Heaviest beetle specimen in larval form

The full-grown larva of the actaeon beetle Megasoma actaeon is native to the northern regions of South America. The heaviest full-grown specimen on record for this beetle's larva was a male that was bred in Japan in 2009, which weighed 228 g (8.04 oz), which is almost as heavy as an adult female common rat! Its mother had been collected in Satipo, Peru. The larva averages 200 g (7 oz).

In adult form the beetle had a body length of 13 cm (5.11 in).

Megasoma actaeon is also the heaviest non-marine arthropod (excluding crustaceans).