Spray and Pour-On Acaricides Killed Tennessee (United States) Field-Collected Haemaphysalis longicornis Nymphs (Acari: Ixodidae) in Laboratory Bioassays

Abstract

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.

Baseline susceptibility of Haemaphysalis longicornis to organophosphate, carbamate, and pyrethroid acaricides

“…Synthetic pyrethroids are among the most commonly used acaricides for tick control on livestock and in the environment. 29,32 Permethrin susceptibility for H. longicornis was similar to that for other tick species in the literature.…”

“…Susceptibility data that are needed for resistance determination are limited in H. longicornis . In vitro studies using commercial acaricides on H. longicornis indicate that pyrethroids, carbamates, and organophosphates are generally effective 26–29 . However, lethal concentrations (LCs) and discriminating concentrations (DCs) for H. longicornis have not been established for any of these pesticide groups.…”

“…In vitro studies using commercial acaricides on H. longicornis indicate that pyrethroids, carbamates, and organophosphates are generally effective. [26][27][28][29] However, lethal concentrations (LCs) and discriminating concentrations (DCs) for H. longicornis have not been established for any of these pesticide groups. Pesticide resistance in H. longicornis has not been formally recognized; however, genetic mechanisms for pyrethroid and OP detoxification, including cytochrome P-450 monooxygenases, glutathione S-transferases, and ATP-binding cassette transporters have been identified in this species.…”

Rapid Discovery and Detection of Haemaphysalis longicornis through the Use of Passive Surveillance and Collaboration: Building a State Tick-Surveillance Network

“…By searching animals at markets, we were able to collect H. longicornis and traceback the tick-infested cattle to owners, confirm H. longicornis-infested farms, and prevent those H. longicornis from moving onto additional farms. Importantly, through permission and conversation, we then earned trust with those producers who let us collect ticks from their properties to confirm H. longicornis populations at those sites and to evaluate the efficacy of available acaricides at killing field-collected H. longicornis nymphs in laboratory bioassays [40]. Tick surveillance and subsequent management efforts at livestock markets should be afforded a priority because these locations cohouse animals, allowing for comingling and interchange of animals from multiple farms, both tick-infested and tick-free (e.g., susceptible farm).…”

Tick Control in a Connected World: Challenges, Solutions, and Public Policy from a United States Border Perspective

“…The recently detected invasive species to the continental U.S., Haemaphysalis longicornis (longhorned tick), is another species with a propensity for high tick burdens on parasitized animals, particularly cattle, and is of medical and veterinary importance due to this aggregation behavior, capacity for parthenogenetic reproduction, and pathogen transmission potential [25][26][27][28]. The longhorned tick has been introduced and proliferated in numerous new regions worldwide and requires intensive surveillance as well as rapid identification and control measures [25,[29][30][31][32].…”