Morphology of a caterpillar: soft-bodied, herbivorous and segmented larva of a butterfly.
Mouth parts: pieces forming the mouth.
Thoracic leg: locomotive appendage.
Segment: one of the portions of the body.
Proleg: caterpillar appendage not used in locomotion.
Spiracle: entrance to the respiratory system.
Postabdominal spine: hard organ of a caterpillar situated behind the abdomen.
Head: foremost part.
Thorax: central part.
Abdomen: rear part of the caterpillar.