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.
Bagworm
A caterpillar that constructs and lives inside a spindle-shaped case of silk and plant debris, dragging its portable shelter along as it feeds on tree foliage.
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Armyworm
A striped, greenish-brown caterpillar that gets its name from its habit of migrating in dense, destructive groups across grass and grain fields.
caterpillar-larvaZebra Longwing Caterpillar
A creamy-white caterpillar dotted with black spots and armed with branching black spines, feeding exclusively on passionflower vines whose chemistry it stores for defense.
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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-larvaTent 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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Tobacco Hornworm
A large, chunky green caterpillar with diagonal white stripes and a curved red-orange horn at its tail end, often found stripping tomato and tobacco plants.
caterpillar-larvaSpiny 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-larvaSod Webworm
A dull, grayish-green caterpillar that hides in silk-lined burrows by day and emerges at night to chew grass blades down to the thatch.
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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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Silkworm
Plump, pale, and utterly dependent on humans, the silkworm is the domesticated caterpillar behind thousands of years of silk production, spinning a single continuous thread of silk to form its cocoon.
caterpillar-larvaSpicebush Swallowtail Caterpillar
A bulging-eyed green caterpillar that lives folded inside its own silk-stitched leaf tent, looking every bit like a miniature snake peering out from cover.
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Woolly Bear Caterpillar
A densely bristled caterpillar banded in black at both ends with a rusty-orange middle section, famous in folklore for supposedly predicting winter severity and for rolling into a tight ball when touched.
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Waxworm
A soft, cream-colored grub found tunneling through beeswax comb, the waxworm is the larva of the wax moth and has become a household staple as fishing bait and reptile feed.
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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.
caterpillar-larvaTussock Moth Caterpillar
A boldly tufted caterpillar bristling with dense brush-like hair tussocks and long dark pencil plumes that give it an almost punk-rock silhouette.
caterpillar-larvaTiger 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.
caterpillar-larvaPainted Lady Caterpillar
A spiky, mottled caterpillar that spins loose silk webbing over thistle or mallow leaves and hides inside its own protective tent while feeding.
caterpillar-larvaPipevine Swallowtail Caterpillar
A dark, velvety caterpillar studded with fleshy orange-tipped tubercles that feeds exclusively on pipevine, storing its host plant's chemistry for later defense as a butterfly.
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Stinging Rose Caterpillar
A boldly striped slug caterpillar in candy-like tones of yellow, orange, and purple, crowned with tufted spine clusters that can sting on contact.
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Milkweed Tussock Caterpillar
Rows of dense orange, black, and white hair tufts run down the back of this milkweed specialist, whose young larvae feed in tight groups that skeletonize milkweed leaves before dispersing to feed alone.
caterpillar-larvaMonarch 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.
caterpillar-larvaMaggot
A pale, legless, tapering grub that wriggles through rotting food and organic waste, the larval stage of a fly.
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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-larvaQuestion Mark Caterpillar
A spiny, variably colored caterpillar named for the silver question-mark-shaped mark on the underside of the adult butterfly's wings.
caterpillar-larvaPolyphemus 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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Inchworm
A slender, twig-mimicking caterpillar that travels by looping its body into an arch and releasing a strand of silk to drop and dangle at the slightest disturbance.
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Mealworm
A tan, segmented larva with a shiny hard exoskeleton that tunnels through stored grain and flour before transforming into a darkling beetle.
caterpillar-larvaGiant Leopard Moth Caterpillar
A jet-black, bristly caterpillar that curls into a tight ball to reveal bright red-orange bands between its segments when disturbed.
caterpillar-larvaMourning 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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Luna Moth Caterpillar
A large, plump, apple-green caterpillar with faint yellow side stripes and rows of small red-orange tubercles, the larval form of one of North America's most beautiful giant silk moths.
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Gypsy Moth Caterpillar
A hairy, mottled gray caterpillar marked with rows of paired blue and red dots down its back, notorious for periodic outbreak years that can strip entire forests bare.
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Gypsy Moth Caterpillar (Spongy Moth)
A bristly, blue-and-red-spotted caterpillar that can strip entire hardwood forests bare during major outbreak years.
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Gulf Fritillary Caterpillar
A vivid burnt-orange caterpillar bristling with rows of branched black spines that specializes almost exclusively on passionflower vines.
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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.
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Hickory Horned Devil
An enormous, blue-green caterpillar armed with long, curved orange-red horns tipped in black, giving it a fearsome dragon-like appearance despite being completely harmless.
caterpillar-larvaForest Tent Caterpillar
Named for the silk mats rather than tents it spins, this blue-gray caterpillar sports a row of pale keyhole- or footprint-shaped spots down its back and can appear in outbreak numbers that strip entire stands of trees bare.
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Grape Leaffolder Caterpillar
This small green caterpillar stitches grape leaves together with silk into a rolled shelter, feeding hidden inside its own leafy tube and leaving skeletonized patches behind.
caterpillar-larvaEastern Black Swallowtail Caterpillar
A striking green-and-black banded caterpillar dotted with yellow spots that flashes a bright orange forked horn when disturbed.
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Fall Webworm
A pale, hairy caterpillar that spins loose, messy silk webs enclosing entire leaf clusters at the tips of tree branches, becoming especially noticeable in late summer and fall.
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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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Io Moth Caterpillar
A bright lime-green caterpillar bristling with clusters of branching, stinging spines and thin red and white racing stripes along its sides.
caterpillar-larvaCodling 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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Eastern Tent Caterpillar
A fuzzy, blue-flecked caterpillar with a pale stripe down its back, famous for spinning large communal silk tents in the forked branches of cherry and apple trees each spring.
caterpillar-larvaCaterpillar
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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Cotton Bollworm
A variably colored caterpillar, ranging from green to brown to nearly pink, that burrows into cotton bolls, corn ears, and tomato fruit, feeding concealed inside the very structures it damages.
caterpillar-larvaCutworm
A plump, dull gray-brown caterpillar that hides in soil by day and emerges at night to sever young seedlings at the base, curling tightly into a C-shape when disturbed.
caterpillar-larvaCabbage White Caterpillar
A velvety, bright green caterpillar with a faint yellow stripe down its back, the larval stage of the common white butterfly seen fluttering around vegetable gardens.
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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.
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