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.
Armyworm
A striped, greenish-brown caterpillar that gets its name from its habit of migrating in dense, destructive groups across grass and grain fields.
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Fall Armyworm
A brownish-green caterpillar marked with a pale inverted "Y" on its head, notorious for rapid, large-scale outbreaks that devastate corn and other grass crops across the globe.
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Armyworm Moth
A plain tan to reddish-brown moth whose caterpillars are famous for marching in large groups across fields, stripping grasses and grain crops as they move.
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Caddisfly Larva
A soft-bodied aquatic larva famous for building a portable protective case from sand, gravel, or plant debris bound together with silk.
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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.
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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.
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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.
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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.
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Mosquito Larva
A wriggling, comma-shaped aquatic larva that hangs from the water's surface to breathe before transforming into a flying adult mosquito.
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Monarch Caterpillar
A boldly banded caterpillar in white, yellow, and black stripes, unmistakable as it munches its way through milkweed leaves before transforming into North America's most famous migratory butterfly.
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Tent Caterpillar
A social, blue-striped caterpillar that builds a conspicuous silken tent in the fork of a tree branch, sheltering large colonies of siblings that emerge together to feed on leaves.
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Saddleback Caterpillar
An unmistakable stout caterpillar with a bright green saddle-shaped patch on a brown back, bristling with clusters of spines along its stocky body.
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Puss Caterpillar
A caterpillar disguised as a tuft of soft fur, its dense coat of silky hairs conceals rows of spines beneath, making it one of the most deceptively harmless-looking stinging caterpillars in North America.
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Tiger Swallowtail Caterpillar
A smooth green caterpillar with a swollen thorax marked by two large fake eyespots, giving it an uncanny resemblance to a tiny snake's head.
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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.
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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.
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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.
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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.
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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.
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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.
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Polyphemus Moth Caterpillar
A plump, apple-green giant silk moth larva with rows of silvery spots that swells to the size of a large finger before spinning a papery brown cocoon.
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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.
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Mourning Cloak Caterpillar
A gregarious, velvety black caterpillar speckled with white dots and a striking row of brick-red spots down its back, often seen feeding in clusters on willow branches.
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Question Mark Caterpillar
A spiny, variably colored caterpillar named for the silver question-mark-shaped mark on the underside of the adult butterfly's wings.
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