46

Specialized habitats

need to be drought tolerant. There is also the

question of where food comes from, considering

the lack of vegetation.

Beetles that inhabit beaches often obtain their

nutrition indirectly from the sea, feeding on

marine life that has been washed up on the beach.

Whether piles of seaweed or the carcasses of

marine animals, ranging from jellyfish to whales,

most decaying organic matter is attractive to some

beetle scavengers, and often to predatory beetles

that eat the larvae of other insects, particularly

flies, which can be hugely abundant. The sea may

also deposit land vegetation, fruits, drowned land

animals, and driftwood, all of which are exploited

as a food source by some beach-living beetles.

Some beetle species specialize in driftwood, and

have been transported around the world in

floating timber.

The majority of beach-living beetles belong

to the families Carabidae, Staphylinidae,

Histeridae, and Tenebrionidae, though

some smaller families are also

characteristic of beach habitats,

for example the Phycosecidae

in Australia. The inhabitants

of driftwood include

wood-boring Curculionidae

and Oedemeridae. Many

carabids and staphylinids

on sandy beaches also

feed directly on marine

organisms such as

sandhoppers (Crustacea:

Amphipoda). Almost all

SAND

Loose sand is another specialized habitat that

many organisms have failed to colonize, but which

supports a varied range of beetle species. Two

major environments consist largely of sand:

beaches, which may merge into sand dunes, and

deserts. While these two habitats have certain

features in common, there are many differences,

and they are used by different groups of beetles.

Sand, whether on deserts or beaches, contains

little or no organic matter, so plants do not grow

well on it. As a result, there is little shade, and

inhabitants are exposed to the sun and to

predators during the day, unless they can hide

beneath debris or bury themselves. Sand also does

not retain moisture well, so such habitats are

usually very dry. Therefore, beetles that inhabit

any sandy environments, especially desert beetles,

left | Stenocara eburnea (Tenebrionidae)

One of the white, desert-adapted

Pimeliinae, this beetle is from Africa’s

Namib desert.