Biology ETDs

Publication Date

Summer 7-30-2023


Research on insect symbiosis is dominated by insect–bacteria models, however, the role of fungal symbionts in insects is poorly understood. Fungi are de novo synthesizers of many essential nutrients, therefore, insect–fungal pairings can permit specialization on nutritionally deprived diets. Here, I address the costs and benefits of symbiosis using a system of beetle–fungal symbiosis. Specifically, I ask 1) when reared on a low-quality diet, does the beetle increase the number of viable symbionts to compensate for a heightened nutritional demand, and 2) Is the conferred fitness benefit of the symbiont only present in low-quality diets? When reared on low-quality diets, there was no variation in fungal titer in beetles; moreover, there was no cost attributed to hosting symbiont populations when dietary provisions were not required. These findings contrast with many obligate insect–bacterial pairings and suggest that there is no plasticity in resource contribution between partners.




Symbiosis, Beetle, Fungal Symbiont, Obligate Symbiosis, Costs and Benefits

Document Type


Degree Name


Level of Degree


Department Name

UNM Biology Department

First Committee Member (Chair)

Dr. Vincent Martinson

Second Committee Member

Dr. Donald Natvig

Third Committee Member

Dr. Hannah Marx


This version of the thesis includes revised lower case roman numerals and M.S. listed on the abstract page.

Included in

Biology Commons