Polarization-sensitive photoreceptors affect the visual choices of stable flies

Sunday, November 13, 2022

3:06 PM – 3:18 PM PT

Location: Vancouver Convention Centre, Meeting Room 224

Presenting Author(s)

Adam J. Blake

Postdoctoral Researcher
University of Washington
Burnaby, British Columbia, Canada

Co-Author(s)

ST

Stephanie To

Simon Fraser University
Burnaby, British Columbia, Canada
Emmanuel Hung

MPM Student
Simon Fraser University
Burnaby, British Columbia, Canada
GN

Geoffrey Ng

Simon Fraser University
Burnaby, British Columbia, Canada
JQ

James Qian

Simon Fraser University
Burnaby, British Columbia, Canada
GG

Gerhard Gries

Professor
Simon Fraser University
Burnaby, British Columbia, Canada

Many insects have polarization-sensitive photoreceptors that they use in a variety of ecological contexts including host location. We investigated the effect of polarized light on host- foraging by stable flies, Stomoxys calcitrans, which are blood-feeding livestock pests. Histological studies of the flies’ compound eye revealed two subtypes of ommatidia matching the appearance of pale and yellow ommatidia in other calyptrate flies. The central R7 and R8 photoreceptors show a micro-structure indicative of polarization sensitivity. This similarity in appearance suggests that the yellow R7 photoreceptor is sensitive to violet light, whereas the pale R7 and R8 photoreceptors are sensitive to UV and blue light, respectively. Electroretinogram recordings with color light adaptation further show that stable flies share a similar set of photoreceptors with other flies. In behavioural experiments, stable flies discriminated between stimuli that differed in both the degree and axis of polarization. By manipulation the spectral composition of light in test stimuli, the flies’ discrimination of polarization characteristics could be impaired, suggesting that the flies’ perception of color and polarization is mixed. These findings will enhance our understanding of polarization vision and foraging behavior in stable flies and inform the design of stable fly traps.