A test of Differential Predation on Different Colored Morphs of Hyles lineata (Lepidoptera: Sphingidae) Larvae

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Kirsten Zornado '21


Hyles lineata larvae have multiple different color morphs (black with yellow stripes, green with black and yellow dots, and green with black stripes) that appear in different frequencies depending on what they eat as larvae. This is a phenomenon known as phenotypic plasticity. This study investigates whether these color morphs had any impacts on the likelihood of the larvae being attacked by predators. We hypothesized that the black coloration may be consistent with warning coloration. If this is true, the black form should be attacked significantly less than the other two forms. We tested this hypothesis by setting out clay caterpillars in the natural areas around Redlands, CA for 48 hours, and seeing how many individuals of each color morph were attacked. We found that in our overall data set, the black and green dot forms were attacked significantly less than the green stripe form, though there was some disparity in the results at individual sites. We hope to do further research on this subject by testing the same study areas again next year, and carrying out an additional experiment using humans to find the caterpillars, to rule out camouflage as an explanation for why the green stripe form was attacked significantly more than the other color morphs.