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Washington State University Molecular Plant Sciences


Associate Professor, Department of Entomology  Ph.D., University of Arizona, USA



Our work in the Crowder lab seeks to understand how farming practices, land-use, and abiotic conditions impact insect communities and plant-insect interactions. Most of our research is conducted in agricultural ecosystems, at the interface of basic and applied science. Our research helps guide efforts to conserve and restore ecosystems and promote sustainable agriculture while providing fundamental insight into the processes that affect the structure and function of insect communities.

We currently have three main areas of inquiry within the lab:

(1) Plant-insect-pathogen interactions: Many pathogens of plants are transmitted by arthropod vectors, and such pathogens can devastate agricultural productivity. Our lab works to understand the ecological and molecular mechanisms by which insect vectors interact with plants and pathogens. This includes understanding the molecular basis and chemical ecology of plant resistance to pathogens and insects, and assessing how variable soil microbial communities impact plant responses to insects and pathogens. We are currently working on aphid-borne viral pathogens of legume and wheat crops as well as psyllid-borne bacterial pathogens of potato crops

(2) Plant-pollinator interactions: Insects are critical for food production due to their ability to pollinate many crop plants (70% of the major food crops humans eat are pollinated by insects). Our lab’s work on pollinators focuses on strategies to conserve pollinator diversity within agricultural systems. At the molecular scale, we strive to understand how abiotic and biotic stressors of plants affect phenotypic traits (flower size, color, development time) that are important for pollinators, and the molecular mechanisms that alter these traits in response to stress

(3) Integrated pest management and landscape ecology: Insect communities are impacted by factors operating at broad scales, including the structure of farming landscapes and environmental conditions. Our lab’s work in this area seeks to develop predictive models to better understand how insect communities vary across agricultural landscapes to aid in pest management.

Representative publications:

Chisholm PJ, Busch JW, Crowder DW (2019) Effects of life history and ecology on virus evolutionary potential. Virus Research 265, 1-9.

Orpet RJ, Goldberger JR, Crowder DW, Jones VP (2019) Field evidence and grower perceptions on the roles of an omnivore, European earwig, in apple orchards. Biological Control 132, 189-198.

Chisholm P, Sertsuvalkul N, Casteel CL, Crowder DW (2018) Reciprocal plant-mediated interactions between a virus and a non-vector herbivore. Ecology 99, 2139-2144.

Lichtenberg EM, Kennedy CM, Kremen C, Batary P, Berendse F, Bommarco R, Bosque-Pérez NA, Carvalheiro LG, Snyder WE, Williams NM, Winfree R, Klatt B, Astrom S, Faye B, Brittain C, Chaplin-Kramer R, Clough Y, Connelly H, Danforth B, Diekotter T, Eigenbrode SD, Ekroos J, Elle E, Freitas BM, Fukuda Y, Gaines-Day HR, Gratton C, Holzschuh A, Isaacs R, Isaia M, Jha S, Jonason D, Jones VP, Klein A-M, Krauss J, Letourneau DK, Macfadyen S, Mallinger RE, Martin EA, Martinex E, Memmott J, Morandin L, Neame L, Otieno M, Park MG, Pfiffner L, Pocock M, Ponce C, Potts SG, Poveda K, Ramos M, Rosenheim JA, Rundlof M, Sardinas H, Saunders ME, Schon NL, Sciligo AR, Sidhu CS, Steffan-Dewenter I, Tscharntke T, Vesely M, Weisser WW, Wilson JK, Crowder DW (2017) A global synthesis of the effects of diversified farming systems on arthropod diversity within fields and across agricultural landscapes. Global Change Biology 23, 4946-4957.

Foote NE, Davis TS, Crowder DW, Bosque-Perez NA, Eigenbrode SD (2017) Plant water stress affects interactions between an invasive and a naturalized aphid species on cereal crops. Environmental Entomology 46, 609-616.

Cohen AL, Crowder DW (2017) The impacts of spatial and temporal complexity across landscapes on biological control. Current Opinions in Insect Science 20, 13-18.

Milosavljevic I, Esser AD, Bosque-Perez NA, Crowder DW (2016) The identity of belowground herbivores, not herbivore diversity, mediates impacts on plant productivity. Scientific Reports 6, 39629.

Milne AE, Bell JR, Hutchison WD, van den Bosch F, Mitchell PD, Crowder DW, Parnell S, Whitmore AP (2015) The effect of farmer decisions on pest control with Bt crops: a billion dollar ecology game. PLoS Computational Biology 11, e1004483.

Crowder DW, Reganold JD (2015) Financial performance of organic agriculture on a global scale. Proceedings of the National Academy of Sciences 112, 7611-7616.

Reif KE, Palmer GH, Crowder DW, Ueti MW, Noh SM (2014) Restriction of Francisella novicida genetic diversity during infection of the vector midgut. PLoS Pathogens 10, e1004499.

Crowder DW, Harwood JD (2014) Promoting biological control in a rapidly changing world. Biological Control 75, 1-7.

Chisholm P, Gardiner M, Moon E, Crowder DW (2014) Tools and techniques for investigating impacts of habitat complexity on biological control. Biological Control 75, 48-57.

Crowder DW, Jabbour R (2014) Relationships between biodiversity and biological control in agroecosystems: current status and future challenges. Biological Control 75, 8-17.

Crowder DW, Dykstra E, Brauner J-M, Duffy A, Reed C, Martin E, Peterson W, Carrière Y, Dutilleul P, Owen J (2013) West Nile virus prevalence across landscapes is mediated by local effects of agriculture on vector and host communities. PLoS ONE 8, e55006.

Crowder DW, Northfield TD, Gomulkiewicz R, Snyder WE (2012) Conserving and promoting evenness: Organic farming and fire-based wildland management as case studies. Ecology 93, 2001-2007.

Crowder DW, Northfield TD, Strand MR, Snyder WE (2010) Organic agriculture promotes evenness and natural pest control. Nature 466, 109-112.