Besides being well known as pollinators, butterflies are also food sources for other animals, such as birds, small lizards and frogs. In order to avoid becoming a predator’s delicious meal, butterflies have to develop several strategies to fight back.
Butterflies are great mimics. The one being mimicked is called the model, while the one doing the copying is called the mimic. Generally, the mimic appears poisonous but is actually harmless, whereas the model is really the one that is poisonous. An example is the model, Common Rose (Pachliopta aristolochiae asteris) and the mimic female, Common Mormon (Papilio polytes romulus -f. polytes). Common Rose larvae munch on Aristolochia leaves, which contain alkaloids poisonous to man and other animals. The alkaloids are retained in the body when the caterpillars transform into butterflies.
Common Mormon Female Butterfly
Common Rose Butterfly
The caterpillars of the Great Orange Tip (Hebomoia glaucippe aturia) mimic viper snakes to fend off predators. When disturbed, the caterpillars imitate vipers preparing to strike. Moreover, the caterpillars’ fake eyespots enhance the “stare” of the caterpillars, causing potential predators to have second thoughts before attacking.
Great Orange Tip Caterpillar
There is a disadvantage to not having sharp claws, stingers, venom or pincers like some animals, but Banded Swallowtail (Papilio demolion demolion) larvae aren’t completely defenceless. They imitate bird droppings to fool hungry birds. In this sense, birds will not eat their own yucky poop.
Banded Swallowtail Caterpillar
3. Chemical defence
Shortly after predators consume Leopard Lacewing (Cethosia cyane) caterpillars, they begin to vomit or feel sick. This is due to the chemical substance found in Adenia leaves, which is the food plant for Leopard Lacewing caterpillars. Even though predators survive from feeling ill, they learn to avoid these caterpillars next time.
II. Defensive liquids
On the other hand, the 1st and 2nd instars of Paper Kite (Idea leuconoe chersonesia) caterpillars secrete a defensive liquid, building a wall of foam around themselves. This is for protection from ants that commonly feed on them. When the ants come in contact with this barrier, they back away, clean their legs and antennae and leave the caterpillar alone.
4. Leaf rolling or stay undercover
Hesperiid (Skipper) larvae stay inside rolled-up leaves to avoid predation. Moreover, caterpillars have also adapted the behaviour of feeding only at night, since at nighttime there are less predators compared to daytime.