Visual Morphology, Flight Behavior and Diel Cycle of Aedes aegypti and Culex quinquefasciatus Mosquitoes

Authors

Elina Barredo, Florida International UniversityFollow

Document Type

Dissertation

Degree

Doctor of Philosophy (PhD)

Major/Program

Biology

First Advisor's Name

Matthew DeGennaro

First Advisor's Committee Title

committee chair

Second Advisor's Name

Jamie Theobald

Second Advisor's Committee Title

committee chair

Third Advisor's Name

Lidia Kos

Third Advisor's Committee Title

committee member

Fourth Advisor's Name

Jose M. Eirin-Lopez

Fourth Advisor's Committee Title

committee member

Fifth Advisor's Name

Fenfei Leng

Fifth Advisor's Committee Title

committee member

Keywords

Behavioral neurobiology, behavior and ethology, entomology

Date of Defense

3-16-2023

Abstract

Mosquitoes have a well-earned reputation for being despicable bloodsuckers that carry disease. They are also an incredibly diverse group of insects, with representative species on virtually every continent. Sympatric species of mosquitoes often occupy different time-of-day niches; for instance, malaria vectors are known for their nocturnality while dengue vectors are day biters. As flying creatures, mosquitoes rely on their ability to process visual cues to find resources and avoid danger. Therefore, the visual system of each species must be suitable for performing tasks with the available light of their diel niche. Urban illumination at night disrupts local fauna, including anthropogenic mosquitoes, but its impacts in disease transmission, and how we could better prevent bites remains elusive. My doctorate work aimed to better understand the visual system and diel behaviors of mosquito vectors. Using a rigidly tethered flight arena assay, we found that the yellow fever mosquito, Aedes aegypti, shifts its visual attention once it transitions from seeking hosts to finding breeding sites. Next, I explored the visual morphology of the diurnal Aedes aegypti and nocturnal Culex quinquefasciatus. The visual function of insect compound eyes is greatly determined by their anatomy, so that features like ommatidial number, size and interommatidial angle reflect the visual needs of a species. Results from this study suggest that the compound eyes of Cx. quinquefasciatus have adapted to maximize light capture by enlarging their eye facets, while Ae. aegypti likely trade-off contrast sensitivity for better spatial acuity. Using a free flight locomotor activity assay, we then tested the effects of artificial light at night (ALAN) in the diel cycle of each species. ALAN was simulated by full spectrum LEDs that stayed on (~1 lux) all night. Compared to the dark night group, this treatment significantly reduced the activity of Ae. aegypti during sunrise and in anticipation of sunset. For Cx. quinquefasciatus, the morning peak of activity when exposed to ALAN was still pronounced but shifted to earlier in the morning. These findings strengthen the hypothesis that human activity modulates the daily rhythm of anthropophilic mosquitoes.

Identifier

FIDC011023

ORCID

https://orcid.org/0000-0001-7515-3878

Previously Published In

Barredo, E., & DeGennaro, M. (2020). Not Just from Blood: Mosquito Nutrient Acquisition from Nectar Sources. Trends in Parasitology, 36(5), 473–484. https://doi.org/10.1016/j.pt.2020.02.003

Barredo, Elina et al. (2022), Carbon dioxide and blood-feeding shift visual cue tracking during navigation in Aedes aegypti mosquitoes, Dryad, Dataset, https://doi.org/10.5061/dryad.z8w9ghxfv

Recommended Citation

Barredo, Elina, "Visual Morphology, Flight Behavior and Diel Cycle of Aedes aegypti and Culex quinquefasciatus Mosquitoes" (2023). FIU Electronic Theses and Dissertations. 5300.
https://digitalcommons.fiu.edu/etd/5300