By Burt Rutherford

The oft quoted saying of“ may you live in interesting times” has become far too well-worn for beef producers. For those in the beef business, it seems“ interesting times” pile up on top of each other.

On the upside, prices for all classes of cattle are beyond eyebrow-raising levels and expected to remain there for several more years. But then are the things that befuddle beef producers and cause them to adapt, adjust and pivot, sometimes on a well-worn dime.

Now is such a time, as the beef business learns to live with New World Screwworm( NWS) and the Asian longhorned tick and the Theileriosis disease it spreads. Fortunately for beef producers, they don’ t have to fight those battles alone.

Asian longhorned tick and Theileria

The Asian longhorned tick was officially reported in 2017, according to USDA’ s Animal and Plant Health Inspection Service( APHIS). However, specimens of the invasive tick were first reported as early as 2010 and that’ s where the rub comes in.

These invasive ticks are vectors for Theileriosis, a protozoan parasitic disease in cattle. The rub is that the symptoms closely mimic Anaplasmosis and thus Theileriosis was likely misdiagnosed early on. While both diseases destroy red blood cells, Theileriosis cannot be controlled with antibiotics like Anaplasmosis. In fact, there is no treatment for Theileriosis available in the U. S. beyond supportive care.

The Asian longhorned tick is a unique and fascinatingly horrible pest. Perhaps the most fascinating is it reproduces asexually with females cloning themselves, often quickly and in large numbers. In fact, each adult tick can lay more than 3,000 eggs.

“ Every single tick lays eggs, every single tick can expand the population,” said Cassandra Olds, Ph. D., entomologist at Kansas State University.

Additionally, Asian longhorned ticks are opportunistic in that

they will attach and feed on any warm-blooded animal. That’ s important, at least to the ticks, because they require three hosts to complete their two-year lifecycle. The eggs hatch into larvae, which require a blood meal before dropping off to molt into a nymph. The nymphs then attach to another host, take a blood meal and drop off to molt into an adult. The adult attaches to a third host, lays eggs and starts the whole process over again.

However, while the ticks will attach to any warm-blooded animal including birds, they prefer cattle. And all three stages can be found at the same time on cattle, all of which are taking a blood meal. While wildlife and even dogs and cats can be part of the ticks’ lifecycle, only cattle can get Theileriosis.

There are two Theileria genotypes that affect cattle. Theileria orientalis Ikeda is the genotype most often found, but the genotype Chitose has been reported, also causing disease symptoms.

Early on, experts thought only Asian longhorned ticks spread Theileriosis. Then the disease began to appear in herds where the ticks were absent. Now biting flies and sucking lice may also spread the disease, further complicating the issue.

However, the longhorned ticks are still the driver in areas where they occur, Dr. Olds said, because they can replicate the parasite inside their salivary glands.“ So a tick doesn’ t have to take in a high amount of the parasite to develop a high amount in itself and then transmit it to a new animal.”

With biting flies and sucking lice, the parasite is present in the blood in their mouth but does not replicate, so they can spread smaller amounts of the parasite when they take a blood meal from another animal. Beyond that, it’ s possible the parasite can spread from other mechanical means, such as blood on a needle from an infected animal.

That adds several layers of management for beef producers in tick-prone areas. No acaricide is specifically labeled for the Asian longhorned tick, but any tick prevention product could

12 NATIONAL CATTLEMEN DIRECTIONS 2026