Tick Sampling Methods

For our purposes, we sampled Black-Legged Ticks to test for Lyme disease so that an accurate prediction can be made on how many ticks in the Lansing area are carriers of Lyme disease.  

There are many methods that can be used to trap and sample for Black-Legged Ticks. One method is to place  mouse or other small mammal live traps throughout a forest and check them regularly in order to examine the captured animals for ticks and even Lyme Disease. Another method is CO2-baited traps which tends to be more successful in capturing Tick larvae rather than adults. The easiest method to collect ticks is the drag sampling method, which uses a one meter square white cloth. It is used to drag through the underbrush of a forest to allow ticks to grab onto it.

Pictures of our Tick sampling can be viewed in Lansing Area Tick Sampling Pictures

Below is a list of material and a step by step guide on how to correctly sample ticks using the drag method. 

Materials and General Equipment: 

* White coveralls (preferred) or white pants and long-sleeve shirt (NOT treated with repellent)
* White socks (NOT treated with repellent)
* Boots (preferably without eyelets or use duct tape to cover the holes)
* Flagging or surveyor’s tape (optional)
* Mosquito head nets (optional and seasonal)
* Datasheet (Appendix 1)
* Cooler for transporting tick samples
* Ice packs, or wet ice, for preserving ticks in the field
* Pencils and permanent marker pens for collection vials
* Thermometer (preferably digital)
* GPS unit (optional)
* Mobile phone (optional)
* Magnifying glass to see ticks easier (optional)
* Garbage bags (to contain clothes and other equipment after sampling prior to disposal)

Tick Collecting Equipment:

 * 1m squared piece of flannel cloth

* 1.2m wooden stick (or plastic piping)

* 3m piece of cord/rope

* Duct tape 

* Needle-nose forceps and fine paint brush for transferring ticks

* Labelled snap-cap plastic vials (for tick samples)

* Filter paper

* Plastic, re-sealable zipper storage bags

* Paper towels

Method of Sampling

1. The first step is to make a drag cloth. Attach a 1.2m wooden stick (or plastic piping) across the end of a 1m squared sheet of cloth. Then attach a 3m cord to both ends of the stick (or plastic piping) to use to pull the drag cloth through the environment. Extra pieces of cloth may be needed in the field. The cloth can become soiled and damaged as it is used.

2. Sampling should be conducted for a minimum of three hours at each location of interest that has a suitable habitat (i.e. woods, grassland, and trail margins). The person(s) conducting the sampling should walk at a moderate pace through the environment, and be
ensuring that as much of the drag cloth as possible remains in contact with the ground and vegetation. Make sure to check the clothing of all people present and the drag cloth approximately every 40 to 50 paces for ticks.

3. Remove any ticks encountered on the drag cloth (or on the clothing of the drag sampler) with fine forceps, or a fine paint brush, and place them into a collection vial. Clearly label the collection vial with the sampling location, the date of sampling, and the collector’s name. Collectors may place all ticks from a particular sampling location into a single collection vial, and then record an estimate of the number of ticks collected written on the label.

4. Store tick vials in a cooler with ice, while in the field, and immediately transfer them to a freezer at the end of each day. The collectors should add moistened filter paper to collection vials, or place the vials in a seal-able plastic bag containing moistened paper towel. This is to ensure that the ticks do not die and deteriorate in the field. Specimens should be shipped to the testing lab, on freezer packs, for species identification and possible diagnostic testing.

5. Complete data sheets (Appendix A) immediately after conducting sampling at each location. Remember, it is critical to keep detailed records of sites sampled. this includes when ticks are not found (the localities with ticks will likely change over time). All of the data should be entered into an electronic database and backed up.

References

Ontario Agency for Health Protection and Promotion (Public Health Ontario). Tick dragging: standard
operating procedure. Toronto, ON: Queen’s Printer for Ontario; 2015.