- Who
- Megasoma rhinoceros beetles, Goliathus beetles, Titan beetle (Titanus giganteus)
- What
- 40–50 gram(s)
- Where
- Not Applicable ()
- When
Much debate has surrounded the question of the heaviest beetle for decades, with no one species yet conclusively determined to be the definitive record holder. Weights of around 40–50 g (1.4–1.7 oz) have been cited for a number of of Goliath beetles (family Scarabaeidae) of equatorial Africa, including Goliathus regius, G. meleagris, G. goliatus (=G. giganteus) and G. druryi. Similar weights have been reported for two species of rhinoceros beetle, the Actaeon beetle (Megasoma actaeon) and the elephant beetle (M. elephas), as well as for the titan beetle (Titanus giganteus) of South America. However, it is important to note that this applies to mature adults only; the larvae of some of these species may weigh around twice as much, or more.
The heaviest beetle larvae (and indeed heaviest insect larvae overall) are those of the Actaeon beetle. One male bred in Japan in 2009 weighed 228 g (8 oz) – about the same weight as a brown rat. It is native to the northern regions of South America; this specimen's mother had been collected in Peru.
Meanwhile, the heaviest insect specimen for which there is reliable evidence is a pregnant female Little Barrier giant wētā or wētāpunga (Deinacrida heteracantha) weighing 71 g (2.5 oz), which was discovered in 2011 by US scientist Mark Moffett. This grasshopper-like bug is native to Little Barrier Island, off New Zealand's North Island.
One of these contenders, the titan beetle, does take the title for the longest beetle in terms of body size alone, with a body length of 15 cm (6 in). But even this is contested, the Hercules beetle (Dynastes hercules), a rhinoceros beetles, also of South America, can reach 17 cm (7 in) long overall, due to a long pair of horns - one extending from the head, the other from the thorax.
