Grzegorz (Greg) Krawczyk, Ph.D.

Grzegorz (Greg) Krawczyk, Ph.D.

  • Extension Tree Fruit Entomologist
  • Research Professor
Department of Entomology
Fruit Research and Extension Center
The Pennsylvania State University
P.O. Box 330

Biglerville, PA 17307-0330

Areas of Expertise

  • Insect plant interactions
  • Integrated pest management
  • Biological control
  • Tree fruit insect pests
  • Insects rearing
  • Laboratory and field bioassays
  • Invasive insect pests
  • Pesticide resistance


  • Ph. D. (1996) Michigan State University
  • M. Sc. (1986) Agricultural University, Lublin, Poland

Research Activities & Interests

Integrated pest management in agricultural ecosystems

  • Sustainable fruit production methods
  • Biology and management of tree fruit insect pests
  • Pesticide resistance management in agricultural ecosystems
  • Phytophagous and predatory mite management in orchard ecosystems
  • Insect rearing techniques/laboratory bioassays

Recent Publications 

  • Sultan, M. M., A. Zahid, L. He, D. Choi, G. Krawczyk,H. Zhu and P. Heinemann. 2021. Development of LiDAR-guided section-based tree canopy density measurement syetm for precision spray applications. Computers and Electronics in Agriculture. (in press)
  • Peterson, D.M, E. Talamas, G. Krawczyk. 2021. Survey for adventive populations of the samurai wasp, Trissolcus japonicus(Hymenoptera: Scelionidae) at commercial fruit orchards and the surrounding forest. Insects DOI: 10.3390/insects12030258 (in press)
  • Alford, A., T. P. Kuchar, G. C. Hamilton, P. Jentsch, J. F. Walgenbach and C. Welty. 2020. Baseline toxicity of the insecticides bifenthrin and thiamethoxam on Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) collected from the Eastern U.S.A. 2020. Journal of Economic Entomology. 113(2), 1043–1046, doi: 10.1093/jee/toz361
  • Joshi, N.K., Hull, L.A. and Krawczyk, G. (2020). Insecticide baseline sensitivity in codling moth (Cydia pomonella) populations from orchards under different management practices. J. Entomol. Sci. Vol. 55, No. 1
  • Ludwick, D., W. R. Morrison III, A. L. Acebes-Doria, A. M. Agnello, J. C. Bergh, M. L. Buffington, G. C. Hamilton, J. K. Harper, K. A. Hoelmer, G. Krawczyk, T. P. Kuhar, D. G. Pfeiffer, A. L. Nielsen, K. B. Rice, C. Rodriguez-Saona, P. W. Shearer, P.M. Shrewsbury, E. J. Talamas, J. F. Walgenbach, N. G. Wiman, and T. C. Leskey.  2020. Invasion of brown marmorated stink bug (Hemiptera: Pentatomidae) into the USA: Developing a national response to an invasive species crisis through collaborative research and outreach efforts. Journal of Integrated Pest Management 11(1): 4; 1–16. doi: 10.1093/jipm/pmaa001
  • Krawczyk, G., H. Peterson, H. Rice and E.H. Winzeler. 2020. Insecticide treated nets as an alternative tool to manage brown marmorated stink bug, Halyomorpha halys (Stal). Pennsylvania Fruit News 100(1): 20-22
  • Acebes-Doria, A,  A. Agnello, D. Alston, H. Andrews, E. Beers, C. J. Bergh, R. Bessin, B. Blaauw, D.G. Buntin, E. Burkness, S. Chen, T. Cottrell, K. Daane, L. Fann, S. Fleisher, C. Guedot, L. Gut, G. Hamilton, R. Hilton, K. Hoelmer, W. Hutchison, P. Jentsch, G. Krawczyk, T. Kuhar, J. Lee, J. Milnes, A. Nielsen, D. Patel, B. Short, A. Sial, L. Spears, K. Tatman, M. Toews, J. Walgenbach, C. Welty, N. Wiman, J. van Zoeren, and T. Leskey. 2019.  Season-long Monitoring of the Brown Marmorated Stink Bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), Throughout the United States using Commercially Available Traps and Lures. J. Econ. Entomol. doi: 10.1093/jee/toz240
  • Leach, H., D. J. Biddinger, G. Krawczyk, E. Smyers, and J. M. Urban. 2019. Evaluation of Insecticides for Control of the Spotted Lanternfly, Lycorma delicatula, (Hemiptera: Fulgoridae), a New Pest of Fruit in the Northeastern U.S. Crop Protection.
  • Krawczyk, G., H. Morrin and C. Hirt. 2019. Alternative methods to manage brown marmorated stink bug, Halyomorpha halys. IOBC-WPRS Bulletin 146 (2019):114-118
  • Peterson, H., J. Ali and G. Krawczyk. 2019. Biocontrol of invasive Halyomorpha halys.  IOBC-WPRS Bulletin 146 (2019): 119-120
  • Krawczyk, G., H. Leach, C. Hirt, H. Rice and J. Urban. 2019. Potential New Invasive Pest Species in United States – Spotted Lanternfly, Lycorma delicatula. IOBC-WPRS Bulletin 146 (2019): 132-136.
  • Hayek, A. E., L. F. Solter, J. V. Maddox, W. F. Huand, A. S. Estep, G. Krawczyk, D. C. Weber, N. D. Sanscrainte and J. J. Becnel. 2017. Nosema maddoxisp. nov. (Microsporidia, Nosematidae), a widespread pathogen of green stink bug Chinavia hilarisand the brown marmorated stink bug, Halyomorpha halys(Stal).  J. Eukaryotic Microbiology 65: 315-330, doi:10.1111/jeu.12475
  • Mujica, V.,  M. Preti,  E. Basoalto,  L. Cichón, E. Fuentes-Contreras,W. Barros-Parada,G. Krawczyk, M. Z. Nunes, J. Walgenbach, R. Hansenand A. Knight, 2018. Improved monitoring of oriental fruit moth (Lepidoptera: Tortricidae) with terpinyl acetate plus acetic acid membrane lures.  Journal of Applied Entomology,doi: 10.1111/jen.12528
  • Morrison, W., B. Blaauw, B. Short, A. Nielsen, C. J. Bergh, G.  Krawczyk, Y-L. Park, B. Butler, A. Khrimian, and T. Leskey. 2018.  Successful management of Halyomorpha halys(Hemiptera: Pentatomidae) in commercial apple orchards with an attract-and-kill strategy. Pest Management Science. doi:10.1002/ps.5156
  • Krawczyk, G., H. Morin and C. Hirt. 2018. Alternative methods to manage brown pest management Scincemarmorated stink bug Halyomorpha halys (Stal) as component of IPM practices in Pennsylvania orchards. Pennsylvania Fruit News 98(1): 17-19
  • Krawczyk, G., M. Zanelato Nunes, H. Morin and L. Shaak. 2017. New endeavors in monitoring and management of brown marmorated stink bug Halyomorpha halys(Hemiptera: Pentatomidae) in eastern United States. IOBC-WPRS Bulletin. 123: 50-56
  • Krawczyk, G. and L. Shaak. 2017. Field experience with monitoring Grapholita molesta(Busck) in peach and apple orchards treated with mating disruption. IOBC-WPRS Bulletin 126: 79-81
  • Kuchar, T., B. Short, G. Krawczyk and T. Leskey. 2017.  Deltamethrin- incorporated nets as an integrated pest management tool for the invasive Halyomorpha halys(Hemiptera: Pentatomidae). Journal of Economic Entomology. 110(2):543-545, doi: 10.1093/jee/tow321
  • Joshi, N. K.,E.G. Rajotte, K. J. Naithani, G. Krawczyk and L. A. Hull. 2016. Population dynamics and flight phenology model of codling moth differ between commercial and abandoned apple orchards ecosystems.  Front. Physiol. 7:408. doi: 10.3389/fphys.2016.00408
  • Nielsen, A., S. Fleischer, G. Hamilton, T. Hancock, G. Krawczyk, J. Lee, E. Ogburn, J. Pote, A. Raudenbush, A. Rucker, M. Saunders, V. Skillman, J. Sullivan, J. Timer, J. Walgenbach, N. Wiman, and T. Leskey. 2016. Phenology of Halyomorpha halysdescribed using female reproductive development. Ecology and Evolution. DOI: 10.1002.ece3.3125
  • Joshi. N. K.,E. G. Rajotte, C. T. Myers, G. Krawczyk and L. A. Hull. 2015. Development of a susceptibility Index of apple cultivars for codling moth, Cydia pomonella (L) (Lepidoptera: Tortricidae) oviposition.  Front. Plant Sci. 6:992. Doi:10.3389/fpls.2015.00992
  • Krawczyk, G., B. Lehman., J. Park and L. A. Hull.  2015. Field validation of digital insect traps for monitoring lepidopteran pests in orchards. IOBC-WPRS Bulletin. 109: 47-51.
  • Leskey, T.C., A. Agnello, J. C. Bergh, G. P. Dively, G. C. Hamilton, P. Jentsch, A. Khrimian, G.Krawczyk, T. P. Kuhar; D. Lee, W. R. Morrison III, D. F. Polk, C. Rodriguez-Saona, P. W. Shearer, B. D. Short, P. M. Shrewsbury, J. F. Walgenbach; D. C. Weber, C. Welty, J. Whalen, N. Wiman and F. Zaman. 2015. Attraction of the Invasive Halyomorpha halys (Hemiptera: Pentatomidae) to Traps Baited with Semiochemicals Stimuli across the United States. Environ. Ent. 44(3): 746-756
  • Soergel, D. C.,N. Ostiguy, S. J. Fleisher, R. R. Troyer, E. G. Rajotte and G. Krawczyk. 2015.  Sunflower as a potential trap crop of Halyomorpha halys(Hemiptera: Pentatomidae) in pepper fields. Environ. Entomol. DOI:
  • Rice, K. B, C. Bergh, E. Bergman, D. Biddinger, C. Dieckhoff, G. Dively, H. Fraser, T.   Gariepy, G. Hamilton, T. Haye, A. Herbert, K. Hoelmer, C. Hooks, A. Jones, G. Krawczyk, T. Kuhar, W. Mitchell, A. Nielsen, D. Pfeiffer, M. Raup, C. Rodriguez-Saona, P. Shearer, P. Shrewsbury, D. Vengugopal, J. Whalen, N. Wiman, T. Leskey, and J. Tooker. 2014.  Biology, Ecology, and Management of Brown Marmorated Stink Bug (Halyomorpha halys).  Journal of Pest Management. Vol 5 (3): DOI:
  • Shimat, J., J. W. Stallings, T. C. Leskey, G. Krawczyk, D. Polk, B. Butler and J.C. Bergh. 2014. Spatial Distribution of Brown Marmorated Stink Bug (Hemiptera: Pentatomidae) Injury at Harvest in Mid –Atlantic Apple Orchards. J. Econ. Entomol. 107(5): 1839-1848

  • Krawczyk,G, L. A. Hull and M. E. Reed. 2012. Successes and Challenges with adoption of whole farm mating disruption programs by commercial fruit growers in Eastern United States – a Pennsylvania perspective. IOBC/wprs Bulletin Vol.74: 65-71
  • Leskey, T.C., G.C. Hamilton, A.L. Nielsen, D.F. Polk, C.Rodriguez-Saona, J.C/ Bergh, D. A. Herbert, T.P. Kuhar, D. Pfeiffer, G. Dively, C.R.R. Hooks, M.J. Raupp, P.M. Shrewsbury, G. Krawczyk, P.W. Shearer, J. Whalen, C. Koplinka-Loehr, E. Myers, D. Inkley, K.A. Hoelmer, D-Y. Lee, and S.E. Wright.  2012.  Pest Status of the Brown Marmorated Stink Bug, Halyomorpha halys (Stål), in the USA.  Outlooks on Pest Management.  DOI: 10.1564/23aug00: 1-9. 
  • Bohnenblust, E., L. A. Hull, G. Krawczyk, and N. K. Joshi. 2011. Capture of two moth species in traps placed at different heights in sex pheromone treated apple orchards.  J. Entomol. Sci. 46(3): 223-231.
  • Bohnenblust, E., L. A. Hull, and G. Krawczyk. 2011. A comparison of various mating disruption technologies for control of two internally feeding Lepidoptera in apples. Entomologia Experimentalis et Applicata. DOI: 10.1111/j.1570-7458.2010.01089.x
  • Joshi N. K., L.A. Hull, E.G. Rajotte, G. Krawczyk, E. Bohnenblust (2011). Evaluating sex- pheromone- and kairomone-based lures for attracting codling moth adults in mating disruption versus conventionally managed apple orchards in Pennsylvania. Pest  Management Science. DOI 10.1002/ps.2194.
  • Brown, M. W., C. R. Mathews and G. Krawczyk. 2010. Extrafloral nectar in an Apple Ecosystem to Enhance Biological Control. J. Econ. Entomol. 103(5): 1657-1664.
  • Brown, M. W., C. R. Mathews and G. Krawczyk. 2010. Analyzing the results of a biodiversity experiment: Enhancing parasitism of Platynota idaeusalis (Lepidoptera: Tortricidae) IOBC/wprs Bulletin Vol 54: 13-14.
  • Krawczyk, G., L. A. Hull, E. Bohnenblust. 2010. Utilization of Mating Disruption and Codling Moth Granulosis virus (CMGV) in Conventional Commercial Apple Orchards in Pennsylvania, USA. IOBC/wprs Bulletin Vol 54: 71-74
  • Agnello, A., A. Atanassov, J. C. Bergh, D. J. Biddinger, L. J. Gut, M. J. Haas, J. K. Harper, H. W. Hogmire, L. A. Hull, L. F. Kime, G. Krawczyk, P. S. McGhee, J. P. Nyrop, W. H. Reissig, P. W. Shearer, R. W. Straub, R. T. Villanueva, and J. F. Walgenbach.  2009.  Reduced-risk pest management programs for eastern U.S. apple and peach orchards:  a 4–year regional project. American Entomologist 55(3): 184-197.
  • Myers, C.T., G. Krawczyk and A.M. Agnello. 2009. Response of Tortricid Moths and Non-Target Insects to Pheromone Trap Color in Commercial Apple Orchards.  J. Entomol. Science. 44(1): 69-77
  • Joshi, N. K., L. A. Hull, G. Krawczyk, and E. G. Rajotte.  2008.  Field results of mating disruption technologies for the control of codling moth, Cydia pomonella (L.), and oriental fruit moth, Grapholita molesta (Busck) in Pennsylvania apple orchards. Aspects of Applied Biology (84) 153-161. 
  • Myers, C. T., L. A. Hull and G. Krawczyk.  2007. Effects of orchard host plants (apple and peach) on development of Oriental fruit moth (Lepidoptera: Tortricidae). J. Econ. Entomol. 100(2): 421-430
  • Myers, C. T., Hull, L. A., and G. Krawczyk.  2006.  Comparative survival rates of Oriental fruit moth (Lepidoptera: Tortricidae) larvae on shoots and fruit of apple and peach.  J. Econ. Entomol. 99(4): 1299-1309.
  • Myers, C. T., L. A. Hull and G. Krawczyk.  2006.  Early-season host plant fruit impact on reproductive parameters of the oriental fruit moth (Lepidoptera: Tortricidae).  Journal of Entomological Science.  41(1): 65-74.
  • Myers, C. T., L. A. Hull and G. Krawczyk.  2006.  Effects of orchard host plants on the oviposition preference of the Oriental fruit moth (Lepidoptera: Tortricidae).  J. Econ. Entomol.  99(4): 1176-1183.
  • Myers, C. T., L. A. Hull, and G. Krawczyk.  2006  Seasonal and cultivar associated variation in the oviposition behavior of the Oriental fruit moth, (Lepidoptera: Tortricidae) adults and feeding behavior of neonate larvae in apples. J. Econ Entomol. 99(2): 349-358.
  • Hong, C., B. McPheron, G. Krawczyk and L. A. Hull.  2003. Laboratory evaluation of surface residue toxicity of insecticides to apple maggot flies. International Pest Control 45(2): 92-93, 97