Sujaya Rao
Professor, Field Crop Entomologist

Pest Management in Grass Seed and Rotational Crops
Native Bee Pollinators in Agricultural and Native Landscapes

OSU Campus
Department of Crop and Soil Science
4050 Cordley Hall
Corvallis, OR 97331
United States
(541) 737-9038


Pest Management in Grass Seed and Rotational Crops:

Objectives of the program: 1) Identify new pests entering Oregon, and determine their pest status; 2) Examine the biology for identification of weak links that can be targeted for pest management; 3) Develop pest management strategies with minimal negative impact on the environment. Current research and achievements:

  1. Hylastinus obscurus, clover crown borer, a pest in red cloer seed production: biology, distribution, and evaluation of pest monitoring and management strategies.
  2. Tipula paludosa and T. oleracea, exotic crane fly pests: development of a molecular marker for early identification at the immature stage; evaluation of the impact of the insect pathogen, Bacillus thuringiensis israelensis on larvae.
  3. Oulema melanopus, the cereal leaf beetle: field evaluation of its aggregation pheromone, biological control using the larval parasitoid Tetrastichu julis, host preference behavior.
  4. Sphenophorus spp., billbugs: development of a molecular marker for early identification at the immature stage, distribution and damage in bluegrass.
  5. Epichloe typhina, choke disease pathogen: examination of its biology and interactions with host grasses and Botanophila spp., choke flies that serve as a vector for fertilization in the fungus, population genetic study for comparison of populations in Oregon with those in areas of endemism in Europe.
  6. Chirothrips manicatus, seed-feeding thrips: crop range and impact on seed yield.

Native Bee Pollinators in Agricultural and Native Landscapes:

Objectives: Determine the diversity and abundance of native bees in diverse cropping systems and surrounding habitats, and evaluate the impacts of bumble bees and honey bees in pollination. Specific areas of research:

    Red and arrow leaf clover

Wild habitat - West Eugene Wetlands

I accept graduate students for Crop and Soil Science


Hoffman, G. D. and Rao, S. 2014. Fertilization of Epichloë typhina stromata by mycophagous slugs. Mycologia 106: 1-7. doi:10.3852/13-069.

Rao, S. and Skyrm, K. M. 2013. Nest density of the native bumble bee, Bombus nevadensis Cresson (Hymenoptera: Apoidea), in an agricultural landscape. Journal of the Kansas Entomological Society. 86: 93-97.

Hoffman, G. D. and Rao, S. 2013. Association of slugs with the fungal pathogen Epichloë typhina (Ascomycotina: Clavicipitaceae): potential role in stroma fertilization and disease spread. Annals of Applied Biology. 162: 324-334.  DOI: 10.1111/aab.12024.

Rao, S. and Strange, J. P. 2012. Bumble Bee (Hymenoptera: Apidae) Foraging Distance and Colony Density Associated with a Late-Season Mass Flowering Crop Environ. Entomol.41: 905-915.

Rao, S., Alderman, S.C, Kaser, J. M. and Hoffman, G. D. 2012.Fertilization of Epichloë typhina in cultivated Dactylis glomerata by factors besides Botanophila flies. In:Young CA, Aiken G, McCulley, R, Strickland, and Schardl CL, (eds). Epichloae,endophytes of cool season grasses: Implications, utilization and biology. pp: 122-126.

Roberts, D. Vyhnanek, K., and Rao, S. 2012. Multi-agency team uses university archival tool to conserve vital project information. Journal of Extension. 50(2): Article 2TOT8.

Roberts, D., and Rao, S. 2012. Extension leads multi-agency team in suppressing a pest in the west. Journal of Extension. 50(2): Article 2FEA10.

Kimoto C, DeBano SJ, Thorp RW, Rao S, Stephen WP. 2012. Investigating temporal patterns of a native bee community in a remnant North American bunchgrass prairie using blue vane traps. Journal of Insect Science 12:108.Available online: http://www.insectscience. org/12.108.

Maxfield-Taylor, S., Rao, S. and Skrym, K. 2011. A scientific note on the first record of Sphaerularia bombi (Nematoda: Tylenchida: Sphaerularidae), a parasite of bumble bee queens, in the Pacific Northwest. The Pan-Pacific Entomologist 87: 136-139.

Skyrm, K.M., Rao, S. and Stephen, W.P. 2011.  A scientific note on bivoltinism in western North American bumble bees. Apidologie. DOI: 10.1007/s13592-011-0086-9.

Hoffman, G. D. and Rao, S. 2011. Cereal leaf beetle, Oulema melanopus (L.) (Coleoptera: Chrysomelidae) oviposition site selection on oats: the effect of plant architecture, plant and leaf age, tissue toughness, and hardness. Entomologia Experimentalis et Applicata 141: 232-244.

Scherr, M., Wooster, D. and Rao, S. 2011. Interactions between macroinvertebrate taxa and complex environmental gradients influencing abundance and distribution in the Umatilla River, northeastern Oregon. Journal of Freshwater Ecology 26: 255-266.

Broussard, M., Rao, S., Stephen, W. P. and White, L. 2011. Native bees, honey bees and pollination in Oregon cranberries. HortScience 46(6): 885-888.

Rao, S., Stephen, W. P., Kimoto, C., and DeBano, S. 2010. The status of the 'red listed' Bombus (Bombus) occidentalis (Hymenoptera: Apiformes) in northeastern Oregon. Northwest Science 85: 64-67.

Hoffman, G., and Rao, S. 2010. Cereal Leaf Beetle, Oulema melanopus (L.) (Coleoptera: Chrysomelidae), attraction to oat plantings of different ages. Journal of the Entomological Society of British Columbia 107:57-66.

Scherr, M., Wooster, D. and Rao, S. 2010. Effects of temperature on growth rate, development, and behavior of Epeorus albertae (Ephemeroptera: Heptageniidae) nymphs. Environmental Entomology 309: 2107-2024.

Maynard, G. and Rao, S. 2010. The solitary bee, Leioproctus (Leioproctus) nigrofulvus, in SE Australia: Unique termite-mound-nesting behavior and impacts of bushfires on local populations. Pan-Pacific Entomologist 86: 14-19.

Rao, S. and Stephen, W. P. 2010. Abundance and diversity of native bumble bees associated with agricultural crops: The Willamette Valley Experience. Psyche doi:10.1155/2010/ 354072.

Rao, S., Alderman, A., and Murphy, A. 2010. Floret-infesting thrips in grass seed crops: Crop host range and seed loss. Seed Technology. 32: 26-36.

Alderman, S.C., Rao, S., and Martin, R. 2010. First report of Dicyma pulvinata on Epichloë  typhina and potential for E. typhina control. Plant Health Progress. doi:10.1094/PHP-2010-0216-01-RS.

Fun Fact


  • Distinguished Achievement Award in Teaching, Entomological Society of America. 2010.
  • James and Mildred Oldfield / E. R. Jackman Team Award, College of Agricultural Sciences, Oregon State University. 2010.
  • Administrator's Award for team work in IPM, APHIS PPQ. 2010.
  • Deputy Administrator's Safeguarding Award for IPM team research, USDA. 2009.
  • Western Region Extension Director’s Award of Excellence. 2009.
  • Insect Pest Management Team Award, Pacific Branch, Entomological Society of America. 2009
  • Hodson Alumnus Award, Department of Entomology, University of Minnesota, 2009.
  • OECD Fellowship (Organization for Economic Cooperation and Development), France. 2008.
  • L.L. Stewart Faculty Scholar, Oregon State University. 2007.
  • Distinguished Achievement Award in Teaching, Pacific Branch, Entomological Society of America. 2007.
  • Educator of the Year Award, Linn Soil and Water Conservation District, Linn County, Oregon. 2006.
  • James and Mildred Oldfield / E. R. Jackman Team Award, College of Agriculture, Oregon State University. 2006 - Rural Science Education.
  • Rural Studies Program Faculty Fellow, Rural Studies Program, Oregon State University. 2006.
  • Distinguished Achievement Award in Teaching, Pacific Branch, Entomological Society of America. 2004.
  • James and Mildred Oldfield / E. R. Jackman Team Award, College of Agriculture, Oregon State University. 2004 - Discovery Days.
  • Excellence in Entomology Outreach Award, Department of Entomology, Oregon State University. 2003.
  • Henry & Sylvia Richardson Award, Entomological Society of America (ESA). 1992.
  • Travel Award, Commission on the Status of Women, University of Delaware. 1992.
  • H. Comstock Award, North Central Branch, ESA. 1991.
  • President's Prize, Display Presentation, ESA Student competition. 1991.
  • Doctoral Dissertation Fellowship, University of Minnesota. 1990.
  • Philip C. Hamm Memorial Graduate Student Scholarship Award, University of Minnesota. 1990
  • Granovsky Pest Management Scholarship, University of Minnesota. 1990
  • Graduate Student Award (Ph.D. - paper presentation), North Central Branch, ESA. 1989
  • Linnaean Games championship (with 3 other team members), North Central Branch, ESA. 1989.