1/4 inch, gray.

Four dark stripes on the back.

Two large compound eyes.

Broad, fleshy mouthparts project from lower part of head.

Straw-colored face.

Four stages: egg, larva (maggot), pupa, adult.

Adults lay eggs in manure, spilled feed and other organic matter.

Does not bite.

Adults become active in April.

Life cycle requires only 7-10 days in hot weather.

Adult can lay 4-6 batches of 100-150 eggs.

Single fly can produce more than 12 generations in one summer.

Adults prefer areas in or near housing structures, near breeding material.

Most active on hot, sunny days but congregate at night inside buildings on ceilings, walls, posts or pipes.

Can transmit more than 100 disease-causing germs, both human and animal.

Can be extremely aggravating to animals.

1/4 inch, lighter gray than housefly.

Four dark stripes on back.

Two large compound eyes.

Broad, fleshy mouthparts.

Nearly same size and appearance as housefly.

Four stages.

15-25 day life cycle.

Lays eggs in fresh unencrusted cow manure.

Feeds on animal secretions such as tears, saliva, nasal mucus, blood and serum from wounds.

Female needs animal fluids containing proteins for eggs to develop.

Does not bite, but distresses animals.

Prefers pastures.

Can overwinter as adults inside of buildings.

Usually found near head of animal.

Spreads pinkeye, infectious abortion and eye worms which can cause severe weight loss (33 pounds) and blindness in cattle.

Distresses animals which can result in weight loss due to disinterest in feeding and reduced milk production.

1/4 inch, dark gray with checkered abdomen.

Four dark stripes on back.

Black spots on back and abdomen.

Similar to housefly in size and appearance.

Four stages.

Female needs three blood meals to produce each batch of eggs.

Both male and female are bloodsuckers and will bite any warm-blooded animal, including humans.

Prefers decaying organic matter for breeding rather than manure or spilled milk.

Likes to feed on ears and legs, attacking only during the day.

Life cycle takes 13-18 days at 75-85 degrees with up to 800 eggs per female lifetime.

When not feeding, often found resting on trees, buildings and posts.

Can be found in and around buildings as well as in pastures and feedlots.

Can cause weight retardation and probable decreases in milk production due to increased heart rate, respiration rate and animal temperature with just 25-50 flies present.

Studies show milk losses as high as 30-40% (Iowa State).

1/8 inch, dark gray.

Lacks dark bands found on house and stable flies.

Piercing-sucking mouthparts

Four stages.

Needs extremely fresh manure and warm temperatures for full development.

10 day life cycle in summer.

Lays eggs in fresh manure, normally outside.

Feeds on animal blood 20-40 times per day.

Faces downward while feeding and bites animal primarily on back and sides.

A cow with 250 flies could be bitten over 1,000,000 times during the typical fly season.

Adults prefer open pastures and spend most of their time on animals.

Will travel 10 miles to locate food source.

Bite wound can attract other pests and serve as an entry point for infection.

Can reduce milk production 10-20% and retard weight 15-50 pounds (14%) on feeder cattle.

Causes $365 million loss to cattle industry annually.