Idaho Pest Library

Tetramorium caespitum

Pavement ants are small, dark brown to black ants measuring 2.5-4mm long (about half the size of a grain of rice). Under...

Camponotus species

Carpenter ants are among the largest ants in North America, measuring 6-13mm long (about a quarter inch). Most around Bo...

Tapinoma sessile

Odorous house ants are small, brown to black ants that produce a distinctive "rotten coconut" smell when crushed. They'r...

Monomorium pharaonis

Pharaoh ants are tiny (1.5-2mm), light yellow to reddish-brown with a darker abdomen. They're almost translucent, so mos...

Cimex lectularius

Bed bugs are flat, oval, reddish-brown insects about the size of an apple seed (4-7mm). After feeding, they become more ...

Blattella germanica

German cockroaches are small light-brown roaches with two dark parallel stripes that run from the back of the head down ...

Lepisma saccharina

Silverfish are small, carrot-shaped bugs covered in silvery scales. They have two long antennae and three tail-like appe...

Culicidae family

Mosquitoes are small, slender flies, about 3 to 6mm long, with long legs and a needle-like proboscis. Only the females b...

Ctenocephalides felis/canis

Fleas are tiny dark reddish-brown insects, about 1.5 to 3.3mm long, with flat side-to-side bodies built to slip through ...

Ixodidae family

Ticks aren't insects. They're arachnids, related to spiders, with eight legs and a flat oval body that balloons out once...

Culicoides spp.

Biting midges, commonly called no-see-ums, are tiny flying insects barely visible to the naked eye. They look like minia...

Anthrenus spp., Attagenus spp.

Adult carpet beetles are small, oval, and usually marked with colorful mottled patterns. Common species include varied c...

Plodia interpunctella

Indian meal moths are easily identified by their distinctive wings: the inner half is creamy-white and the outer half is...

Psychodidae family

Drain flies (also called moth flies) are tiny, fuzzy gray flies about 2 to 5mm long with leaf-shaped wings that sit roof...

Drosophila melanogaster

Fruit flies are tiny tan flies with bright red eyes, about 1/8 inch long. You'll spot them hovering around ripening frui...

Musca domestica

House flies are medium-sized gray flies, about 6-7mm long, with four dark stripes running down the thorax. They have lar...

Latrodectus hesperus

Females are shiny jet-black with a red hourglass on the underside of a globular abdomen. That hourglass is the giveaway....

Eratigena agrestis

Hobo spiders are medium-sized brown spiders, about 10-14mm in the body. The giveaway is a chevron (V-shaped) pattern on ...

Lycosidae family

Wolf spiders are big, hairy, fast-moving spiders, usually 10-35mm body length. They are brown, gray, or tan with darker ...

Eratigena atrica

Giant house spiders are among the largest spiders in Idaho, with leg spans up to 75mm (3 inches). They're brown with mot...

Cheiracanthium species

Yellow sac spiders are small (5-10mm) pale yellow to light green spiders with slightly darker jaws. They build small sil...

Pholcus phalangioides

Cellar spiders have small tan bodies (6-9mm) with extremely long, thin legs that can span 50mm or more. They build loose...

Loxosceles reclusa

Brown recluse spiders are identified by the distinctive dark violin-shaped marking on their cephalothorax (head region),...

Mus musculus

House mice are small rodents with dusty gray to light brown fur, oversized ears for their body, and long scaly tails abo...

Rattus norvegicus

Norway rats are big, heavy-bodied rodents measuring 7-10 inches, with tails shorter than their body. They've got brown o...

Rattus rattus

Roof rats are sleek, agile rodents with tails longer than their body. They've got dark brown to black fur, large ears, p...

Microtus spp.

Voles (meadow mice) are small, stocky rodents with short tails, small ears, and blunt snouts. They're often confused wit...

Scalopus aquaticus

Moles are easily identified by their large, paddle-like front feet designed for digging. They have pointed snouts, tiny ...

Thomomys spp.

Pocket gophers are medium-sized burrowing rodents with small eyes and ears, large front teeth, and external fur-lined ch...

Vespula species

Yellowjackets are black and yellow striped wasps, often confused with bees. Key differences: yellowjackets have smooth b...

Polistes species

Paper wasps are slender wasps with long legs that dangle in flight, about 16-25mm long (roughly the length of a papercli...

Dolichovespula maculata

Bald-faced hornets are large black wasps with bright white markings on their face and the tip of the abdomen. They build...

Sceliphron caementarium

Mud daubers are distinctive wasps with extremely thin, thread-like waists connecting thorax and abdomen. They can be bla...

Forficula auricularia

Earwigs are easy to spot once you've seen one. Long, flat, reddish-brown bodies (about half an inch to an inch) with a p...

Halyomorpha halys

Brown marmorated stink bugs are shield-shaped insects, 14-17mm long, with mottled brown coloring. Key identifiers includ...

Harmonia axyridis

Asian lady beetles look similar to native ladybugs but have distinguishing features: a black "M" or "W" shape behind the...

Pollenia species

Cluster flies are slightly larger than house flies, with dark gray bodies covered in golden-yellow hairs. They move slug...

Boisea trivittata

Box elder bugs are black bugs with distinctive red or orange markings on their backs. Adults are about 12-14mm long with...

Arocatus melanocephalus

Elm seed bugs are small, oval insects with dark brown/black bodies and distinctive rust-red edges on their wings. They h...

Scutigera coleoptrata (house centipede) and others

Centipedes have flattened, segmented bodies with one pair of legs per segment. House centipedes have extremely long legs...

Diplopoda class

Millipedes have cylindrical, segmented bodies with two pairs of legs per segment (unlike centipedes' one pair). They cur...

Armadillidium vulgare (pillbug), Porcellio laevis (sowbug)

Sowbugs and pillbugs (roly-polies) are crustaceans, not insects. They're closer cousins to shrimp and crabs than to anyt...

Acheta domesticus (house), Gryllus spp. (field)

Crickets have cylindrical bodies, long antennae, and enlarged hind legs for jumping. House crickets are yellowish-brown ...

Collembola order

Springtails are tiny, wingless arthropods with a forked tail-like structure (furcula) that allows them to jump. They're ...

Bryobia praetiosa

Clover mites are tiny, oval mites with a characteristic reddish-brown color. Their front legs are much longer than other...