The Goliath beetle (genus Goliathus) is a titan of a beetle, with adults being amongst the largest of insects at 4.5 inches long and nearly 2 ounces. It is the larvae, however, that brings the Goliath beetle to the number one spot in this list. The larvae are truly enormous and are the heaviest insects on the entire planet as they can reach weights of 3.5 ounces. The life cycle of these mighty beetles is poorly understood, but the larvae are successfully reared in captivity on protein-rich foods like dog food. In their native habitat in the tropical forests of Africa the adults feed primarily on sugary foods like plant sap and fruit. Read more about the Goliath beetle here.
The Giant Weta (Deinacrida heteracantha) is an enormous species of cricket that, though dwarfed by the larvae of the Goliath beetle, holds the title of the heaviest adult insect. The largest known individual clocked in a 2.5 ounces, though this species generally does not get much longer than 3 inches. It is found in New Zealand, coming at out night to feed on vegetation, and is threatened by the introduction of rats to its habitat.
Gargantuan Stick Insect
Though it is far lighter than all the other insects in this list, the gargantuan stick insect, Ctenomorpha gargantua, makes up for low weight with sheer length. It is by far the longest insect on the planet, reaching astounding lengths of more than 22 inches long. This species is very rare in the wild, living in the canopies of Australian forests and feeding on vegetation. It is so rare, in fact, that only 3 females have ever been found in the wild.
Dynastes hercules, the Hercules beetle, is an enormous beetle from Central and South America that is one of the longest confirmed species of beetle at nearly 7 inches of length, including the enormous horn that protrudes from the head of the male. They use this horn to fight other males so that they can mate with females, often harming each other in the process. The larvae of this species feed on rotting wood and the adults consume nectar and fruit. Read more about the Hercules beetle here.
Sabertooth Longhorn Beetle
The sabertooth longhorn beetle (Macrodontia cervicornis) is a fearsome insect with enormous mandibles that make it 7 inches long and thus one of the largest beetles and thus one of the largest insects. Though it is much lighter than the Hercules beetle it is known to grow slightly longer. Despite a fearsome appearance, however, the sabertooth longhorn beetle feeds on rotting wood and is not harmful to people.