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George E Heimpel - One of the best experts on this subject based on the ideXlab platform.
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a field based assessment of the parasitoid aphelinus certus as a biological control agent of Soybean Aphid in north america
Biological Control, 2020Co-Authors: James Rudolph Miksanek, George E HeimpelAbstract:Abstract Damaging outbreaks of Soybean Aphid continue to occur in North America despite the valuable biological control services provided by resident natural enemies. The adventive parasitoid Aphelinus certus Yasnosh (Hymenoptera: Aphelinidae) has recently established in North America and has been hypothesized to be a key component of the resident natural enemy community, but there have been few studies evaluating the efficacy of this parasitoid in suppressing Soybean Aphid populations. We used an exclusion cage study to quantify the effect of A. certus on Soybean Aphid population growth at four sites spanning western and east-central Minnesota from 2017–2019. There were minimal differences in Soybean Aphid population growth between experimental treatments that excluded natural enemies and control treatments, suggesting that parasitism of Soybean Aphid by A. certus did not have a strong impact on Soybean Aphid population growth during this study. Because, for example, A. certus larvae can reduce host reproduction prior to mortality (resulting in underestimates of effects in short-term studies), our results reflect the challenges of using exclusion cages to assess the effect of individual natural enemy species, especially those with complex life cycles.
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impact of the parasitoid aphelinus certus on Soybean Aphid populations
Biological Control, 2018Co-Authors: Joe M Kaser, George E HeimpelAbstract:Abstract Aphelinus certus Yasnosh (Hymenoptera: Aphelinidae) is an accidentally introduced parasitoid of the Soybean Aphid, Aphis glycines Matsumura (Hemiptera: Aphididae) in North America and it has become one of the most common natural enemies of Soybean Aphids in its adventive range. It is unclear, however, if increased prevalence of A. certus has resulted in increased biological control. We conducted an exclusion-cage experiment designed to isolate the impact of parasitoids from that of other resident natural enemies (mainly predators) of the Soybean Aphid. We found that A. certus greatly outnumbered all other Soybean Aphid parasitoids, and that it significantly reduced Soybean Aphid populations over a time span of less than two weeks compared to controls. Moreover, parasitoids alone resulted in Aphid densities that were statistically equivalent to the combined effect of predators and parasitoids. Across all treatment cages, there was a significant negative association between parasitism rate and Aphid population growth, with predicted zero Aphid growth occurring at a parasitism rate of 42.2%.
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combined effects of host plant resistance and intraguild predation on the Soybean Aphid parasitoid binodoxys communis in the field
Biological Control, 2012Co-Authors: Jeremy M Chacon, Mark K Asplen, George E HeimpelAbstract:Soybean varieties that exhibit resistance to the Soybean Aphid Aphis glycines have been developed for use in North America. In principle, host-plant resistance to Soybean Aphid can influence the interactions between the Soybean Aphid and its natural enemies. Resistance could change the quality of Soybean Aphids as a food source, the availability of Soybean Aphids, or resistance traits could directly affect Aphid predators and parasitoids. Here, we focus on the effect of Soybean Aphid resistance on the interactions between Soybean Aphids, the parasitoid Binodoxys communis (Hymenoptera: Braconidae), and predators of these two species. We determined whether host-plant resistance affected within-season persistence of B. communis by releasing parasitoids into resistant and susceptible Soybean plots. We observed higher B. communis densities in susceptible Soybean plots than in resistant plots. There were also higher overall levels of intraguild predation of B. communis in susceptible plots, although the per-capita risk of intraguild predation of B. communis was affected neither by plant genotype nor by Aphid density. We discuss these effects and whether they were caused by direct effects of the resistant plants on B. communis or indirect effects through Soybean Aphid or predators.
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ecology and management of the Soybean Aphid in north america
Annual Review of Entomology, 2011Co-Authors: David W Ragsdale, Douglas A Landis, George E Heimpel, Jacques Brodeur, Nicolas DesneuxAbstract:The Soybean Aphid, Aphis glycines Matsumura, has become the single most important arthropod pest of Soybeans in North America. Native to Asia, this invasive species was first discovered in North America in July 2000 and has rapidly spread throughout the northcentral United States, much of southeastern Canada, and the northeastern United States. In response, important elements of the ecology of the Soybean Aphid in North America have been elucidated, with economic thresholds, sampling plans, and chemical control recommendations widely adopted. Aphid-resistant Soybean varieties were available to growers in 2010. The preexisting community of Aphid natural enemies has been highly effective in suppressing Aphid populations in many situations, and classical biological control efforts have focused on the addition of parasitoids of Asian origin. The keys to sustainable management of this pest include understanding linkages between the Soybean Aphid and other introduced and native species in a landscape context al...
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european buckthorn and asian Soybean Aphid as components of an extensive invasional meltdown in north america
Biological Invasions, 2010Co-Authors: George E Heimpel, Douglas A Landis, Keith R Hopper, Mark K Asplen, Lee E Frelich, Kim A Hoelmer, Zeynep Sezen, Kongming WuAbstract:We consider the possibility of an extensive invasional meltdown occurring in central North America involving eleven Eurasian species. The scenario begins with the potential co-facilitation between the European earthworm Lumbricus terrestris and European buckthorn, Rhamnus cathartica. Once introduced, European buckthorn has served as the overwintering host for two important invasive crop pests, oat crown rust, Puccinea coronata and the Soybean Aphid, Aphis glycines. The spread of R. cathartica itself may have been aided by seed dispersal by the European starling, Sturnus vulgaris, and the presence of L. terrestris has likely facilitated the invasion of Bipalium adventitium, an Asian predatory flatworm that specializes on earthworms. Beyond this, the Soybean Aphid is consumed by a number of introduced species, including the lady beetle Harmonia axyridis, the ground beetle Agonum muelleri and the parasitoid Aphelinus certus. We hypothesize that the presence of Soybean Aphid increases regional abundances of these species. We discuss both the evidence for this multi-species invasional meltdown scenario and potential implications of meltdown dynamics for invasive species management. The particular management issues that we discuss are: (1) opportunities for managing multiple invasive species simultaneously by targeting facilitator species, and (2) implications of meltdown dynamics for biological control introductions against the Soybean Aphid.
Glen L Hartman - One of the best experts on this subject based on the ideXlab platform.
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Characterization and genetics of multiple Soybean Aphid biotype resistance in five Soybean plant introductions
Theoretical and Applied Genetics, 2017Co-Authors: Curtis B Hill, Derek Shiao, Glen L HartmanAbstract:Key message Five Soybean plant introductions expressed antibiosis resistance to multiple Soybean Aphid biotypes. Two introductions had resistance genes located in the Rag1, Rag2 , and Rag3 regions; one introduction had resistance genes located in the Rag1, Rag2 , and rag4 regions; one introduction had resistance genes located in the Rag1 and Rag2 regions; and one introduction had a resistance gene located in the Rag2 region. Abstract Soybean Aphid ( Aphis glycines Matsumura) is the most important Soybean [ Glycine max (L.) Merr.] insect pest in the USA. The objectives of this study were to characterize the resistance expressed in five plant introductions (PIs) to four Soybean Aphid biotypes, determine the mode of resistance inheritance, and identify markers associated with genes controlling resistance in these accessions. Five Soybean PIs, from an initial set of 3000 PIs, were tested for resistance against Soybean Aphid biotypes 1, 2, 3, and 4 in choice and no-choice tests. Of these five PIs, PI 587663, PI 587677, and PI 587685 expressed antibiosis against all four biotypes, while PI 587972 and PI 594592 expressed antibiosis against biotypes 1, 2, and 3. F_2 populations derived from PI 587663 and PI 587972 were evaluated for resistance against Soybean Aphid biotype 1, and populations derived from PIs 587677, 587685, and 594592 were tested against biotype 3. In addition, F_2:3 plants were tested against biotypes 2 and 3. Genomic DNA from F_2 plants was screened with markers linked to Rag1, Rag2, Rag3 , and rag4 Soybean Aphid-resistance genes. Results showed that PI 587663 and PI 594592 each had three genes with variable gene action located in the Rag1, Rag2 , and Rag3 regions. PI 587677 had three genes with variable gene action located in the Rag1, Rag2 and rag4 regions. PI 587685 had one dominant gene located in the Rag1 region and an additive gene in the Rag2 region. PI 587972 had one dominant gene located in the Rag2 region controlling antixenosis- or antibiosis-type resistance to Soybean Aphid biotypes 1, 2, or 3. PIs 587663, 587677, and 587685 also showed antibiosis-type resistance against biotype 4. Information on multi-biotype Aphid resistance and resistance gene markers will be useful for improving Soybean Aphid resistance in commercial Soybean cultivars.
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Soybean Aphid intrabiotype variability based on colonization of specific Soybean genotypes
Insect Science, 2014Co-Authors: Michelle L. Pawlowski, Curtis B Hill, David J Voegtlin, Glen L HartmanAbstract:The Soybean Aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is one of the most destructive insect pests on Soybeans in the United States. One method for managing this pest is through host plant resistance. Since its arrival in 2000, 4 Aphid biotypes have been identified that are able to overcome Soybean Aphid resistance (Rag) genes. A Soybean Aphid isolate collected from Moline, Illinois readily colonized Soybean plants with the Soybean Aphid resistance gene Rag2, unlike biotypes 1 and 2, but similar to Soybean Aphid biotype 3. Two no-choice experiments compared the virulence of the Moline isolate with biotype 3. In both experiments, differences in Aphid population counts were not significant (P > 0.05) on Soybean genotypes LD08–12957a (Rag2) and LD11–5413a (Rag2), but the Aphid counts for the Moline isolate were significantly (P
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inheritance of Soybean Aphid resistance in 21 Soybean plant introductions
Theoretical and Applied Genetics, 2014Co-Authors: Perry B. Cregan, Curtis B Hill, Glen L Hartman, Brian W. DiersAbstract:Key Message The Rag2 region was frequently identified among 21 F 2 populations evaluated for Soybean Aphid resistance, and dominant gene action and single-gene resistance were also commonly identified.
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Inheritance of Soybean Aphid resistance in 21 Soybean plant introductions
Theoretical and Applied Genetics, 2014Co-Authors: Perry B. Cregan, Curtis B Hill, Glen L Hartman, Brian W. DiersAbstract:Key Message The Rag2 region was frequently identified among 21 F _ 2 populations evaluated for Soybean Aphid resistance, and dominant gene action and single-gene resistance were also commonly identified. Abstract The Soybean Aphid [ Aphis glycines Matsumura (Hemiptera: Aphididae)] is one of the most important insect pests of Soybean [ Glycine max (L.) Merr] in the northern USA and southern Canada, and four resistance loci ( Rag1 – rag4 ) have been discovered since the pest was identified in the USA in 2000. The objective of this research was to determine whether resistance expression in recently identified Soybean Aphid-resistant plant introductions (PIs) was associated with the four Rag loci using a collection of 21 F_2 populations. The F_2 populations were phenotyped with Soybean Aphid biotype 1, which is avirulent on plants having any of the currently identified Rag genes, using choice tests in the greenhouse and were tested with genetic markers linked to the four Rag loci. The phenotyping results indicate that Soybean Aphid resistance is controlled by a single dominant gene in 14 PIs, by two genes in three PIs, and four PIs had no clear Mendelian inheritance patterns. Genetic markers flanking Rag2 were significantly associated with Aphid resistance in 20 PIs, the Rag1 region was significantly identified in five PIs, and the Rag3 region was identified in one PI. These results show that single dominant gene action at the Rag2 region may be a major source for Aphid resistance in the USDA Soybean germplasm collection.
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a new Soybean Aphid hemiptera Aphididae biotype identified
Journal of Economic Entomology, 2010Co-Authors: Curtis B Hill, Laura Crull, Theresa K Herman, David J Voegtlin, Glen L HartmanAbstract:Shortly after its arrival, the Soybean Aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), became established as the most important insect pest of Soybean, Glycine max L. (Merr.), in the northern part of the North American Soybean production region. Soybean resistance is an environmentally sustainable method to manage the pest and new Soybean Aphid resistant cultivars are beginning to be deployed into production. However, an earlier study identifying a Soybean Aphid biotype that could colonize plants with the Rag1 resistance gene has raised concerns about the durability of Soybean Aphid resistance genes. Choice and nonchoice tests conducted in this study characterized the colonization of a Soybean Aphid isolate, collected from the overwintering host Frangula alnus P. Mill in Springfield Fen, IN, on different Aphid resistant Soybean genotypes. This isolate readily colonized plants with the Rag2 resistance gene, distinguishing it from the two biotypes previously characterized and indicating that it represented a new biotype named biotype 3. The identification of Soybean Aphid biotypes that can overcome Rag1 and Rag2 resistance, even before Soybean cultivars with the resistance genes have been deployed in production, suggests that there is high variability in virulence within Soybean Aphid populations present in North America. Such variability in virulence gives the pest a high potential to adapt to and reduce the effective life of resistance genes deployed in production. The search for new Soybean Aphid resistance genes must, therefore, continue, along with the development of alternative sustainable strategies to manage the pest.
Douglas A Landis - One of the best experts on this subject based on the ideXlab platform.
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ecology and management of the Soybean Aphid in north america
Annual Review of Entomology, 2011Co-Authors: David W Ragsdale, Douglas A Landis, George E Heimpel, Jacques Brodeur, Nicolas DesneuxAbstract:The Soybean Aphid, Aphis glycines Matsumura, has become the single most important arthropod pest of Soybeans in North America. Native to Asia, this invasive species was first discovered in North America in July 2000 and has rapidly spread throughout the northcentral United States, much of southeastern Canada, and the northeastern United States. In response, important elements of the ecology of the Soybean Aphid in North America have been elucidated, with economic thresholds, sampling plans, and chemical control recommendations widely adopted. Aphid-resistant Soybean varieties were available to growers in 2010. The preexisting community of Aphid natural enemies has been highly effective in suppressing Aphid populations in many situations, and classical biological control efforts have focused on the addition of parasitoids of Asian origin. The keys to sustainable management of this pest include understanding linkages between the Soybean Aphid and other introduced and native species in a landscape context al...
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european buckthorn and asian Soybean Aphid as components of an extensive invasional meltdown in north america
Biological Invasions, 2010Co-Authors: George E Heimpel, Douglas A Landis, Keith R Hopper, Mark K Asplen, Lee E Frelich, Kim A Hoelmer, Zeynep Sezen, Kongming WuAbstract:We consider the possibility of an extensive invasional meltdown occurring in central North America involving eleven Eurasian species. The scenario begins with the potential co-facilitation between the European earthworm Lumbricus terrestris and European buckthorn, Rhamnus cathartica. Once introduced, European buckthorn has served as the overwintering host for two important invasive crop pests, oat crown rust, Puccinea coronata and the Soybean Aphid, Aphis glycines. The spread of R. cathartica itself may have been aided by seed dispersal by the European starling, Sturnus vulgaris, and the presence of L. terrestris has likely facilitated the invasion of Bipalium adventitium, an Asian predatory flatworm that specializes on earthworms. Beyond this, the Soybean Aphid is consumed by a number of introduced species, including the lady beetle Harmonia axyridis, the ground beetle Agonum muelleri and the parasitoid Aphelinus certus. We hypothesize that the presence of Soybean Aphid increases regional abundances of these species. We discuss both the evidence for this multi-species invasional meltdown scenario and potential implications of meltdown dynamics for invasive species management. The particular management issues that we discuss are: (1) opportunities for managing multiple invasive species simultaneously by targeting facilitator species, and (2) implications of meltdown dynamics for biological control introductions against the Soybean Aphid.
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potential for biotic interference of a classical biological control agent of the Soybean Aphid
Biological Control, 2008Co-Authors: Jeremy M Chacon, Douglas A Landis, George E HeimpelAbstract:The degree to which resident biota can inhibit the ability of an introduced biological control agent to establish and be effective is termed biotic interference. Studying biotic interference prior to a release using the actual agent is logistically difficult, however, due to quarantine restrictions. An alternative solution is to study biotic interference against a surrogate species in the intended range of introduction, with the expectation that biotic interference against the actual agent will be similar. This study assessed how biotic interference, mostly by generalist predators, may affect establishment of classical biological control agents of the Soybean Aphid, Aphis glycines Matsumura, in North America. The parasitoid Aphidius colemani Viereck was used as a surrogate for Asian Aphidiine braconids such as Binodoxys communis (Gahan). We conducted a factorial field experiment that measured the effect of releasing A. colemani and of excluding resident natural enemies using field cages on Soybean Aphid populations. We also conducted molecular gut-contents analyses on predators collected in release plots to determine which species fed upon A. colemani. Releasing A. colemani in open field plots increased Soybean Aphid control beyond that observed in open field plots alone, despite indications that intraguild predation of A. colemani occurred. Thus, biotic interference was not sufficient to eliminate the contribution of A. colemani on Soybean Aphid suppression during the course of our experiment. Molecular gut-contents analysis revealed that at least two predators, Harmonia axyridis (Pallas) and Chrysoperla carnea Stephens, engaged in intraguild predation against A. colemani. The prolonged effect of intraguild predation on parasitoid establishment remains to be determined.
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Soybean Aphid predators and their use in integrated pest management
Annals of The Entomological Society of America, 2004Co-Authors: Claire E Rutledge, Robert J Oneil, Douglas A LandisAbstract:The discovery of the Soybean Aphid, Aphis glycines Matsumura, in U.S. Soybean production systems in 2000 has provided a unique opportunity to study the interaction of a new invader with existing natural enemy communities. One research thrust has been examining the role of predators in Soybean Aphid dynamics in the Midwest. We discuss the roles of predatory arthropods in field crops and set forth a conceptual model that we have followed to identify key predators in the Soybean Aphid system. We identify Orius insidiosus (Say) and Harmonia axyridis (Pallas) as potentially key predators and show our findings on their phenology in Soybean fields and their impact on Soybean Aphid population dynamics. Finally, we discuss how this information can be used in integrated pest management programs for Soybean Aphid and point to gaps in our knowledge where future studies are needed.
Erin W. Hodgson - One of the best experts on this subject based on the ideXlab platform.
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Soybean Aphid Efficacy Screening Program, 2014
Arthropod Management Tests, 2020Co-Authors: Erin W. Hodgson, Greg VannostrandAbstract:Soybean Aphid, Aphis glycines Matsumura, has drastically changed Soybean pest management in the North Central region. To date, SBA can be successfully managed by timely scouting and foliar insecticides. Host plant resistance is the newest Soybean Aphid management tool and is complementary to the existing chemical control. In 2014, we established plots at two Iowa State University Research Farms (Northeast and Northwest) on 24 May and 22 May, respectively. NK S25-E5 Soybean variety was used for all the Soybean Aphid-susceptible treatments, and LD09-05484A Soybean variety was used for the Rag1 -containing treatments. Plots were arranged in an RCB design with four replications. Each plot was six rows in width and 50 ft in length. Treatments containing a …
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Soybean Aphid Efficacy Evaluation in Northeast Iowa
Farm Progress Reports, 2020Co-Authors: Erin W. Hodgson, Greg Vannostrand, Kenneth T. PecinovskyAbstract:Introduction Soybean, Glycine max (L.), grown in Iowa and most of the north central region of the United States, has not required regular insecticide use. The Soybean Aphid, Aphis glycines (Hemiptera: Aphididae), causes yield losses from direct plant feeding, and has been shown to transmit several plant viruses. In Iowa, Soybean Aphid can colonize Soybean fields in June and has developed into outbreaks in July and August capable of reducing yields by nearly 40 percent.
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Soybean Aphid Efficacy Evaluation
Farm Progress Reports, 2020Co-Authors: Erin W. Hodgson, Greg Vannostrand, Kenneth T. PecinovskyAbstract:Soybean, Glycine max (L.), grown in Iowa and most of the north central region of the United States has not required regular insecticide usage. The Soybean Aphid, Aphis glycines (Hemiptera: Aphididae), is the most important Soybean pest in Iowa and is capable of reducing yield by 40 percent. Nymphs and adults feed on sap within the phloem and can vector several plant viruses. In Iowa, Soybean Aphids have been a persistent pest that can colonize fields from June through September. Their summer population dynamics are dependent on weather and other environmental conditions.
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detection of stress induced by Soybean Aphid hemiptera Aphididae using multispectral imagery from unmanned aerial vehicles
Journal of Economic Entomology, 2020Co-Authors: Zachary P Marston, Ian V Macrae, Erin W. Hodgson, Theresa M Cira, Joseph F Knight, Robert L KochAbstract:Soybean Aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is a common pest of Soybean, Glycine max (L.) Merrill (Fabales: Fabaceae), in North America requiring frequent scouting as part of an integrated pest management plan. Current scouting methods are time consuming and provide incomplete coverage of Soybean. Unmanned aerial vehicles (UAVs) are capable of collecting high-resolution imagery that offer more detailed coverage in agricultural fields than traditional scouting methods. Recently, it was documented that changes to the spectral reflectance of Soybean canopies caused by Aphid-induced stress could be detected from ground-based sensors; however, it remained unknown whether these changes could also be detected from UAV-based sensors. Small-plot trials were conducted in 2017 and 2018 where cages were used to manipulate Aphid populations. Additional open-field trials were conducted in 2018 where insecticides were used to create a gradient of Aphid pressure. Whole-plant Soybean Aphid densities were recorded along with UAV-based multispectral imagery. Simple linear regressions were used to determine whether UAV-based multispectral reflectance was associated with Aphid populations. Our findings indicate that near-infrared reflectance decreased with increasing Soybean Aphid populations in caged trials when cumulative Aphid days surpassed the economic injury level, and in open-field trials when Soybean Aphid populations were above the economic threshold. These findings provide the first documentation of Soybean Aphid-induced stress being detected from UAV-based multispectral imagery and advance the use of UAVs for remote scouting of Soybean Aphid and other field crop pests.
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Residual Testing of Sefina? Insecticide on Soybean Aphid
2019Co-Authors: Erin W. Hodgson, Greg Vannostrand, Ashley Dean, Kent R. BernsAbstract:Soybean, Glycine max (L.), grown in Iowa and most of the north central region of the United States has not required regular insecticide usage. Soybean Aphid glycines (Hemiptera: Aphididae), is the most important Soybean insect pest in Iowa and is capable of reducing yield by 40 percent if left untreated. Some populations of Soybean Aphid have become resistant to pyrethroid insecticides. This creates a need to evaluate new insecticidal modes of action for crop protection.
David W Ragsdale - One of the best experts on this subject based on the ideXlab platform.
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biology of the Soybean Aphid aphis glycines hemiptera Aphididae in the united states
Journal of Integrated Pest Management, 2011Co-Authors: Kelley J Tilmon, Matthew E Oneal, Erin W. Hodgson, David W RagsdaleAbstract:The Soybean Aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is a significant insect pest of Soybean in the north-central region of the United States and southern Canada, and if left untreated can reduce yield value by $2.4 billion annually. The Soybean Aphid is native to eastern Asia, where Soybean was first domesticated, and was first detected in the United States in 2000. It quickly spread within 4 years of its discovery across 22 states and three provinces of Canada. Heavy infestations can result in a covering of sooty mold, yellow and wrinkled leaves, stunted plants, and aborted pods leading to significant yield loss of 40% or more. It can also transmit plant viruses such as Soybean mosaic virus and Alfalfa mosaic virus. The Soybean Aphid has a complex life cycle that involves different physical forms, sexual stages, and two host plant species-Soybean and buckthorn (the overwintering host). Plant nutrition, natural enemies, climate, and weather all affect population growth rate, but the typical population doubling time is ≈6-7 days. Though at present management is primarily through broad-spectrum insecticides, biological control has a significant impact on Soybean Aphid population growth, and Aphid-resistant Soybean varieties are becoming increasingly available.
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ecology and management of the Soybean Aphid in north america
Annual Review of Entomology, 2011Co-Authors: David W Ragsdale, Douglas A Landis, George E Heimpel, Jacques Brodeur, Nicolas DesneuxAbstract:The Soybean Aphid, Aphis glycines Matsumura, has become the single most important arthropod pest of Soybeans in North America. Native to Asia, this invasive species was first discovered in North America in July 2000 and has rapidly spread throughout the northcentral United States, much of southeastern Canada, and the northeastern United States. In response, important elements of the ecology of the Soybean Aphid in North America have been elucidated, with economic thresholds, sampling plans, and chemical control recommendations widely adopted. Aphid-resistant Soybean varieties were available to growers in 2010. The preexisting community of Aphid natural enemies has been highly effective in suppressing Aphid populations in many situations, and classical biological control efforts have focused on the addition of parasitoids of Asian origin. The keys to sustainable management of this pest include understanding linkages between the Soybean Aphid and other introduced and native species in a landscape context al...
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probability of cost effective management of Soybean Aphid hemiptera Aphididae in north america
Journal of Economic Entomology, 2009Co-Authors: Kevin D Johnson, Matthew E Oneal, David W Ragsdale, Erin W. Hodgson, Scott M Swinton, Bruce D Potter, Christina D Difonzo, Philip M Dixon, Alejandro C CostamagnaAbstract:ABSTRACT Soybean Aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is one of the most damaging pests of Soybean, Glycine max (L.) Merrill, in the midwestern United States and Canada. We compared three Soybean Aphid management techniques in three midwestern states (Iowa, Michigan, and Minnesota) for a 3-yr period (2005–2007). Management techniques included an untreated control, an insecticidal seed treatment, an insecticide fungicide tank-mix applied at flowering (i.e., a prophylactic treatment), and an integrated pest management (IPM) treatment (i.e., an insecticide applied based on a weekly scouting and an economic threshold). In 2005 and 2007, multiple locations experienced Aphid population levels that exceeded the economic threshold, resulting in the application of the IPM treatment. Regardless of the timing of the application, all insecticide treatments reduced Aphid populations compared with the untreated, and all treatments protected yield as compared with the untreated. Treatment efficacy and...
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economic threshold for Soybean Aphid hemiptera Aphididae
Journal of Economic Entomology, 2007Co-Authors: David W Ragsdale, Matthew E Oneal, Ian V Macrae, Erin W. Hodgson, Brian P Mccornack, Robert C Venette, Bruce D Potter, K D Johnson, R J Oneil, Christina D DifonzoAbstract:Soybean Aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), reached damaging levels in 2003 and 2005 in Soybean, Glycine max (L.) Merrill, in most northern U.S. states and Canadian provinces, and it has become one of the most important pests of Soybean throughout the North Central region. A common experimental protocol was adopted by participants in six states who provided data from 19 yield-loss experiments conducted over a 3-yr period. Population doubling times for field populations of Soybean Aphid averaged 6.8 d ± 0.8 d (mean ± SEM). The average economic threshold (ET) over all control costs, market values, and yield was 273 ± 38 (mean ± 95% confidence interval [CI], range 111–567) Aphids per plant. This ET provides a 7-d lead time before Aphid populations are expected to exceed the economic injury level (EIL) of 674 ± 95 (mean ± 95% CI, range 275–1,399) Aphids per plant. Peak Aphid density in 18 of the 19 location-years occurred during Soybean growth stages R3 (beginning pod formation) to R5 (full size pod) with a single data set having Aphid populations peaking at R6 (full size green seed). The ET developed here is strongly supported through Soybean growth stage R5. Setting an ET at lower Aphid densities increases the risk to producers by treating an Aphid population that is growing too slowly to exceed the EIL in 7 d, eliminates generalist predators, and exposes a larger portion of the Soybean Aphid population to selection by insecticides, which could lead to development of insecticide resistance.
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field validation of speed scouting for Soybean Aphid
Crop Management, 2007Co-Authors: Erin W. Hodgson, Matthew E Oneal, Eileen M Cullen, David W Ragsdale, Brian P Mccornack, K A Koch, Kevin D Johnson, Heidi Kraiss, Chris Difonzo, Lisa M BehnkenAbstract:Agricultural professionals are spending increasing amounts of time making treatment decisions for Soybean Aphid, Aphis glycines Matsumura. In an effort to reduce the time required to make treatment decisions, a binomial sequential sampling plan called "Speed Scouting" was developed for Soybean Aphid. In 2005, we validated Speed Scouting using commercial fields in Minnesota and replicated small plot trials in four states in the North Central Region of the USA (Iowa, Michigan, Minnesota, and Wisconsin). In commercial fields, yield (bu/acre ± S.E.) was significantly higher in areas of the fields where treatment was applied based on Speed Scouting (50.7 ± 1.7) compared to untreated controls (46.9 ± 1.6). When comparing treatment decisions based on Speed Scouting and whole-plant counts, the same decision was reached 79% of the time. Results from 5 of the 6 small plot trials showed no significant yield difference when Aphid control decisions were made using Speed Scouting compared to whole-plant counts using an economic threshold of 250 Aphids per plant. Speed Scouting is a conservative sampling plan, and consistently recommended treatment before populations reached the economic threshold using whole-plant counts. Using either sampling method, Soybean Aphid management should rely on multiple samples over time to accurately assess population growth rates to avoid unnecessary foliar applications.