Xylophagy

Xylophagy is a term used in ecology to describe the habits of an herbivorous animal whose diet consists primarily (often solely) of wood. The word derives from Greek ξυλοφάγος (xulophagos) "eating wood", from ξύλον (xulon) "wood" and φαγεῖν (phagein) "to eat", an ancient Greek name for a kind of a worm-eating bird. Animals feeding only on dead wood are called sapro-xylophagous or saproxylic.

Xylophagous insects

Most such animals are arthropods, primarily insects of various kinds, in which the behavior is quite common, and found in many different orders. It is not uncommon for insects to specialize to various degrees; in some cases, they limit themselves to certain plant groups (a taxonomic specialization), and in others, it is the physical characteristics of the wood itself (e.g., state of decay, hardness, whether the wood is alive or dead, or the choice of heartwood versus sapwood versus bark).

Many xylophagous insects have symbiotic protozoa and/or bacteria in their digestive system which assist in the breakdown of cellulose, others (e.g., the termite family Termitidae) possess their own cellulase. Others, especially among the groups feeding on decaying wood, apparently derive much of their nutrition from the digestion of various fungi that are growing amidst the wood fibers. Such insects often carry the spores of the fungi in special structures on their bodies (called "mycangia"), and infect the host tree themselves when they are laying their eggs.

Dynastinae

Dynastinae or rhinoceros beetles are a subfamily of the scarab beetle family (Scarabaeidae). Other common names – some for particular groups of rhinoceros beetles – are for example Hercules beetles, unicorn beetles or horn beetles. Over 300 species of rhinoceros beetles are known.

Many rhinoceros beetles are well known for their unique shapes and large sizes. Some famous species are, for example, the Atlas beetle (Chalcosoma atlas), common rhinoceros beetle (Xylotrupes ulysses), elephant beetle (Megasoma elephas), European rhinoceros beetle (Oryctes nasicornis), Hercules beetle (Dynastes hercules), Japanese rhinoceros beetle or kabutomushi (Allomyrina dichotoma), ox beetle (Strategus aloeus) and the unicorn beetle (Dynastes tityus).

Description and ecology

The Dynastinae are among the largest of beetles, reaching more than 150 mm (6 in) in length, but are completely harmless to humans because they cannot bite or sting. Some species have been anecdotally claimed to lift up to 850 times their own weight. Their common names refer to the characteristic horns borne only by the males of most species in the group. Each has a horn on the head and another horn pointing forward from the center of the thorax. The horns are used in fighting other males during mating season, and for digging. The size of the horn is a good indicator of nutrition and physical health.

European rhinoceros beetle

The European rhinoceros beetle (Oryctes nasicornis) is a large flying beetle belonging to the subfamily Dynastinae.

Subspecies