Key to Genera

It should be noted that this guide is designed for the identification of ‘hard’ ticks (Ixodidae) and not ‘soft’ ticks (Argasidae).  General differences between the two can be seen below:

A= Hard tick (Ixodidae)  B= Soft tick (Argasidae)

When distinguishing between the genera a useful place to start is by looking at the gnathosoma of the specimen.  (shown below).

Dorsal view of the gnathosoma of the different genera of Ixodid tick (click image for close up)

Ventral view of the gnathosoma of the different genera of Ixodid tick (click image for close up)

It should be noted that while providing a useful initial guide, the size and shape of the gnathosoma should not be used alone for identification, as some species may not have a ‘typical’ gnathosoma.  For example Haemaphysalis inermis lacks the lateral protrusion on article ii of the palps.

 

Key

1.)  Gnathosoma projecting anteriorly and visible from dorsal view; scutum present, covering the dorsal surface completely (male) or the anterior portion only (female);

 

Ixodidae 2

 2a.)  Anal groove surrounding the anus distinct anteriorly (Prostriata);

 Ixodes

 2b.)  Anal groove entirely posterior to the anus (Metastriata);

3

3a.)  Eyes absent;


4

3b.)  Eyes present;

5

4.)  Palps short and broad, about 2x as wide as article ii with lateral projections at the base (projections absent in H. inermis);

Haemaphysalis

5a.)  Palps wider than long or, at most, only slightly longer than their width;

6

5b.)  Palps much longer than wide;

10

6a.)  Basis capituli usually hexagonal dorsally; medium-sized or small ticks, usually without ornamentation;

7

6b.)  Basis capituli rectangular dorsally; large ticks with an ornate scutum/conscutum;

Dermacentor

7a.)  Festoons absent; anal groove faint or indistinct;

                                                                                                           

8

7b.)  Festoons present; anal groove distinct;

                                                                           

9

8.)  Palps short with dorsal and lateral ridges;

Rhipicephalus (Boophilus)

9.)  Basis capituli without lateral protuberance; males with ventral plates;

Rhipicephalus

10.)  Article ii of palps less than 2x as long as iii segment; scutum inornate;

Hyalomma

11.)  Article ii of palps more than 2x as long as article iii; scutum ornate; male without ventral plates;

Amblyomma

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