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Roger R Youngman, PhD

Title Professor and Extension Specialist Phone (540) 231- 9118 Fax (540) 231-9131 E-Mail youngman@vt.edu Address 308 Price Hall Virginia Tech Blacksburg, VA 24061 Web Additional Web Site

I have a 75% extension, 15% research, and 10% teaching appointment in the Department of Entomology. My primary responsibility is to develop integrated pest management (IPM) programs and research-based extension information for field corn, alfalfa, grass hay and pasture, and commercial turfgrass. IPM strives to combine different management strategies in ways that provide growers with effective, long-term solutions to recurring pest problems. There are many benefits of an IPM approach. For grain and forage crops, the grower can expect improved yields and forage quality. For turfgrass, the end user can expect turf that is visually appealing and better suited to withstand pest pressure. Overall, this translates into lower pest control costs and decreased risk to the environment from fewer unnecessary insecticide applications.

Instruction and graduate student education:
I serve as instructor for one-third of AT 0434 (Pest Control: Insects, Diseases, and Weeds; 4 credits) every fall. I place a strong emphasis on having my students gain an appreciation of the entomological principles of insect identification, biology, and insect ecology as related to agricultural and turfgrass systems. Additional topics of discussion include genetically-engineered crops, resistance management, and IPM. My section of AT 0434 has been available online since 1997. My course web site contains over 50 web pages of lecture notes and related handouts in addition to approximately 250 slides and other visual aids. The laboratory handouts and insect identification keys were revised and added to the course web site in 2003.

Graduate students are critical to the success of my research and extension programs.  I work to ensure that my students are thoroughly grounded in the principles of entomology, IPM, quantitative ecology, and statistics.  In addition, my students are exposed to the many challenges unique to field research programs.  Currently, I serve as major advisor to one MSLFS student and co-major advisor to one Ph.D. student.

Blurb last modified at 2007-08-12 10:32:24.0.

Future Direction

My primary research and extension efforts have focused on creating research-based pest management programs for key pests of corn, alfalfa, and grass hay and pasture. My lab has developed economic thresholds and inexpensive monitoring tools in addition to conducting timing and rate studies for optimizing judicious insecticide use. Supporting work has involved multi-year investigations on integrating biological control, crop rotation, and resistant varieties into existing corn and alfalfa IPM programs. I will continue to pursue similar studies in the future to keep abreast of rapidly changing technologies and their potential for impacting existing IPM programs. In addition, I plan to significantly expand my research and extension education efforts on improving pest management for several key pests of commercial turfgrass.

Professional Memberships

• Entomological Society of America
• Epsilon Sigma Phi
• Gamma Sigma Delta - Honor Society of Agriculture
• Geogia Entomological Society
• Golf Course Superintendents Association of America
• Sigma Xi (Scientific Research Society)
• South Carolina Entomological Society

Personnel

• Faculty
  • Laub, Curt
• Student
  • Jordan, Timothy

Former Students and Faculty Associates

• Siddharth Tiwari (2006) - Postdoctoral research associate (email: stiwari@vt.edu)
• Roberto J Cordero (2005) - Research Entomologist/Technical Rep. Seminis Seeds - Monsanto Corp.
• Theresa (Tree) A Dellinger (2003) - (email: tdellin@vt.edu)
• Thomas P Kuhar (2000) - Associate Professor (email: tkuhar@vt.edu)
• David G Midgarden (1992) -

Projects

• Combined effects of alfalfa weevil and potato leafhopper on yield and forage quality of glandular-haired alfalfa → website
  A three-year Virginia field study found that a commercial leafhopper-resistant alfalfa variety did not provide acceptable resistance to potato leafhopper. Our cost-benefit analysis indicated that growers who planted this ineffective variety lost nearly $31 more per acre than growers who planted one of the many standard, non-leafhopper resistant varieties suited to Virginia.
  
  
• Commercial Turfgrass IPM: Novel Insecticides for Managing White Grubs and Cutworms
  The annual white grub complex and black cutworm are two of the most important pest groups affecting turf in Virginia. Insecticide management costs for these pests alone are estimated at hundreds of thousands of dollars annually. Recent industry research has produced two new insecticides, chloroantraniliprole for white grubs, and indoxacarb for cutworms. My current research on Virginia sod farms and golf courses is evaluating timing and rate options for these materials. It is expected that our findings will improve resistant management options for white grubs and cutworms as well as other important pests of commercial turfgrass in the near future.
  
  
• Developing a fall sampling method for predicting spring-planted corn fields with economic infestations of secondary insect pests
  Fall sampling for secondary soil insects on corn has become important to corn growers who plan on using seed-applied insecticides for these pests. This relatively new seed-applied insecticide technology requires that growers order this technology at the same time they place their seed orders, which is usually done in late fall or early winter. Consequently, the information gained from standard pre-plant sampling methods typically done two weeks before spring planting is too late to be useful. In fall 2005 and 2006, a standard soil sampling method and a more efficient sampling method we developed for detecting annual white grubs were compared in fifteen fields in eastern Virginia. The results indicated no significant difference in numbers of annual white grubs detected between the two sampling methods.
  
  
• Ecology and management of wireworms
  Wireworms are the larval stage of click beetles and can be serious underground pests of many crops particularly potatoes. A number of research grants have been obtained by Dr. Kuhar to study the management of this important pest group. Projects include the following: 1) Monitoring species complex, 2)Evaluating sampling methods, 3) Investigating habitat preferences, 4)studying the phenology of wireworms with potato crop development, and 5)Evaluating novel insecticide chemistries and timings for control.
  
  
• Evaluation of soil sampling methods and management options for secondary pests on field corn in eastern Virginia
  Numerous on-farm trials since 2003 have indicated that the Virginia-developed, baited wire trap method consistently attracts more wireworms and correctly identifies more cornfields at risk to wireworms, seedcorn maggot, and annual white grubs (i.e., secondary pests) than the bait station method. These secondary pests attack corn seeds and seedlings soon after planting, which leads to reduced plant stands, poor seedling vigor, and lower grain and forage yields. In addition, two new seed-applied insecticides continue to show promise as powerful management tools for use against these secondary pests.
  
  
• Extension - Alfalfa and Grass Hay Pest Management → website
  Alfalfa serves as a high quality source of feed for the beef and dairy cattle industries in Virginia. A total of 110,000 acres of alfalfa were grown in Virginia in 2005, which produced 396,000 tons of hay valued at $50 million (2006 Va. Agric. Statistics Bull.). Grass hay production is another important livestock feed for Virginia. In 2005, grass hay production on 1.2 million acres produced 2.6 million tons of hay valued at $270 million. Alfalfa weevil and potato leafhopper are the main insect pests on alfalfa, whereas bluegrass billbug and Japanese beetle (one of the most damaging of the annual white grub species) are the main pests on grass hay and pasture fields. Grass hay pest management represents a new direction for my lab. This is largely in response to the bluegrass billbug and Japanese beetle outbreak on tens of thousands of acres of Virginia orchardgrass in 2005.
  
  
• Extension - Commercial Turfgrass IPM
  There are over 1.7 million acres of maintained turf in Virginia with nearly 40% of this total in commercial turf farms, golf courses, parks, schools, and industrial sites according to an August 2006 survey published by Virginia's Turfgrass Industry. As society becomes more urbanized, the need for expanded educational opportunities emphasizing environmental stewardship in turfgrass management are being realized. In 2006, the Virginia Tech Turf Team working with the Virginia Turfgrass Council has begun to address these educational opportunities by continuing to offer several Turfgrass workshops around the state and the week long Turf Short course held in Blacksburg every year. In addition, the Virginia Turfgrass Field Day, which also is held annually in Blacksburg, was expanded to a two-day educational event. The first day featured an equipment demonstration component and expanded tours of the applied research at the Virginia Tech Golf Course, Glade Road Research Center, and the Turfgrass Research Center. The second day took a new look in that specific research tours for the four primary segments of the turfgrass industry (Golf, Sports Turf, Lawn/landscape, and Sod Production) were showcased.
  
  
• Extension - Large Animals and Poultry Pest Management
  The 2005 cash receipts for all livestock, poultry, and associated products (e.g., milk and eggs) totaled more than $2.52 billion for Virginia producers (2006 Va. Agric. Statistics Bull.). More specifically, the combined cash receipts for cattle and calves, broilers, turkeys, hogs, and sheep and lambs totaled $2.16 billion for 2005. The major insect pests of all Virginia animal production operations are biting flies, lice, and nuisance flies associated with improper waste management.
  
  
• Extension - Management of Soil and Stalk Boring Insects on Field Corn
  Field corn harvested for grain and silage serves as a high quality source of feed for the beef, dairy cattle, and poultry industries in Virginia. Cash receipts for corn grain production in 2005 totaled more than $89 million, in addition to $68 million in gross value for corn silage production (2006 Va. Agric. Statistics Bull.). The primary insect pests on corn in Virginia are the western corn rootworm and European corn borer. In addition to these, several secondary pests, such as annual white grubs, wireworms, and seedcorn maggot continue to be a main focus area for my extension and applied research efforts.
  
  
• Host effects of leafhopper resistant glandular-haired alfalfa on alfalfa weevil and potato leafhopper populations in Virginia → website
  A three-year field study indicated that the leafhopper resistant alfalfa variety in this study did not provide acceptable resistance to potato leafhopper. This particular leafhopper resistant variety, which was sold at a premium for such purpose, is no longer being marketed by the parent company.
  
  
• Investigations on the interaction between spatially separated herbivores on field corn
  Greenhouse studies were conducted in 2004, 2005, and 2006 to examine the reciprocal effects of aboveground herbivory by European corn borer, Ostrinia nubilalis Hübner (Lepidoptera: Crambidae), and belowground herbivory by root knot nematode, Meloidogyne incognita Chitwood (Tylenchida: Heteroderidae), on one another at three growth stages of corn, Zea mays L. Although numerous studies have been published on the interactions between different herbivorous insects on a common host plant, few of this nature have been published on insect-nematode interactions on a common host plant.
  
  
• Relationship of European corn borer on whole-plant corn yield
  Previous research has focused almost exclusively on the impact of European corn borer on corn grown for grain. Findings from our two-year field study have indicated that 3-4 tunnels per stalk are necessary before economic loss occurs in whole-plant yield. The significance of this is that our field surveys have shown that this level of tunneling pressure rarely occurs in field corn in Virginia. These findings promise to offer growers in Virginia as well as in other Mid-Atlantic states much needed information on the impact of European corn borer on corn grown for silage.
  
  

Courses

• AT 00 Agricultural Technology Pest Control: Insects, Diseases, and Weeds: Lab Section of Insect Segment → website
  The laboratory section of the insect segment of Agricultural Technology AT0434 is used to familiarize students with basic insect identification and to teach students to distinguish between different types of damage caused by pests most likely to be encountered by graduates of this program.
  
  
• AT 0434 Pest Control: Insects, Diseases & Weeds → website
  I place a strong emphasis on having my students gain an appreciation of the entomological principles of insect identification, biology, and insect ecology as related to agricultural and turfgrass systems. Additional topics of discussion include genetically-engineered crops, resistance management, and IPM. My section of AT 0434 has been available online since 1997. My course web site contains over 50 web pages of lecture notes and related handouts in addition to approximately 250 slides and other visual aids. The laboratory handouts and insect identification keys were revised and added to the course web site in 2003.
  
  

Recent Publications

• Dellinger, T. A., Luckhart, S., Youngman, R. R. 2008. Molecular variation in populations of Bathyplectes anurus (Thomson) (Hymenoptera: Ichneumonidae), a parasitoid of Hypera postica (Gyllenhal) (Coleoptera: Curculionidae), in Virginia and other alfalfa-growing states. Argicultural and Forest Entomol. Submitted 2007
• Hitchner, E., Kuhar, T. P., Dickens, J. C., Youngman, R. R., Schultz, P. B., Pfeiffer, D. G. 2008. Host plant choice experiments of Colorado potato beetle (Coleoptera: Chrysomelidae) in Virginia. J. Econ. Entomol. 101: 859-865
• Jordan, T., Laub, C., Youngman, R. R. 2007. Slugs in field corn. Va. Coop. Ext. pub. 444-109
• Laub, C., Youngman, R. R. 2007. Tachinid fly parasitoids. In Lamp, W. O., R. C. Berberet, L. G. Higley, and C. R. Baird (eds) Handbook of Rangeland and Forage Insects (180 pp.). Entomological Society of America. APS Press
• Youngman, R. R. 2007. Wasp parasitoids. In Lamp, W. O., R. C. Berberet, L. G. Higley, and C. R. Baird (eds) Handbook of Rangeland and Forage Insects (180 pp.). Entomological Society of America. APS Press
• Cordero, R. J., Kuhar, T. P., Speese, III, J., Youngman, R. R., Lewis, E. ., Bloomquist, J. R. 2006. Field efficacy of insecticides for control of lepidopteran pests on collards in Virginia. . Plant Health Progress. doi:10.1094/PHP-2006-0105-01-RS.
• Cordero, R. J., Kuhar, T. P., Speese, III, J., Youngman, R. R., Lewis, E. ., Bloomquist, J. R., Kok, L. T., Bratsch, A. D. 2006. Field efficacy of insecticides for control of lepidopteran pests on collards in Virginia. Online. Plant Health Progress doi:10.1094/PHP-2006-0105-01-RS
• Dellinger, T. A., Youngman, R. R., Laub, C., Brewster, C. C., Kuhar, T. P. 2006. Yield and forage quality of glandular-haired alfalfa under alfalfa weevil (Coleoptera: Curculionidae) and potato leafhopper (Homoptera: Cicadellidae) pest pressure in Virginia. J. Econ. Entomol. 99(4): 1235-1244
• Hoffmann, M. P., Pitcher, S. A., Cheever, S. A., Gardner, J., Losey, J. E., Laub, C., Youngman, R. R., Kuhar, T. P. 2006. Efficacy of inoculative releases of Trichogramma ostriniae (Hymenoptera: Trichogrammatidae) against European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), in field corn.. Biol. Contr. 36: 345-349.
• Tiwari, S., Youngman, R. R., Laub, C. 2006. Japanese beetle in field corn. Va. Coop. Ext. pub. 444-106
• Youngman, R. R., Bloomquist, J. R., Hall, J. B., Paulson, S. L., Whittier, W. D. 2006. Agricultural Animal Pest Control: A Guide for Livestock Managers in Virginia (134 pp.). Va. Coop. Ext. pub. 456-215
• Dellinger, T. A., Youngman, R. R., Laub, C., Brewster, C. C., Kuhar, T. P. 2005. Host effects of glandular-haired alfalfa on alfalfa weevil (Coleoptera: Curculionidae) and potato leafhopper (Homoptera: Cicadellidae) populations in Virginia. J. Econ. Entomol. 98: 72-81.
• Hagood, E., Baudoin, A., Day, E. R., Derr, J., Eisenback, J. D., Faircloth, J., Grisso, R., Herbert, Jr, D. A., Hipkins, P. L., Johnson, C. S., Kuhar, T. P., Pfeiffer, D. G., Phipps, P., Semtner, P. J., Speese, III, J., Stromberg, E., Waldenmaier, C., Wilson, H., Yoder, K., Youngman, R. R. 2005. Agricultural Plant Pest Control: A Guide for Agricultural Plant Pest Managers in Virginia (270 pp). Va. Coop. Ext. pub. 456-214
• Jackson, B. T., Paulson, S. L., Youngman, R. R., Scheffel, S., Hawkins, B. 2005. Oviposition preferences of Culex restuans and Culex pipiens (Diptera: Culicidae for selected infusions in oviposition traps and gravid traps. J. American Mosquito Control Association. Vol. 21: 360-365
• Tiwari, S., Laub, C., Youngman, R. R. 2005. Asiatic garden beetle in field corn. Va. Coop. Ext. pub. 444-108
• Schooley, T. N., Stromberg, E., Laub, C., Youngman, R. R., Weaver, M. J., Hagood, E. 2004. Crop Profile for Alfalfa in Virginia. National IPM Centers. [http://www.ipmcenters.org/cropprofiles/docs/vaalfalfa.html] 18pp.
• Youngman, R. R., Tiwari, S. 2004. Recent advances and developments in corn integrated pest management. Pp. 209-245. In A. R. Horowitz and I. Ishaaya [eds.], Insect Pest Management - Field and Protected Crops, Springer-Verlag Berlin Heidelberg (Book Chapter)
• Dellinger, T. A., Youngman, R. R., Laub, C. 2003. Recovery of Oomyzus incertus (Hymenoptera: Eulophidae), a larval parasitoid of Hypera postica (Coleoptera: Curculionidae), in Virginia. J. Entomol. Sci. 38 (1): 141-142
• Kuhar, T. P., Youngman, R. R., Laub, C. 2001. Alfalfa Weevil (Coleoptera: Curculionidae) phenology with its host crop and parasitoids in Virginia. . J. Entomol. Sci. 36: 352-365.
• Kuhar, T. P., Youngman, R. R., Laub, C. 2000. Population dynamics and mortality of the alfalfa weevil (Coleoptera: Curculionidae) in Virginia.. J. Entomol. Sci. 36: 352-365.
• Kuhar, T. P., Youngman, R. R., Laub, C. 1999. Alfalfa weevil (Coleoptera: Curculionidae) pest status and incidence of Bathyplectes anurus (Hymenoptera: Ichneumonidae) and Zoophthora phytonomi (Zygomycetes: Entomophthorales) in Virginia. . J. Econ. Entomol. 92: 1184-1189.
• Kuhar, T. P., Youngman, R. R. 1998. Olson yellow sticky trap: a decision-making tool for sampling western corn rootworm (Coleoptera: Chrysomelidae) adults in field corn. . J. Econ. Entomol. 91: 957-963.
• Kuhar, T. P., Laub, C., Youngman, R. R. 1997. Risk of western corn rootworm (Coleoptera: Chrysomelidae) damage to continuous corn in Virginia.. J. Entomol. Sci. 32: 281-289.
• Youngman, R. R., Kuhar, T. P., Midgarden, D. G. 1996. . Effect of trap area on efficiency of yellow sticky traps for sampling western corn rootworm (Coleoptera: Chrysomelidae) adults in corn. . J. Entomol. Sci. 31: 277-285.
• Kuhar, T. P., Youngman, R. R. 1995. Sex ratio and sexual dimorphism in western corn rootworm (Coleoptera: Chrysomelidae) adults on yellow sticky traps in corn. . Environ. Entomol. 24: 1408-1413.

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