Defense expression in the aphid Myzocallis asclepiadis.By McMartin, K.A. & S.B. Malcolm.
McMartin, K.A. & S.B. Malcolm. 2008. Defense expression in the aphid Myzocallis asclepiadis
. Final Report. Pierce Cedar Creek Institute, Hastings, MI. 15 pp.
The aphid Myzocallis asclepiadisis
a relatively unknown species that feeds on the common milkweed Asclepias syriaca. This aphid is very mobile and mobility appears to be the primary defense against predators. However, over the course of the summer, the aphid changes color, from a pale yellow-green to having orange spots. This aphid could be a model to answer the question of how aposematism evolves. In this study, a natural, unmanipulated population of My. asclepiadisis
was monitored, and experiments manipulating development and density to determine the nature of the color change were conducted. However, it does not appear that development and density are cues for color change. Photographic analysis of color and HPLC analysis are underway to determine the extent of color change and whether that change corresponds to an increase in cardenolide sequestration.