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.

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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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.
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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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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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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.
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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.
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Forest 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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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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Spicebush 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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Painted 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.
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Cabbage 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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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.
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Pipevine 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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Zebra 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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Eastern 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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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.
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Fox Moth
A stout, reddish-brown moth with a pale diagonal band across each forewing, closely resembling a fox in color, most often noticed as its large, densely furred dark caterpillar basking on open ground in spring.
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Tussock Moth
A moth with a striking split lifestyle: winged, drab gray-brown males fly to seek out flightless, grub-like females, while the ornate caterpillars sport dense tufts of colorful bristly hair.
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Gypsy Moth (Spongy Moth)
A strongly sexually dimorphic moth, recently renamed the Spongy Moth for its distinctive spongy, tan egg masses, whose caterpillars are known for periodically defoliating oak and other hardwood trees in large outbreak years.
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Salt Marsh Moth
A fluffy white tiger moth with black-speckled forewings and an orange-and-black abdomen, best known through its fast-moving, densely bristled caterpillar that wanders widely in late summer.
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Pine Processionary Moth
An unremarkable grey-brown moth known almost entirely through its larvae, which build large silken nests in pine trees and travel to feed in long, head-to-tail processions covered in fine defensive hairs.
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Imperial Moth
One of the largest and most variably patterned silk moths in North America, with broad yellow wings mottled in shades of purple, brown, and pink, and a caterpillar that can grow to impressive size on a wide range of forest trees.
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Puss Moth
A stout, furry gray-and-white moth named for its dense, cat-like coat of hair, best known for its bizarre green caterpillar with a hump-backed, face-like front end and forked tail filaments used in defensive displays.
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