Controlling House Flies and Dark-Eyed Fruit Flies in Hog Barns

By Mike Catangui, Ph. D |

Dark-eyed fruit flies (Drosophila repleta) in a hog barn. (Photo: Dr. Mike Catangui)

Controlling flies indoors

  1. To immediately reduce adult house fly (Musca domestica) and dark-eyed fruit fly (Drosophila repleta) numbers, apply ULD® BP-100 (or Stryker® 100 or EverGreen® 100) as a fog over the animals using a Hurricane™ fogger or a STIHL® SR 450 mist blower. Apply undiluted at the rate of one fluid ounce per 1,000 cubic feet of space. Reapply as necessary. Fog inside the rooms and the immediate outside aisles and walkways. Also fog areas where flies tend to congregate such as on the walls, pen railings, ceilings, windows, siding, eaves and fan housing.
  2. Treat the fly breeding sites with Neporex® 2SG. House fly and dark-eyed fruit fly larvae can breed in any fermenting organic matter on the slotted floor such as spilled feed, manure and slimy water. Mix one pound of Neporex 2SG per gallon of water and thoroughly spray the entire area of the slotted floor at the rate of one gallon spray mixture per 200 square feet of area. Also spray through the slots to reach the “crust” underneath where fly larvae might breed. Use an ordinary hand-pump or backpack sprayer that can deliver a coarse spray at low pressure. Repeat applications may be made at no more than once every 21 days. Elector® PSP applied as a spray at 0.2 fluid ounce (6 ml) per one gallon of water to treat 200 square feet of area can also be used in lieu of, or in rotation with, Neporex 2SG.
  3. Apply PT Alpine® Pressurized Fly Bait in areas where adult house flies tend to congregate. Apply only in areas that are out of reach of the hogs to avoid accidental ingestion or contamination. Do not apply bait close to doors and other entry points as flies might be inadvertently lured into the building.
  4. During cleanout or when the animals are not in the barn, apply Onslaught® FastCap as an empty-barn residual spray on surfaces where adult house flies and black fruit flies may rest or congregate. Mix 0.5 fluid ounce of Onslaught FastCap per gallon of water and apply as a residual spray using a backpack sprayer. One gallon of spray mixture can spray about 1,000 square feet of area. The rooms can be restocked once the sprayed surfaces have completely dried out.

Controlling flies outdoors

  1. To immediately reduce fly numbers, apply ULD BP-100 (or Stryker 100 or Evergreen 100) as a fog using a Hurricane fogger or a STIHL SR 450 mist blower. Apply undiluted at the rate of one fluid ounce per 1,000 cubic feet of space. Reapply as necessary.
  2. Apply Onslaught FastCap as a residual spray on surfaces where adult house flies and black fruit flies may rest or congregate. Mix 0.5 fluid ounce of Onslaught FastCap per gallon of water and apply as a residual spray using a backpack sprayer. One gallon of spray mixture can spray about 1,000 square feet of area. Make sure that the spray does not drift into the building when animals are present inside.
  3. Use StarBar® QuikStrike® Fly Bait around the exterior perimeter (away from entry points) to lure and kill house flies away from the building. Rotate among StarBar QuikStrike Fly Bait, Starbar® Golden Malrin® Fly Bait and QuickBayt® Fly Bait every three months.
  4. In addition to spraying for adult flies, the compost piles (if present) will need to be treated with larvicides to control the fly maggots where they breed during the summer months. Treat the compost piles with Neporex 2SG and Elector PSP once a month as follows.
    a.Neporex 2SG applied as a granule using the STIHL SR 450 at a rate of one pound per 200 square feet of area. Alternatively, Neporex 2SG can also be dissolved in water (one pound per one gallon water) and sprayed at one gallon mixture per 200 square feet area.
    b.Elector PSP applied as a spray at 0.2 fluid ounce (6 ml) per 1 gallon water to treat 200 square feet of area.
    c.The above larvicides can be applied using an ordinary sprayer or a STIHL SR 450 mist blower. The latter can apply either solid or liquid formulations with minor adjustments in the tank.
  5. For large area spraying outdoors, an A1 Mist Sprayer can be considered, www.mistsprayers.com.

    For more information, please contact your MWI Animal Health Territory Manager. Prior to using any product mentioned in this article, carefully read and follow all available instructions, warnings and safety information made available by the product’s manufacturer. 

About the Author

Dr. Mike Catangui

Mike Catangui, Ph. D

Entomologist, Parasitologist
MWI Animal Health
Dr. Catangui is a member of MWI's Technical Services groups. As a team, this group provides our clients with targeted expertise in integrated pest management, proactive disease/pathogen and performance management, animal drinking water quality improvement, biosecurity, and cleaning and disinfection. 
View Bio