Viceroys are smaller then monarchs but the real give away is the black line running through the hind wing, which monarchs do not have. It is believed that the similar coloration helps to fool some predators that avoid eating monarchs because they are toxic because of the milkweed that they eat as a caterpillar. Viceroy caterpillars do not eat milkweed, they mostly feed on tree leaves such as willow, aspen, apple, and cherry, so they are not toxic but it is not necessary to be toxic if you look like another butterfly that is.
Sunday, January 16, 2011
At first glance many people would think that this is a monarch but this is actually a viceroy butterfly. The viceroy is in the same family as the Monarch, Nymphalidae or brushfoots, but it is in a different subfamily Limenitidinae, which includes the admirals.