larvae inside. Some larvae can survive even in
these circumstances, but their development is
greatly slowed down by the lack of nutrient
content. In an extreme example, larvae of the
North American jewel beetle Buprestis aurulenta,
which typically last two to three years, emerged as
adults from structural timber 25 years after it was
harvested, dried, and processed!
On the opposite end of the decay spectrum,
compost also consists mainly of rotting plant
matter, but is very damp and filled with diverse
communities of fungi, microbes, and
invertebrates. This rich resource supports the
largest known beetle larvae, the giant white
grubs of some rhinoceros beetles, such as the
South and Central American genera Dynastes
and Megasoma (Scarabaeidae: Dynastinae).
Many other scarabaeoid larvae develop in
very moist and nutrient-rich decaying
vegetation, from stag beetles in wet decayed
subterranean wood to dung beetles—since dung
is just dead vegetation that has passed through the
gut of a vertebrate.
Based on comparison of related species, it is
thought that the still-undiscovered larva of the
biggest beetle of all, the South American Giant
Longhorn Titanus giganteus (Cerambycidae), feeds
on the decaying dead roots of giant trees under
the soil, deep in the Amazonian jungles. It has still
never been seen by scientists.
above | Priacma serrata (Cupedidae)
From the USA, this beetle develops
in dead wood. It is among the few
living representatives of the ancient
Archostemata.
below | Megasoma actaeon (Scarabaeidae)
The heaviest known beetle, weighing
in at over 7 ounces (200 grams), is the
compost-feeding larva of a Central
American rhinoceros beetle.