Date of Award

Summer 6-2022

Degree Type

Masters Thesis

Degree Name

Master of Science (MS)

School

Biological, Environmental, and Earth Sciences

Committee Chair

Donald Yee

Committee Chair School

Biological, Environmental, and Earth Sciences

Committee Member 2

Jake Schaefer

Committee Member 2 School

Biological, Environmental, and Earth Sciences

Committee Member 3

Alonso Ramírez

Abstract

Freshwater rock pools can serve as habitat for aquatic insects. Flash-flooding can have profound effects on insect communities in streams and rivers, but these effects have not been studied on freshwater rock pools. The goal of this thesis was to describe ecological patterns of the Sonadora River rock pool insect community at the Luquillo Experiment Forrest, Puerto Rico, specifically in response to intense flash-flooding, and then perform experiments to elucidate possible processes to explain those patterns. The rock pools contained primarily three taxa of Dipteran (true-fly) larvae, in order of decreasing abundance, 1) a newly discovered species of ceratopogonid (biting midges, Dasyhelea grisea species group), 2) chironomids (non-biting midges, tribe Chironomini), and 3) mosquitoes (Culicidae, Culex secutor). The Dasyhelea were rock pool specialists, while the other taxa were generalists and could be found in other aquatic habitats. Dasyhelea larvae possessed some resistance to flooding, while the other taxa did not. The presence and abundance of these insects responded differently to various environmental variables including rock pool height, volume, temperature, distance to river bank, canopy openness, and flooding disturbance. It was then hypothesized that the adult insects should be making oviposition choices that maximize offspring survival (preference-performance hypothesis, PPH). It was unclear if PPH was supported for Dasyhelea with respect rock pool height and detritus amounts, but PPH was not supported for Cx. secutor and container volume.

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