Management of Haemaphysalis longicornis (Acari: Ixodidae) on a cow–calf farm in East Tennessee, USA

Abstract

Haemaphysalis longicornis Neumann is an exotic and invasive tick species rapidly expanding across the United States. Large infestations of these ticks on cattle can cause anemia, and in eastern regions of the country, they are transmitting Theileria orientalis Ikeda within herds. Methods for managing H. longicornis in the environment are rarely successful and rely on chemicals. To document population effects from producer management decisions, we investigated the change in H. longicornis populations to different tick management practices chosen by producers at 3 different H. longicornis-infested farms. Farm 1 kept a closed herd, chose to cut brush monthly, used on-animal acaricides, and allowed us to drag weekly. Farm 2 kept an open herd, chose to cut brush yearly, did not use on-animal acaricides, and allowed us to drag for ticks weekly/monthly. Farm 3 kept an open herd, chose to cut brush yearly, used on-animal acaracides, and allowed us to drag for ticks monthly. We assessed H. longicornis populations responding to those methods over time using active surveillance methods at each farm. Management decisions on Farms 1 and 3 significantly reduced H. longicornis on farms. Importantly, Farm 1 management decisions reduced the chance of a tick being present by 90%; the number of questing ticks collected fell from 5,000 to 12 H. longicornis in 2 years. Therefore, combined management strategies such as keeping a closed herd, use of on-animal chemical control, mechanical control, and reducing the amount of vegetation on farms were effective ways for producers to manage Haemaphysalis longicornis Neuman (Ixodidae).

Environmental variables serve as predictors of the invasive Asian longhorned tick (Haemaphysalis longicornis Neumann): An approach for targeted tick surveillance

“…Each farm chose their own management options after being provided guidance [22]. Farm 1 significantly reduced their H. longicornis populations after three years by keeping a closed herd, using an insecticidal spray, mowing pastures monthly to knee height, and allowing us to collect ticks regularly; while the other farms either kept an open herd, did not use a spray, or only mowed pastures yearly [23]. At farm 1, there were twelve transects in year one and then fifteen transects in year two to account for the reduced tick populations.…”