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Coleoptera - beetles

Blister beetle
Meloidae
5/8 in.

Stag beetle
Lucanidae
1 1/4 in.

Nearly all beetles have four wings; the upper front pair is hardened, whereas the hind pair is membranous and folded beneath the front wings for protection. Metamorphosis is complete. Both the larvae and adults have chewing mouthparts. The larvae of beetles often are called grubs.

Beetles make up approximately 40% of all insect species. They are found almost everywhere. For example, whirligig beetles and diving beetles live in water, whereas cucumber beetles, Mexican bean beetles, and alfalfa weevils feed on vegetation. Plum curculio attack fruits; granary weevils feed in stored grains; and stag beetles live in stumps and decaying logs. Others, such as scavenger beetles, live on dead animals. Some Coleoptera, such as lady beetles and ground beetles, are beneficial, because they feed on injurious insects. Many beetles are very destructive agricultural pests.

The stylopids are unusual beetles that are parasitic on other insects such as wasps. Some entomologists consider them a separate order called Strepsiptera.

Long-horned beetle Cerambycidae 5/8 in.	Click beetle Elateridae 1/2 in.
Spotted cucumber beetle Chrysomelidae 3/16 in.	Elm leaf beetle Chrysomelidae 1/4 in.
Tortoise beetle Chrysomelidae 3/16 in.	Carion beetle Silphidae 3/4 in.
Colorado potato beetle Chrysomelidae 3/8 in.	Spinach flea beetle Chrysomelidae 3/16 in.
Sap beetle Nitidulidae 1/4 in.	Rove beetle Staphylinidae 5/8 in.
Alfalfa beetle Curculionidae 1/8 in.	Metallic wood borer Buprestidae 5/8 in.
Cadelle Trogossitidae 5/16 in.	Soldier beetle Cantharridae 1/2 in.
Locust leaf miner Chrysomelidae 1/4 in.	Firefly Lampyridae 1/2 in.
Snout beetle Curculionidae 1/2 in.	June beetle Scarabaeidae 5/8 in.
Japanese beetle Scarabaeidae 3/8 in.	Rose chafer Scarabaeidae 3/8 in.
Mexican bean beetle Coccinellidae 1/4 in.	Lady beetle Coccinellidae 1/4 in.
Whirligig beetle Gyrinidae 1/2 in.	Larder beetle Dermestidae 3/8 in.
Tiger beetle Cicindelidae 1/2 in.	Ground beetle Carabidae 3/4 in.
Saw-toothed grain beetle Cucujidae 1/8 in.	Flour beetle Tenebrionidae 1/8 in.
Spider beetle Ptinidae 1/8 in.	Darkling beetle Tenebrionidae 3/8 in.
Net-winged beetle Lycidae 5/8 in.	Carpet beetle Dermestidae 1/16 in.