Bug Encyclopedia
Search and identify bugs & insects — beetles, butterflies, moths, ants, bees, spiders and more — with size, habitat, danger, behavior, and how to tell them apart.

Sawfly
A wasp relative that never stings, best known for its caterpillar-like larvae that strip leaves from roses, pines, and other garden plants in tidy rows.
wasp
Slug
A soft-bodied, shell-less land mollusk that glides on a muscular foot, leaving a silvery mucus trail as it forages across damp ground and vegetation.
other
Bristly Rose Slug
Despite its caterpillar-like, slug-shaped body covered in fine bristles, this pale green larva is actually the offspring of a small sawfly and feeds on rose leaves by skeletonizing them from the underside.
caterpillar-larva
Grub Worm
A plump, C-shaped, creamy-white larva with a distinct brown head, living underground where it feeds on grass and plant roots before eventually maturing into a scarab beetle.
beetle
Parsley Worm
Banded in green, black, and yellow, the parsley worm rears up and flashes a bright orange, forked scent gland when disturbed, a signature defense of black swallowtail caterpillars.
caterpillar-larva
Caddisfly Larva
A soft-bodied aquatic larva famous for building a portable protective case from sand, gravel, or plant debris bound together with silk.
aquatic-insect
Hag Moth Caterpillar (Monkey Slug)
One of the strangest caterpillars in North America, with curling, hair-covered arm-like projections that make it look uncannily like a tiny tuft of matted fur or a miniature spider monkey.
caterpillar-larva
Fishfly Larva
A flattened, armor-plated predator of stream bottoms, the fishfly larva spends one to three years underwater seizing prey with sickle-shaped jaws before briefly taking wing as a short-lived winged adult.
aquatic-insect
Spiny Oak-slug Caterpillar
A tiny, flattened slug-shaped caterpillar in shades of green, orange, or purple, bristling with clusters of branched spines that can deliver a sting if handled.
caterpillar-larva
Codling Moth Larva
The classic 'worm in the apple,' this pinkish-white caterpillar tunnels straight to the core of apples and pears, leaving a telltale frass-plugged entry hole behind.
caterpillar-larva
Alderfly Larva
Fringed with feathery gill filaments along its sides, the alderfly larva crawls through soft pond and stream sediments hunting smaller invertebrates before eventually leaving the water entirely to pupate on land.
aquatic-insect
Mosquito Larva
A wriggling, comma-shaped aquatic larva that hangs from the water's surface to breathe before transforming into a flying adult mosquito.
aquatic-insect
Crane Fly Larva
Thick-skinned and worm-like, the crane fly larva, often called a leatherjacket, burrows through wet mud and decaying vegetation at the edges of ponds and streams, breaking down plant material as it grows.
aquatic-insect
Black Fly Larva
Anchored to submerged rocks in fast-flowing streams by a silken thread, the black fly larva bends into the current and combs the water for drifting particles with a pair of delicate, fan-shaped feeding brushes.
aquatic-insect
Horse Fly Larva
Hidden in the wet mud along pond and stream margins, the horse fly larva is a tapered, tough-skinned predator that hunts other small soil and mud-dwelling invertebrates before eventually transforming into the familiar biting fly.
aquatic-insect
Soldier Fly Larva
Flattened, leathery, and tapered at both ends, the soldier fly larva drifts just beneath the surface film of ponds and marshes, filtering algae and organic debris while breathing through a fringe of water-repellent hairs at its tail.
aquatic-insect
Phantom Midge Larva
Almost invisible in open water, the phantom midge larva is a slender, transparent predator that drifts through the water column, using a pair of internal gas-filled sacs to hover at precise depths while hunting tiny prey.
aquatic-insect
Dobsonfly Larva (Hellgrammite)
A large, fierce-looking aquatic larva with strong pinching jaws and fringed side gills, spending years hunting under stream rocks before becoming a giant winged dobsonfly.
aquatic-insect
Non-Biting Midge Larva (Bloodworm)
Wriggling through soft bottom mud in dense colonies, the bloodworm gets its striking red color from a specialized blood pigment that lets it survive in oxygen-poor water where few other insects can.
aquatic-insect
Diving Beetle Larva (Water Tiger)
Nicknamed the water tiger, the larva of a predaceous diving beetle is an elongated, sickle-jawed hunter that stalks the shallows and seizes prey many times its own size.
beetle
Fireflies Larvae Glowworm
The larval form of fireflies, often called glowworms, are flattened, segmented crawlers that glow with a steady greenish light. These little predators hunt slugs, snails, and worms in damp ground.
beetle
Caterpillar
The soft-bodied, segmented larval stage of butterflies and moths, recognized by its worm-like shape, multiple pairs of stubby legs, and voracious appetite for leaves.
caterpillar-larva
Black Swallowtail Caterpillar
A striking green caterpillar banded with black and dotted with yellow spots, famous for the bright orange, forked osmeterium it flicks out when disturbed.
caterpillar-larva
Tomato Hornworm
A large, thick green caterpillar with diagonal white stripes and a distinctive curved horn at its tail end, often found stripping leaves from tomato plants in gardens.
caterpillar-larva