HIDE AND SEEK: AN EXPLORATION OF ANTIPREDATOR AND PREDATOR AVOIDANCE MECHANISMS IN ORTHOPODOMYIA SIGNIFERA IN RESPONSE TO PREDATION FROM TOXORHYNCHITES RUTILUS

Author

Nathaniel DahlbergFollow

Date of Award

Spring 2023

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

Miguel Acevedo

Abstract

There have been many observations of larval Orthopodomyia signifera coexisting with the predator Toxorhynchites rutilus. There are three hypotheses that could explain how Or. signifera resists predation from Tx. rutilus. The first hypothesis states that larvae adapt behavioral changes that limit predation. The second hypothesis states thoracic setae serve as a physical defense that prevents Tx. rutilus from grasping Or. signifera. The third hypothesis states Or. signifera possess a chemical defense indicated by aposematic coloration. To test the first hypothesis larval Or. signifera were exposed to conspecific and heterospecific predation cues and their behavior was observed. Both cues caused Or. signifera to change their behavior, with conspecific cues causing the most stringent defensive behavior and heterospecific cues causing moderate defensive behavior. This led to the confirmation of the first hypothesis. To test the second hypothesis the rate of successful strikes of Tx. rutilus on Or. signifera and Aedes albopictus were compared. There was no significant difference in the successful strike rate of Tx. rutilus on Or. signifera and Ae. albopictus and the second hypothesis was rejected. For the third hypothesis the functional response of Tx. rutilus on Ae. albopictus and Or. signifera when exposed to a natural and artificial diet was compared. Diet was not a factor, however, Or. signifera had significantly longer handling time and fewer 2^nd strikes in comparison with Ae. albopictus. The third hypothesis was inconclusive as the results could indicate a physical or chemical defense.

Copyright

Nathaniel Dahlberg

Recommended Citation

Dahlberg, Nathaniel, "HIDE AND SEEK: AN EXPLORATION OF ANTIPREDATOR AND PREDATOR AVOIDANCE MECHANISMS IN ORTHOPODOMYIA SIGNIFERA IN RESPONSE TO PREDATION FROM TOXORHYNCHITES RUTILUS" (2023). Master's Theses. 952.
https://aquila.usm.edu/masters_theses/952