There are many types of medically important ticks. This course is limited to basic tick identification, as well as taking the necessary steps to obtain a species-level identification. Ticks can be quite difficult to identify depending on whether the mouthparts are present and on the stage of (blood meal) engorgement.
Ticks belong to the class Arachnida, subclass Acari, and order Ixodida.
Two important families of ticks: Soft Ticks (Argasidae) and Hard Ticks (Ixodidae)
What parts stand out in tick morphology?
- Haller's organ (used for sensing; Haller's organ is a minute cavity at the terminal segment of the first pair of a tick's legs)
- Toothed hypostome (appendage on the mouth - looks like a row of teeth)
- Long versus short mouthparts
- Fused cephalothorax (head) and abdomen
Soft ticks have:
- A soft leathery body
- No scutum (plate)
- Mouthparts lie ventrally (not visible when viewed from above).
- 8 legs in the adult
- Size is 2-5 mm long.
- Male and female may have different appearances.
Hard ticks have:- Mouthparts lie anteriorly (and are visible when viewed from above)
- Plate called a scutum is present
- Engorged hard ticks may look like soft ticks.
4. CDC. Image# 5964. "This photograph depicts a dorsal view of two North American ticks, a soft tick representative of the family, Argasidae on the left, and an example of a hard tick of the family, Ixodidae on the right. Soft ticks are oval, or pear-shaped, with mouthparts that are more easily seen from the ventral view. Hard ticks possess a dorsal plate, or scutum." PHIL public domain. Created 1975. https://phil.cdc.gov/Details.aspx?pid=5964
