Progress 10/01/10 to 01/31/13

Outputs
Target Audience: The PI retired 02/01/2013 and no progres was made. This project will be terminated. Changes/Problems: The PI retired 02/01/2013 and no progress was made. This project will be terminated. What opportunities for training and professional development has the project provided? The PI retired 02/01/2013 and no progress was made. This project will be terminated. How have the results been disseminated to communities of interest? The PI retired 02/01/2013 and no progress was made. This project will be terminated. What do you plan to do during the next reporting period to accomplish the goals? The PI retired 02/01/2013 and no progress was made. This project will be terminated.

Impacts
What was accomplished under these goals? The PI retired 02/01/2013 and no progress was made. This project will be terminated.

Publications

Progress 01/01/12 to 12/31/12

Outputs
OUTPUTS: More than a third of the known aphid-attacking parasitoids (Hymenoptera, Aphidiidae) in the region have been discovered, named and described under this project. The project has expanded the knowledge base on parasitoids of interest and merit in the bio-regulation of pest aphids. Most recently, a 2-yr study was published on the parasitoid guild of aphids on rabbitbrush, delineating species with cross-over capabilities between aphids of rabbitbrush and potatoes and other crops. Since some of the parasitoids in rabbitbrush environments are linked with pest aphids in neighboring croplands, conserving tracts of native biota containing rabbitbrush has important merit. In collaboration with others, new information was also released on 1) the eriosomatine aphids in the moss-root substrata of forests in the Pacific Northwest - their distribution, morphotypes, and effect on plant health, 2) a review and key to the world's parasitoids of blackberry aphid and the aphid's role as a beneficial host reservoir, 3) the invasive aphids of Hawaii, 4) updated IPM guidelines for green peach aphid and other arthropod pests of commercial potatoes in Washington, Oregon, and Idaho, and 5) product efficacy comparisons between experimental, new, and standard seed-applied products for control of aphids and wireworms in small grains. PARTICIPANTS: Keith S. Pike, Professor, Dept. of Entomology; see authors in publications section. TARGET AUDIENCES: Growers, fieldsmen, crop consultants, scientists PROJECT MODIFICATIONS: Project leader K.S. Pike will retire from Washington State University effective April 2, 2013.

Impacts
Aphid and parasitoid findings strengthened the knowledge base and understanding of pest and beneficial species, their interactions, distributions, seasonal occurrence, host and habitat associations, and biocontrol value. Information to the potato industry enabled growers to effectively and more equitably manage pest species. Experimental, new, and standard insecticide efficacy comparisons supported new development of products of merit.

Publications

• Foottit R.G., E. Maw, K.S. Pike, R.H. Messing. 2012. The aphids of Hawaii: annotated list and key to species of an adventive fauna. Pacific Science. 66:1-30.
• Pike K.S., G. Graf, R.G. Foottit, E. Maw, C.von Dohlen, J. Harpel, A. Pantoja, S. Emmert, A. Hagerty. 2012. Eriosomatine aphids (Hemiptera, Aphididae, Eriosomatinae) associated with moss and roots of conifer and willow in forests of the Pacific Northwest of North America. The Canadian Entomologist. 144:555-576.
• Havelka J., Z. Tomanovic, N.G. Kavallieratos, E. Rakhshani, X. Pons, A. Petrovic, K.S. Pike, P. Stary. 2012. Review and key to the world parasitoids (Hymenoptera: Braconidae: Aphidiinae) of Aphis ruborum (Hemiptera: Aphididae) and its role as a host reservoir. Annals of the Entomol. Soc. of Amer. 105:386-394.
• Hollingbery E., K.S. Pike, G. Graf, D. Graf. 2012. Parasitoids (Hymenoptera, Braconidae, Aphidiinae) of rabbitbrush aphids and linkage with agriculturally important pest aphids in Washington State. The Canadian Entomologist. 144:621-634.
• Messing R.H., K.S. Pike, R.G. Foottit. 2012. Invasive Aphids in Hawaii. College of Tropical Agriculture and Human Resource.

Progress 01/01/11 to 12/31/11

Outputs
OUTPUTS: Effective management of green peach aphid and Colorado potato beetle in potatoes with reduced chemical treatment was achieved without diminishing potato yields or tuber quality. The approach, which centers on the use of a single applied seed or at-plant neonicotinoid systemic, is now being adopted by the industry and is expected to become the standard control approach in the region. Managing these pests with minimal chemical reliance is beneficial on several fronts - it lowers not only farm costs and end user exposure to pesticides, but also lessens the negative impacts and disruption on natural enemy communities. PARTICIPANTS: K. Pike, J. Alvarez, G. Graf, A. Jensen, S. Mathur, T. Murray, D.A. Raworth, S. Rondon, A. Schreiber, P. Stary, L. Tanigoshi TARGET AUDIENCES: Growers, fieldsmen, crop consultants, scientists PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Managing green peach aphid and Colorado potato beetle pests in potatoes with minimal chemical reliance is beneficial on several fronts - it lowers farm costs and end user exposure to pesticides, and minimizes negative impacts and disruption on natural enemy communities. In collaboration with others, comprehensive IPM guidelines for green peach aphid, Colorado potato beetle, and other arthropod pests in commercial potatoes were web-posted for producers in Washington, Oregon, and Idaho. Additionally, information was released on Aphidius ericaphidis, a self-sustaining, naturally regulating aphid parasitoid predominant in commercial blueberries in eastern and western Washington and in southwestern Canada.

Publications

• Pike, K.S., P. Stary, G. Graf, D. Raworth, S. Mathur, L.K. Tanigoshi, and T.A. Murray. 2011. A new species of Aphidius Nees (Hymenoptera, Braconidae, Aphidiinae) of Ericaphis fimbriata (Richards) (Hempitera, Aphididae) and key to parasitoids of blueberry aphid in the Pacific Northwest. Zootaxa 2802:58-62.

Progress 01/01/10 to 12/31/10

Outputs
OUTPUTS: Molecular and morphometric approaches were used to document genetic differences in aphids previously grouped together and referred to as banana aphids. Two distinct genotypes or species were defined: Pentalonia nigronervosa typically on banana; Pentalonia caladii typically on various plants in the order Zingiberales and in the family Araceae, including important food and ornamental plants such as ginger (Alpinia, Zingiber), cardamom (Elettaria), taro (Colocasia), Caladium, Costus, Dieffenbachia, Hedychium, Heliconia and Xanthosoma. The new discovery is important to banana cultures worldwide as all past works and literature dealing with banana aphids and their management fail to recognize the distinctions in the two species. Pentalonia nigronervosa is a well known vector of banana bunchy top virus (BBTV), but it is not known if P. caladii also acts as a virus vector, or if the virus can be transferred to plants that it colonizes. New studies are in progress to determine the economic importance of the two aphid species to banana, including their role in disease pathogen transmission. In other collaborative work, information was released on 1) naturally occurring, naturally regulating aphid parasitoids in western Washington; 2) improved IPM guidelines for green peach aphid and other arthropod pests in commercial potatoes in Washington, Oregon, and Idaho; 3) species composition, seasonal abundance, and virus vector potential of aphids in rhubarb in Alaska; 4) new synonymy, host and distributional data, and keys to aphids of the genus Myzodium; and 5) product efficacy comparisons between experimental, new, and standard products for controlling aphids and wireworms in small grains. PARTICIPANTS: K. Pike, J. Alvarez, S. Emmert, R. Foottit, G. Graf, A. Hagerty, J. Harpel, A. Jensen, J. Kuhl, E. Maw, A. Pantoja, G. Miller, R. Miller, S. Rondon, A. Schreiber, P. Stary. TARGET AUDIENCES: Growers, fieldsmen, crop consultants, scientists PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Molecular and biometric assessments provided reliable means to delineate and characterize aphid taxa, recognize cryptic species, reveal host lineages, and resolve species complexes. New findings on Pentalonia aphids clarified the target species for more directed and likely cost-effective management in the future. Information to the potato industry enabled growers to better address and timely manage aphids and other troublesome pests. Parasitoid findings strengthened the knowledge base and understanding of beneficial species complexes, host associations, and biocontrol value. Experimental, new, and standard insecticide efficacy comparisons of aphids and wireworms in small grains supported development of products of merit.

Publications

• Pantoja, A., A.Hagerty, S.Emmert, J.C.Kuhl, K.S.Pike, J.Alvarez, and A.S.Jensen. 2010. Aphids (Homoptera: Aphididae) associated with rhubarb in the Matanuska Valley, Alaska: species composition, seasonal abundance, and potential virus vectors.. J. of the Entomol. Soc. of British Columbia. 107:1-7.
• Foottit, R.G., E.Maw, K.S.Pike, and R.H.Miller. 2010. The identity of Pentalonia nigronervosa Coquerel and P. caladii van der Goot (Hemiptera: Aphididae) based on molecular and morphometric analysis. Zootaxa 2358:25-38.
• Pike, K.S., R.G.Foottit, E.Maw, G.Miller, A.Pantoja, J.Harpel, S.Emmert, and A.Hagerty. 2010. Molecular and biometric assessment of Myzodium mimulicola (Drew & Sampson) (Hemiptera, Aphididae), new synonymy, host, and distributional data. Zootaxa 142:448-457.

Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: Advances in DNA barcodes to explore aphid diversity, relationships, and pest complexes were documented. Complications in definition and accurate identification of aphid life forms have long challenged growers, fieldsmen, crop consultants, and researchers. The presence of different morphological forms of a single species on different hosts and at different times of the year makes it difficult to consistently associate routinely collected field samples with particular species definitions. DNA barcodes have proven effective in characterizing aphid taxa, delineating species boundaries, recognizing cryptic species, detecting invasives, revealing host associated lineages, and resolving pest complexes important in effective pest management. Using both barcodes and morphological differences, two new native North American species of aphids (Braggia columbiana and Braggia longicauda) colonizing buckwheat were named, described, and illustrated. Neither is considered pestiferous, but rather beneficial as hosts of an important primary parasitoid, Lysiphlebus testaceipes, which in turn attacks aphid pests in alfalfa, apples, asparagus, beans, cabbage, canola, cherries, clover, corn, hops, peaches, potatoes, and small grains. Although buckwheats are not always found in close proximity to farmlands, they can be added, as nurseries are successful now in cultivating them for use in landscapes as ornamentals and as attractants for bee pollinators and butterflies. PARTICIPANTS: K. Pike, R. Foottit, E. Maw, G. Graf, P. Stary, R. Hammon, D. Miller, C. von Dohlen TARGET AUDIENCES: Growers, fieldsmen, crop consultants, scientists PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
DNA barcodes provide reliable means to distinguish and characterize aphid taxa, detect invasives, reveal host associated lineages, analyze diverse faunas, and resolve pest complexes. New species of Braggia aphids discovered on buckwheat along with associated parasitoids, offer opportunities through landscape management to stabilize, if not enhance, natural regulation of pest aphids in farmland.

Publications

• Pike, K.S., G.Graf, R.G.Foottit, E.Maw, P.Stary, R.Hammon, and D.S.Miller. 2009. New species of Braggia (Hemiptera: Aphididae, Aphidinae) on buckwheat in western North America. The Canadian Entomologist. 141:561-581.
• Foottit, R.G., E.Maw, and K.S.Pike. 2009. DNA barcodes to explore diversity in aphids (Hemiptera: Aphididae and Adelgidae). Redia 92:87-91.

Progress 01/01/08 to 12/31/08

Outputs
OUTPUTS: First phase biocontrol research on wasp parasitoids of blueberry aphids (Ericaphis fimbriata) on highbush blueberry (Vaccinium corymbosum) in the Pacific Northwest was published - a joint effort with Canadian scientists. The blueberry aphid transmits a commercially important Carlavirus known as blueberry scorch virus. A number of primary and secondary parasitoids were found in blueberry ecosystems east and west of the Washington Cascade Range and in southwestern British Columbia, but only a few dominated, and the dominant species varied with geographical area. Seasonal parasitoid population patterns in Canada suggested that properly timed massed-reared spring releases of one of the dominant parasitoids, Praon unicum, might prove useful in augmentative biological control of the blueberry aphid, at least for some areas. In other work, new information was released on 1) green peach aphid field population trends and management options in commercial potatoes in Washington, 2) insecticide performance patterns in seed-, at-plant soil-, and foliar-applied treatments in commercial potatoes, 3) improved IPM guidelines for insects and mites in potatoes in Washington, Oregon, and Idaho (collaborative release with others), 4) product efficacy comparisons between experimental, new, and standard products for controlling aphids and wireworm in wheat, and 5) new aphid species discoveries in the Olympic National Park and Cascade Mountains of Washington State. PARTICIPANTS: K.S. Pike, Project Leader, D. A Raworth, L. K. Tanigoshi, S. Mathur, G. Graf, J. Crosslin, P. B. Hamm, T. M. Mowry, P. Nolte, H. Mojtahedi, A. Jensen, A. Schreiber, J. Alvarez, J. Freilich, S. I. Rondon, P. Stary TARGET AUDIENCES: Blueberry, potato, and small grain industries, aphid biocontrol specialists, insecticide industries, aphid and aphid-parasitoid systematists PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Parasitoid findings are useful in understanding beneficial species complexes, seasonal dynamics, and biocontrol value. Information released to the potato industry enables growers to better address and timely manage aphid pests. Experimental, new, and standard insecticide efficacy comparisons of aphids and wireworms in wheat support new registrations of products of merit.

Publications

• Raworth, D.A., K.S.Pike, L.K.Tanigoshi, S.Mathur, and G.Graf. 2008. Primary and secondary parasitoids (Hymenoptera) of aphids (Hemiptera: Aphididae) on blueberry and other Vaccinium in the Pacific Northwest. Environmental Entomology 37:472-477.
• Crosslin, J., P.B.Hamm, K.S.Pike, T.M.Mowry, P.Nolte, and H.Mojtahedi. 2008. Management of Diseases caused by Viruses and Virus-like Pathogens. Plant Health Management, 2nd Edition. APS Press, St. Paul, MN (Chap. 17) pp. 161-169.

Progress 01/01/07 to 12/31/07

Outputs
OUTPUTS: The first comprehensive key to North American Trioxys (parasitoids associated with aphids in arboreal, grassy riparian, sagebrush, and selected agro-ecosystem habitats) was published in 2007. Full species illustrations accompany the key, along with summary tables on geographic origin, distribution, hosts, and diagnostic features. The work represents a major step forward in providing the means to accurately identify aphidiine parasitoids. Keys to other genera are still sorely needed, and consequently, are being developed under this project. Parallel to the parasitoid work is an ongoing effort to characterize all aphid species that occur in western North America and the Pacific Basin. Special attention is being given to pestiferous and invasive genotypes and biotypes relative to distribution, spread, and host range. Molecular and biometric techniques are being employed to distinguish closely allied species. Additionally, collaborative work with others has led to the release of new information on: 1) a new handbook on small grain insects; 2) a comprehensive IPM program for insects and mites in potatoes for the Pacific Northwest; 3) insecticide treatment regime performance control of green peach aphids in commercial potatoes in Washington; 4) new species descriptions for Trioxys and Binodoxys parasitoids of small grain and soybean aphids; 5) role of aphids in the etiology of black death, a new disease of Helleborus in North America; and 6) aphid-ant-flora associations in Palau with comparisons to other Pacific islands PARTICIPANTS: M. Brewer, G. D. Buntin, L. J. Dutoit, K. C. Eastwell, J. L. Fulbright, S. D. Gaimari, L. Hansen, O. Idechiil, A. Jensen, J. B. Karen, M. Kaiser, S. Langley, R. H. Miller, T. Noma, K. S. Pike, G. Reed, A. Schreiber, P. Stary, J. R. Vockerroth, J. A. Webster, M. J. Weiss TARGET AUDIENCES: Small grain, potato, and soybean industries; nurseries involved with Helleborus production and marketing; aphid and aphid-parasitoid systematists; aphid biocontrol specialists; and Pacific island ecologists/ conservationists.

Impacts
1) The new aphid parasitoid key opens the way for more definitive work on Trioxys as a biocontrol agent. 2) The new handbook on small grain insects brings together extensive and up-to-date information on identification, biology, and management of all major and minor arthropod pest and beneficial species associated with wheat, barley, oats, rye, and triticale. It contains 170 photos, maps, and illustrations to guide the user. It is designed for practitioners of integrated pest management (IPM) programs, growers, crop consultants, extension agents, agricultural sales representatives, entomologists, students, and other interested scientists. 3) The latest IPM strategies for cost-effective control of green peach aphid and other arthropods pests in potatoes are provided to the industry. 4) Etiology and management options for control of black death of Helleborus are published. 5) The first comprehensive assessment of aphid-ant-flora associations in Palau is completed as a baseline for recognizing future change.

Publications

• Pike, K.S. 2007. Bird cherry-oat aphid, pp. 37-38. In G. D. Buntin, K. S. Pike, M. J. Weiss, J. A. Webster (eds). Handbook of Small Grain Insects. Entomol. Soc. of Am. Handbook Series, published in cooperation with the Am. Phytopath. Soc. APS Press, St. Paul, MN, 120 pp.
• Pike, K.S., P. Stary, G.D. Buntin, and J.B. Karen. 2007. Parasitoids (Hymenoptera) of Small Grain Pests. pp. 94-96. In G. D. Buntin, K. S. Pike, M. J. Weiss, J. A. Webster (eds). Handbook of Small Grain Insects. Entomol. Soc. of Am. Handbook Series, published in cooperation with the Am. Phytopath. Soc. APS Press, St. Paul, MN, 120 pp.
• Buntin, G.D., and K.S. Pike. 2007. Identification of Insects and Diagnosis of Injury. p. 24-26. In G. D. Buntin, K. S. Pike, M. J. Weiss, J. A. Webster (eds). Handbook of Small Grain Insects. Entomol. Soc. of Am. Handbook Series, published in cooperation with the Am. Phytopath. Soc. APS Press, St. Paul, MN, 120 pp.
• Fulbright, J.L., K.S. Pike, and P. Stary. 2007. A Key to the North American species of Trioxys (Hymenoptera: Braconidae, Aphidiinae), with a summary of the geographic distribution, hosts, and species diagnostic features. Proc. of the Entomol. Soc. of WA. 09:779-790.
• Kaiser, M., T. Noma, M. Brewer, K.S. Pike, J.R. Vockerroth, and S.D. Gaimari. 2007. Hymenopteran parasitoids and dipteran predators founding utilizing soybean aphid after its midwestern United States invasion. Annals of the Entomol. Soc. of Am. 100:196-205.
• Eastwell, K.C., L.J. Dutoit, and K.S. Pike. 2007. Etiology of black death, a new disease of Helleborus species in North America. Hellebores, A Comprehensive Guide. (Eds. C. C. Burrel and J. K. Tyler) Timber Press, Portland, OR.
• Pike, K.S., P. Stary, M. Brewer, T. Noma, S. Langley, and M. Kaiser. 2007. A new species of Binodoxys (Hymenoptera: Braconidae, Aphidiinae & Aphelinidae), parasitoid of the soybean aphid, Aphis glycines Matsumura, with comments on biocontrol. Proc. of the Entomol. Soc. of WA. 109:359-365.
• Fulbright, J.L., and K.S. Pike. 2007. A new species of Trioxys (Hymenoptera: Braconidae, Aphidiinae & Aphelinidae) parasitic on bird cherry-oat aphid, Rhopalosiphum padi (L.) (Hemiptera). Proc. of the Entomol. Soc. of WA. 109:541-546.
• Buntin, G.D., K.S. Pike, M.J. Weiss, and J.A. Webster. 2007. Handbook of Small Grain Insects. Entomological Society of America Handbook Series, published in cooperation with the Am. Phytopath. Soc. APS Press, St. Paul, MN, 120 pp.
• Idechiil, O., R.H. Miller, K.S. Pike, and L. Hansen. 2007. Aphids (Hemiptera: Aphididae), Ants (Hymenoptera: Formicidae) and associated flora of Palau with comparisons to other Pacific Islands. Micronesica. 39(2):141-170
• Schreiber, A., A. Jensen, K. Pike, and G. Reed. 2007. Integrated pest management program for insects and mites in Idaho, Oregon, and Washington potatoes. http://potato.prosser.wsu.edu.

Progress 01/01/06 to 12/31/06

Outputs
New species of aphid-attacking wasp parasitoids associated with agriculturally important aphids in North America were discovered; two were newly named and described, and evaluated for biocontrol value (publications in press). One of these, a native species and member of the genus Trioxys, was discovered in central Washington attacking bird cherry-oat in reed canary grass along waterways and roadsides. Its host association is relatively unique in that it is one of only two Trioxys worldwide, in a genus of 70+ species that uses bird cherry-oat aphid as a host. Another new parasitoid, a member of the genus Binodoxys, was found in Michigan attacking soybean aphid. It is one of several native species adapting to the aphid and contributing to its biocontrol. A third new parasitoid, yet to be named and described, was found attacking blueberry aphid in Washington and southern British Columbia. Though previously unrecognized, this parasitoid is commonly abundant in commercial blueberries. Additional work led to the release of new information on 1) green peach aphid regional field population trends and management options in commercial potatoes in Washington, 2) invasive aphids of Hawaii, and 3) molecular markers for identification of hyperparasitoids in parasitoids of cereal aphids.

Impacts
Parasitoid findings were useful in understanding beneficial species complexes, seasonal dynamics, and biocontrol value, and in developing pest control strategies with the least parasitoid disruption. The Washington potato industry provided a real-time window on green peach aphid field status and population growth trends, enabling growers to better manage pests. The status of invasive aphids of Hawaii was determined, facilitating management policy planning.

Publications

• Chen, Y., K.S. Pike, M.H. Greenstone, and K.A.Shufran. 2006. Molecular markers for identification of the hyperparasitoids Dendrocerus carpenteri and Alloxysta xanthopa in Lysiphlebus testaceipes parasitizing cer. BioControl. 51:183-194.
• Messing, R.H., R.G. Foottit, and K.S. Pike. 2006. New records of invasive aphids in Hawaii. Bishop Museum Occasional Papers. 88:26-30.
• Messing, R.H., M. Tremblay, E. Mondor, R.G. Foottit, and K.S.Pike. 2006. Invasive aphids attack native Hawaiian plants. Biological Invasions (on-line publication: http://www.springerlink.com/content/9300465521266513/fulltext.html.

Progress 01/01/05 to 12/31/05

Outputs
A wide spectrum of wild grasses and wheat were intensely sampled in eastern Washington (2003-2005)to obtain plant tissue for BYDV assessment and determine species of colonizing aphids and associated aphid-attacking parasites. In total, 729 sites were assessed, 317 from wheat, 412 from other grains, wild grasses, and cat-tail. The work represents the most comprehensive assessment of its type ever made in the region. All of the major wheat production areas were evaluated. New information has been revealed on aphid-parasitoid distribution patterns, habitat relationships, occurrence frequencies, population densities, and BYDV serotypes. Future work will focus on the impact of the aphid-virus complex on current and advancing wheat lines in conjunction with the states uniform variety testing program. Also, new information was published on aphid natural enemies in wheat in the Great Plains, and predator-pest communities in potatoes in Washington.

Impacts
The findings from these studies are useful in redefining control guidelines for the aphid-virus complex in wheat, and understanding pest community dynamics in potatoes.

Publications

• Koss, A. M., A. S. Jensen, A. Schreiber, K. S. Pike and W. E. Snyder. 2005. A comparison of predator and pest communities in Washington potato fields treated with broad-spectrum, selective or organic insecticides. Environmental Entomology. 34: 87-95.
• Noma, T., M. J. Brewer, K. S. Pike, and S. D. Gaimari. 2005. Hymenopteran parasitoids and dipteran predators of Diuraphis noxia (Homoptera: Aphididae) in the westcentral Great Plains: species records and geographic range. Biocontrol 50:97-111.

Progress 01/01/04 to 12/31/04

Outputs
Green peach aphid population status (growth trends, abundance, flight activity) and status of other potato pests across the Columbia Basin were weekly monitored and assessed throughout the 2004 growing season for the Washington Potato Industry. Field sites included locations in Adams, Benton, Franklin, Grant, Klickitat, Walla Walla, and Yakima counties. The findings, together with management options and recommendations, were provided to growers, fieldmen, scientists, and other stakeholders by toll-free aphid hotline (1-888-673-6273), website postings (www.potato.prosser.wsu.edu), and personal contact. The hotline and website postings were additionally used as a forum for discussing various aphid topics and related subjects. This was the sixth year that aphids were regionally assessed in potatoes in Washington. Additionally, new information was published on the aphids of Ceanothus velutinus, and their associated parasitoids .

Impacts
The Washington potato industry was informed in a timely mannerof aphid field status and current treatment recommendations for timely pest management.

Publications

• Jensen, A., P. Hamm, P. Thomas, J. Crosslin, J. Munyaneza, A. Schreiber, and K. Pike. 2004. Purple top, BLTVA, and leafhoppers: an update. Potato Progress IV (No. 3): 1-3.
• Pike, K. S., R. G. Foottit, P. Stary, D. Allison, G. Graf, and E. Maw. 2004. Aphis boydstoni, n. sp. and Aphis ceanothi Clarke (Hemiptera: Aphididae: Aphidinae: Aphidini) on Ceanothus velutinus Douglas, including associated parasitoids. Proc. Entomol. Soc. Wash. 106: 801-810.

Progress 01/01/03 to 12/31/03

Outputs
A new book entitled Aphids of Western North America North of Mexico, with Keys to Subfamilies and Genera for Female Alatae was completed. The region, rich in aphid fauna, is comprised of 15 subfamilies, 178 genera, and more than 1,000 species. Unique to the work is a portfolio of photo-illustrations for each genus. In total more than 2,200 illustrations are shown. Also, a synopsis is provided for each genus on the chief distinguishing features, species and pest species of the region, host plants, primary parasitoids, and references to species descriptions. Among aphids illustrated are many of the species of regional pest or possible pest significance. In addition to the book, descriptions were published on a new species of aphid and a new species of aphidiine parasitoid in northwestern USA. Also, findings were released on a newly discovered aphid in the Mariana Islands.

Impacts
The new resources assist in the identification of aphids and aphidiine parasitoids, and broadens the knowledge base on their relationships, role and importance in the region.

Publications

• Miller, R.H., O. Idechiil, R.G. Foottit, and K.S. Pike. 2003. Uroleucon formosanum (Takahashi) (Homoptera: Aphididae) found on Youngia japonica (L.) DC on Guam and Rota in the Mariana Islands. Proc. Hawaiian Entomol. Soc. 36:125-127.
• Pike, K. S., and P. Stary. 2003. Ericaphis louisae, n. sp. (Hemiptera: Aphidinae: Macrosiphini) on Luetkea pectinata (Pursh) (Rosaceae), and a key to Ericaphis species. Proc. Entomol. Soc. Wash. 105: 459-465.
• Pike, K. S., L. L. Boydston, and D. W. Allison. 2003. Aphids of Western North America North of Mexico with Keys to Subfamilies and Genera for Female Alatae. Washington State University, Cooperative Extension MISC0523, Pullman, Washington, pp. 282. ISBN 0-9721994-3-8
• Pike, K. S., P. Stary, and G. Graf. 2003. Description of a new species of Braconidae, Monoctonus allisoni (Hymenoptera, Braconidae, Aphidiinae) and discussion of the aphid-parasitoid guild for Nasonovia spp. (Hemipteraa, Aphididae) in northwestern USA. Proc. Entomol. Soc. Wash. 105: 379-386.

Progress 01/01/02 to 12/31/02

Outputs
Field research was completed on green peach aphid (Myzus persicae) relative to its winter survival (anholocyclic populations) on watercress, mallow, tumble mustard, shepherd's-purse, flixweed, and stork's-bill. It is clear now that asexual populations exist year around in Washington, which means there is a variety of different weed hosts from which the aphid originates in the spring and summer to infest potatoes. It is also clear now why programs attempted years ago to control the aphid during its sexual phase on peach trees were futile - its full biology in the temperate zone was not recognized. Green peach aphid populations on the weedy hosts are attacked by aphidiid parasites (minute wasps that utilize strictly aphids, no other organisms). The role and importance of these parasites in keeping the target aphid from reaching pest status in potatoes is still under evaluation. In addition to the studies on green peach aphid, new findings were published on the aphidiid parasites of Guam, and of juniper aphids.

Impacts
Research findings are helping to establish improved management measures for aphid pests in potatoes and small grains. Systematic research on newly discovered aphid-parasites in and about the agricultural regions of Washington is a support essential to the applied research. A multitude of intertwining connections exists between pest and beneficials species involved directly and indirectly in the cropping systems.

Publications

• Miller, R., K. Pike, P. Stary. 2002. Aphid parasitoids (Hymenoptera:, Aphidiidae) of Guam. Micronesica 34(2): 87-103.
• Pike, K. S., and P. E. Thomas. 2002. New discovery and importance of overwintering pathways of green peach aphid. Wash. State Commission, Potato Progress 2(3).
• Pike, K., P. Stary, G. Graf, and D. Allison. 2002. Pauesia columbiana sp. n. (Hymenoptera: Braconidae: Aphidiinae) on juniper aphids, and key to related species. Proc. Entomol. Soc. Wash. 104: 646-654.

Progress 01/01/01 to 12/31/01

Outputs
A number of different Old World aphid-attacking wasp parasites, selective for certain aphids, including green peach aphid in potatoes, have been introduced over the last several years into eastern Washington to strengthen the existing pool of indigenous aphid-parasites. Three species have emerged as dominant aphid biocontrol agents in potatoes: Aphidius ervi, Aphidius matricariae, and Diaeretiella rapae. A. matricariae is the premier parasite of the three against green peach aphid. In 2001, it eliminated aphids completely in selected potato fields in Grant and Yakima Counties. Presently, this parasite is not distributed in all potato producing areas in Washington, but it is spreading. A. ervi and D. rapae are long-established parasites, and though widely distributed, are not found in all fields of potatoes. Further work is needed to reveal the intertwining factors in the environment influencing parasite movement in and out of potatoes. In addition to the Washington studies, work on the aphidiid parasites of Guam was summarized and published. All of the Guam aphidiids are introduced, as are the aphids they attack.

Impacts
Aphid parasites can be highly effective as biocontrol agents. Steps have and are being taken to ensure their presence in small grains, potatoes, and selected other crops attacked by aphids.

Publications

• No publications reported this period

Progress 01/01/00 to 12/31/00

Outputs
A comprehensive assessment of all wasp-attacking, aphid-parasitoid species (Hymenoptera, Braconidae, Aphidiinae) in Northwest USA was published in 2000. Eighty-one parasitoid species in 19 genera are now recognized; 35 species are new to the region; 20 species are newly described. Seventy genera of aphids (200+ spp.) are attacked by parasitoids; 400+ parasitoid- aphid associations are documented; and hundreds more tritrophic (parasitoid-aphid-plant) combinations are reported for the first time in North America. The work summarizes six years of field research. It constitutes a foundation for future studies in biosystematics; parasitoid guilds; population genetics; host adaptation, switching, and cross habitat movement; geographic spread of exotic species; interspecies population development; ecosystem relationships and effects on parasitoid and predator complexes, and target pests; application and advantages of aphid-plant biodiversity for stabilizing, and/or increasing parasitoids of merit; and possible export and uses of Northwest parasitoids to other global areas. Some of the introduced parasitoid species have become effective biocontrol agents, such as Diaeretiella rapae against cereal aphids in small grains; others are becoming common, such as Aphidius matricariae against green peach aphid in potatoes. Additionally, work on aphid fauna, associated flora and parasitoids of Guam was completed.

Impacts
Effective parasitic controls have been realized against some Northwest pest aphids. Fundamental information on aphid parasitoids, acquired by this project, is providing insight and direction into the use and enhanced use of parasitoids for natural control of troublesome aphids in agriculture, and other settings.

Publications

• Pike, K. S., P. Stary, T. Miller, G. Graf, D. Allison, L. Boydston, and R. Miller. 2000. Aphid parasitoids (Hymenoptera, Braconidae, Aphidiinae) of Northwest USA. Proc. Entomol. Soc. Wash. 102:688-740.
• Pike, K. S., R. H. Miller, and P. Stary. 2000. Aphid fauna (Hemiptera: Aphididae) and associated flora of Guam. Micronesica 33(1/2):181-209.

Progress 01/01/99 to 12/31/99

Outputs
New bioregulatory agents (aphid-attacking parasitic wasps: Aphidius colemani and A. picipes) of green peach aphid (GPA) were successfully mass reared and introduced in 1999 into the main potato growing areas of eastern Washington (Adams, Benton, Franklin, Grant, Klickitat, Walla Walla, and Yakima Counties; 20+ releases, 100,000+ parasitoids). These agents are expanding the existing pool of beneficials, and some are expected to impact GPA populations during the earliest parts of the growing season when numbers are few -- attacking the aphid on potatoes, but more importantly, attacking it on its herbaceous weed hosts before it migrates to potatoes. Reduction of GPA in early season will lower the risk of major virus problems, particularly in long season potatoes such as Russets. In 2000, contingent on authorization (USDA approved permit has been requested), a new strain of Aphidius picipes, having cool season activity, will be imported from eastern Europe, mass reared, and released in Washington. Because the threshold for GPA as a virus-vector is extremely low (0.5 aphid/plant), chemical controls will continue to be the main element in the management scheme. Bioagents will not eliminate the aphid, but they are expected to reduce the problem and play a more important role in the future when the right compliment of species or species-strains are in place, and new softer chemicals favoring higher survivorship of the beneficials come into wide-area use. In 1999, the potato industry was kept apprised of GPA activity, flight trends, field population development, and controls by toll-free hotline.

Impacts
Reduction of GPA in early season will lower the risk of major virus problems, particularly in long season potatoes such as Russets.

Publications

• Pike, K.S., Stary, P, Miller, T., Allison, D., Boydston, L., Graf, G.. 1999. Host range and habitats of the aphid-parasitoid Diaeretiella rapae (M'Intosh) (Hym.: Aphidiidae) in Washington State. Environ. Entomol. 28(1): 61-71.
• Pike, K.S., Stary, P., Miller, T., Miller, R., Allison, D., Graf, G., Boydston, L. 1999. Ephedrus clavicornis sp. n. (Hymenoptera, Braconidae, Aphidiinae), an aphid parasitoid of the Pacific Northwest, and key to Nearctic Ephedrus. J. Kansas Entomol. Soc. 72: 10-16.
• Stary, P., and Pike, K.S. 1999. Uses of beneficial insect diversity in agroecosystem management, pp. 49-67. In M. Collins (ed.), Importance of Biodiversity in Agroecosystems. Advances in Agroecology Series, Lewis Publishers.

Progress 01/01/98 to 12/31/98

Outputs
The project's focus is on bird cherry-oat aphid and English grain aphid on small grains, pea aphid on peas and alfalfa, and apple aphid on apples, with an emphasis on biologically based IPM (use of augmentative exotic wasp parasitoids [e.g., Aphelinus asychis, Aphidius colemani, A. picipes, A rhopalosiphi], landscape management, planting dates, and limited insecticide use). Expected outcomes: increased natural regulation of the aphids; new recommendations on habitat refugia for on-farm enhancement of aphid natural enemies; decreased use of insecticides with little or no out-of-pocket expense to growers; new recommendations on insecticides of least hazard to beneficials; and a new bulletin for small grain growers on beneficial parasitoids (merit and methods for on-farm conservation). The work has included an assessment of the aphids of the Pacific Northwest USA and their associated parasitic wasp and predatory fly fauna. Collections and baseline data have been or are being established on all aphid-associated native and introduced aphelinid and aphidiid primary parasitoids, hyperparasitoids (Alloxysta, Asaphes, Dendrocerus, Lytoxysta, Pachyneuron, and Phaenoglyphis), and aphid-predatory Diptera. The collections assembled to date, constitute the most comprehensive collections of their type in North America, and serve as a foundation for studies on biodiversity, spatial and temporal distributions, systematics, faunistic linkages, and genetics.

Impacts
(N/A)

Publications

• Pike, K. S., P. Stary, T. Miller, D. Allison, L. Boydston, G. Graf & R. Gillespie. 1997. Small grain aphid parasitoids (Hymenoptera: Aphelinidae and Aphidiidae) of Washington: distribution, relative abundance, and seasonal occurrence; and key to known North American species. Environ. Entomol. 26: 1299-1311.
• Stary, P., & K. S. Pike. 1998. Uses of beneficial insect diversity in agroecosystem management. In M. Collins (ed.), Importance of Biodiversity in Agroecosystems. Advances in Agroecology Series, Lewis Publishers

Progress 01/01/97 to 12/31/97

Outputs
The project has resulted in the discovery of new trophic level associations useful in developing structured ecology for aphid-parasite enhancement in the field. The region is among one of the most aphid-parasite rich in the world, with more than 65 species identified. The opportunities to utilize these natural agents for aphid control are many. In wheat and barley, Russian wheat aphid populations have been significantly reduced, generally to noneconomic levels, by parasites and other natural enemies. Current targets for improved biocontrol include bird cherry-oat aphid (BCOA), the premier vector of barley yellow dwarf virus, English grain aphid, and pea aphid. BCOA is attacked mainly by a single native species of parasite, Lysiphlebus testaceipes -- its presence and activity in wheat can be characterized as modest. This aphid can be especially troublesome on winter wheat in the fall. English grain aphid is attacked by three species of parasites, but often inadequately, especially in late May to July when wheat is in the flowering to soft dough stages. Pea aphid is inadequately controlled by parasites in peas in late spring and summer. To improve biocontrol levels for all three aphids, two new exotic aphid-parasites, Aphidius rhopalosiphi and Aphidius picipes, are being added to the existing pool of beneficial agents.

Impacts
(N/A)

Publications

• No publications reported this period

Progress 01/01/96 to 12/30/96

Outputs
Discovery research on aphid parasitoids in the field has been completed in part.New information was obtained on cereal aphid parasitoid species population diversity (13 spp. linked to one or more small grain aphids; three are new to science), relative abundance, alternate hosts connections, and spatial and temporal distributions across differing precipitation and cropping zones in eastern Washington. The preeminent parasitic species (most abundant, most frequent, most widely distributed) attacking grain aphids are indigenous species; their adaptation to introduced non-native aphids has been widespread and rapid, e.g., Russian wheat aphid, first detected in 1987, is now attacked by more than six species of indigenous parasitoids. Newly introduced parasitoids (reported previously) are beginning to be established (Aphelinus albipodus, A. asychis, Aphidius colemani, and A. matricariae), but as of yet, are not important in the bioregulation of grain aphids in Washington. Studies are in progress to determine the habitat diversification, protective refugia, and agroecosystem structure requisite to improve prey/host sustainment and aphid biological control.

Impacts
(N/A)

Publications

• PIKE K and TANIGOSHI LK. 1996. Insect pests and management technologies in dryland wheat in Washington. Amer. J. Alternative Agric. 11:104-107.
• PIKE K and STARY P. 1996. New species of Pauesia (Hymenoptera, Braconidae, Aphidiinae) parasitoids on Cinara (Homoptera, Aphididae, Lachninae) associated with conifers in the PNW. Proc. Entomol. Soc. Wash. 98:324-331.
• PIKE K, STARY P, MILLER R, ALLISON D, BOYDSTON R, GRAF G. and MILLER T. 1996. New species and host records of aphid parasitoids (Hymenoptera: Braconidae: Aphidiinae) from the PNW USA. Proc. Entomol. Soc. Wash. 98:570-591.

Progress 01/01/95 to 12/30/95

Outputs
A first phase inventory of the aphid-parasitoids (Hymenoptera, Braconidae & Aphelinidae) of Washington State was completed in 1994. The region is rich in aphid parasitoids with more than 50 species from 13 genera (Adialytus spp., Aphelinus spp., Aphidius spp., Binodoxys spp., Diaeretiella rapae, Ephedrus spp., Euaphidius spp., Lysiphlebus spp., Monoctonus spp., Pauesia spp., Praon spp., Trioxys spp., and Xenostigmus bifasciatus). Of the total, ten represented new species, and of these, several were found attacking economic aphids and may be valuable for redistribution and use globally. Another six species represented material introduced into North America for aphid control on alfalfa, barley, peas, walnut, and wheat. The cumulative parasitoid-aphid-plant information obtained, in part, illustrates the biological characteristics and interlinkage associations of the species, and provides a faunistic basis for further studies into biodiversity, biosystematics, population structure, species succession, host regulation and biological pest control.

Impacts
(N/A)

Publications

Progress 01/01/94 to 12/30/94

Outputs
Wawawai, a new soft white spring wheat with Hessian fly resistance, was releasedin 1994. The new release represents the joint efforts of many (C. Konzak, WSU Wheat breeder, K. Pike, WSU entomologist, and J. Hatchett, USDA-ARS entomolgist, Manhattan, KS) over many years. It is the 3rd variety developed for the PNW (earlier releases included Waid, a durum wheat, and Wakanz, a soft white wheat). The new wheat is quality and yield competitive with other soft white wheats, and equal to Wakanz in resistance to Hessian fly. Its resistance is mongenic, governed by a single gene (H3), and antibiotic (prevents larval development). Its advantage over Wakanz is its resistance to stem rust (Wawawai yields 2-3 times that of Wakanz in the presence of stem rust). Because of the severity of the fly in recent years in eastern WA and northern ID, Wawawai is expected to become the dominant cultivar. Seed stocks are currently being increased to meet expected demands. Spring barleys are another means of managing the fly. In side-by-side variety trials, NW barleys were shown to be about 80 times more resistant than susceptible wheats.

Impacts
(N/A)

Publications

Progress 01/01/93 to 12/30/93

Outputs
Hessian fly infestations and associated crop injury were wide spread in spring wheats in southeastern Washington in 1993. The most severe cases resulted in crop failure. Lack of genetic resistance in spring wheats coupled with climatic conditions favoring the insect, prompted the outbreak. Estimated average yield reductions in the Palouse region exceeded 40% in late planted spring wheats. Experimental field trials (B. Miller, WSU Agronomist) at Farmington, WA, showed susceptible varieties (Butte 86, Centennial, Edwall, Penawawa, Spillman, Sprite, Treasure, Wadual, and Wampum, yield avg.=45.5 hl/ha; range, 22.8-67.6 hl/ha) yielded 47% less than resistant entries (WA7176, WA7712, Westbred 926, yield avg.=86.4 hl/ha; range, 82.8-91.6 hl/ha). Because of the extent of injury, research efforts to incorporate Hessian fly resistance into new lines were increased. Only 3 commercial wheat varieties in the NW, 'Wakanz' (soft white), 'Westbred 926' (hard red), and 'Waid' (durum), are resistant to Hessian fly, and the former is susceptible to stem rust. A new resistant soft white wheat, 'WA7712', developed cooperatively with C. Konzak (WSU Breeder, Pullman), is expected to be released in 1994.

Impacts
(N/A)

Publications

Progress 01/01/92 to 12/30/92

Outputs
Imidacloprid, a new systemic insecticide (1-((6-Chloro-3-pyridinyl)methyl)-4,5-dihydro-N- nitro-1-H-imidazol-2-a mine; nitroguanidine class chemistry), was evaluated in greenhouse and field trials in Washington and Oregon, 1991-1992, as a seed treatment of wheat and barley to control Russian wheat aphid (RWA), Diuraphis noxia, in spring and fall plantings. The treatment protected new plantings from developing RWA infestations from one to three month. It significantly reduced plant damage in all plantings and increased yields in three of three field trials where plots were entirely infested. As a seed treatment, imidacloprid offers an environmentally safer approach to RWA control than is possible with wide- spectrum aerial or in-furrow granular insecticide treatments. It is especially low risk to nontarget organisms, such as man, beneficial insects, and wildlife. It meets other criteria characteristic of an ideal seed treatment, including compatibility with the commonly used seed fungicides, carboxin (VitavaxSC) and triadimenol (BaytanSC).

Impacts
(N/A)

Publications

Progress 01/01/91 to 12/30/91

Outputs
A network of aphid suction traps, in operation since the mid-80's in the PacificNorthwest, has proved useful in determining the diversity of aphid species in th region, their intensities, seasonal activities, and geographical distributions, and in documenting the advance of the Russian wheat aphid (RWA). The network's catch of aphids has led to the establishment of one of the largest aphid collections in North America, and to the founding of an extensive computer data base on aphid flight. The data base serves as a reference now in defining the relative significance of in-coming trap catches, and in projecting future aphid activity. A complete picture on the RWA flight periodicities, aerial and seasonal densities, and dispersal is under current preparation for publication. The RWA, like other cereal aphids, is vulnerable to changes in weather -- its abundance, population development, dispersal, and flight patterns vary substantially geographically and seasonally. In-state technical reports on RWA and other cereal aphids were released weekly during the growing season through cooperative extension. These reports helped growers recognize when control actions against the aphids were and were not requisite.

Impacts
(N/A)

Publications

Progress 01/01/90 to 12/30/90

Outputs
Known N. Amer. aphids (winged forms) that feed and colonize on the foliage and roots of small grains were characterized in new publication. A key, numerical statistics, and over 250 illustrations comprise the work. Research findings on Russian wheat aphid (RWA) biology, flight, distribution, identification, damage, host plants, plant resistance, natural enemies/biological control, and management were summarized in a new NW bulletin. An index on RWA research projects worldwide was published to help scientists and administrators in coordinating projects. Cooperating with Wash. St. Univ. Extension, 24 aphid reports were issued between Apr & Nov providing current season information to growers on aphid status, aerial flight/movement, population densities, natural enemy releases, and strategies for aphid management. Progress to enhance biological control of RWA in WA was made through the release of nearly 100,000 exotic natural enemies (6 parasitoids and 4 predators) in 1990. Since 1988, more than 250,000 natural enemies have been released at 35 sites in the state. 1990 releases consisted of at least 500 individuals/release. Predators were from the USDA/APHIS-Niles Michigan Lab while parasitoids were mass propagated at Wash. St. Univ. In 1991 a target number of 300,000 beneficials will be reared instate for release against RWA, and augmented with coccinellids reared by USDA/APHIS. Most releases are targeted for conservation reserve plantings (CRP grasses) & nontreated fields of barley & wheat.

Impacts
(N/A)

Publications

Progress 01/01/89 to 12/30/89

Outputs
Russian wheat aphid, first detected in Washington in October 1987, is now widespread in eastern Washington. As a new pest, it has caused differing levels of crop damage, ranging from negligible to total crop loss. In addition to wheat and barley, it is capable of colonizing a wide range of grasses, including the conservation reserve program (CRP) grasses, grown widely in the western states. In collaboration with USDA/ARS personnel at the Western Regional Plant Introduction Station, Pullman, systemic fungal endophytes (Acremonium sp.) were shown to enhance resistance to RWA in selected grasses. Results, based on 7 greenhouse trials, showed endophyte-infected perennial rye grass (Lolium perenne L.) and tall fescue (Festuca arundinacea Schreb.) support only low populations of RWA. Occurrence of Acremonium sp. in other grasses and the nature of the resistance (feeding deterrent or a toxic factor) is under present study. In Washington, as in most parts of the world where small grains are produced, six species of aphids, Russian wheat aphid (Diuraphis noxia), greenbug (Schizaphis graminum), bird cherry-oat aphid (Rhopalosiphum padi), corn leaf aphid (Rhopalosiphum maidis), English grain aphid (Sitobion avenae), and rose grass aphid (Metopolophium dirhodum) account for the majority of the species present. Accurate recognition of the immature stages can be troublesome, yet important to certain studies on aphid-plant interactions and biology.

Impacts
(N/A)

Publications

Progress 01/01/88 to 12/30/88

Outputs
Russian wheat aphid (RWA) advanced from the Texas-Colorado region to the Pacific NW. Beginning in 1988, small founder colonies along WA's southern border led to a rapid spread of the aphid throughout eastern WA. During the summer, RWA prospered on volunteer barley and wheat, on late-planted grains used for ground cover, and to some extent on conservation reserve and native grasses. In the autumn, RWA moved into newly seeded fields of small grains, where in some cases, 100% of the plants became infested. In October, the WSDA supported by the project, established a crisis exemption for chlorphyrifos use on wheat to control RWS (effective 12/1/88). During the Oct.-Nov. period, more than 100,000 ha received insecticide (disulfoton, dimethoate, or chlorphyrifos) treatment. Biological control of RWA -- In July 1988, 2 species of coccinellid predators (Hippodamia variegata (HV) and Propylea quatuorecim-punctata (P14)) were released near Pasco, WA (cooperative effort with USDA/APHIS) on infested orchard grass; in August and Sep.4 releases of 5 different parasitic wasps (Aphelinus varipes, Aphidius matricariae, Aphidius rhophalosiphi, Ephedrus plagiator, and Praon volucre) were made in a pilot project near Pullman, WA on RWA-infested Hordeum grasses. The wasps were obtained as a result of exploration/recovery efforts by USDA and CAB International Biological Control Institute. The parasties before release were cycled through USDA France and Texas SAES quarantine facilities.

Impacts
(N/A)

Publications

Progress 01/01/87 to 12/30/87

Outputs
A 5-year field study, conducted under natural conditions in central Washington on the effects of cereal aphids and barley yellow dwarf virus (PAV- and RMV-like isolates) on yields of winter wheat and winter barley, documented the yields losses associated with the pest complex under different autumn climatic situations. Average yield losses in winter wheat with no aphid control were: 10.4%, for plots seeded 8/20 to 8/31; 14.0%, 9/1 to 9/10; 9.0%, 9/11 to 9/20; 6.1%, 9/21 to 9/30; and 0%, 10/1 to 10/10. Average yield losses in winter barley with no aphid control were: 20.3%, for plots seeded 8/20 to 8/31; 20.1%, 9/1 to 9/10; 16.7%, 9/11 to 9/20; and 10.6%, 9/21 to 9/30. Yields from plots seeded after September were not generally affected by the aphid-virus. This was because of fewer flying cereal aphids to infest the later seedings, and fewer days of suitable fall temperatures for aphid build-up and virus spread in the fields. The predominant aphid in the wheat during the fall was Rhopalosiphum padi; the predominant aphid in barley was R. maidis. For the latter species, populations were 8 to 9 greater in the barley, and may account for the slightly greater injury to barley. For agronomic reasons, principally enhanced yield potential and reduced soil erosion, early fall plantings are generally preferred in Washington. The studies here, provide a clearer basis now for protecting such planings from the fall attack by the cereal; aphids and virus.

Impacts
(N/A)

Publications

Progress 01/01/86 to 12/30/86

Outputs
A network of insect suction traps (24 total traps, each 8 m in height) with a 30.5-cm orifice) as placed in operation in 1985/86 in the major agricultural areas of Washington and Idaho as a means to: characterize the flight activity of the cereal and other aphid species, and alert growers of potential aphid problems. The network, which is jointly managed by Washington State University and the University of Idaho, caught more than 80,000 apohids (ca. 170 spp.) in 1986. An average of 82% (51 spp.) of the total catch were aphids of economic concern; 58% (9 spp.) of the total catch were cereal aphids. On a region-wide basis, the occurrence and proportion of species changed constantly, and was often very different between areas. From July to November, the seasonal occurrence and peak densities of the aphids were summarized and the results, with interpretative commentary, were mailed weekly to various Washington and Idaho growers, fieldmen, county agents, and scientists as a pest and crop management tool. Rhopalosiphum maidis, a common regional aphid pest of barley, was shown to transmit RMV-type barley yellow dwarf virus to barley, a virus-type not previously recognized in Washington.

Impacts
(N/A)

Publications

Progress 01/01/85 to 12/30/85

Outputs
Research documenting barley yellow dwarf virus infectivity of fall migrant alatecereal aphids, timing primary spread of virus in wheat and barley, species composition and relative virus transmission capability of resident aphids, in-fields movement and population development of autumn grain aphids and their effects on winter wheat, and wireworm seed treatment control in small grains was published. A network of 15 insect suction traps was established in eastern Washington and southern Idaho in cooperation with the University of Idaho to document aphid flight across the primary wheat and barley production areas of the two states. The traps are useful in determining alate species composition, seasonal vector occurrence, abundance, population trends, flight patterns, and in providing early warning of potential aphid/virus problems.

Impacts
(N/A)

Publications

Progress 01/01/84 to 12/30/84

Outputs
Six aphid species (Rhopalosiphum padi, Metopolophium dirhodum, Schizaphis graminum, Sitobion avenae, Rhopalosiphum maidis, and Rhopalosiphum insertum) are now recognized to feed and reproduce on, and transmit barley yellow dwarf virus (BYDV) to wheat and barley in Washington. Of these, R. padi is the most important. It is present every year, is generally the most abundant, and is an efficient vector of BYDV. M. dirhodium is an efficient vector, but it is not typically abundant in fields. It is relatively cold hardy and may contribute substantially to virus spread during mild winters. S. graminum, when present, may be comparable to R. padi in importance, but in the last 3-crop seasons has been largely absent from fields. S. avenae is not usually abundant in the fall and is less efficient in transmitting virus than R. padi and M. dirhodum. R. maidis is uncommon in wheat in Washington, but is sometimes numerous in barley in October-November. It is the least efficient virus vector of the grain aphids. R. insertum is not common in fields in Washington. The fall flight of grain aphids, based on suction trap catches (four, 8.0 m high suction traps now operating in Central Washington), extends from late August to early November. Virus transmission rates of winged aphids range from 1-14% in the fall. Transmission rates for in-field colonizing aphids (largely wingless forms) may be substantially higher than for migrating aphids if weather favors their development and no controls are implemented.

Impacts
(N/A)

Publications