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.

Screwworm Fly
A metallic blue-green blowfly whose larvae are unusual among maggots for feeding on living tissue rather than carrion, drawn to even small open wounds on warm-blooded animals. The species has been the target of one of the most successful large-scale insect eradication campaigns in history across much of North America.
fly
Long-Legged Fly
A jewel-bright little fly that flashes metallic green, blue, or bronze in the sunlight as it darts across leaves on comically long, stilt-like legs, pausing to perform quick territorial displays. Both adults and larvae are active hunters of even smaller insects, making this tiny fly a useful predator in gardens and wetlands alike.
fly
Tachinid Fly
A bristly, house-fly-like insect that looks unremarkable at a glance but hides one of the most important ecological roles among flies: its larvae develop as internal parasites of caterpillars, beetles, and other insects, quietly regulating populations across the landscape. Gardeners often welcome tachinid flies as natural allies against crop-damaging pests.
flyDobsonfly
A massive, primitive-looking insect whose males brandish absurdly long, curved mandibles used for wrestling rivals rather than for feeding.
aquatic-insectTiger 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-larvaStonefly Nymph
A flattened, armored aquatic nymph that clings tightly to rocks in swift, cold streams, serving as one of the most reliable signs of pristine water quality.
aquatic-insect
Dragonfly Nymph
A stocky, camouflaged underwater predator that spends months or years stalking prey along the pond bottom before transforming into an aerial dragonfly.
aquatic-insectDamselfly Nymph
A slender aquatic predator with three feathery tail gills, patiently stalking small prey among pond plants before emerging as a delicate flying damselfly.
aquatic-insect
Cottonwood Borer
A large, boldly patterned longhorn beetle in black and chalky white checkerboard markings, often found clinging to the trunks of cottonwood and poplar trees near its larvae's root tunnels.
beetleWireworm
Slender, shiny, and armor-hard, the wireworm is the long-lived soil-dwelling larva of a click beetle, spending years underground feeding on seeds, roots, and tubers before ever taking beetle form.
beetleMaggot
A pale, legless, tapering grub that wriggles through rotting food and organic waste, the larval stage of a fly.
caterpillar-larva
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
Mealworm
A tan, segmented larva with a shiny hard exoskeleton that tunnels through stored grain and flour before transforming into a darkling beetle.
caterpillar-larvaMayfly Nymph
A short-lived aquatic grazer with feathery gills along its abdomen, living for months underwater before a brief, spectacular mass emergence as a winged adult.
aquatic-insectAntlion
An insect best known for its larval stage, the doodlebug, which digs a small conical pit trap in loose sand to ambush unwary ants, while the winged adult resembles a slender, delicate damselfly.
otherRat-Tailed Maggot
Named for its long, thin, telescoping breathing tube, the rat-tailed maggot is the aquatic larva of the drone fly, thriving in stagnant, low-oxygen water where few other insects can survive.
aquatic-insect
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-larvaRoot Maggot
A small, legless white grub that lives hidden in the soil, tunneling into the roots of cabbage-family vegetables where it feeds unseen.
fly
Lacewing
A delicate, pale green insect with large, transparent, intricately veined wings and shining golden or copper-colored eyes, valued as a natural predator of aphids in its larval form.
other
Cabbage White
A common, small white butterfly with one or two black wing spots, whose green caterpillars are a familiar sight feeding on cabbage-family garden plants.
butterfly
Black Swallowtail
A striking black swallowtail with two rows of yellow spots and a patch of blue scaling on the hindwings, whose green-and-black banded caterpillars are a familiar sight on garden dill, parsley, and carrot foliage.
butterfly
Bumblebee Carpenter Bee
A large, robust bee that closely resembles a bumblebee at a glance but has a smooth, shiny, hairless abdomen and a habit of boring round nesting tunnels into bare wood.
bee
Bee Fly
A fuzzy, bee-mimicking fly with a long, forward-pointing proboscis that hovers motionless in front of spring flowers while sipping nectar.
flyCave Spider
A long-legged orb weaver adapted to the twilight zone of caves, spinning large webs across cavern mouths and dangling its egg sacs from silk threads deep within the darkness.
spider