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Beetle feeding habits

BEETLE FEEDING HABITS

Coleoptera, the Neuroptera, which includes

lacewings and antlions, are also almost all

predators as adults and larvae. It is tempting

to think it might be the ancestral state in beetles

and their relatives, but the Archostemata, which

are the best represented group in the ancient

fossil record, and are thought to most resemble

ancestral beetles, are wood and detritus feeders.

Here, predation is defined as the killing and

consuming of other animals. Those beetles that

eat meat which is already dead—for example,

burying beetles (Silphidae) and many scarab

beetles (Scarabaeoidea)—are classified as

scavengers or necrophages.

Meat is a very high-energy food source, which

is usually easy to metabolize, but first it needs

to be caught. The adaptations of predators are

therefore geared toward speed, strength, and

stealth, instead of toward detoxifying and

breaking down complex chemicals, as required

by herbivores. While hunting for prey, predators

are exposed to risks and enemies of their own, so

efficiency is in their best interest, and targeting a

few larger prey items is often more efficient than

hunting down large numbers of small insects.

The ground beetles (Carabidae) are a good

example of active predators, with long legs

adapted for running, good eyesight, and powerful

forward-facing mandibles. Most of the temperate

species hunt at night on the forest floor, attacking

worms, slugs, and snails. Some carabids hunt

faster-moving prey, and this is taken to an extreme

PREDATORS

Predation, feeding on other animals, is a

common feeding strategy for beetles. Almost

all the suborder Adephaga, which includes the

ground beetles (Carabidae) and diving beetles

(Dytiscidae), are predatory, as are a large part

of the suborder Polyphaga, for example most

of the Coccinellidae (ladybugs), Staphylinidae

(rove beetles), and Cleridae (checkered beetles).

The large insect order most closely related to

left | Carabus intricatus (Carabidae) The Blue Ground

Beetle, a rare species in Europe, is a nocturnal predator

in woodlands, here feeding on an earthworm.