While beef producers in northern U.S. states are keeping an eye out for the New World Screwworm, another invasive pest is on the mind of livestock producers. Bill Halfman, extension beef outreach specialist for the University of Wisconsin, talked about another invasive pest producers need to be on the lookout for.
“Yeah, so there’s been a tick called the Asian longhorn tick that was first discovered in the United States over on the East Coast in about 2017, and it’s been moving west steadily since then. The tick is an interesting creature in that it doesn’t need to mate with males in order to reproduce. So, most of the ticks that are hatched out in the United States are females, and they can go through their life cycle and then lay eggs and reproduce without male ticks, which makes them able to multiply very rapidly.”
The pest usually establishes itself in pastures.
“In pasture fields where they become established and find a lot of species to feed on and reproduce, they can multiply quite rapidly. Last year, the tick was first identified and discovered in Iowa. It was in southern Iowa, but still pretty close. It’s also been identified in Illinois and Michigan. The tick is spread by hitching a ride on an animal that’s been moved around as we move a lot of livestock around the countryside.”
It’s not been identified in Wisconsin yet.
“It’s not officially been identified in Wisconsin yet. We hope it’s not here, but it’s very important for folks to keep a lookout on it because the double whammy with this is that the tick is a vector for a disease called Theileria. There are several strains of Theileria, but it is very problematic and can cause problems for cattle. Some cattle will get it and never show any symptoms of any problem at all. This is also not a food safety issue; it’s more of an animal health-related issue, and so we may have some animals that you see showing some symptoms similar to anaplasmosis or similar to some of those kinds of things.”
He said there’s no vaccine against the disease caused by the tick.
“Lethargic. Not eating. If they’re not responding, have your vet checked. See what you got. There is a small percent of animals that, when they get their initial infection of Theileria, it will kill them. They’ve seen some cases where it’s been typical as like zero to five percent, and obviously we don’t want to lose any animals, but they’ve seen some isolated incidents when there’s some stress factor involved where we may see up to 20 percent die. Once the animal has Theileria, they don’t get over it. There’s not a vaccine at this point in time.”