Butterflies+Defenses

**Caterpillars** Caterpillars are soft bodied and slow moving. This makes them easy prey for predators, like birds, wasps, and mammals to mention just a few. In order to protect themselves from predators, caterpillars use different strategies, including:
 * Caterpillar and Butterfly Defense Mechanisms **
 * **Poison** Some caterpillars are poisonous to predators. These caterpillars get their toxicity from the plants they eat. Generally, the brightly colored larva are poisonous; their color is a reminder to predators about their toxicity. Some poisonous caterpillars include the Monarch and the Pipevine Swallowtail.
 * **Camouflage** Some caterpillars blend into their surroundings extraordinarily well. Many are a shade of green that matches their host plant. Others look inedible objects, like bird droppings (the young Tiger Swallowtail larva).
 * Eyespots** Some caterpillars have eyespots that make them look like a bigger, more dangerous animal, like a snake. An eye spot is a circular, eye-like marking found on the body of some caterpillars. These eyespots make the insect look like the face of a much larger animal and may scare away some predators.
 * **Hiding** Some caterpillars encase themselves in a folded leaf or other hiding place.[[image:Yellowjacket.gif]]
 * **Hiding** Some caterpillars encase themselves in a folded leaf or other hiding place.[[image:Yellowjacket.gif]]
 * **Hiding** Some caterpillars encase themselves in a folded leaf or other hiding place.[[image:Yellowjacket.gif]]

media type="youtube" key="79PWlike_r8" width="425" height="350"media type="youtube" key="aTo8qLTP4TY" width="425" height="350" While the larvae of this buitiful swallowtail is "muching" my wild lime, let's make a little observation on their defensive behavior. Papilio cresphontes caterpillar feeds on citrus plants, and lo...
 * **Bad smells** Some caterpillars can emit very bad smells to ward off predators. They have an osmeterium, an orange, y-shaped gland on their neck which gives off a strong, unpleasant odor when the caterpillar is threatened. This keeps away dangerous wasps and flies that try to lay eggs in the caterpillar; these eggs would eventually kill the caterpillar as they hatch inside its body and eat its tissues. Many swallowtails have an osmeterium, including the Zebra Swallowtail.

media type="youtube" key="Og7v4KYsuSc" width="425" height="350" One of the most effective defense mechanisms used by monarch butterflies to protect themselves from their predators is the use of milkweeds. During the 1960s researchers discovered that cardenolides are chemicals in milkweed that made monarchs toxic and bittertasting. The graph below shows the range of cardenolide concentrations found in one species of milkweed, A. Viridis, and adult monarchs that fed on that milkweed as larvae. Since many adult monarchs do not eat milkweed, the figure shows that they have stored the cardenolides that they ingested as larvae.
 * Defense Mechanisms in Monarch Butterflies **
 * Figure 2: Monarch releasing fluids to protect them from predators**