Haemaphysalis longicornis Neumann (Asian longhorned tick) is an exotic and invasive tick species presenting a health and economic threat to the United States (U.S.) cattle industry due to its ability to transmit pathogens and infest hosts in large numbers. The objective of this study was to evaluate available products at causing H. longicornis mortality in a laboratory bioassay. The efficacy of products was evaluated at label rates using H. longicornis nymphs collected from a cattle farm in eastern Tennessee in two different bioassays (spray or dip) against untreated controls. After exposure, ticks were transferred to clean petri dishes and checked for mortality at 0, 1, 2, 3, 4, 21, 24, and 48 h post exposure. No mortality occurred in the untreated controls, whereas all treated ticks were dead within 24 h of exposure (P < 0.0001). These findings support the hypothesis that currently available spray and pour-on products are effective at causing H. longicornis mortality. We conclude that these acaricides can be used as a component to prevent H. longicornis dispersal and for control in the U.S.


Commonly Used Acaricides Found Effective on Invasive Tick

Haemaphysalis longicornis tick

The Asian longhorned tick (Haemaphysalis longicornis), an invasive species in the U.S., is a threat to cattle and other livestock. A new study finds several pesticides used to manage other tick species are equally effective against the new arrival. (Photo by danabarb via iNaturalist, CC BY-NC 4.0)

By Andrew Porterfield

The Asian longhorned tick (Haemaphysalis longicornis), a long-time cattle parasite in Asia, New Zealand and Australia, was discovered in the U.S. on a sheep in New Jersey in 2017, though the tick may have been in the country years earlier. Like too many invasive exotic species, it spread quickly and is now found in several eastern U.S. states. Also like invasive, exotic species, there is always a risk that it could evade eradication methods used on other ticks.