Extension

The horn fly project is an ongoing project that is conducted on an annual basis to see how different insecticidal ear tags perform from year to year. The following information is from the Summer of 2011. 

 

Facts About Horn Flies

• Considered the most important external parasite of cattle
• With high summertime populations, they cause cattle to lose weight and lower milk production
• Economic infestations range from 200 to 300 or more flies per animal and usually develop in late May or June and then persist into the fall
• Horn flies reduce beef production efficiency and the economic loss is manifested in growing cattle
• Normally, growing cattle gain an extra 1.5 pounds per week when horn flies are controlled
• Horn flies are a greater problem in pastured cattle because they require a fresh, intact manure pad to complete their life cycle
• Adult horn flies spend their entire lives resting and feeding on cattle, although female flies leave cattle occasionally to lay eggs
• Life cycle development from egg to adult fly requires about two weeks
• Because the horn fly spends all of its adult life on cattle, control with insecticides can be highly effective
• Just as the habits of the horn fly make the pest vulnerable to insecticide treatments, this same behavior can create problems with insecticide resistance
• Continuous use of the same insecticide or class of insecticides will eventually result in fly populations that cannot be controlled 

 

Project Details

Fly counts are taken weekly from four groups of fifteen cattle each. Three groups were treated with different insecticidal ear tags. The fourth group is the control.

 

The ear tags used in this project include XP 820, Warrior, and Python Magnum.

 

Weekly Graphs 

The following are weekly graphs with the average number of flies for each of the four groups. These graphs show how each of the tags performed on a weekly basis compared to the control group.

• Week 1

   

• Week 2

   

• Week 3

   

• Week 4

   

• Week 5

   

• Week 6

   

• Week 7

   

• Week 8

   

• Week 9

   

• Week 10
   
• Week 11
   
• Week 12
   
• Week 13
   
• Week 14
   
• Week 15
   
• Week 16
   
• Week 17
   
• Week 18
   

 

Insecticide Ear Tag Information

• Information to know before buying ear tags and different types of insecticidal ear tags

 

Actual Fly Counts

The following pictures are actual live cattle with estimated fly numbers to allow you to compare to your animals at home.