Date of Thesis
Fall 2024
Description
Although insects are the most diverse animal group occupying diverse habitats, recent studies have shown a decline in some insect groups. Fireflies are among the most charismatic insect species, and recent reports suggest that populations of some species are declining. Likely contributors to firefly declines include anthropogenic changes including climate change, light pollution, use of pesticides, bacterial infection, and changes to land use leading to habitat loss. However, little is known about the impact of these anthropogenic changes on individual firefly fitness and how certain environmental factors such as diet and aging impact their ability to survive. To better understand how local environmental conditions influence firefly fitness, we captured 1075 wild adult male common eastern fireflies, Photinus pyralis, in the summer of 2022 over their annual seasonal emergence at three locations that differ in their level of human disturbance. For each firefly, we measured body size and condition, metrics correlated with individual firefly survival and reproduction. We found that body size and condition were correlated and varied with environmental conditions over the season and across different habitats. Although the body condition of P. pyralis declined at all 3 locations, the decline was minimal at the least disturbed location collected at the least disturbed location. To understand how diet impacts the survival and physiology of P. pyralis, we captured 338 male P. pyralis at three different locations in the summer of 2023 and measured mass and body condition at both injection and death. A subset of P. pyralis was given access to 10% sucrose and a subset was given access to water. A subset of the control and treatment groups were infected with Serratia marcescens and another with a sterile control solution. We found that access to 10% sucrose allows P. pyralis to survive significantly longer in the lab and have better physiological conditions. However, access to 10% sucrose did not impact the ability to survive infection. We also aged a subset in the lab for 4 days to determine the effect of aging on survival. We found that aging P. pyralis in the lab reduces their survival in the lab but has no impact on infection. These results highlight the need for further studies in other firefly species to determine if these factors also impact fitness and survival in those species. This can improve our understanding of factors contributing to declines and develop data-informed conservation practices that could serve as a model for conserving other insect populations.
Keywords
Fireflies, conservation, human disturbance, immunity, diet, aging
Access Type
Masters Thesis
Degree Type
Master of Science
Major
Biology
First Advisor
Prof. Moria Chambers
Second Advisor
Prof. Sarah Lower
Third Advisor
Prof. Marie Pizzorno
Recommended Citation
Simpson, Edith, "Contribution of environment and diet on the physiology and immunity of the common Eastern Firefly, Photinus pyralis" (2024). Master’s Theses. 284.
https://digitalcommons.bucknell.edu/masters_theses/284