The largest butterflies are Ornithoptera alexandrae, Ornithoptera goliath supremus and Ornithoptera goliath procus. Females of each species usually span 9 to 10 inches (23-26cm), exceptional specimens approach 11 inches (28cm).
The largest moths are Attacus caesar and Coscinocura hercules. Females of each species usually span 10-11 inches (26-28cm), and exceptional specimens approach 12 inches (31cm). Thysania agrippina can reach 12 inches in span, but its wings cover much less area.
The largest beetles are Titanus giganteus and Macrodontia cervicornis, and can reach a length of 16cm. Exceptional specimens approach 17cm. Dynastes hercules and Dynastes neptunus may also reach that length, but half that is thoracic horn. The heaviest are Megasoma mars, Megasoma actaeon and Goliathus goliath, which may weigh up to 6 ounces. They have been known to smash street lamps when they fly into them!
The longest insect is the phasmid Pharnacia serratipes, which can reach a length, including legs, of 22 inches (56cm). Hermarchus australis and Hermarchus morosus can grow 20 inches long(52cm) and are twice as massive as Pharnacia.
The biggest ant is Dinoponera gigantea of Brazil. Typical body length is 3cm, overall length 6cm.
The biggest wasp is the mygale hunter, Pepsis staudingeri, with a wingspan of 11cm, and a body length of 7cm. One species of its prey is the world's biggest spider, Theraphosa leblondi, whose legs can span 26cm.
The largest known insect of all time was Meganura monii, a Devonian-Permian dragonfly with a wingspan of 24 inches (62cm).