The Experts below are selected from a list of 201 Experts worldwide ranked by ideXlab platform
R. L. Meagher - One of the best experts on this subject based on the ideXlab platform.
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genetic characterization of Fall Armyworm infesting south africa and india indicate recent introduction from a common source population
PLOS ONE, 2019Co-Authors: R. N. Nagoshi, Isabel Dhanani, R Asokan, H M Mahadevaswamy, Chicknayakanahalli M Kalleshwaraswamy, R. L. MeagherAbstract:The invasion of the Western Hemisphere native Fall Armyworm (Spodoptera frugiperda; J. E. Smith) (Lepidoptera: Noctuidae) into the Eastern Hemisphere has been notable for the rapidity and geographical breadth of new detections. In the year following the first discovery in western sub-Saharan Africa in 2016, infestations have been documented in most sub-Saharan maize growing regions and has now expanded beyond Africa with populations recently reported in India. These observations could indicate a remarkable capacity for rapid establishment and long-distance dissemination. However, while Fall Armyworm does exhibit extended migration in North America where it annually traverses thousands of kilometers, this behavior is known to be dependent on highly favorable wind patterns and so can’t be assumed to occur in all locations. An alternative possibility is that the species has long been present in Africa, and perhaps the rest of the hemisphere, but was undetected until the enhanced monitoring that resulted after its initial discovery. Determining whether the Fall Armyworm in the Eastern Hemisphere is newly arrived or long pre-existing is important for assessing the risks of significant economic impacts, as the former indicates a change in pest composition while the latter does not. This study examined this issue by comparing collections from two geographically distant locations, South Africa and India. Sequence comparisons were used to quantify differences between the South Africa and India collections, assess the likelihood of their sharing a common source population, and their possible relationship with previously characterized Fall Armyworm from other regions of Africa. The results indicate genetic homogeneity between the South African and Indian Fall Armyworm populations tested and substantial similarities between these and collections from eastern Africa. The implications of these findings on Fall Armyworm population behavior and composition are discussed.
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intraspecific differences in plant defense induction by Fall Armyworm strains
New Phytologist, 2018Co-Authors: Flor E Acevedo, R. L. Meagher, Michelle Peiffer, Dawn S Luthe, Gary W FeltonAbstract:The underlying adaptive mechanisms by which insect strains are associated with specific plants are largely unknown. In this study, we investigated the role of herbivore-induced defenses in the host plant association of Fall Armyworm (Spodoptera frugiperda) strains. We tested the expression of herbivore-induced defense-related genes and the activity of plant-defensive proteins in maize and Bermuda grass upon feeding by Fall Armyworm strains. The rice strain caterpillars induced greater accumulation of proteinase inhibitors in maize than the corn strain caterpillars. In Bermuda grass, feeding by the corn strain suppressed induction of trypsin inhibitor activity whereas the rice strain induced greater activity levels. Differences in elicitation of these plant defenses by the two strains seems to be due to differences in the activity levels of the salivary enzyme phospholipase C. The levels of plant defense responses were negatively correlated with caterpillar growth, indicating a fitness effect. Our results indicate that specific elicitors in the saliva of Fall Armyworm stains trigger differential levels of plant defense responses that affect caterpillar growth and thus may influence host plant associations in field conditions. The composition and secretion of plant defense elicitors may have a strong influence in the host plant association of insect herbivores.
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Delimiting Strategic Zones for the Development of Fall Armyworm (Lepidoptera: Noctuidae) on Corn in the State of Florida.
Journal of Economic Entomology, 2018Co-Authors: Adriano G. Garcia, Rod N Nagoshi, Wesley Augusto Conde Godoy, J. M. G Thomas, R. L. MeagherAbstract:The Fall Armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), cannot survive prolonged periods of freezing temperatures, thereby limiting where it can overwinter in North America. Climate change is anticipated to reduce the frequency of freeze days in Florida over the decades, with the potential consequence of a significant expansion of the overwintering range, whose northern limit in North America was assessed between 27 and 28°N in the last century. To assess this possibility, the development of the Fall Armyworm on corn leaves, one of the main host plants in the United States, was determined at five constant temperatures ranging from 14 to 30°C. Based on the development time, the thermal constant and the lower threshold temperature were used to estimate the number of generations of Fall Armyworm at 42 locations in the state of Florida, from 2006 to 2016. Maps were constructed to provide a visual description of the interpolated data, using GIS (Geographic Information System). The highest number of generations was observed in the counties farther south, an area that showed the highest temperatures during the years and plays a strategic role in maintaining Fall Armyworm populations in corn fields. Additionally, we conclude that in the absence of freeze periods, the northern limit for Fall Armyworm overwintering should be between 28 and 29°N.
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parasitoids attacking Fall Armyworm lepidoptera noctuidae in sweet corn habitats
Biological Control, 2016Co-Authors: R. L. Meagher, R. N. Nagoshi, Gregg S Nuessly, Mirian M HayroeAbstract:Abstract Fall Armyworm larvae, Spodoptera frugiperda (J. E. Smith), were collected from sweet corn plants (Zea mays L.) in fields located in three south Florida counties. Fields were sampled from 2010 to 2015 during the Fall and spring seasons. Larvae were transferred to the laboratory to complete development. The objective of the study was to identify the common parasitoids emerging from larvae that are present in sweet corn habitats where insecticides are traditionally used. A total of 8353 Fall Armyworm larvae were collected, of which 60.6% (5062) developed into moths after feeding on corn tissue and artificial diet. Parasitoids emerged from 2365 larvae (28.3%), and parasitism ranged from 1% to 91.7%, depending on site. Parasitism was higher at the University of Florida Everglades Research and Education (EREC) in Belle Glade (50.4 ± 11.8%) than at other locations in south Florida. Parasitism was comparable between Fall and spring seasons, but was much higher in unsprayed fields (44.0 ± 9.6%) than in the sprayed fields (15.0 ± 2.5%). The two most common parasitoids that emerged from larvae were the solitary endoparasitoids Cotesia marginiventris (Cresson), found in 23 of the 25 sites sampled, and Chelonus insularis Cresson, found in 18 of the 25 sites sampled. Other parasitoid species that emerged from Fall Armyworm larvae were Aleiodes laphygmae (Viereck), Euplectrus platyhypenae Howard, Meteorus spp., Ophion flavidus Brulle, and unidentified species of Tachinidae. Techniques to improve the management of Fall Armyworm in overwintering areas of south Florida using conservation biological control are discussed.
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Modeling seasonal migration of Fall Armyworm moths
International Journal of Biometeorology, 2016Co-Authors: J. K. Westbrook, R. N. Nagoshi, R. L. Meagher, S. J. Fleischer, S. JairamAbstract:Fall Armyworm, Spodoptera frugiperda (J.E. Smith), is a highly mobile insect pest of a wide range of host crops. However, this pest of tropical origin cannot survive extended periods of freezing temperature but must migrate northward each spring if it is to re-infest cropping areas in temperate regions. The northward limit of the winter-breeding region for North America extends to southern regions of Texas and Florida, but infestations are regularly reported as far north as Québec and Ontario provinces in Canada by the end of summer. Recent genetic analyses have characterized migratory pathways from these winter-breeding regions, but knowledge is lacking on the atmosphere’s role in influencing the timing, distance, and direction of migratory flights. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to simulate migratory flight of Fall Armyworm moths from distinct winter-breeding source areas. Model simulations identified regions of dominant immigration from the Florida and Texas source areas and overlapping immigrant populations in the Alabama–Georgia and Pennsylvania–Mid-Atlantic regions. This simulated migratory pattern corroborates a previous migratory map based on the distribution of Fall Armyworm haplotype profiles. We found a significant regression between the simulated first week of moth immigration and first week of moth capture (for locations which captured ≥10 moths), which on average indicated that the model simulated first immigration 2 weeks before first captures in pheromone traps. The results contribute to knowledge of Fall Armyworm population ecology on a continental scale and will aid in the prediction and interpretation of inter-annual variability of insect migration patterns including those in response to climatic change and adoption rates of transgenic cultivars.
R. N. Nagoshi - One of the best experts on this subject based on the ideXlab platform.
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Genetic characterization of Fall Armyworm ( Spodoptera frugiperda ) in Ecuador and comparisons with regional populations identify likely migratory relationships
PLOS ONE, 2019Co-Authors: R. N. Nagoshi, Benjamin Y. Nagoshi, Ernesto Cañarte, Bernardo Navarrete, Ramón Solórzano, Sandra Garcés-carreraAbstract:Fall Armyworm, Spodoptera frugiperda (J. E. Smith), is an important agricultural pest native to the Americas that has recently been introduced into the Eastern Hemisphere where it has spread rapidly through most of Africa and much of Asia. The long-term economic consequences of this invasion will depend on how the species and important subpopulations become distributed upon reaching equilibrium, which is expected to be influenced by a number of factors including climate, geography, agricultural practices, and seasonal winds, among others. Much of our understanding of Fall Armyworm movements have come from mapping genetically defined subpopulations in the Western Hemisphere, particularly in North America where annual long-distance migrations of thousands of kilometers have been documented and modeled. In contrast, Fall Armyworm mapping in much of the rest of the hemisphere is relatively incomplete, with the northern portion of South America particularly lacking despite its potential importance for understanding Fall Armyworm migration patterns. Here we describe the first genetic description of Fall Armyworm infesting corn in Ecuador, which lies near a likely migration conduit based on the location of regional trade winds. The results were compared with populations from corn habitats in select locations in the Caribbean and South America to investigate the possible migratory relationship between these populations and was further assessed with respect to prevailing wind patterns and the distribution of locations with climate favorable for Fall Armyworm population establishment and growth.
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genetic characterization of Fall Armyworm infesting south africa and india indicate recent introduction from a common source population
PLOS ONE, 2019Co-Authors: R. N. Nagoshi, Isabel Dhanani, R Asokan, H M Mahadevaswamy, Chicknayakanahalli M Kalleshwaraswamy, R. L. MeagherAbstract:The invasion of the Western Hemisphere native Fall Armyworm (Spodoptera frugiperda; J. E. Smith) (Lepidoptera: Noctuidae) into the Eastern Hemisphere has been notable for the rapidity and geographical breadth of new detections. In the year following the first discovery in western sub-Saharan Africa in 2016, infestations have been documented in most sub-Saharan maize growing regions and has now expanded beyond Africa with populations recently reported in India. These observations could indicate a remarkable capacity for rapid establishment and long-distance dissemination. However, while Fall Armyworm does exhibit extended migration in North America where it annually traverses thousands of kilometers, this behavior is known to be dependent on highly favorable wind patterns and so can’t be assumed to occur in all locations. An alternative possibility is that the species has long been present in Africa, and perhaps the rest of the hemisphere, but was undetected until the enhanced monitoring that resulted after its initial discovery. Determining whether the Fall Armyworm in the Eastern Hemisphere is newly arrived or long pre-existing is important for assessing the risks of significant economic impacts, as the former indicates a change in pest composition while the latter does not. This study examined this issue by comparing collections from two geographically distant locations, South Africa and India. Sequence comparisons were used to quantify differences between the South Africa and India collections, assess the likelihood of their sharing a common source population, and their possible relationship with previously characterized Fall Armyworm from other regions of Africa. The results indicate genetic homogeneity between the South African and Indian Fall Armyworm populations tested and substantial similarities between these and collections from eastern Africa. The implications of these findings on Fall Armyworm population behavior and composition are discussed.
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parasitoids attacking Fall Armyworm lepidoptera noctuidae in sweet corn habitats
Biological Control, 2016Co-Authors: R. L. Meagher, R. N. Nagoshi, Gregg S Nuessly, Mirian M HayroeAbstract:Abstract Fall Armyworm larvae, Spodoptera frugiperda (J. E. Smith), were collected from sweet corn plants (Zea mays L.) in fields located in three south Florida counties. Fields were sampled from 2010 to 2015 during the Fall and spring seasons. Larvae were transferred to the laboratory to complete development. The objective of the study was to identify the common parasitoids emerging from larvae that are present in sweet corn habitats where insecticides are traditionally used. A total of 8353 Fall Armyworm larvae were collected, of which 60.6% (5062) developed into moths after feeding on corn tissue and artificial diet. Parasitoids emerged from 2365 larvae (28.3%), and parasitism ranged from 1% to 91.7%, depending on site. Parasitism was higher at the University of Florida Everglades Research and Education (EREC) in Belle Glade (50.4 ± 11.8%) than at other locations in south Florida. Parasitism was comparable between Fall and spring seasons, but was much higher in unsprayed fields (44.0 ± 9.6%) than in the sprayed fields (15.0 ± 2.5%). The two most common parasitoids that emerged from larvae were the solitary endoparasitoids Cotesia marginiventris (Cresson), found in 23 of the 25 sites sampled, and Chelonus insularis Cresson, found in 18 of the 25 sites sampled. Other parasitoid species that emerged from Fall Armyworm larvae were Aleiodes laphygmae (Viereck), Euplectrus platyhypenae Howard, Meteorus spp., Ophion flavidus Brulle, and unidentified species of Tachinidae. Techniques to improve the management of Fall Armyworm in overwintering areas of south Florida using conservation biological control are discussed.
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Modeling seasonal migration of Fall Armyworm moths
International Journal of Biometeorology, 2016Co-Authors: J. K. Westbrook, R. N. Nagoshi, R. L. Meagher, S. J. Fleischer, S. JairamAbstract:Fall Armyworm, Spodoptera frugiperda (J.E. Smith), is a highly mobile insect pest of a wide range of host crops. However, this pest of tropical origin cannot survive extended periods of freezing temperature but must migrate northward each spring if it is to re-infest cropping areas in temperate regions. The northward limit of the winter-breeding region for North America extends to southern regions of Texas and Florida, but infestations are regularly reported as far north as Québec and Ontario provinces in Canada by the end of summer. Recent genetic analyses have characterized migratory pathways from these winter-breeding regions, but knowledge is lacking on the atmosphere’s role in influencing the timing, distance, and direction of migratory flights. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to simulate migratory flight of Fall Armyworm moths from distinct winter-breeding source areas. Model simulations identified regions of dominant immigration from the Florida and Texas source areas and overlapping immigrant populations in the Alabama–Georgia and Pennsylvania–Mid-Atlantic regions. This simulated migratory pattern corroborates a previous migratory map based on the distribution of Fall Armyworm haplotype profiles. We found a significant regression between the simulated first week of moth immigration and first week of moth capture (for locations which captured ≥10 moths), which on average indicated that the model simulated first immigration 2 weeks before first captures in pheromone traps. The results contribute to knowledge of Fall Armyworm population ecology on a continental scale and will aid in the prediction and interpretation of inter-annual variability of insect migration patterns including those in response to climatic change and adoption rates of transgenic cultivars.
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modeling seasonal migration of Fall Armyworm moths
International Journal of Biometeorology, 2016Co-Authors: J. K. Westbrook, R. N. Nagoshi, R. L. Meagher, S. J. Fleischer, S. JairamAbstract:Fall Armyworm, Spodoptera frugiperda (J.E. Smith), is a highly mobile insect pest of a wide range of host crops. However, this pest of tropical origin cannot survive extended periods of freezing temperature but must migrate northward each spring if it is to re-infest cropping areas in temperate regions. The northward limit of the winter-breeding region for North America extends to southern regions of Texas and Florida, but infestations are regularly reported as far north as Quebec and Ontario provinces in Canada by the end of summer. Recent genetic analyses have characterized migratory pathways from these winter-breeding regions, but knowledge is lacking on the atmosphere’s role in influencing the timing, distance, and direction of migratory flights. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to simulate migratory flight of Fall Armyworm moths from distinct winter-breeding source areas. Model simulations identified regions of dominant immigration from the Florida and Texas source areas and overlapping immigrant populations in the Alabama–Georgia and Pennsylvania–Mid-Atlantic regions. This simulated migratory pattern corroborates a previous migratory map based on the distribution of Fall Armyworm haplotype profiles. We found a significant regression between the simulated first week of moth immigration and first week of moth capture (for locations which captured ≥10 moths), which on average indicated that the model simulated first immigration 2 weeks before first captures in pheromone traps. The results contribute to knowledge of Fall Armyworm population ecology on a continental scale and will aid in the prediction and interpretation of inter-annual variability of insect migration patterns including those in response to climatic change and adoption rates of transgenic cultivars.
S. Jairam - One of the best experts on this subject based on the ideXlab platform.
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Modeling seasonal migration of Fall Armyworm moths
International Journal of Biometeorology, 2016Co-Authors: J. K. Westbrook, R. N. Nagoshi, R. L. Meagher, S. J. Fleischer, S. JairamAbstract:Fall Armyworm, Spodoptera frugiperda (J.E. Smith), is a highly mobile insect pest of a wide range of host crops. However, this pest of tropical origin cannot survive extended periods of freezing temperature but must migrate northward each spring if it is to re-infest cropping areas in temperate regions. The northward limit of the winter-breeding region for North America extends to southern regions of Texas and Florida, but infestations are regularly reported as far north as Québec and Ontario provinces in Canada by the end of summer. Recent genetic analyses have characterized migratory pathways from these winter-breeding regions, but knowledge is lacking on the atmosphere’s role in influencing the timing, distance, and direction of migratory flights. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to simulate migratory flight of Fall Armyworm moths from distinct winter-breeding source areas. Model simulations identified regions of dominant immigration from the Florida and Texas source areas and overlapping immigrant populations in the Alabama–Georgia and Pennsylvania–Mid-Atlantic regions. This simulated migratory pattern corroborates a previous migratory map based on the distribution of Fall Armyworm haplotype profiles. We found a significant regression between the simulated first week of moth immigration and first week of moth capture (for locations which captured ≥10 moths), which on average indicated that the model simulated first immigration 2 weeks before first captures in pheromone traps. The results contribute to knowledge of Fall Armyworm population ecology on a continental scale and will aid in the prediction and interpretation of inter-annual variability of insect migration patterns including those in response to climatic change and adoption rates of transgenic cultivars.
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modeling seasonal migration of Fall Armyworm moths
International Journal of Biometeorology, 2016Co-Authors: J. K. Westbrook, R. N. Nagoshi, R. L. Meagher, S. J. Fleischer, S. JairamAbstract:Fall Armyworm, Spodoptera frugiperda (J.E. Smith), is a highly mobile insect pest of a wide range of host crops. However, this pest of tropical origin cannot survive extended periods of freezing temperature but must migrate northward each spring if it is to re-infest cropping areas in temperate regions. The northward limit of the winter-breeding region for North America extends to southern regions of Texas and Florida, but infestations are regularly reported as far north as Quebec and Ontario provinces in Canada by the end of summer. Recent genetic analyses have characterized migratory pathways from these winter-breeding regions, but knowledge is lacking on the atmosphere’s role in influencing the timing, distance, and direction of migratory flights. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to simulate migratory flight of Fall Armyworm moths from distinct winter-breeding source areas. Model simulations identified regions of dominant immigration from the Florida and Texas source areas and overlapping immigrant populations in the Alabama–Georgia and Pennsylvania–Mid-Atlantic regions. This simulated migratory pattern corroborates a previous migratory map based on the distribution of Fall Armyworm haplotype profiles. We found a significant regression between the simulated first week of moth immigration and first week of moth capture (for locations which captured ≥10 moths), which on average indicated that the model simulated first immigration 2 weeks before first captures in pheromone traps. The results contribute to knowledge of Fall Armyworm population ecology on a continental scale and will aid in the prediction and interpretation of inter-annual variability of insect migration patterns including those in response to climatic change and adoption rates of transgenic cultivars.
J. K. Westbrook - One of the best experts on this subject based on the ideXlab platform.
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Modeling seasonal migration of Fall Armyworm moths
International Journal of Biometeorology, 2016Co-Authors: J. K. Westbrook, R. N. Nagoshi, R. L. Meagher, S. J. Fleischer, S. JairamAbstract:Fall Armyworm, Spodoptera frugiperda (J.E. Smith), is a highly mobile insect pest of a wide range of host crops. However, this pest of tropical origin cannot survive extended periods of freezing temperature but must migrate northward each spring if it is to re-infest cropping areas in temperate regions. The northward limit of the winter-breeding region for North America extends to southern regions of Texas and Florida, but infestations are regularly reported as far north as Québec and Ontario provinces in Canada by the end of summer. Recent genetic analyses have characterized migratory pathways from these winter-breeding regions, but knowledge is lacking on the atmosphere’s role in influencing the timing, distance, and direction of migratory flights. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to simulate migratory flight of Fall Armyworm moths from distinct winter-breeding source areas. Model simulations identified regions of dominant immigration from the Florida and Texas source areas and overlapping immigrant populations in the Alabama–Georgia and Pennsylvania–Mid-Atlantic regions. This simulated migratory pattern corroborates a previous migratory map based on the distribution of Fall Armyworm haplotype profiles. We found a significant regression between the simulated first week of moth immigration and first week of moth capture (for locations which captured ≥10 moths), which on average indicated that the model simulated first immigration 2 weeks before first captures in pheromone traps. The results contribute to knowledge of Fall Armyworm population ecology on a continental scale and will aid in the prediction and interpretation of inter-annual variability of insect migration patterns including those in response to climatic change and adoption rates of transgenic cultivars.
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modeling seasonal migration of Fall Armyworm moths
International Journal of Biometeorology, 2016Co-Authors: J. K. Westbrook, R. N. Nagoshi, R. L. Meagher, S. J. Fleischer, S. JairamAbstract:Fall Armyworm, Spodoptera frugiperda (J.E. Smith), is a highly mobile insect pest of a wide range of host crops. However, this pest of tropical origin cannot survive extended periods of freezing temperature but must migrate northward each spring if it is to re-infest cropping areas in temperate regions. The northward limit of the winter-breeding region for North America extends to southern regions of Texas and Florida, but infestations are regularly reported as far north as Quebec and Ontario provinces in Canada by the end of summer. Recent genetic analyses have characterized migratory pathways from these winter-breeding regions, but knowledge is lacking on the atmosphere’s role in influencing the timing, distance, and direction of migratory flights. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to simulate migratory flight of Fall Armyworm moths from distinct winter-breeding source areas. Model simulations identified regions of dominant immigration from the Florida and Texas source areas and overlapping immigrant populations in the Alabama–Georgia and Pennsylvania–Mid-Atlantic regions. This simulated migratory pattern corroborates a previous migratory map based on the distribution of Fall Armyworm haplotype profiles. We found a significant regression between the simulated first week of moth immigration and first week of moth capture (for locations which captured ≥10 moths), which on average indicated that the model simulated first immigration 2 weeks before first captures in pheromone traps. The results contribute to knowledge of Fall Armyworm population ecology on a continental scale and will aid in the prediction and interpretation of inter-annual variability of insect migration patterns including those in response to climatic change and adoption rates of transgenic cultivars.
S. J. Fleischer - One of the best experts on this subject based on the ideXlab platform.
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Modeling seasonal migration of Fall Armyworm moths
International Journal of Biometeorology, 2016Co-Authors: J. K. Westbrook, R. N. Nagoshi, R. L. Meagher, S. J. Fleischer, S. JairamAbstract:Fall Armyworm, Spodoptera frugiperda (J.E. Smith), is a highly mobile insect pest of a wide range of host crops. However, this pest of tropical origin cannot survive extended periods of freezing temperature but must migrate northward each spring if it is to re-infest cropping areas in temperate regions. The northward limit of the winter-breeding region for North America extends to southern regions of Texas and Florida, but infestations are regularly reported as far north as Québec and Ontario provinces in Canada by the end of summer. Recent genetic analyses have characterized migratory pathways from these winter-breeding regions, but knowledge is lacking on the atmosphere’s role in influencing the timing, distance, and direction of migratory flights. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to simulate migratory flight of Fall Armyworm moths from distinct winter-breeding source areas. Model simulations identified regions of dominant immigration from the Florida and Texas source areas and overlapping immigrant populations in the Alabama–Georgia and Pennsylvania–Mid-Atlantic regions. This simulated migratory pattern corroborates a previous migratory map based on the distribution of Fall Armyworm haplotype profiles. We found a significant regression between the simulated first week of moth immigration and first week of moth capture (for locations which captured ≥10 moths), which on average indicated that the model simulated first immigration 2 weeks before first captures in pheromone traps. The results contribute to knowledge of Fall Armyworm population ecology on a continental scale and will aid in the prediction and interpretation of inter-annual variability of insect migration patterns including those in response to climatic change and adoption rates of transgenic cultivars.
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modeling seasonal migration of Fall Armyworm moths
International Journal of Biometeorology, 2016Co-Authors: J. K. Westbrook, R. N. Nagoshi, R. L. Meagher, S. J. Fleischer, S. JairamAbstract:Fall Armyworm, Spodoptera frugiperda (J.E. Smith), is a highly mobile insect pest of a wide range of host crops. However, this pest of tropical origin cannot survive extended periods of freezing temperature but must migrate northward each spring if it is to re-infest cropping areas in temperate regions. The northward limit of the winter-breeding region for North America extends to southern regions of Texas and Florida, but infestations are regularly reported as far north as Quebec and Ontario provinces in Canada by the end of summer. Recent genetic analyses have characterized migratory pathways from these winter-breeding regions, but knowledge is lacking on the atmosphere’s role in influencing the timing, distance, and direction of migratory flights. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to simulate migratory flight of Fall Armyworm moths from distinct winter-breeding source areas. Model simulations identified regions of dominant immigration from the Florida and Texas source areas and overlapping immigrant populations in the Alabama–Georgia and Pennsylvania–Mid-Atlantic regions. This simulated migratory pattern corroborates a previous migratory map based on the distribution of Fall Armyworm haplotype profiles. We found a significant regression between the simulated first week of moth immigration and first week of moth capture (for locations which captured ≥10 moths), which on average indicated that the model simulated first immigration 2 weeks before first captures in pheromone traps. The results contribute to knowledge of Fall Armyworm population ecology on a continental scale and will aid in the prediction and interpretation of inter-annual variability of insect migration patterns including those in response to climatic change and adoption rates of transgenic cultivars.
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texas is the overwintering source of Fall Armyworm in central pennsylvania implications for migration into the northeastern united states
Environmental Entomology, 2009Co-Authors: R. N. Nagoshi, S. J. Fleischer, R. L. MeagherAbstract:Fall Armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), infestations in most of North America arise from annual migrations of populations that overwinter in southern Texas and Florida. Cytochrome oxidase I haplotype profiles within the Fall Armyworm corn strain, the subgroup that preferentially infests corn (Zea mays L.), can differentiate the Texas and Florida populations. We use this molecular metric to show that Fall Armyworms in central Pennsylvania originate from Texas, indicating the existence of a migratory pathway from Texas to the northeastern United States. These results were compared with historical trapping data for Fall Armyworm and another migratory noctuid, corn earworm Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), in the Pennsylvania and Maryland corn-producing areas to better define lepidopteran migratory pathways.