Undergraduate Research: An Archive - 2022 Program

Sean Crites ’22
ECOLOGY AND EVOLUTIONARY BIOLOGY
Senior Thesis Research Funding Awardee
THESIS TITLE
Smelling for
Consumption: An
Investigation of the
Genetic Underpinnings
of Host-Odor Preference
in Culex pipiens
Mosquitoes
ADVISER
Lindy McBride,
Assistant Professor of
Ecology and
Evolutionary Biology
and Neuroscience
Culex pipiens, or the common house mosquito,
offers an opportunity to investigate host
preference because it exists as two behaviorally
different forms: the bird-preferring pipiens and
the mammal-preferring molestus. I worked with
my adviser to collect C. pipiens individuals in
the Schuylkill River Park area of Philadelphia
in summer 2021 using paired traps baited with
synthetic human and chicken odor blends. We
found that the C. pipiens population was wellmixed,
but due to concentration errors with
the odor blends, there was no consistent allelic
differentiation between individuals collected
from mammal- and chicken-baited traps. Despite
these challenges, we identified between 42-253
single nucleotide polymorphisms that were
divergent between paired chicken- and mammalbaited
traps. Two genes — ionotropic receptor
25a and odorant receptor 203 — were promising
candidates for additional study. Future research
should investigate these genes and identify
additional genes associated with host preference
to elucidate C. pipiens’ transition from preferring
birds to humans.
CONSERVATION
AND BIODIVERSITY
10