Management of the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), in Iowa

dc.contributor.author Johnson, Kevin
dc.contributor.department Entomology
dc.date 2020-06-20T02:34:52.000
dc.date.accessioned 2020-06-30T08:14:41Z
dc.date.available 2020-06-30T08:14:41Z
dc.date.copyright Sun Jan 01 00:00:00 UTC 2006
dc.date.issued 2006-01-01
dc.description.abstract <p>In North America, the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae) is a pest of soybeans, Glycine max (L.) Merrill. The main goal of this research was to verify the preliminary economic threshold for A. glycines management in Iowa. Secondary goals included; verifying an alternative sampling techniques for estimating A. glycines populations, evaluating the effect of planting date on A. glycines population growth, and investigating the potential of managing both C. trifurcata and A. glycines with a single insecticide program. In 2004-2005, replicated experiments were established at three locations. Results from both years indicate that there is no detectable effect on soybean yield from an insecticide (lambda-cyhalothrin) application made below the current 250 A. glycines per plant economic threshold. Insecticide applications made at 250 A. glycines per plant protected yields when A. glycines populations continued to increase in the control treatment. The insecticide treatment triggered by a binomial sequential sampling (speed scouting) technique resulted in soybean exposure to A. glycines and soybean yield equal to the insecticide treatment applied using an enumerative sampling technique. Insecticide applications triggered by either enumerative sampling or speed scouting resulted in higher yields compared to control treatment when A. glycines populations reached 250 A. glycines per plant. A delay in soybean planting did not result in differences in soybean exposure to A. glycines. However, in both 2004 and 2005 yields in the late planting dates were not protected by insecticide applications. In 2005, foliar insecticides applied based on threshold of 250 A. glycines per plant reduced aphid exposure and protected yield better than preventative insecticide applications (seed treatments). Emphasizing the importance of insecticide timing when managing A. glycines, a foliar formulation of imidacloprid, was applied at threshold of 250 A. glycines per plant reduced A. glycines exposure and had greater yield protection than when imidacloprid was applied as a seed treatment. Experimental evidence from this research supports the current recommendations for soybean aphid management in Iowa (weekly scouting and a foliar insecticide applied when mean populations reach 250 A. glycines per plant on at least 38 plants and are increasing).</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/rtd/19303/
dc.identifier.articleid 20302
dc.identifier.contextkey 18174286
dc.identifier.doi https://doi.org/10.31274/rtd-20200618-15
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath rtd/19303
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/73299
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/rtd/19303/Johnson_ISU_2006_J645.pdf|||Fri Jan 14 21:54:40 UTC 2022
dc.subject.keywords Entomology
dc.title Management of the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), in Iowa
dc.type article
dc.type.genre thesis
dspace.entity.type Publication
relation.isOrgUnitOfPublication f47c8cad-50be-4fb0-8870-902ff536748c
thesis.degree.discipline Entomology
thesis.degree.level thesis
thesis.degree.name Master of Science
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