Practice question

Monarch and viceroy butterflies are now widely treated as a Müllerian mimicry pair because both are unpalatable and share a similar orange-and-black warning pattern. Monarch larvae sequester cardenolides from milkweeds, although toxicity varies with host plant and individual. Viceroys possess their own deterrent compounds, including salicylate-derived chemicals obtained from willow relatives, and feeding experiments have shown that they can be unpalatable to birds. Because both participants impose a cost on predators, resemblance helps predators learn and remember one generalized avoidance signal, distributing educational attacks across the two species. Older textbooks often presented the palatable viceroy as a Batesian mimic of the monarch; that interpretation has been revised by evidence of viceroy defense. A bee-like harmless fly is a clearer Batesian example, a crab spider near a flower involves crypsis or aggressive mimicry, and harmless kingsnakes resembling venomous coral snakes form a Batesian system. Müllerian classification depends on demonstrated defense in both partners, not resemblance alone.