Assessment of potential effects and detection efficacy of a fluorescent marking system on a medically important hard tick, Haemaphysalis longicornis (Acari: Ixodidae).

Background: Although Haemaphysalis longicornis (Acari: Ixodidae) is an important disease vector, its small size restricts the tracking methods applicable. Recently, fluorescent marking as a conventional detection method for small arthropods has been improved by combining it with an ultraviolet laser. We examined the application potential of this new fluorescent marking system (FMS) for tracking H. longicornis by evaluating the effect of fluorescent marking on the ticks and detection efficacy.

Results: Under laboratory conditions, fluorescent marking did not significantly affect the survivorship, movement patterns, and CO response of H. longicornis at all three developmental stages. Fluorescent-marked individuals could be detected at distances ranging from 12 to 29 m under dark, increasing with the body size. Finally, in grassland, >90% of fluorescent-marked individuals were retrieved at night regardless of developmental stage. However, the overall detection rate (<42%) was substantially reduced during the day.

Conclusioin: Our results show that FMS can reliably detect H. longicornis at night. Nevertheless, fluorescent-marked individuals are not as conspicuous under sunlight when they are illuminated with ultraviolet lasers, limiting the use of FMS during the day. Therefore, the development of an alternative tracking method is warranted for an effective detection of ticks during the day. © 2019 Society of Chemical Industry.