Warm Weather And Flies
US - With warmer weather comes concerns about flies and the economic and health costs associated with them.
9 May 2007
2 minute read
USDA estimates yearly losses in cattle production due to horn flies approach $730 million, while more than $270 million is spent each year to control insects and other external pest in horses.
These pests cause loss in gains, feed on blood and mucus discharges, and transfer and spread disease. Successful control involves a multifaceted approach and a through knowledge of the habits and life cycle of each pest.
Horn flies resembles house flies but are smaller. They spend almost their entire adult life on the cow (they will also use horses as a host if cows are not present although they cannot complete their life cycle), usually on the back or sides, but moving to the underside of the belly during the heat of the day. Both sexes feed up to 40 times a day for 10-25 minutes at a time. The female lays eggs in fresh manure where the developing larvae feed.
Under ideal conditions, the life cycle from egg to egg-laying adult can be 10-14 days. In southern states such as Virginia, there is normally a spring and fall spike in fly numbers, the reason being that manure pats tend to dry out in late summer.
The second major pest, and maybe the hardest to control, is the face fly. This fly is much larger than the horn fly and only periodically feeds on secretions from the eyes and nose and saliva. These are important pests because they transmit pinkeye between animals.
