Chris Mullin, Ph.D.

Department Focus Areas

Chemical Ecology
Ecological Applications

Research Interests

Toxicology, pesticides and pollinator health, molecular mode of action of natural and synthetic toxins, insect gustation, selective biopesticides

Teaching

Chemical Ecology
Modern Pesticide Technologies and Methods in their Analysis

Research Activities & Interests

My approach to elucidate precise, selective chemical methods of pest control is to focus on insects that feed on specialized plant organs as guides to discovery. Model insects studied have included adults of the pollen-feeding Diabroticite pests, pollen- and seed-feeding Carabidae beneficials, and pollen- and nectar feeding honey bees. The habitual consumption of pollen is primarily associated with amino acid taste neuroreceptors, that provide selective molecular targets for behavioral and insecticidal action. Seeds are rapidly becoming the delivery system for many materials including seed protectants (fungicides, insecticides, herbicides, elicitors), biological inoculants, and nutrients in addition to genetics. Most high-valued seeds, notably transgenic corn, soybeans and cotton, are now treated with systemic neonicotinoid insecticides plus multiple fungicides to assure excellent crop establishment where pests and diseases exist. Currently, the International Seed Federation assesses the commercial world seed market at $30 billion, with the US share being $5.7 billion (19%). The US is the top importer and exporter of seed. The increasing pervasiveness of treated seeds indicates that considerable impact to the environment, unaware seed handlers and bees may occur. Practical outcomes for this work include identifying selective pesticides that promote non-target species, and assisting in development of regulatory processes that assure safety of domestic and imported seeds and products from the hive. I am presently focused on study of the role of pesticides in honey bee Colony Collapse Disorder and overall pollinator decline. To achieve this, we develop analytical methods, particularly using LC-MS, to monitor and determine the fate of pest control chemicals and their formulation ingredients within bee ecosystems.

Relevant Publications

Johnson, R. M., M. D. Ellis, C. A. Mullin, and M. Frazier. 2010. Pesticides and honey bee toxicity - U.S.A. Apidologie 41: 312-331.

Mullin, C. A., M. Frazier, J. L. Frazier, S. Ashcraft, R. Simonds, D. vanEngelsdorp, J. S. Pettis. 2010. High levels of miticides and agrochemicals in North American apiaries: Implications for honey bee health. PLoS ONE 5: 1-19 e9754.

vanEngelsdorp D, N. Speybroeck, J. D. Evans, B. K. Nguyen, C. Mullin, M. Frazier, J. Frazier, D. Cox-Foster, Y. Chen, D. R. Tarpy, E. Haubruge, J. S. Pettis, and C. Saegerman. 2010.  Weighing risk factors associated with bee Colony Collapse Disorder by Classification and Regression Tree Analysis. J. Econ. Entomol. 103:1517-1523.

Leslie, T. W., D. J. Biddinger, C. A. Mullin, S. J. Fleischer. 2009. Carabidae population dynamics and temporal partitioning: Response to coupled neonicotinoid-transgenic technologies in maize.  Environ. Entomol. 38: 935-943.

Matveeva, E. G., C. Morisseau, M. H. Goodrow, C. Mullin, and B. D. Hammock. 2009. Tryptophan fluorescence quenching by enzyme inhibitors as a tool for enzyme active site structure investigation: Epoxide hydrolase. Cur. Pharmac. Biotechnol. 10: 589-599.

vanEngelsdorp, D., J. D. Evans, L. Donovall, C. Mullin, M. Frazier, J. Frazier, D. R. Tarpy, J. Hayes Jr., J. S. Pettis. 2009. Entombed pollen": A new condition in honey bee colonies associated with increased risk of colony mortality. J. Invert. Pathol. 101: 147-149.

vanEngelsdorp, D., J. D. Evans, C. Saegerman, C. Mullin, E. Haubruge, B. K. Nguyen, M. Frazier, J. Frazier, D. Cox-Foster, Y. Chen, R. Underwood, D. R. Tarpy, J. S. Pettis. 2009. Colony Collapse Disorder: A descriptive study. PLoS ONE 4: 1-17 e6481.

Frazier, M., Mullin, C., Frazier, J., Ashcraft, S. 2008. What have pesticides got to do with it? Am. Bee J. 148: 521-523.

Kim, J. H. and C. A. Mullin. 2007. An isorhamnetin rhamnoglycoside serves as a co-stimulant for sugars and amino acids in feeding responses of adult western corn rootworm (Diabrotica virgifera virgifera ) to corn (Zea mays) pollen.  J. Chem. Ecol. 33: 501-512.

Mullin, CA, Saunders, MC, II, Leslie, TW, Biddinger, DJ, Fleischer, S J (2005) Toxic and behavioral effects to Carabidae of seed treatments used on cry3Bb1- and cry1Ab/c-protected corn, Environ. Entomol., 34 (6), 1626-1636

Kim JH, Mullin CA, Antifeedant effects of proteinase inhibitors on feeding of adult western corn rootworm, Diabrotica virgifera virgifera, Journal of Chemical Ecology, 29(4), 795-810, 2003

Kim JH, Mullin CA, Impact of cysteine proteinase inhibition in midgut fluid and oral secretion on fecundity and pollen consumption of western corn rootworm (Diabrotica virgifera virgifera), Archives of Insect Biochemistry and Physiology, 52(3), 139-54, 2003

Mullin CA, Kim JH, Phytochemical action at amino acid chemosensory receptors: An approach to biopesticides, In Advances in Biopesticide Research. O Koul and GS Dhaliwal (eds.), Vol. 1, Phytochemical Biopesticides. Harwood Academic Publishers, Amsterdam , pp. 45-71, 2001

Lin S, Mullin CA, Lipid, polyamide, and flavonol phagostimulants for adult western corn rootworm from sunflower (Helianthus annuus L.) pollen, Journal of Agricultural and Food Chemistry, 47(3), 1223-9, March 1999 Abstract

Hollister B, Mullin CA, Isolation and identification of primary metabolite feeding stimulants for adult western corn rootworm, Diabrotica virgifera virgifera LeConte, from host pollens, Journal of Chemical Ecology, 25, 1263-1280, 1999