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.

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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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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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.
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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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Tussock 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.
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Cecropia Moth Caterpillar
North America's largest native caterpillar, a bulky blue-green giant studded with rows of bright red, yellow, and blue knobby tubercles resembling tiny coral formations.
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Buck Moth Caterpillar
A dark, spiny caterpillar covered in branched spines that marches across oak-lined sidewalks in dense groups each spring.
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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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American Dagger Moth Caterpillar
A pale, sulfur-yellow to cream fuzzball bristling with dense tufts of hair and long black 'pencils' projecting from both ends, the American dagger moth caterpillar is one of the most recognizable hairy caterpillars on hardwood trees in fall.
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Southern Flannel Moth (Puss Caterpillar Moth)
A small, densely furred tan-to-orange moth best known for its unusual larva, a soft-looking, cat-tailed caterpillar whose fluffy coat hides rows of venomous spines.
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Giant 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.
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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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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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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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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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Winter Moth
A small tan-brown moth unusual for flying in the cold of late autumn and early winter, with strongly dimorphic sexes: fully winged males and flightless, near-wingless females that climb tree trunks to lay eggs.
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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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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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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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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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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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Codling Moth
A small, inconspicuous grey-brown moth best known through the work of its larva, the classic apple 'worm' that tunnels into fruit, making this tiny moth one of the most economically significant insects in orchards worldwide.
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