Insecticide-impregnated ear tags were first introduced in the late 1970s and have been used to reduce face fly and horn fly populations. Active ingredients in insecticide ear tags kill flies by direct contact. Small amounts of insecticide are released from the ear tag into the oils present on animal’s hair. The face, neck, topline and flanks receive the most product through natural grooming behavior. Interaction between cattle enhances the transfer of product between animals.

Nebraska’s spring weather conditions have made it more difficult to predict the emergence of horn flies. If the current weather pattern continues, we should start to see horn fly emergence in the southeast part of the state in early May, reaching northern Nebraska by late May. If we experience an abrupt and sustained warm-up, horn fly numbers could reach or exceed the Economic Injury Level (EIL) statewide by the end of May. The EIL represents a fly population of 200 flies per animal that negatively impacts cattle production enough to warrant paying for a fly control measure.

Key Points

Spring is an appropriate time for tick education. Ticks may be active all year long if temperatures outside are above freezing, but May and June are the months when people pick up the most ticks. There are three tick species established in Nebraska that carry and spread diseases to humans and animals, including the lone star tick. Lone star ticks are widely distributed across the East, South and Central United States, extending across the southeastern portion of Nebraska (see figures at the end of the article).