It s that time of year again. Fly populations are starting to increase. The two main problems are from horn flies that can decrease production and face flies carry the bacteria that cause Pinkeye. Horn flies can cause cattle to have decreased weight gains. They cause these losses by biting through the skin of the cattle and sucking fluids from underneath the skin.
Face flies irritate the cattle s eyes by using rasp-like mouth parts to stimulate tear production.
The face flies feed off these excess tears. More importantly, the face flies carry the causative agent of Pinkeye, Moraxella bovis. This bacteria causes tremendous damage to the eye and also very large economic losses. So, one of the primary goals of face fly control is the prevention of Pinkeye. To give you an idea how the population of these flies increases during the season, refer to the two graphs below.