John Marshall Clark

John Marshall Clark, Ph.D.

Professor of Environmental Toxicology and Chemistry

Director, Massachusetts Pesticide Analysis Laboratory

Photo of J. Marshall Clark

Pronouns: he, him, his

Office phone: 413-545-1052

Fax: 413-577-4267

Email: jclark [at] vasci [dot] umass [dot] edu

Office location: N311A Morrill I

Ph.D.: Michigan State University, 1981
Postdoctoral Training: Marine Biology Laboratory, Woods Hole, MA
Honors: Lilly Teaching Fellow, 1990-1991

Curriculum Vitae

  555-Environmental Toxicology in Context
ANIML SCI  585-Animal and Environmental Toxicology


ENV SCI 191,194, 315, 535, 585, 592








Environmental Toxicology

Extent, detection and management of the human head louse, Pediculus capitis, resistant to pediculicides. An automated artificial membrane/blood feeding system allows the maintenance of human head louse populations without human or animal hosts. We currently are carrying out the first population genetic analysis of resistance in head lice and basic biochemistry and molecular analysis of the mechanisms of resistance (see figure below). We have identified both oxidative, hydrolytic and target site insensitivity (knockdown resistance, kdr) resistance mechanisms and are developing DNA-based diagnostics for their detection for resistance management.


A. Head louse eggs and exuviae attached to human hair tuft. An adult female lice started to lay eggs 16 hr after being placed on the artificial membrane feeding system. First instars molted into second instars at 48 hr. and molted into third instars 96 hr after being placed on the artificial membrane feeding system.

B. Feeding activity of head louse (2nd instar) via the artificial membrane feeding system.

Age-grading Aedes aegypti, the vector of dengue virus. In collaboration with Drs. T. Scott and J. Edman (UC-Davis), we have begun the study of the aging process of adult female mosquitoes that vector dengue virus and in particular how the vector capacity of the female changes over time. To date, we have developed an age-grading model based on cuticular hydrocarbons that ages Aegypti females to 15 days or older with 70% accuracy. Although this method is a significant step forward, we have begun to examine additional biochemical and molecular processes implicated in the aging process, including various proteomic approaches.

Action of pyrethroids on voltage-sensitive calcium channels from rat brain. CS-syndrome pyrethroid insecticides evoke a massive release of neurotransmitter during intoxication. A synaptosomal preparation from presynaptic nerve terminals allows the monitoring of neurotransmitter release, calcium uptake and membrane depolarization, simultaneously, and the examination of the agonistic/antagonistic aspects of mixtures of similarly acting pesticides. CS-syndrome pyrethroids have been determined to be potent and stereospecific agonists of N-type calcium channels, an action that is consistent with the choreoathetosis writhing syndrome of poisoning.

Environmental Chemistry

Minimizing recreational exposures to turf pesticides. The potential for significant exposure to pesticides via turf is enormous if one considers the amount of pesticide used and the area treated when including lawns, golf courses, parks, athletic fields, etc. We have detailed these exposure situations via dislodgeable foliar residues as estimates for dermal exposure and volatile residues as estimates for inhalation exposure to design mitigation strategies. Recently, we have begun extensive dosimetry and biomonitoring studies to determine actual human exposure levels during a round of golf. This information will be critical in the evaluations of the actual “risk cup” input associated with turf pesticides.

Developmental effects of contaminants on salinity preference and seawater survival of Atlantic salmon: Integrating physiology and behavior. In collaboration with the Department of Natural Resource Conservation (UMASS-Amherst) and the US Fisheries and Wildlife Department, we are assessing the estrogenic effects of nonylphenol and PCBs, which are common contaminants in rivers due to sewage treatment plants, industrial sites and storage sites, on the osmoregulatory response during parr-smolt transformation of Atlantic salmon. We will carry out a tissue-specific analysis of these compounds to see if levels in the hypothalamus and thyroid correlate to specific hormonally controlled behaviors and changes in specific enzyme levels of these tissues.

Clark MJ, Symington SB.  2012.  Advances in the mode of action of pyrethroids.. Topics in current chemistry. 314:49-72.
Pittendrigh BR, Berenbaum MR, Seufferheld MJ, Margam VM, Strycharz JP, Yoon KS, Sun W, Reenan R, Lee SH, Clark JM.  2011.  Simplify, simplify: Lifestyle and compact genome of the body louse provide a unique functional genomics opportunity.. Communicative & integrative biology. 4(2):188-91.
Kim JH, Min JS, Kang JS, Kwon DH, Yoon KS, Strycharz J, Koh YH, Pittendrigh BR, Clark MJ, Lee SH.  2011.  Comparison of the humoral and cellular immune responses between body and head lice following bacterial challenge.. Insect biochemistry and molecular biology. 41(5):332-9.
Yoon KS, Strycharz JP, Baek JH, Sun W, Kim JH, Kang JS, Pittendrigh BR, Lee SH, Clark JM.  2011.  Brief exposures of human body lice to sublethal amounts of ivermectin over-transcribes detoxification genes involved in tolerance.. Insect molecular biology. 20(6):687-99.
Hodgdon HE, Yoon KS, Previte DJ, Kim HJ, Aboelghar GE, Lee SH, Clark MJ.  2010.  Determination of knockdown resistance allele frequencies in global human head louse populations using the serial invasive signal amplification reaction.. Pest management science. 66(9):1031-40.
Kirkness EF, Haas BJ, Sun W, Braig HR, Perotti AM, Clark JM, Lee SH, Robertson HM, Kennedy RC, Elhaik E et al..  2010.  Genome sequences of the human body louse and its primary endosymbiont provide insights into the permanent parasitic lifestyle.. Proceedings of the National Academy of Sciences of the United States of America. 107(27):12168-73.
Putnam RA, Doherty JJ, Clark MJ.  2008.  Golfer exposure to chlorpyrifos and carbaryl following application to turfgrass.. Journal of agricultural and food chemistry. 56(15):6616-22.
Strycharz JP, Yoon KS, Clark MJ.  2008.  A new ivermectin formulation topically kills permethrin-resistant human head lice (Anoplura: Pediculidae).. Journal of medical entomology. 45(1):75-81.
Yoon KS, Kwon DH, Strycharz JP, Hollingsworth CS, Lee SH, Clark MJ.  2008.  Biochemical and molecular analysis of deltamethrin resistance in the common bed bug (Hemiptera: Cimicidae).. Journal of medical entomology. 45(6):1092-101.
Clark MJ, Symington SB.  2007.  Pyrethroid action on calcium channels: neurotoxicological implications.. Invertebrate neuroscience : IN. 7(1):3-16.
Qiu L, Gao J-R, Clark MJ.  2005.  Sequencing and characterization of a cDNA encoding a ferritin subunit of Colorado potato beetle, Leptinotarsa decemlineata.. Archives of insect biochemistry and physiology. 60(3):140-50.
Gerade BB, Lee SH, Scott TW, Edman JD, Harrington LC, Kitthawee S, Jones JW, Clark JM.  2004.  Field validation of Aedes aegypti (Diptera: Culicidae) age estimation by analysis of cuticular hydrocarbons.. Journal of medical entomology. 41(2):231-8.
Putnam RA, Nelson JO, Clark MJ.  2003.  The persistence and degradation of chlorothalonil and chlorpyrifos in a cranberry bog.. Journal of agricultural and food chemistry. 51(1):170-6.
Yoon KS, Gao J-R, Lee SH, Clark MJ, Brown L, Taplin D.  2003.  Permethrin-resistant human head lice, Pediculus capitis, and their treatment.. Archives of dermatology. 139(8):994-1000.
Desena ML, Clark JM, Edman JD, Symington SB, Scott TW, Clark GG, Peters TM.  1999.  Potential for aging female Aedes aegypti (Diptera: Culicidae) by gas chromatographic analysis of cuticular hydrocarbons, including a field evaluation.. Journal of medical entomology. 36(6):811-23.
Desena ML, Clark JM, Edman JD, Symington SB, Scott TW, Clark GG, Peters TM.  1999.  Potential for aging female Aedes aegypti (Diptera: Culicidae) by gas chromatographic analysis of cuticular hydrocarbons, including a field evaluation.. Journal of medical entomology. 36(6):811-23.
Desena ML, Edman JD, Clark JM, Symington SB, Scott TW.  1999.  Aedes aegypti (Diptera: Culicidae) age determination by cuticular hydrocarbon analysis of female legs.. Journal of medical entomology. 36(6):824-30.
Martin PJ, Clark JM, Edman JD.  1995.  Preliminary study of synergism of acid rain and diflubenzuron.. Bulletin of environmental contamination and toxicology. 54(6):833-6.
Clark JM, Scott JG, Campos F, Bloomquist JR.  1995.  Resistance to avermectins: extent, mechanisms, and management implications.. Annual review of entomology. 40:1-30.
Clark JM, Marion JR, Tessier DM, Brooks MW, Coli WM.  1991.  Airborne drift residues collected near apple orchard environments due to application of insecticide mixtures.. Bulletin of environmental contamination and toxicology. 46(6):829-36.
Kittayapong P, Clark JM, Edman JD, Potter TL, Lavine BK, Marion JR, Brooks M.  1990.  Cuticular lipid differences between the malaria vector and non-vector forms of the Anopheles maculatus complex.. Medical and veterinary entomology. 4(4):405-13.
Name Phone Office
Safie , Saida Departmental Assistant 413-545-4626 N423 Morrill I
Doherty , Jeff Research Assistant Professor 413-545-4369 N429 Morrill I
Bermingham , Danielle Undergraduate Research Assistant 4135451038 N429 Morrill I
Roy , Anish Undergraduate Research Assistant 413-545-1038 N429 Morrill I
McDonald , Rose Undergraduate Student 413-545-1038 N429 Morrill I