This is the second short news article written by students, during the professional development class of Spring 2023, about each other's research.

Student Research Spotlight - Bijay Subedi

By Ethan Dean

Nothing is better than a fresh home-grown tomato. Not only are tomatoes a key ingredient in many foods, including sandwiches, taco toppings, and pizza sauces, but they are the most produced non-grain crop in the world (FAO, 2022). Despite its great taste, our pizza is under attack from many different factors, including climate change. The increasing frequency of drought will impact plant health, the insect communities living on tomatoes, and the tiny living things (“microbes”) that fill our agricultural fields.

Aphids are one of the many pests on tomato plants in the field, and lady beetles are their natural predators. There are many different types of microbes in the soil, which can help plants grow better and stay healthy. However, when there is a drought, the availability of resources and the types of microbes in the field change, and tomato plants might have to reallocate resources to survive. This change could also change the nutritional resources available to pest aphids.  Bijay Subedi, a Ph.D. student in Entomology in Monica Kersch-Becker's lab at Penn State, hypothesizes that if there is a drought, the compounding effects of disrupted soil microbial diversity and plant health will change the pest ecosystem by reducing the presence of natural predators, potentially impacting the biological control of pests.

According to Bijay, many of the problems tomatoes are experiencing are tied to umbrella events that are all happening due to climate change. To test the impacts of the many different inputs to this system, Bijay plans to do a field experiment with hundreds of plants where he simulates drought conditions and observes the effects on the plant, the soil microbial community and the insect communities. Bijay will be analyzing the composition of the soil microbiome, painstakingly assessing which plants the aphids choose to feed on, and whether their natural predators prefer to visit the drought-stress plants in search of their prey. Also taking note of the different predators that live in the fields, he will be effectively observing the change in the ecosystem as it is happening.

Thus far, Bijay has conducted pilot studies in greenhouses and hoop houses to practice the techniques that will be needed for his field experiment in the coming summer.  If the study results support Bijay's hypothesis, we will have a much better understanding of what changes will happen to the pest communities and biological control of pests in tomato fields in response to changing climates.  Scientists and growers can use this information to help grow crops that are more resistant to changing environmental conditions.

Bijay is advised in his research by Dr. Monica Kersch-Becker, Assistant Professor of Arthropod Ecology at Penn State University.