The stable fly is about the size of a house fly, but darker in color. The abdomen has dark irregular spots. The proboscis (mouthpart) protrudes bayonet-like in front of the head. The life cycle consists of egg larva pupae and adult. The life cycle can be completed in 21-24 days during the summer months. Stable flies breed in decaying wet organic matter, which includes spilled feed, manure mixed with wet soil, grass clippings and wet hay in areas where big bales are fed and in racks or bunks or stack yards, where hay accumulates on the wet ground. Stable flies feed on blood, usually by attacking the front legs of cattle or horses, although they will feed on other warm-blooded animals as well. Stable flies overwinter as slowly developing larvae in breeding areas but below the frost line. As temperatures warm in the spring, they migrate closer to the surface and pupate. The first adults that emerge probably freeze, but eventually enough survive to mate and deposit eggs for the new generation.
Stable flies normally are considered pests of confined cattle at dairies or feedlots, but more recently, they have been noted as pests of range cattle as well. They feed on the front legs of cattle primarily, and cattle under attack will bunch with each animal attempting to protect its front legs. Losses occur from both the bunching, which increases or causes heat stress and from annoyance and use of energy to try to dislodge the flies by tail switching, stamping their feet, and throwing their heads down by their front legs. Range and pasture cattle will bunch downwind by a fence and fight flies in the same manner. Nebraska studies have shown decreased weight gains from 0.2 – 0.4 pound for feedlot cattle depending on the fly numbers and temperatures. Weight losses of a similar magnitude have been recorded for grazing steers.
Stable fly control for confined cattle starts with good sanitation, cleaning up spilled feed, fixing leaky waterers, providing good drainage from the pens and building, maintaining good mounds, cleaning pens, scraping behind feed bunk apron and restricting pen size to create better drying conditions.
Considerable research has been conducted on biological control of stable flies with parasites. Small wasps, termed pteromalids, parasitize stable fly and house fly pupae. Several commercial insectaries have several species of these for sale. Some researchers claim success with inundative releases of these parasites. Our experience with them was that they did not provide adequate control at release rates considerably higher than recommended, and that they were more expensive than standard control methods. This research was conducted at feedlots and dairies with confined cattle.
The insecticides recommended for stable fly control are listed at the end of the chapter. Stable fly control with insecticides may be achieved with two application methods. One is knockdown spray applied into fly infested areas, which kills flies by spray contact. The other method is the application of residual sprays to fly resting areas or shady surfaces. The mist applications as area sprays may be applied with hydraulic sprayers, aircraft or mist blowers. If the feedlot or dairy has a windbreak around some of it, misting in the trees during the hot part of the day, when flies seek shade, may be more effective than spraying the feedlot pens. Control of stable flies on range or pasture cattle is difficult. In Nebraska studies, cattle had to be sprayed three times per week to keep stable flies at levels that did not impact grazing steer weight gains.
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Insecticides Suggested for Treatment of Flies on Cattle |
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Insecticide |
ApplicationMethod |
Application Rate |
Restrictions and Comments |
|
Coumaphos (Co-Ral)
(Co-Ral Fly and Tick Spray)
(Co-Ral) |
Spray or Sponge
Spray
Spray |
11.6 % ELI 1 pt/25 gal water
6.5 % EC 2 qt/50 gal water or 10 oz/4 gal water
25 % WP 4 oz/12.5 gal water |
Restricted-use Pesticide
For horses not intended for slaughter. No more than 6 treatments per year, no less than 10 days apart. |
|
Fenvalerate (Ectrin) |
Spray |
10 % WDL 2 oz/12 gal water |
Apply 8 oz of diluted spray per horse. Do not apply to horses intended for slaughter. |
|
Methoxychlor
|
Spray or wipe-on |
0.05 % Ready to use
|
Follow label instructions. |
|
Permethrin (Atroban)
(Buss Off)
(Ectiban)
(Gardstar)
(Permectrin II) |
Spray
Wipe-on, Spray or Pour-on
Spray
Spray
Spray |
11 % EC 1 pt/25 gal water or 3 tbsp/2.5 gal water
7.4 % Permethrin + 7.4 % PBO
5.7 % EC 1 qt/25 gal water or 22 tbsp/1 gal water
40 % EC 5-12.5 ml/2 gal water
10 % EC 2 oz/3 gal water |
Spray to thoroughly wet animal. Repeat every 10-14 days.
Repeat application every 14 days.
Apply 30-60 ml per horse.
Spray thoroughly to wet horse. Repeat in 14-21 days. |
|
Pyrethrins |
Mist, spray or wipe-on |
0.05-1.0 % Pyrethrins + Piperonyl Butoxide Many formulations of ready to use. |
Follow label instructions. |
|
Stirofos (Rabon) |
Feed Additive |
7.76 % ROL |
Follow label directions. Horn and face fly control only. |
The information herein is supplied with the understanding that no discrimination is intended and that listing of commercial products, necessary to this guide, implies no endorsement by the authors or the Extension Services of Nebraska, Colorado, Wyoming or Montana. Criticism of products or equipment not listed is neither implied nor intended. Due to constantly changing labels, laws and regulations, the Extension Services can assume no liability for the suggested use of chemicals contained herein. Pesticides must be applied legally complying with all label directions and precautions on the pesticide container and any supplemental labeling and rules of state and federal pesticide regulatory agencies. State rules and regulations and special pesticide use allowances may vary from state to state: contact your State Department of Agriculture for the rules, regulations and allowances applicable in your state and locality. |
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Categories: Livestock Insects, Cattle, Stable Flies
Date: 03/28/2003