasitoids, such as M. cingulum. This decrease in host-associated selection may have favored the colonization of this new host. Finally, throughout this experiment we observed selection at two allozyme loci (or at linked loci): Tpi and Mpi. The Tpi locus is tightly linked with the genes involved in the response of the male to the sex pheromone and in developmental timing. The location of these traits on the Z chromosome may play a role in shortening the time required for the evolution of premating barriers.
Yan Thomas - One of the best experts on this subject based on the ideXlab platform.
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Genetic Isolation between two sympatric host plant races of the European corn borer, Ostrinia nubilalis Hubner. II: assortative mating and host-plant preferences for oviposition
Heredity, 2005Co-Authors: Marietherese Bethenod, Yan Thomas, Laurent Pelozuelo, Brigitte Frerot, Francois Rousset, G. Genestier, Denis BourguetAbstract:The European corn borer, Ostrinia nubilalis Hubner, colonized maize ( Zea mays L.) after its introduction into Europe about 500 years ago and is now considered one of the main pests of this crop. In northern France, two sympatric host races have been described: one feeding on maize and the other on mugwort ( Artemisia vulgaris L.) and hop ( Humulus lupulus L.). In a previous study, we showed that mating between the two races may be impeded by differences in the timing of moth emergence and in the composition of the sex pheromone produced by the females. In this study, we further investigated the Genetic Isolation of these two races using strains from the maize (Z strain) and mugwort ( E strain) races selected for diagnostic alleles at two allozyme loci. In a cage containing maize and mugwort plants and located in natural conditions, mating between individuals of the same strain occurred more often than mating between males and females of the E and Z strains. In particular, we obtained no evidence for crosses between Z females and E males. We also found that females of the Z strain laid their eggs almost exclusively on maize, whereas females of the E strain laid their eggs preferentially, but not exclusively, on mugwort. These results suggest that the Genetic differentiation between the two host races may also be favored by host-plant preference, one of the first steps toward sympatric speciation.
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Genetic Isolation between two sympatric host plant races of the european corn borer ostrinia nubilalis hubner i sex pheromone moth emergence timing and parasitism
Evolution, 2003Co-Authors: Yan Thomas, Marietherese Bethenod, Laurent Pelozuelo, Brigitte Frerot, Denis BourguetAbstract:Abstract Adaptation to different environments may be a powerful source of Genetic differentiation between populations. The biological traits selected in each environment can pleiotropically induce assortative mating between individuals of these Genetically differentiated populations. This situation may facilitate sympatric speciation. Successful host shifts in phytophagous insects provide some of the best evidence for the ecological speciation that occurs, or has occurred, in sympatry. The European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), colonized maize after its introduction into Europe by humans about 500 years ago. In northern France, two sympatric host races feed on maize (Zea mays) and mugwort (Artemisia vulgaris), respectively. We investigated the factors involved in the Genetic Isolation of these two races at a field site near Paris, France. We identified two biological differences that might make a significant contribution to the Genetic divergence between sympatric populations fe...
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Genetic Isolation between two sympatric host plant races of the european corn borer ostrinia nubilalis hubner i sex pheromone moth emergence timing and parasitism
Evolution, 2003Co-Authors: Yan Thomas, Marietherese Bethenod, Laurent Pelozuelo, Brigitte Frerot, Denis BourguetAbstract:Abstract Adaptation to different environments may be a powerful source of Genetic differentiation between populations. The biological traits selected in each environment can pleiotropically induce assortative mating between individuals of these Genetically differentiated populations. This situation may facilitate sympatric speciation. Successful host shifts in phytophagous insects provide some of the best evidence for the ecological speciation that occurs, or has occurred, in sympatry. The European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), colonized maize after its introduction into Europe by humans about 500 years ago. In northern France, two sympatric host races feed on maize (Zea mays) and mugwort (Artemisia vulgaris), respectively. We investigated the factors involved in the Genetic Isolation of these two races at a field site near Paris, France. We identified two biological differences that might make a significant contribution to the Genetic divergence between sympatric populations fe...
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Genetic Isolation between two sympatric host-plant races of the European corn borer, Ostrinia nubilalis Hubner. I. Sex pheromone, moth emergence timing, and parasitism
Evolution - International Journal of Organic Evolution, 2003Co-Authors: Yan Thomas, Marietherese Bethenod, Laurent Pelozuelo, Brigitte Frerot, Denis BourguetAbstract:Adaptation to different environments may be a powerful source of Genetic differentiation between populations. The biological traits selected in each environment can pleiotropically induce assortative mating between individuals of these Genetically differentiated populations. This situation may facilitate sympatric speciation. Successful host shifts in phytophagous insects provide some of the best evidence for the ecological speciation that occurs, or has occurred, in sympatry. The European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), colonized maize after its introduction into Europe by humans about 500 years ago. In northern France, two sympatric host races feed on maize (Zea mays) and mugwort (Artemisia vulgaris), respectively. We investigated the factors involved in the Genetic Isolation of these two races at a field site near Paris, France. We identified two biological differences that might make a significant contribution to the Genetic divergence between sympatric populations feeding on the two host plants. First, assortative mating may be due to differences in the moth emergence pattern between the two races: mugwort-race moths emerged on average 10 days earlier than maize-race moths. In addition, the males emerged earlier than females in both races. Hence, the likelihood of mating between maize-race males and mugwort-race females was higher than that of mating between mugwort-race males and maize-race females. Second, the females feeding on mugwort and maize produced sex pheromones with different E/Z isomeric ratios of ⌬-11-tetradecenyl acetate. This difference in mate recognition systems reinforces the potential for assortative mating in the two races. During the experiment, overwintering mortality was much lower on maize than on mugwort. This difference was due to a braconid parasitoid wasp, Macrocentrus cingulum, that killed more than 50% of the larvae overwintering on mugwort but did not infest larvae diapausing on maize. Hence, by colonizing maize, European corn borer populations probably escaped from numerous predators, competitors, and parasitoids, such as M. cingulum. This decrease in host-associated selection may have favored the colonization of this new host. Finally, throughout this experiment we observed selection at two allozyme loci (or at linked loci): Tpi and Mpi. The Tpi locus is tightly linked with the genes involved in the response of the male to the sex pheromone and in developmental timing. The location of these traits on the Z chromosome may play a role in shortening the time required for the evolution of premating barriers.
Marietherese Bethenod - One of the best experts on this subject based on the ideXlab platform.
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Genetic Isolation between two sympatric host plant races of the European corn borer, Ostrinia nubilalis Hubner. II: assortative mating and host-plant preferences for oviposition
Heredity, 2005Co-Authors: Marietherese Bethenod, Yan Thomas, Laurent Pelozuelo, Brigitte Frerot, Francois Rousset, G. Genestier, Denis BourguetAbstract:The European corn borer, Ostrinia nubilalis Hubner, colonized maize ( Zea mays L.) after its introduction into Europe about 500 years ago and is now considered one of the main pests of this crop. In northern France, two sympatric host races have been described: one feeding on maize and the other on mugwort ( Artemisia vulgaris L.) and hop ( Humulus lupulus L.). In a previous study, we showed that mating between the two races may be impeded by differences in the timing of moth emergence and in the composition of the sex pheromone produced by the females. In this study, we further investigated the Genetic Isolation of these two races using strains from the maize (Z strain) and mugwort ( E strain) races selected for diagnostic alleles at two allozyme loci. In a cage containing maize and mugwort plants and located in natural conditions, mating between individuals of the same strain occurred more often than mating between males and females of the E and Z strains. In particular, we obtained no evidence for crosses between Z females and E males. We also found that females of the Z strain laid their eggs almost exclusively on maize, whereas females of the E strain laid their eggs preferentially, but not exclusively, on mugwort. These results suggest that the Genetic differentiation between the two host races may also be favored by host-plant preference, one of the first steps toward sympatric speciation.
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Genetic Isolation between two sympatric host plant races of the european corn borer ostrinia nubilalis hubner i sex pheromone moth emergence timing and parasitism
Evolution, 2003Co-Authors: Yan Thomas, Marietherese Bethenod, Laurent Pelozuelo, Brigitte Frerot, Denis BourguetAbstract:Abstract Adaptation to different environments may be a powerful source of Genetic differentiation between populations. The biological traits selected in each environment can pleiotropically induce assortative mating between individuals of these Genetically differentiated populations. This situation may facilitate sympatric speciation. Successful host shifts in phytophagous insects provide some of the best evidence for the ecological speciation that occurs, or has occurred, in sympatry. The European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), colonized maize after its introduction into Europe by humans about 500 years ago. In northern France, two sympatric host races feed on maize (Zea mays) and mugwort (Artemisia vulgaris), respectively. We investigated the factors involved in the Genetic Isolation of these two races at a field site near Paris, France. We identified two biological differences that might make a significant contribution to the Genetic divergence between sympatric populations fe...
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Genetic Isolation between two sympatric host plant races of the european corn borer ostrinia nubilalis hubner i sex pheromone moth emergence timing and parasitism
Evolution, 2003Co-Authors: Yan Thomas, Marietherese Bethenod, Laurent Pelozuelo, Brigitte Frerot, Denis BourguetAbstract:Abstract Adaptation to different environments may be a powerful source of Genetic differentiation between populations. The biological traits selected in each environment can pleiotropically induce assortative mating between individuals of these Genetically differentiated populations. This situation may facilitate sympatric speciation. Successful host shifts in phytophagous insects provide some of the best evidence for the ecological speciation that occurs, or has occurred, in sympatry. The European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), colonized maize after its introduction into Europe by humans about 500 years ago. In northern France, two sympatric host races feed on maize (Zea mays) and mugwort (Artemisia vulgaris), respectively. We investigated the factors involved in the Genetic Isolation of these two races at a field site near Paris, France. We identified two biological differences that might make a significant contribution to the Genetic divergence between sympatric populations fe...
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Genetic Isolation between two sympatric host-plant races of the European corn borer, Ostrinia nubilalis Hubner. I. Sex pheromone, moth emergence timing, and parasitism
Evolution - International Journal of Organic Evolution, 2003Co-Authors: Yan Thomas, Marietherese Bethenod, Laurent Pelozuelo, Brigitte Frerot, Denis BourguetAbstract:Adaptation to different environments may be a powerful source of Genetic differentiation between populations. The biological traits selected in each environment can pleiotropically induce assortative mating between individuals of these Genetically differentiated populations. This situation may facilitate sympatric speciation. Successful host shifts in phytophagous insects provide some of the best evidence for the ecological speciation that occurs, or has occurred, in sympatry. The European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), colonized maize after its introduction into Europe by humans about 500 years ago. In northern France, two sympatric host races feed on maize (Zea mays) and mugwort (Artemisia vulgaris), respectively. We investigated the factors involved in the Genetic Isolation of these two races at a field site near Paris, France. We identified two biological differences that might make a significant contribution to the Genetic divergence between sympatric populations feeding on the two host plants. First, assortative mating may be due to differences in the moth emergence pattern between the two races: mugwort-race moths emerged on average 10 days earlier than maize-race moths. In addition, the males emerged earlier than females in both races. Hence, the likelihood of mating between maize-race males and mugwort-race females was higher than that of mating between mugwort-race males and maize-race females. Second, the females feeding on mugwort and maize produced sex pheromones with different E/Z isomeric ratios of ⌬-11-tetradecenyl acetate. This difference in mate recognition systems reinforces the potential for assortative mating in the two races. During the experiment, overwintering mortality was much lower on maize than on mugwort. This difference was due to a braconid parasitoid wasp, Macrocentrus cingulum, that killed more than 50% of the larvae overwintering on mugwort but did not infest larvae diapausing on maize. Hence, by colonizing maize, European corn borer populations probably escaped from numerous predators, competitors, and parasitoids, such as M. cingulum. This decrease in host-associated selection may have favored the colonization of this new host. Finally, throughout this experiment we observed selection at two allozyme loci (or at linked loci): Tpi and Mpi. The Tpi locus is tightly linked with the genes involved in the response of the male to the sex pheromone and in developmental timing. The location of these traits on the Z chromosome may play a role in shortening the time required for the evolution of premating barriers.
Laurent Pelozuelo - One of the best experts on this subject based on the ideXlab platform.
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Genetic Isolation between two sympatric host plant races of the European corn borer, Ostrinia nubilalis Hubner. II: assortative mating and host-plant preferences for oviposition
Heredity, 2005Co-Authors: Marietherese Bethenod, Yan Thomas, Laurent Pelozuelo, Brigitte Frerot, Francois Rousset, G. Genestier, Denis BourguetAbstract:The European corn borer, Ostrinia nubilalis Hubner, colonized maize ( Zea mays L.) after its introduction into Europe about 500 years ago and is now considered one of the main pests of this crop. In northern France, two sympatric host races have been described: one feeding on maize and the other on mugwort ( Artemisia vulgaris L.) and hop ( Humulus lupulus L.). In a previous study, we showed that mating between the two races may be impeded by differences in the timing of moth emergence and in the composition of the sex pheromone produced by the females. In this study, we further investigated the Genetic Isolation of these two races using strains from the maize (Z strain) and mugwort ( E strain) races selected for diagnostic alleles at two allozyme loci. In a cage containing maize and mugwort plants and located in natural conditions, mating between individuals of the same strain occurred more often than mating between males and females of the E and Z strains. In particular, we obtained no evidence for crosses between Z females and E males. We also found that females of the Z strain laid their eggs almost exclusively on maize, whereas females of the E strain laid their eggs preferentially, but not exclusively, on mugwort. These results suggest that the Genetic differentiation between the two host races may also be favored by host-plant preference, one of the first steps toward sympatric speciation.
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Genetic Isolation between two sympatric host plant races of the european corn borer ostrinia nubilalis hubner i sex pheromone moth emergence timing and parasitism
Evolution, 2003Co-Authors: Yan Thomas, Marietherese Bethenod, Laurent Pelozuelo, Brigitte Frerot, Denis BourguetAbstract:Abstract Adaptation to different environments may be a powerful source of Genetic differentiation between populations. The biological traits selected in each environment can pleiotropically induce assortative mating between individuals of these Genetically differentiated populations. This situation may facilitate sympatric speciation. Successful host shifts in phytophagous insects provide some of the best evidence for the ecological speciation that occurs, or has occurred, in sympatry. The European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), colonized maize after its introduction into Europe by humans about 500 years ago. In northern France, two sympatric host races feed on maize (Zea mays) and mugwort (Artemisia vulgaris), respectively. We investigated the factors involved in the Genetic Isolation of these two races at a field site near Paris, France. We identified two biological differences that might make a significant contribution to the Genetic divergence between sympatric populations fe...
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Genetic Isolation between two sympatric host plant races of the european corn borer ostrinia nubilalis hubner i sex pheromone moth emergence timing and parasitism
Evolution, 2003Co-Authors: Yan Thomas, Marietherese Bethenod, Laurent Pelozuelo, Brigitte Frerot, Denis BourguetAbstract:Abstract Adaptation to different environments may be a powerful source of Genetic differentiation between populations. The biological traits selected in each environment can pleiotropically induce assortative mating between individuals of these Genetically differentiated populations. This situation may facilitate sympatric speciation. Successful host shifts in phytophagous insects provide some of the best evidence for the ecological speciation that occurs, or has occurred, in sympatry. The European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), colonized maize after its introduction into Europe by humans about 500 years ago. In northern France, two sympatric host races feed on maize (Zea mays) and mugwort (Artemisia vulgaris), respectively. We investigated the factors involved in the Genetic Isolation of these two races at a field site near Paris, France. We identified two biological differences that might make a significant contribution to the Genetic divergence between sympatric populations fe...
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Genetic Isolation between two sympatric host-plant races of the European corn borer, Ostrinia nubilalis Hubner. I. Sex pheromone, moth emergence timing, and parasitism
Evolution - International Journal of Organic Evolution, 2003Co-Authors: Yan Thomas, Marietherese Bethenod, Laurent Pelozuelo, Brigitte Frerot, Denis BourguetAbstract:Adaptation to different environments may be a powerful source of Genetic differentiation between populations. The biological traits selected in each environment can pleiotropically induce assortative mating between individuals of these Genetically differentiated populations. This situation may facilitate sympatric speciation. Successful host shifts in phytophagous insects provide some of the best evidence for the ecological speciation that occurs, or has occurred, in sympatry. The European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), colonized maize after its introduction into Europe by humans about 500 years ago. In northern France, two sympatric host races feed on maize (Zea mays) and mugwort (Artemisia vulgaris), respectively. We investigated the factors involved in the Genetic Isolation of these two races at a field site near Paris, France. We identified two biological differences that might make a significant contribution to the Genetic divergence between sympatric populations feeding on the two host plants. First, assortative mating may be due to differences in the moth emergence pattern between the two races: mugwort-race moths emerged on average 10 days earlier than maize-race moths. In addition, the males emerged earlier than females in both races. Hence, the likelihood of mating between maize-race males and mugwort-race females was higher than that of mating between mugwort-race males and maize-race females. Second, the females feeding on mugwort and maize produced sex pheromones with different E/Z isomeric ratios of ⌬-11-tetradecenyl acetate. This difference in mate recognition systems reinforces the potential for assortative mating in the two races. During the experiment, overwintering mortality was much lower on maize than on mugwort. This difference was due to a braconid parasitoid wasp, Macrocentrus cingulum, that killed more than 50% of the larvae overwintering on mugwort but did not infest larvae diapausing on maize. Hence, by colonizing maize, European corn borer populations probably escaped from numerous predators, competitors, and parasitoids, such as M. cingulum. This decrease in host-associated selection may have favored the colonization of this new host. Finally, throughout this experiment we observed selection at two allozyme loci (or at linked loci): Tpi and Mpi. The Tpi locus is tightly linked with the genes involved in the response of the male to the sex pheromone and in developmental timing. The location of these traits on the Z chromosome may play a role in shortening the time required for the evolution of premating barriers.
Brigitte Frerot - One of the best experts on this subject based on the ideXlab platform.
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Genetic Isolation between two sympatric host plant races of the European corn borer, Ostrinia nubilalis Hubner. II: assortative mating and host-plant preferences for oviposition
Heredity, 2005Co-Authors: Marietherese Bethenod, Yan Thomas, Laurent Pelozuelo, Brigitte Frerot, Francois Rousset, G. Genestier, Denis BourguetAbstract:The European corn borer, Ostrinia nubilalis Hubner, colonized maize ( Zea mays L.) after its introduction into Europe about 500 years ago and is now considered one of the main pests of this crop. In northern France, two sympatric host races have been described: one feeding on maize and the other on mugwort ( Artemisia vulgaris L.) and hop ( Humulus lupulus L.). In a previous study, we showed that mating between the two races may be impeded by differences in the timing of moth emergence and in the composition of the sex pheromone produced by the females. In this study, we further investigated the Genetic Isolation of these two races using strains from the maize (Z strain) and mugwort ( E strain) races selected for diagnostic alleles at two allozyme loci. In a cage containing maize and mugwort plants and located in natural conditions, mating between individuals of the same strain occurred more often than mating between males and females of the E and Z strains. In particular, we obtained no evidence for crosses between Z females and E males. We also found that females of the Z strain laid their eggs almost exclusively on maize, whereas females of the E strain laid their eggs preferentially, but not exclusively, on mugwort. These results suggest that the Genetic differentiation between the two host races may also be favored by host-plant preference, one of the first steps toward sympatric speciation.
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Genetic Isolation between two sympatric host plant races of the european corn borer ostrinia nubilalis hubner i sex pheromone moth emergence timing and parasitism
Evolution, 2003Co-Authors: Yan Thomas, Marietherese Bethenod, Laurent Pelozuelo, Brigitte Frerot, Denis BourguetAbstract:Abstract Adaptation to different environments may be a powerful source of Genetic differentiation between populations. The biological traits selected in each environment can pleiotropically induce assortative mating between individuals of these Genetically differentiated populations. This situation may facilitate sympatric speciation. Successful host shifts in phytophagous insects provide some of the best evidence for the ecological speciation that occurs, or has occurred, in sympatry. The European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), colonized maize after its introduction into Europe by humans about 500 years ago. In northern France, two sympatric host races feed on maize (Zea mays) and mugwort (Artemisia vulgaris), respectively. We investigated the factors involved in the Genetic Isolation of these two races at a field site near Paris, France. We identified two biological differences that might make a significant contribution to the Genetic divergence between sympatric populations fe...
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Genetic Isolation between two sympatric host plant races of the european corn borer ostrinia nubilalis hubner i sex pheromone moth emergence timing and parasitism
Evolution, 2003Co-Authors: Yan Thomas, Marietherese Bethenod, Laurent Pelozuelo, Brigitte Frerot, Denis BourguetAbstract:Abstract Adaptation to different environments may be a powerful source of Genetic differentiation between populations. The biological traits selected in each environment can pleiotropically induce assortative mating between individuals of these Genetically differentiated populations. This situation may facilitate sympatric speciation. Successful host shifts in phytophagous insects provide some of the best evidence for the ecological speciation that occurs, or has occurred, in sympatry. The European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), colonized maize after its introduction into Europe by humans about 500 years ago. In northern France, two sympatric host races feed on maize (Zea mays) and mugwort (Artemisia vulgaris), respectively. We investigated the factors involved in the Genetic Isolation of these two races at a field site near Paris, France. We identified two biological differences that might make a significant contribution to the Genetic divergence between sympatric populations fe...
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Genetic Isolation between two sympatric host-plant races of the European corn borer, Ostrinia nubilalis Hubner. I. Sex pheromone, moth emergence timing, and parasitism
Evolution - International Journal of Organic Evolution, 2003Co-Authors: Yan Thomas, Marietherese Bethenod, Laurent Pelozuelo, Brigitte Frerot, Denis BourguetAbstract:Adaptation to different environments may be a powerful source of Genetic differentiation between populations. The biological traits selected in each environment can pleiotropically induce assortative mating between individuals of these Genetically differentiated populations. This situation may facilitate sympatric speciation. Successful host shifts in phytophagous insects provide some of the best evidence for the ecological speciation that occurs, or has occurred, in sympatry. The European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), colonized maize after its introduction into Europe by humans about 500 years ago. In northern France, two sympatric host races feed on maize (Zea mays) and mugwort (Artemisia vulgaris), respectively. We investigated the factors involved in the Genetic Isolation of these two races at a field site near Paris, France. We identified two biological differences that might make a significant contribution to the Genetic divergence between sympatric populations feeding on the two host plants. First, assortative mating may be due to differences in the moth emergence pattern between the two races: mugwort-race moths emerged on average 10 days earlier than maize-race moths. In addition, the males emerged earlier than females in both races. Hence, the likelihood of mating between maize-race males and mugwort-race females was higher than that of mating between mugwort-race males and maize-race females. Second, the females feeding on mugwort and maize produced sex pheromones with different E/Z isomeric ratios of ⌬-11-tetradecenyl acetate. This difference in mate recognition systems reinforces the potential for assortative mating in the two races. During the experiment, overwintering mortality was much lower on maize than on mugwort. This difference was due to a braconid parasitoid wasp, Macrocentrus cingulum, that killed more than 50% of the larvae overwintering on mugwort but did not infest larvae diapausing on maize. Hence, by colonizing maize, European corn borer populations probably escaped from numerous predators, competitors, and parasitoids, such as M. cingulum. This decrease in host-associated selection may have favored the colonization of this new host. Finally, throughout this experiment we observed selection at two allozyme loci (or at linked loci): Tpi and Mpi. The Tpi locus is tightly linked with the genes involved in the response of the male to the sex pheromone and in developmental timing. The location of these traits on the Z chromosome may play a role in shortening the time required for the evolution of premating barriers.