Livestock Insects–Cattle

Black Flies or Simuliums
(Also Called Buffalo Gnats and Turkey Gnats)

John B. Campbell

Identification and Field Biology

Black flies are small (2-5 mm in length), dark colored, with a “humpbacked” appearance.  The females are blood feeders.  Some species attack birds, hence the name Turkey gnats, but most feed on cattle and horses.  S. vittatum feeds in the ears of horses, cattle and other animals.  Eggs are deposited in layers or irregular strings on the surface of objects that are kept moist by water movement or in the water.  Larvae can be found attached to stones, branches, grass or other debris in swift-flowing water.  They attach to the substrate by means of posterior suckers, which contain hooks.  Most species possess mouth brushes, which are used to filter food from water.

Animal Response and Economic Losses

There are no studies relating numbers of black flies to animal losses.  Annoyance of livestock under attack is evident, particularly by those that feed in the ears.  Livestock deaths have been reported in a few instances with outbreak numbers, and calves have been asphyxiated from inhaling too many of the black flies.

Management Approaches

Chemical

Insecticides used as cattle sprays for other livestock insects may provide some reduction in black fly numbers.  Some ranchers use a salve or insect spray in the ears of horses to provide relief to the horse for a period of time.  Insecticide sprays for use on livestock are tabled at the back of this publication.

 

 

Insecticides Suggested for Treatment of Flies on Cattl:

Insecticide

Application

Method

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.

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)

 

Spray

 

50% WP, 4 lb/75 gal of water

 

Apply 0.5 to 1 gal of finished product per animal.

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.

 

 

Categories: Livestock Insects, Cattle, Aquatic Biting Fly Complex, Black Flies, Simuliums, Buffalo Gnats, Turkey Gnats

 

Date: 12/19/06