Blue vs. Yellow Color Preference of Hyles Hawkmoths in Foraging Visitations ofVarious Real and Artificial Flowers

As one of the most important pollinators across North America, there is much incentive to further understand the foraging habits of Hyles hawkmoths. Recent research on the subspecies Hyles lineata has identified a preference for both blue and yellow colored light for flower visitations, with the stronger bias between the two being for blue. However, the blue LED used in this earlier experiment was later discovered to be more intense than the yellow, casting doubt upon this finding. Here, the idea of the former study was revisited, and a binary choice assay was created with these same two blue and yellow LEDs. However, a plastic filter was positioned below the blue one, such that its intensity was decreased to match the yellow. H. lineata moths were reared from eggs, and adults were individually released into a darkened flight chamber where each light projected its color down onto either a white Oenothera flower or false paper flower. Their first visitation was recorded as their preference. Additional testing without the filter was also conducted, as well as paper flower trials with the addition of fragrant Bergamot oil. When light intensities were equalized, the moths actually preferred yellow flowers to blue ones. However, when the filter was removed, a blue preference only reappeared for the moths tested with real flowers. This persistent yellow bias was also maintained through testing with paper flowers and Bergamot oil. Further investigations may identify whether fragrance plays a notable role in the flower color bias of H. lineata