ADVANCEMENT OF THE SCIENCE
ever, that the acaricide was ineective in suppressing the tick population when used following manufacturer recommendations. The reason for this insignificant reduction is unknown. Furthermore, reports of statewide sur- veillance conducted in Tennessee led to the discovery of a novel tick ( Haemaphysalis lon- gicornis , the Asian long-horned tick), which suggests that active surveillance, along with passive surveillance, is essential in identify- ing new species (Trout Fryxell et al., 2021). H . longicornis is native to Asian vegetation and has been reported to possess partheno- genic features (i.e., reproduction by devel- opment of an unfertilized usually female gamete). This feature allows the tick species to rapidly colonize and take over new geo- graphical areas and habitats. This tick is an important vector of human and animal dis- ease agents, resulting in human hemorrhagic fever and reduction in the production of dairy cattle (Beard et al., 2018). Identifying H. longicornis in new locations informs envi- ronmental public health professionals about the negative impacts of this species, as well as its characteristic pathological features and methods of diagnosis. Further, awareness about this tick can inform the development of treatment modalities and safety practices to halt its spread. Special surveillance (i.e., ongoing monitor- ing and collection in significantly important areas) is, however, more eective in identify- ing tick-prone habitats (Lyons et al., 2021). In our study, we conducted tick surveillance to determine the presence of H . longicornis , an invasive tick species in Missouri. Timely iden- tification of this species is important in report- ing new cases, developing treatment modali- ties, and reducing the incidence of disease. It is also crucial to understand the presence of H . longicornis to properly educate the public about safety and preventive practices.
TABLE 1
Conservation Areas ( N = 34) Within Missouri Counties ( N = 22) Surveyed for Ticks, Summer 2019
County
# of Surveyed Sites Conservation Area
Acheson
1 1 1 1 1 1 1 1 1 1 1 6 2 2 2 1 1 1 2 2 2 2
Brickyard Hill
Barry
Stubblefield Access Busiek State Forest
Christian
Clark
Heath Memorial
Gentry Green
Gentry Seat Memorial
Bois-D’Arc Grand Trace
Harrison
Holt
Jameson McCormack
Howard
Rudolf Bennitt
Lawrence
Paris Spring Access
Macon
Atlanta
McDonald
Flag Spring, Powell Tower Site, Huckle Berry Ridge, Buffalo Hills, Mt. Shira Access, Neosho Bicentennial
New Madrid
Seven Island, Donaldson Point
Nodaway
Bilby Ranch, Keever Bridge Access
Ozark
Caney Mountain, Patrick Bridge Access
Pemiscot
Little River
Putnam
Mineral Hills Bee Hallow
Randolph Scotland
Memphis Lake, Indian Hills Arrow-Wood, Hunnewell Lake Weldon Spring, August A. Busch Boston Ferry, Hollister Tower Site
Shelby
St. Charles
Taney
Tick Collection Techniques In 2019, flagging and carbon dioxide-baited sticky traps were used to collect ticks dur- ing the summer months of June, July, and August. In 2021, ticks were collected from veterinary oces throughout the state and by environmental collection using tick drags. Tick Flagging The flagging technique is an improved method of collecting questing ticks (i.e., ticks that actively seek a host by climbing high vegeta- tion, as compared with ticks that sit-and-wait for a bloodmeal) that is recommended by the Centers for Disease Control and Prevention (CDC). This method consists of a 3-ft x 3-ft cloth attached to a pole and exploits the ticks’ questing behavior. To catch ticks, the flag is used to brush the grass back and forth while moving in a forward direction. This movement
helps to trap ticks onto the flag. The ticks are eventually retrieved using forceps and stored in a container for later identification. Tick Dragging Tick dragging is one of the well-known techniques for collecting ticks. This tech- nique consists of a 1-m 2 piece of cloth that is attached to a rod and dragged over vegetation. To determine tick density, CDC advises con- ducting tick dragging along a straight tran- sect for at least 750 m (approximately 1,125– 1,500 steps). The person travels through the vegetation while pulling the cloth behind them, stopping every 10–15 min to check the cloth for ticks. If found, the collected ticks are removed from the cloth with forceps and placed in an alcohol vial for later identifica- tion. Tick dragging is an eective method of collecting I. scapularis .
Methods
Tick Collection Ticks were collected during summer 2019 and summer 2021. In 2019, ticks were col- lected from 34 conservation areas within 22 counties in Missouri (Table 1). In 2021, an additional 31 counties were surveyed for ticks (Figure 1), including Miami County in Kansas and Madison County in Illinois.
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Volume 87 • Number 1
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