Paul J. Semtner

Ph.D., Entomology, 1972, Oklahoma State University

M.S., Entomology, 1970, Oklahoma State University

B.S., Entomology, 1967, Oklahoma State University

  • The tobacco-adapted form of the green peach aphid
    • Insecticide resistance of three color forms of the aphid and the relationship of biochemical characteristics and insecticide resistance
    • Influence of insecticide treatments in the field on the season-long control of the three color forms of the aphid
    • Impact of adverse conditions on the survival of the three color forms of the aphid on their overwintering survival on various winter host plants
    • Effects of temperature on the development and fecundity of the three color morphs on tobacco
  • The impact of cultural practices on tobacco insect pests
    • Conservation tillage is being evaluated for its effects on pest and beneficial insects
  • Biology of the potato tuberworm as a pest of tobacco and its influence on the yield and quality of burley tobacco
    • Assess impact of splitworm damage on the yield and quality of burley tobacco
    • Determine seasonal flight activity in and around tobacco fields and relate to development of infestations on tobacco
  • Insecticide research
    • New, safer, or more environmentally-friendly insecticides for tobacco
    • Evaluate the efficacy of various organic insecticides for aphid management on tobacco
    • Improving tobacco flea beetle management on tobacco after topping
    • Influence of timing and rate of application on insecticide residues in tobacco
  • The objective of the extension program in Virginia is to provide growers with educational programs addressing the profitable production of quality tobacco.  An effective insect management program helps growers improve their profitability.  The extension program for tobacco insect management is closely associated with other programs carried out by extension specialists and Extension agents to provide growers and farm supply dealers with timely research-based information obtained from experiments conducted at the Virginia Tech Southern Piedmont and Southwest Virginia ARECs and on farm.
  • The entomology program emphasizes the following:
    • Insect management in tobacco transplant greenhouses
    • Cultural practices to reduce insect infestations and decrease the need for insecticide applications
    • Use field scouting and economic thresholds to maintain yield and quality and avoid unnecessary insecticide applications
    • Use of selective insecticides with low impact on the environment and avoid the more harmful insecticides
    • Reduce insecticide residues in the cured product
    • Train Extension agents and farm supply dealers so they can help growers with their insect management problems.
    • Update insecticide recommendations annually
  • Extension entomology assists with Master Gardener and pesticide applicator programs.
  • I participate in programs such as the Southern Piedmont AREC Farm and Family Day that provide hands-on experiences for children (pre-K-8) and adults.
  1. Srigiriraju, L., P.J. Semtner, T. Anderson, and J. Bloomquest.  2009. Monitoring for imidacloprid resistance in the tobacco-adapted form of the green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae) in the eastern United States.  Pesticide Science  (Revised and returned to editor)
  2. Srigiriraju, L., P.J. Semtner, T. Anderson, and J. Bloomquest.  2009. Esterase-based resistance in the tobacco-adapted form of the green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae) in the eastern United States.  Archives in Insect Biochemistry and Physiology  (In press).
  3. Srigiriraju, L.  2008.  Quantification of Insecticide Resistance in the Tobacco-Adapted Form of the Green Peach Aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae).   Ph.D. Dissertation.  Virginia Polytechnic Institute and State University, Blacksburg, Virginia.  208 p.
  4. Semtner, P.J., D.R. Peek, and H.L. Jerrell.  2006.  Whitefringed beetle (Coleoptera: Curculionidae) impact on growth and yield on burley tobacco in Virginia.  J. Entomol. Sci.  41(2): 179-183.
  5. Dara, S.K. and P.J. Semtner.  2006.  Introducing Pandora neoaphidis (Zygomycetes: Entomophthorales) into populations of Myzus persicae (Homoptera:  Aphididae) on flue-cured tobacco.  J. Agric. Urban Entomol.  22(3) 173-180.
  6. Dara, S.K. and P.J. Semtner.  2007.  Within-plant distribution of Pandora neoaphidis (Zygomycetes: Entomophthorales) in populations of the tobacco-feeding form of Myzus persicae (Homoptera:  Aphididae) on flue-cured tobacco.  J. Agric. & Urban Entomol.  23 (2): 65-76.