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.

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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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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March Fly
A stout, all-black fly that emerges in sudden, dense swarms during the first warm days of spring, often dangling its long hind legs conspicuously in slow, low flight over grass. Its name comes from its habit of appearing reliably around the start of the month, sometimes on cue near a particular saint's feast day in the traditional European calendar.
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Warble Fly
A furry, bee-mimicking fly that never lands on flowers or feeds as an adult, spending its brief life darting around grazing cattle to lay eggs on their legs and lower body. Herds sometimes react with sudden panicked runs, known as gadding, whenever a warble fly approaches.
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Bot Fly
A stocky, bumblebee-mimicking fly whose adults never feed and live only long enough to mate and locate a rodent or rabbit burrow for their eggs. Despite their harmless, buzzing adult stage, bot flies are best known through the larvae that develop as internal parasites of small mammals.
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Human Bot Fly
A stout, dark-bodied fly from the American tropics famous for an unusual reproductive trick: it captures a blood-feeding mosquito mid-flight and glues its own eggs to the mosquito's body before releasing it to carry them to a future host. The adult itself is rarely seen, spending most of its short life in shaded forest understory.
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Maggot
A pale, legless, tapering grub that wriggles through rotting food and organic waste, the larval stage of a fly.
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Rat-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.
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Root Maggot
A small, legless white grub that lives hidden in the soil, tunneling into the roots of cabbage-family vegetables where it feeds unseen.
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Dung Fly
A hairy, often golden-hued fly commonly seen perched on fresh manure in pastures, where it hunts smaller insects as an adult while its larvae develop within the dung itself.
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Marsh Fly
A slender, unassuming fly best known for larvae with a remarkable diet: nearly every species in the family feeds on aquatic or terrestrial snails and slugs, making marsh flies natural specialists in wetland food webs. Adults are often found resting quietly on sedges and other marsh vegetation near the water's edge.
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Ichneumon Wasp
A slender, long-antennaed parasitoid wasp, often mistaken for a giant mosquito or a stinging insect, that is best known for the extraordinarily long ovipositor some species use to drill into wood and lay eggs on hidden larvae.
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Onion Fly
A slender gray fly closely related to houseflies whose white legless larvae bore into onion bulbs, feeding in clusters within a single rotting bulb.
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Soldier Fly
A wasp-mimicking fly with a flattened, often metallic body that spends its larval life quietly breaking down decaying plant matter or aquatic debris.
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Spotted Wing Drosophila
A tiny reddish-brown fruit fly, each male marked with a single dark spot near the wingtip, notable for laying eggs in ripening rather than overripe fruit.
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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.
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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.
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Carrot Rust Fly
A slender, shiny black fly barely a few millimeters long whose slim yellowish larvae tunnel rust-colored trails through carrot and parsnip roots.
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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.
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Black Soldier Fly
A sleek, dark, wasp-like fly whose larvae are voracious decomposers of decaying organic material, while the short-lived adults do not feed at all.
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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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