Caterpillar scent glands

Title Info
Common name Butterfly, Swallowtail caterpillar
Scientific name Papillionidae
Taxonomic group Lepidoptera
Level Family
Source Dan L. Perlman
Selection and adaptations Coloration
Coloration Mimicry
Behavior Defensive
Organisms Animals
Animals Insects
Lessons Mimicry and Camouflage
Location Palo Verde National Park,Costa Rica,North America

Caterpillar mimic showing scent gland, Costa Rica. If it survives to adulthood, this caterpillar will become a beautiful swallowtail butterfly. In its youth, however, it avoids predation through mimicry, by appearing to be an extremely unpalatable blob of bird excrement, as shown in the companion image. If a predator sees through the disguise and attempts to attack, the caterpillar has a second line of defense. It rears back, extrudes a forked scent gland called the osmeterium and lets off a foul odor, as shown in this image.