Abstract
Invasive species of mosquitoes are a serious ecological and medical threat, leading to millions of deaths annually through disease transmission. The Asian rock pool mosquito, Aedes japonicus japonicus, has been extensively studied as an invasive mosquito ever since the confirmation of its invasion in the United States. The subspecies has thrived in environments that mirror its native Palearctic range and is believed to have diversified genetically since its original introduction. Previous research identified an increasing number of haplotypes present within conserved mitochondrial genes COI and NAD4, with an extensive investigation into the haplotype diversity of species in several states. However, Ohio has been understudied in this capacity. Furthermore, there have been very few documented attempts at multi-generational colonization of the invasive US population in a laboratory setting. To address both research gaps, this study aimed to colonize and investigate the population-level genetic diversity of invasive Ae. j. japonicus mosquitoes collected in three Ohio cities: Wooster, Cleveland, and Newark. The study also aimed to identify whether the size phenotypes described in previous student research were heritable. Reiter-Cummings gravid and CDC light traps were used to trap mosquito specimens at six sites across these three cities. Trapped F0 mosquitoes were separated into large and small colonies based on body size and raised through a modified version of previous experimental laboratory-rearing protocols. Females were provided ATP-salt-enriched bovine blood weekly, and two laboratory generations were reared. Due to the high mortality rate of the small phenotype, the wild-caught F0 generation consisted entirely of large mosquitoes. Despite this, F1 offspring generation consisted of both large and small mosquitoes, indicating that environmental factors such as diet may determine body size. The F2 generation eggs did not hatch, indicating a need for further refinement to the Ae. j. japonicus colonization approach. A subset of mosquitoes from the F0 generation had their DNA isolated, amplified via PCR, and sequenced for either mitochondrial gene. A high haplotype diversity was discovered in the pool of sequences for both COI (n = 38, # of H = 6, Hd = 0.7368, 5.3% matched census) and NAD4 (n = 18, # of H = 7, Hd = 0.8105, 0% matched census). Furthermore, the haplotype comparison revealed an overlap in the haplotypes present between the Wooster and Cleveland mosquitoes for both genes, providing strong evidence that the Cleveland and Wooster populations diverged from the same invasive population. These results align with the diversity and invasive range expansion data reported in Ae. j. japonicus populations from other states. This underscores the need to continue monitoring this species as a potential disease vector, particularly as the climate continues to warm, enabling interactions with confirmed invasive mosquito disease vectors.
Advisor
Nanfack-Minkeu, Ferdinand
Department
Biology
Recommended Citation
Balding, Treg W. Jr., "Bridging the Gap: An Investigation into the Genetic Diversity and Laboratory Colonization of Aedes japonicus japonicus in Northern Ohio" (2025). Senior Independent Study Theses. Paper 11622.
https://openworks.wooster.edu/independentstudy/11622
Disciplines
Biodiversity | Bioinformatics | Genetics | Laboratory and Basic Science Research | Other Microbiology | Virology
Keywords
Aedes japonicus japonicus, invasive mosquito vectors, mosquito trapping, size phenotype, laboratory colonization, haplotype diversity, DNA isolation, PCR, gel electrophoresis, Sanger sequencing
Publication Date
2025
Degree Granted
Bachelor of Arts
Document Type
Senior Independent Study Thesis
© Copyright 2025 Treg W. Balding Jr.