External Structures of Insects
2 pair of wings; some groups (flies) have reduced posterior pair to halteres (little knobs for balance); front pair can be hardened for protection (beetles)
Wings: saclike outgrowths of body wall; mature wings = solid chitin
Butterflies: wings covered with tiny scales (color & patterns!)
Mouthparts: Labrum, mandibles, maxillae, labium with palps in chewing insects; many modifications for special needs