Files and links (1)
CC BY V4.0, Open Access
Dissertation
THE WING POLYPHENIC SAND CRICKET, GRYLLUS FIRMUS: MORPH FORMATION, ENVIRONMENTAL CUES, AND TRANSDUCTION MECHANSMS
Washington State University
Doctor of Philosophy (PhD), Washington State University
01/2021
DOI:
https://doi.org/10.7273/000005475
Handle:
https://hdl.handle.net/2376/119712
Abstract
Wing polyphenisms represent a classic life history trade-off between investment inreproduction or migration. While the analysis of trade-offs known as life history theory explains
why this phenomenon occurs, how it occurs at an evolutionary, developmental, or mechanistic
level remains unknown. The wing polyphenic sand cricket, Gryllus firmus, exhibits markedly
different developmental trajectories based on environmental signals it receives during
development. Upon completing nymphal development this species of cricket ecloses with long
functional wings, or small non-functional wings. This phenotypically plastic response allows the
insect to stay and reproduce when conditions are good or migrate and fly away before
commencing reproduction in poor conditions.
In chapter one I reviewed what is known about the mechanistic underpinnings of the
development of wing polyphenic insects. Through this review I formulated a hypothesis about
which signaling pathway underlies wing development in wing polyphenic taxa, which has been
supported by more recent publications.
vi
In chapter two I assessed the development, morphology, and fitness of G. firmus. This
chapter used two selected lines, one selected for long wing morphs and one for short wing
morphs. A longitudinal ontogenetic framework was utilized to compare developmental
morphology of G. firmus, and a predictable terminal series of instars exhibited across sexes and
morphs was identified, despite exhibiting a variable number of nymphal instars. No significant
differences were found between the presumptive morphs until adult eclosion, lending support to
the hypothesis that the sensitive period in wing polyphenic insects occurs during the terminal
instars.
In my third chapter, I used a field collected line from Florida along with the lab-selected lines to compare responses to
environmental cues across lines. This line was used in conjunction with the selected lines to
assess the cues of nutrition and density.
In chapter four I assess the transduction mechanisms underpinning this environmentally
sensitive phenotype using pharmacological inhibition and RNA interference in both the labselected lines.
This work provides insight on the environmental cues and mechanistic underpinnings of
wing polyphenic insect development. Overall, my dissertation expands our understanding of how
environmentally sensitive phenotypes function at an evolutionary, developmental, and
morphological level.
Metrics
86 File views/ downloads
46 Record Views
Details
- Title
- THE WING POLYPHENIC SAND CRICKET, GRYLLUS FIRMUS: MORPH FORMATION, ENVIRONMENTAL CUES, AND TRANSDUCTION MECHANSMS
- Creators
- Abigail M Hayes
- Contributors
- Laura Lavine (Advisor)Allan Felsot (Committee Member)Richard S Zack (Committee Member)Shirley Luckhart (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Department of Entomology
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Publisher
- Washington State University
- Number of pages
- 186
- Identifiers
- 99900592055801842
- Language
- English
- Resource Type
- Dissertation