About Niranjana Krishnan


  • Iowa State University, Doctor of Philosophy, 2021

Professional links

Niranjana Krishnan

Prof, ast resrch
Biological Sciences
105 Schrenk Hall

573-341-4831 | nkrishnan@mst.edu | Scholars' Mine Profile


  • Iowa State University, Doctor of Philosophy, 2021

Professional links


Niranjana Krishnan (she/her) obtained her PhD in Toxicology from the Entomology department at Iowa State University. Working with Profs. Steven Bradbury and Joel Coats, she assessed the risk of insecticide exposures on monarch butterflies. Niranjana obtained a Bachelor's degree in Microbiology from University of Mumbai and a Master's degree in Biomedical Genetics from Vellore Institute of Technology, India.

Niranjana's current research interest is to apply in vivo, in vitro, and in silico techniques to estimate risk of chemical exposures on insect species, including species of conservation concern. This is being undertaken via three research themes that employ the adverse outcome pathway (AOP) framework:
Research Theme 1: AOP development from molecular initiating events to organismal effects
Research Theme 2: AOP development from organismal to population level effects
Research Theme 3: AOP employment to inform interspecies extrapolation


Expertise areas

Insect toxicology, Ecological Risk Assessment, Pesticides

Current research projects

  • Elucidating arrested pupal ecdysis Neonicotinoids, nicotinic acetylcholine receptor (nAChR) agonists,
    disrupt larval to pupal ecdysis in Lepidoptera. The doses that cause
    this effect are 10 to 100-fold lower than doses that cause outright
    mortality. We are elucidating the mechanism through which
    neonicotinoids, and potentially other chemicals that overstimulate
    nAChRs, cause arrest in pupation. We are also studying if other insect
    orders show a similar effect and investigating the interplay between
    neuroendocrine hormones and neurotransmitters. This project has
    implications for non-target risk assessment and pesticide
  • Assessing interspecies differences in insecticide susceptibility Insects can show large variations in insecticide susceptibility within and across orders. We are undertaking studies to identify species that show high and low susceptibility to major insecticide classes and assessing toxicokinetic and toxicodynamic factors that can help explain differences in susceptibility. The ultimate goal is to identify surrogate target and non-target species for testing and develop a framework that can be used to predict species' responses to untested chemicals.

Ecotoxicology & Risk Assessment Lab

Research interests

Conservation of at-risk invertebrate species, Advancing Tox21 in invertebrate toxicology

Research funding

  • Missouri University of Science and Technology Start-Up Funding

Research grants

  • Elucidation of arrested pupal ecdysis: a novel, newly discovered insecticidal mode of action to manage a diversity of insect pests U.S. Department of Agriculture (January 2022 to December 2023)
  • Elucidating differences in pesticide susceptibility across two butterfly species Missouri S&T First Year Research Experience Program (January to May 2022)
  • Understanding the effect neonicotinoid insecticides have on insect pupal development Iowa State University Henry and Sylvia Richardson Research Incentive Grant (2020)
  • Assessing the risk of insecticides to monarch butterflies Xerces Society The Joan Mosenthal DeWind Award (2019-2020)
  • Evaluation of a Varroa Mite (Varroa destructor)-Active dsRNA via Dietary Exposure to Monarch Butterfly (Danaus plexippus) Larvae Bayer Crop Science (2018-2020)
  • Milkweed in Prairie Plots in Agricultural Landscapes: Assessing Risks of Insecticide Exposure to Monarch Butterfly Larvae Prairie Biotic Research Small Grants (2018-2019).


Publications from Scholars' Mine

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      Awards and recognition


      • Best Paper Award Environmental Toxicology and Chemistry journal 2020
      • Research Excellence Award Iowa State University 2020
      • Supplemental Training for Education Program Award Society of Toxicology 2020
      • Student Attendance Grant Society of Environmental Toxicology & Chemistry 2020
      • Jean L. Laffoon Memorial Scholarship Iowa State University 2020 and 2017
      • Leadership Award Iowa State University 2019
      • Graduate and Professional Student Senate Scholarship Iowa State University 2018
      • AGRO Division Education Award American Chemical Society 2017


      • Selection to the 2019 National ComSciCon Workshop (7% acceptance rate)
      • Winner of the 2019 General Science Post Category from Science Seeker