Arizona Pest Library: Identify Common Pests

The Arizona bark scorpion is the most common, and the only medically significant, scorpion in the Phoenix area. It's light tan, about 2-3 inches, glows blue-green under UV light, and can climb walls and ceilings.

The giant hairy scorpion is North America's largest scorpion, up to 6 inches, named for the brown hairs on its tail and legs. Despite its size, its venom is mild; the much smaller bark scorpion is the dangerous one.

The striped tail (devil) scorpion is a stocky, tan Arizona scorpion with dark stripes down its tail segments. It's far more common in some yards than the bark scorpion but is not a climber and is much less venomous.

The western black widow is a glossy black spider with a red hourglass on the underside of its abdomen. It builds messy, strong webs in dark, low, undisturbed spots around Valley homes.

The desert recluse is a tan spider with a faint violin marking and six eyes in three pairs. True desert recluses live mostly in outlying desert areas and are far rarer in Phoenix yards than people fear.

The giant crab spider, or huntsman, is a large, flat, fast tan spider that can span several inches. It looks alarming on a wall but is a harmless hunter that actually eats other pests, including cockroaches.

The desert (Arizona blond) tarantula is a large, slow, hairy brown spider. Males wander in late summer looking for mates, which is when most people see them crossing yards and driveways.

The sun spider (solifugae / camel spider) is a fast tan arachnid with oversized jaws. Despite wild internet myths, it's small, non-venomous, and harmless, it just runs toward your shadow, not at you.

The pavement ant is a small brown-black ant that nests under sidewalks, driveways, and slabs, leaving little piles of displaced sand at cracks and expansion joints.

The odorous house ant is a tiny dark ant that gives off a rotten-coconut smell when crushed. It trails indoors after water and sweets, especially in kitchens and bathrooms.

The harvester ant is a large red-brown ant that clears a bare, gravel-ringed disc around its nest. It delivers a painful sting and is common in open desert yards.

The crazy ant is a small dark ant named for its fast, erratic, zig-zagging movement instead of neat trails. It forms huge numbers and is drawn to electronics and moisture.

The southern fire ant is a native red-and-black stinging ant common in Valley yards. It swarms and stings when its nest is disturbed, leaving itchy welts.

The American cockroach (palmetto bug / sewer roach) is Arizona's largest common roach, reddish-brown and up to 2 inches. It lives in sewers and drains and comes up into homes through plumbing.

The German cockroach is a small tan roach with two dark stripes behind the head. It breeds explosively indoors and is the hardest roach to eliminate, an infestation rarely clears without treatment.

The Turkestan cockroach is an outdoor roach that has largely replaced the oriental roach in Arizona. Males are tan and fly to lights; females are dark with cream markings. It lives in water and irrigation boxes.

Subterranean termites are the most destructive pest in Arizona. They nest in the soil and build mud tubes to reach wood, and the Valley sits in one of the highest subterranean termite pressure zones in the country.

The desert subterranean termite is Arizona's most destructive termite. It nests in soil, builds mud tubes to reach wood, and can tunnel through walls to attack a home from below.

The western drywood termite lives entirely inside dry wood with no soil contact, infesting attics, framing, and furniture. It gives itself away with piles of tiny six-sided pellets.

The roof rat is a sleek, dark, agile climber that has spread across Phoenix neighborhoods with mature citrus and irrigation. It nests high, in attics, trees, and rooflines, not in burrows.

The Norway rat is a large, heavy-bodied brown rat that burrows at ground level, along foundations, under sheds, and near garbage, unlike the climbing roof rat.

The house mouse is a small gray rodent that squeezes through gaps the size of a dime. It breeds year-round indoors and leaves droppings and gnaw marks in pantries and garages.

The pack rat, or white-throated woodrat, builds bulky stick-and-debris nests (middens) in desert-landscape yards and engine bays. It's notorious for chewing vehicle wiring.

Botta's pocket gopher is a burrowing rodent that lives entirely underground, pushing up fan-shaped soil mounds and severing plant roots from below in lawns and gardens.

The round-tailed ground squirrel is a small, pale, prairie-dog-like rodent that digs open burrows in desert yards and comes out in the heat of the day.

Africanized ('killer') honey bees look nearly identical to European honey bees but defend their colony far more aggressively. In Arizona, most wild honey bee colonies are Africanized.

The carpenter bee is a large, shiny bee that bores round, dime-sized holes into wood beams and fascia to nest. The males hover and buzz aggressively but have no stinger.

The paper wasp builds the familiar open, umbrella-shaped nest of gray papery cells under eaves and patio ceilings. It's slender with long dangling legs in flight.

The mud dauber is a slender, often metallic-blue or black-and-yellow wasp that builds tube-shaped mud nests on walls and eaves. It's solitary and stocks its nest with paralyzed spiders.

The tarantula hawk is a huge black wasp with bright orange wings that hunts tarantulas to feed its young. Its sting is rated among the most painful of any insect, but it's not aggressive toward people.

The house fly is the common gray fly that breeds in garbage, pet waste, and decaying matter. It moves rapidly between filth and food, spreading bacteria as it goes.

The drain fly (moth fly) is a tiny, fuzzy, moth-like fly that breeds in the gelatinous film inside slow or unused drains. Adults sit on walls near sinks and showers.

The fungus gnat is a tiny dark fly that breeds in the moist soil of overwatered houseplants. Adults flit weakly around plants, windows, and screens.

The Aedes aegypti is a small dark, white-marked mosquito that has spread across Phoenix. It bites aggressively during the day and breeds in tiny amounts of standing water.

The Culex is the Valley's common house mosquito, active at dusk and night. It's the main West Nile virus vector in Arizona and breeds in stagnant water.

The field cricket is the large black cricket that surges in late summer, chirping loudly and gathering around exterior lights before slipping into garages and homes.

The Indian house cricket is a pale tan cricket that has become common in the Southwest. It thrives around lights and buildings and can get indoors in large numbers.

The silverfish is a teardrop-shaped, silvery, wingless insect that wriggles like a fish. It seeks humidity and feeds on paper, starches, and stored goods.

The springtail is a minuscule insect that jumps using a tail-like spring. It swarms in damp soil, potting mix, and around overwatered areas and pools, sometimes in huge numbers.

The desert millipede is a large brown, slow-moving, many-legged arthropod that surges out during the summer monsoon. It curls into a spiral when disturbed and is completely harmless.

The giant desert centipede is a large, fast, flattened arthropod, sometimes 6-8 inches, that hunts insects at night. Unlike millipedes, it has a venomous bite.

Pill bugs (roly-polies) and sowbugs are small gray crustaceans that live in damp soil and mulch. Pill bugs roll into a ball; sowbugs can't. Both are harmless moisture-lovers.

The ring-legged earwig is a slender dark earwig with banded legs and pincers at the rear. It's common in Valley yards and slips indoors seeking moisture, but the pincers are mostly for show.

The palo verde root borer is one of Arizona's largest beetles, a 3-inch black beetle that clumsily buzzes around at dusk in summer monsoon season. Its grubs feed on tree roots underground.

The blister beetle is a slender, often brightly marked beetle that releases a chemical (cantharidin) which raises painful blisters on skin if the beetle is crushed against you.

The carpet beetle is a tiny rounded beetle whose larvae feed on wool, silk, feathers, and stored fibers. The bristly larvae do the damage, chewing holes in fabrics and rugs.

The Indian meal moth is the most common pantry moth, its larvae infest flour, grains, cereal, dried fruit, and pet food, leaving silk webbing in the package.

The brown dog tick is the tick that infests Arizona homes and yards with dogs. Unlike most ticks it can complete its whole life cycle indoors, so infestations can explode.

The cat flea is the flea that bites both cats and dogs (and people) in Arizona. It jumps aboard pets, then drops eggs into carpet, bedding, and yard soil where larvae develop.

The conenose, or kissing bug, is a dark cone-headed insect that comes out at night in late spring to feed on blood, often biting around the face, hence the name. In Arizona it's tied to packrat nests.