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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Sunflower and Plant Biology Research » Research » Publications at this Location » Publication #231914
Title: Resistance among cultivated sunflower germplasm to stem-infesting pests in the central Plains

Author
item Charlet, Laurence
item AIKEN, ROBERT
item MILLER, JERRY
item Seiler, Gerald

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/26/2009
Publication Date: 6/1/2009
Citation: Charlet, L.D., Aiken, R.M., Miller, J.F., Seiler, G.J. 2009. Resistance Among Cultivated Sunflower Germplasm to Stem-Infesting Pests in the Central Great Plains. Journal of Economic Entomology. 102(3):1281-1290.

Interpretive Summary: A 7-year field study evaluated 61 sunflower accessions and 31 interspecific crosses for resistance to attack by naturally occurring populations of three stem-infesting pests, the sunflower stem weevil, a longhorned beetle, and a root boring moth at two locations in the central Plains. Impact of these sunflower lines on weevil parasites also was studied. Germplasm with potential sources of resistance to attack from all three stem-infesting species were revealed. Accessions PI 650558, PI 386230, PI 431516 were consistent in averaging low densities of stem weevil larvae per stalk among lines tested and PI 497939 exceeded 25 weevil larvae per stalk in only one year of five years of trials. A number of interspecific crosses also had consistently low densities of weevil larvae per stalk. Populations of both the longhorned beetle and root moth were variable over years, but differences among the lines tested were evident in many trials, revealing potential for developing resistant germplasm. Four accessions (PI 386230, PI 431542, PI 650497, and PI 650558) had low larval densities of stem weevil and root moth larvae in addition to reduced percentage infestation by the longhorned beetle. Seven species of parasites were identified from weevil larvae during the study, but rates of parasitism were generally low (average ranged 0.1 to 3.1% among years) and in most cases significant differences were not evident among the lines tested. Results showed potential for developing resistant genotypes for these pests. The prospect of adding host-plant resistance as an integrated pest management tactic would provide another tool for reducing economic losses from stem-infesting insect pests of sunflower in the central Plains.

Technical Abstract: A 7-year field study evaluated 61 sunflower accessions and 31 interspecific crosses for resistance to attack by naturally occurring populations of three stem-infesting pests, the sunflower stem weevil, Cylindrocopturus adspersus (LeConte) (Coleoptera: Curculionidae), a longhorned beetle, Dectes texanus LeConte (Coleoptera: Cerambycidae), and a root boring moth, Pelochrista womonana (Kearfott) (Lepidoptera: Tortricidae) at two locations in the central Plains. Impact of these germplasm lines on weevil larval parasitoids also was studied. Germplasm with potential sources of resistance to attack from all three stem-infesting species were revealed. Accessions PI 650558, PI 386230, PI 431516 were consistent in averaging low densities of stem weevil larvae per stalk among lines tested and PI 497939 exceeded 25 weevil larvae per stalk in only one year of five years of trials. A number of interspecific crosses also had consistently low densities of C. adspersus larvae per stalk. Populations of both D. texanus and P. womonana were variable over years, but differences among the lines tested were evident in many trials, revealing potential for developing resistant germplasm. Four accessions (PI 386230, PI 431542, PI 650497, and PI 650558) had low larval densities of C. adspersus and P. womonana in addition to reduced percentage infestation by D. texanus. Seven species of hymenopteran parasitoids were identified from C. adspersus larvae during the study, but rates of parasitization were generally low (mean ranged 0.1 to 3.1% among years) and in most cases significant differences were not evident among the lines tested. Results showed potential for developing resistant genotypes for these pests. The prospect of adding host-plant resistance as an integrated pest management tactic would provide another tool for reducing economic losses from stem-infesting insect pests of sunflower in the central Plains.