A career in insect pathology: A tribute to my undergraduate mentor

A budding scientist’s career can be inspired by professors who mentor undergraduates. This inspiration can occur in many different ways such as providing a stimulating and friendly environment in the laboratory, engaging in goal-orientated research with good hypotheses, teaching techniques that are useful in research, and introducing key literature pertinent to the discipline. These elements were present in Dr. Minoru Tamashiro’s laboratory that resulted in a successful career in insect pathology for an undergraduate that matriculated under his tutelage at the University of Hawaii (UH). The interest in insect pathology never waned even after 2 years in the military and 2 years in obtaining a Master's degree in insect ecology at UH.  A PhD in insect pathology at the University of California (UC) Berkeley led to a 35-year professorial appointment in insect pathology at UC Davis with fundamental and applied research focused on entomopathogenic nematodes (EPNs) and leadership positions in the Society for Invertebrate Pathology. EPNs in the genera Steinernema and Heterorhabditis are associated with mutualistic bacteria in the genera Xenorhabdus and Photorhabdus, respectively. When the nematodes infect an insect host, they release the sequestered mutualistic bacterial cells that kill the host within 48 hours. The nematodes reproduce in the cadaver and new infective nematodes are produced. These EPNs occur naturally in soil, infect a number of soil insect pests, and are commercially available as biological control agents. Some of the most interesting findings from my laboratory deal with the behavioral ecology of EPNs. We demonstrated the mechanism of jumping and attachment behavior of several Steinernema species. This finding led to an understanding of why the Formosan subterranean termite, Coptotermes formosanus, are difficult to control with S. carpocapsae. Although EPNs infect termite workers and soldiers, the workers can reduce infection through their grooming behavior. As soldiers cannot groom themselves, soldiers and workers in the same experimental arena had less nematode attachment to their cuticle and therefore, less infection rate compared to soldiers alone.