Largest Insects in the World: Heaviest, Longest and Widest

How do you measure the biggest insect?

Insects are measured in several ways, and each gives a different winner. Weight favors bulky beetles and weta. Body length favors stick insects, especially when the legs are stretched out in front. Wingspan and wing area favor moths and butterflies, which have huge wings but light bodies.

Many famous records also come from single museum specimens or collectors’ reports, and a pregnant female or a well-fed larva can weigh far more than an average adult. Where a figure is an estimate or comes from captivity, we say so below.

1. Giant weta: the heaviest adult insect on record

The Little Barrier Island giant weta, or wetapunga (Deinacrida heteracantha), is a huge, wingless relative of crickets and katydids from New Zealand. Adult females average about 65 mm (2.6 in) in body length and about 32 g (1.1 oz), while males are much smaller, at around 7 g (0.25 oz). A pregnant female weighed at about 71 g (2.5 oz) is the heaviest adult insect reliably recorded, heavier than a typical house mouse.

Wetapunga once lived in forests across northern North Island, but introduced predators, especially rats, wiped them out everywhere except Little Barrier Island (Hauturu-o-Toi). They feed mostly on leaves at night. Thanks to captive breeding, they have now been released onto several predator-free islands, and the IUCN lists the species as Vulnerable.

2. Goliath and elephant beetles: the heaviest beetles

The Goliath beetles (genus Goliathus) of tropical Africa are among the heaviest insects on Earth. Males measure about 6–11 cm (2.4–4.3 in), and big adults can exceed 50 g (1.8 oz). Their larvae are heavier still: fully grown Goliath beetle grubs can weigh more than 100 g (3.5 oz), with reports of about 115 g (4 oz).

The elephant and actaeon beetles (genus Megasoma) of Central and South America are similarly bulky, and it is likely that the biggest of them, or of the Goliath beetles, can outweigh the record weta. Reliable weights are rarely published, so no single species has an undisputed title. For the full beetle contest, see what is the biggest beetle?

3. Titan and Hercules beetles: biggest body and longest horn

Two other beetles are famous for length rather than weight. The titan beetle (Titanus giganteus) of the Amazon and the Guianas has the longest body of any known beetle, with the biggest specimens reaching about 17 cm (6.7 in) without horns.

The Hercules beetle (Dynastes hercules) of Central and South America is the longest beetle if horns are counted. Large males measure about 15–17 cm (6–7 in), and a few have been recorded at about 18 cm (7 in), but much of that length is the long thoracic horn they use in fights.

4. Giant stick insects: the longest insects

Stick insects, or walking sticks, are the longest insects alive. The record holder is an undescribed species from southern China, informally called Phryganistria “chinensis”, found in 2014. A wild female measured 62.4 cm (24.6 in) with its legs extended, and one of its captive-bred offspring reached 64 cm (25 in) in 2016, at the Insect Museum of West China in Chengdu.

Before that, the title belonged to Chan’s megastick (Phobaeticus chani) from Borneo. A specimen at the Natural History Museum in London measures 56.7 cm (22.3 in) with the front legs extended, and its body alone is 35.7 cm (14.1 in). Australia’s gargantuan stick insect (Ctenomorpha gargantua) has been confirmed at 56.5 cm (22.2 in).

Stick insects are very light for their length. The heaviest is a much stouter species, the jungle nymph (Heteropteryx dilatata) of Southeast Asia, whose largest females weigh around 65 g (2.3 oz). North America’s own stick insects, such as the northern walkingstick, are far smaller.

5. White witch moth: the widest wingspan

The white witch (Thysania agrippina), a moth of tropical forests from Mexico to South America, has the widest wingspan of any living insect. Most are smaller, but the largest verified specimen, from Brazil, spanned about 30.8 cm (12.1 in). Its long, narrow wings are patterned in gray and brown zigzags that blend with tree bark.

6. Atlas and Hercules moths: the biggest wings

The Atlas moth (Attacus atlas) of South and Southeast Asia usually has a wingspan of about 24–28 cm (9.5–11 in), and its broad wings make it one of the bulkiest-looking insects in flight. The Hercules moth (Coscinocera hercules) of New Guinea and northern Australia has a similar wingspan and the largest documented wing area of any living insect, about 300 cm² (47 sq in).

Adults of both species have no working mouthparts. They live for only a week or two on fat stored by their caterpillars. Read more in what is the largest moth?

7. Queen Alexandra’s birdwing: the largest butterfly

The Queen Alexandra’s birdwing (Ornithoptera alexandrae) is the world’s largest butterfly. Females reach wingspans of about 25–28 cm (10–11 in) and a body length of about 8 cm (3.1 in); males are smaller, usually around 16–20 cm (6–8 in) across, with shimmering green and blue wings. It lives only in a small area of coastal rainforest in Oro Province, Papua New Guinea. The IUCN lists it as Endangered, and international trade in it is banned under CITES Appendix I.

Other giant insects

Several other groups produce remarkable giants:

• Giant water bugs: the largest, Lethocerus grandis and Lethocerus maximus of Central and South America, can exceed 12 cm (4.7 in) in length.
• Damselflies and dragonflies: the helicopter damselfly Megaloprepus caerulatus of Central and South America has a wingspan of up to 19 cm (7.5 in), the largest of any living odonate. Australia’s giant petaltail, Petalura ingentissima, has the widest wingspan of any living dragonfly, about 16.5 cm (6.5 in).
• Hornets: the northern giant hornet (Vespa mandarinia) of East Asia is the world’s largest hornet; its queens can be about 5 cm (2 in) long or more.
• Wasps: tarantula hawk wasps (genus Pepsis) of the Americas have wingspans of up to about 12 cm (4.8 in).
• Cockroaches: the Australian giant burrowing cockroach can weigh about 33 g (1.2 oz), the heaviest of its group.

Griffinflies: the largest insects that ever lived

The biggest insects known to science are extinct. Griffinflies (order Meganisoptera) were huge predatory relatives of dragonflies. Meganeura monyi, discovered in the coal measures of Commentry, France, lived about 300 million years ago and had a wingspan of about 65–75 cm (2.1–2.5 ft).

The record goes to Meganeuropsis permiana, described from fossils found at Elmo, Kansas, which lived roughly 290–284 million years ago. Its estimated wingspan was up to 71 cm (28 in), with a body nearly 43 cm (17 in) long.

Why aren’t insects that big today?

There is no single answer. One popular idea links the giants to higher oxygen levels in the air during the Late Carboniferous, because insects breathe through a network of tiny tubes, called tracheae, that work less efficiently as bodies grow. However, giant griffinflies survived into later times when oxygen was lower, so other factors probably mattered too.

One strong candidate is predators. Before birds, bats and flying reptiles appeared, insects had the skies to themselves; once fast flying vertebrates evolved, very large, slow insects would have been easy prey. Insects must also shed their stiff outer skeleton to grow, which becomes risky and costly for a very large animal.

Largest insects in Europe and North America

Europe’s insects are modest beside the tropical giants. The European stag beetle is usually named as Europe’s largest beetle, with males reaching about 75 mm (3 in) including their antler-like jaws. The giant peacock moth of southern Europe is the continent’s largest moth, with a wingspan of up to about 15 cm (6 in).

In North America, the giant walkingstick (Megaphasma denticrus) of the south-central United States is usually named as the longest insect, at up to about 15–18 cm (6–7 in). The cecropia moth is the largest native moth, with females spanning roughly 13–15 cm (5–6 in) or a little more.

Largest insects compared