Largest moth

The world's largest moth, in terms of overall size, is the atlas moth (Attacus atlas), found natively in South-east Asia. Their wingspan alone is 30 cm (11.8 in), and they are often mistaken for birds. They have no mouth and therefore live for about four days, relying on fatty deposits.

The rare owlet moth (Thysania agrippina), aka white witch, of Central and South America has also had a wingspan of 30.8 cm (1 ft 1 in) reported for a female found in 1934 and several other more recent examples have measured in the 28–30-cm (11–11.8-in) range.

The Hercules moth (Coscinocera hercules) of tropical Australia and New Guinea, meanwhile, has a slightly smaller wingspan of 28 cm (11 in) but a total wing area of up to 263.2 cm² (404.5 sq in). Males also have a long swallowtail which makes them the largest in terms of length. In 1948, an unconfirmed wingspan of 36 cm (1 ft 2 in) was reported for a female captured near the post office in the coastal town of Innisfail in Queensland, Australia.

In terms of weight, another moth takes the heavyweight title: native to eastern Australia and New Zealand, an adult female specimen of the giant wood moth (Endoxyla cinereus) tipped the scales at 31.2 g (1.1 oz). Atlas moths, by comparison, weigh in the range of 25–28 g (0.88–0.98 oz), with the larger females reaching the greater weights.

At the other end of the scale, of the 180,000 species of Lepidoptera documented, the smallest-known moths sit within two families: Gracillariidae (leaf miner moths) and Nepticulidae (pygmy moths). Species from both, including examples from the genera Stigmella, Johanssoniella (=Enteucha) and Porphyrosela, have wingspans as small as 2.6–2.8 mm (0.10–0.11 in), making them more than 100 times smaller than the atlas.