Date of Award
Spring 6-12-2026
Document Type
Masters Thesis
Degree Name
M.S. in Biological Sciences
Organizational Unit
College of Natural Science and Mathematics, Biological Sciences
First Advisor
Robin Tinghitella
Second Advisor
Shannon Murphy
Third Advisor
Erica Larson
Fourth Advisor
Michael Kerwin
Copyright Statement / License for Reuse
All Rights Reserved.
Keywords
Abundance, Artificial light at night (ALAN), Fitness, Human impacts, Pacific field cricket
Abstract
Anthropogenic pollutants like artificial light at night (ALAN) and noise impact most of the land in the US and have broad negative impacts on biodiversity. ALAN has increased in extent and severity over ~60 years and may be associated with global insect declines. Nocturnal insects may be particularly vulnerable. Here, we test how ALAN impacts behavior and fitness in the nocturnal Pacific field cricket, Teleogryllus oceanicus. We ask how ALAN impacts cricket abundance (using a field experiment), and fitness through survival and reproduction (in a lab study) using light treatments that mimic common lighting regimes (both bright white light and yellow-shifted light) in Hawaii, where the crickets live. If ALAN negatively impacts fitness through changes in development time, body size, survival, or mating success, we expect to also find that animals avoid artificially lit habitats in the field, given the associated fitness costs. In the field, we established “phantom streetlights” by establishing lit areas in a rural field where T. oceanicus naturally occur and there is little, if any, ALAN. We measured how light influenced cricket abundance and distribution over the course of >24 hours of exposure. In the lab, we established treatments (100 lux white LED, 100 lux yellow-shifted LED, 200 lux white LED, and a dark control) inside of replicate incubators, randomly assigning the animals to treatments at hatching and rearing them under these conditions throughout their lives. At adulthood, we measured key traits including survival to eclosion, development time, adult size, sex ratio, and courtship success. We found in the field study that cricket abundance did not differ between locations where we added ALAN and locations where we did not, regardless of the intensity and color temperature of the light. In the lab, however, some traits, like body size and development time were negatively affected by ALAN, while others were not. Animals reared in ALAN treatments took longer to develop to adulthood and achieved smaller adult sizes than those reared under control conditions. Interestingly, though, survival to adulthood and sex ratio were not impacted by ALAN, and both courtship singing and mounting were more likely under artificial light than in the dark. The positive impacts of ALAN on mating success may compensate for or outweigh the negative impacts, consistent with our finding in the field that ALAN does not impact cricket abundance.
Copyright Date
6-2026
Publication Statement
Copyright is held by the author. User is responsible for all copyright compliance.
Rights Holder
Kayla J. Martinez
Provenance
Received from ProQuest
File Format
application/pdf
Language
English (eng)
Extent
46 pgs
File Size
829 KB
Supplementary File Description
Table S1. Gender Abundance and Table S2. Lighting Treatments
File Format: application/pdf
Language: English (eng)
Extent: 2 pgs
File Size: 95.5 KB
Recommended Citation
Martinez, Kayla J., "Impacts of Artificial Light at Night on the Local Abundance and Key Fitness-Related Traits of the Nocturnal Pacific Field Cricket" (2026). Electronic Theses and Dissertations. 2723.
https://digitalcommons.du.edu/etd/2723
Table S1. and Table S2.