Pest identification

It's not hard to know when you have a problem, but knowing exactly what the problem is can be much more difficult. This page identifies many of the common pests, their physical attributes and issues.

Bed bugs

These nocturnal blood-feeding pests of humans are oval shaped reddish brown insects, 1 – 5 mm (1/16 inches to 3/16 inches) long.

Learn more

Ants

Pavement Ants

An introduced pest from Europe, Pavement ants are 2-4 millimeters long and range from dark brown to black in colour.

Learn more

Carpenter Ants

Nesting inside our structures, Carpenter ants are large black ants with polymorphic (varying sized) workers. One species in southern Ontario is black with a red thorax.   Workers range from 6 – 12 mm and winged swarmers up to 18mm. Queens are rarely seen and can be as large as 20mm long.

Learn more

Pharaoh Ants

Tiny and almost translucent, Pharaoh ants are yellow or reddish-brown in colour and are very small (2 mm in length).

Learn more

Cockroaches

German Cockroach

The German cockroach is brown with two black horizontal stripes on their pronotum (the shield-like structure partially covering the insects head and thorax) from behind their head to the base of their wings. They are 11 mm to 16 mm in size (adults are ½ inches to 5/8 inches long). Adults are winged. Immature cockroaches do not have wings and are light brown with varying dark brown markings.

Learn more

Fleas

Flea

Mainly pests of pets, Fleas will also take a bite out of humans. Adults are 1 to 4 mm long and are black to reddish-brown in colour. They are flattened laterally to pass easily through the fur of animals.

Learn more

Bees and Wasps

Yellow Jackets

There are 3 species in Southern Ontario with black and yellow bands on a smooth abdomen. Quite often confused with honeybees which are thicker insects with hairy bodies. Yellow jackets are typically 12mm in length.

Learn more

Bald Faced Hornet

With a very painful sting, Bald Faced Hornets are 13 to 20mm and black with white or bluish markings.

Learn more

Carpenter Bee

Carpenter bees are thick and robust with a shiny abdomen.   They are black or mainly black with yellow or white markings. Commonly confused with Bumble bees which are hairy with larger yellow markings.

Learn more

Pantry Pests

Sawtoothed Grain Beetles

A slender dark brown to black beetle 2.5 – 3mm with jagged edges on the thorax.

Learn more

Merchant Grain Beetles

A slender dark brown to black beetle 2.5 – 3mm with jagged edges on the thorax.

Learn more

Drugstore Beetles

Approximately 1/10 inch in length, reddish-brown in colour and oval shaped. Hair appears in lines on the insects hard shell (elytra).

Learn more

Confused and Red Flour Beetles

Flour beetles are small 3-6mm long and reddish-brown in colour.

Learn more

Indian Meal Moths

Adults are 8 – 10mm long, outer half of their wings are dark gray or copper coloured with tan or yellowish-grey upper half of their wings. Larvae are off-white with brown heads.

Learn more

Mediterranean Flour Moths

The adults of this species are 12 mm long with dark zigzag markings across the wings. The larvae are off-white with a darker head and small black spots on the body.

Learn more

Spiders

Black Widow Spider

Adult females are black with a bright red hourglass marking on the abdomen. Immature females may have two red dots that have not yet developed into the telltale hourglass marking.

Learn more

Brown Recluse Spider

Light to medium brown 6 to 20mm with markings on their cephalothorax, with a black line coming from it that looks like a violin with the neck of the violin pointing to the rear of the spider.

Learn more
Image Attributions