Joseph Thaddeus Walls, III

  • Ph.D. Student
  • Advised by: Dr. Cristina Rosa
Joseph Thaddeus Walls, III
301 Buckhout Lab (office)
410 Buckhout Lab (lab)

University Park, PA 16802
Work Phone: 814-863-1932
Fax: 814-863-7217


  1. B.S., Biology, Truman State University
  2. M.S., Entomology from Penn State University

The overall goal of my research is to elucidate the effects of climate change on plant defenses and virus evolution. Specifically I work with Tomato spotted wilt orthotospovirus (TSWV) in tomato. I track changes in the abscisic acid (ABA), jasmonic acid (JA), and salicylic acid (SA) pathways with virus infection and various climatic conditions. In 2018 I was awarded the Northeast Sustainable Agriculture Research and Education graduate student grant to pursue a project that involves using phytohormones (e.g. ABA, JA, and SA) as a method of controlling TSWV.

I am also researching how RNA interference/gene silencing affects virus evolution. RNAi is a recently deployed method used to control disease and pests in agriculture, yet we know little about the long-term effects of RNAi on pests and pathogens. My research uses a "leaky" system in which plants display incomplete resistance to TSWV to see how the virulence and virus genome change over time.

I am pursuing a dual-title degree in International Agriculture and Development. For this dual title I will be conducting some of my research in Nepal using elevation changes as a proxy for climate change. I will look at disease incidence of Tomato yellow leaf curl virus and extrapolate how disease pressure may change along with the climate.

During my free time I can be found hiking, climbing, camping, and anything else outdoors. I also really enjoy cooking and grilling for groups of people. My specialty is pancakes on an open fire.


Walls III JT, Caciagli P, Tooker JF, Russo JM, Rajotte EG, Rosa C. 2016. Modeling the decision process for barley yellow dwarf management. Computers and Electronics in Agriculture 127:775-786.