Ticks of Domestic Animals in Africa - Alan R Walker - Science Writer

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Worldwide genera
Group 5: the small sized ticks (less than 3mm) ((Boophilus),
Margaropus and Haemaphysalis), all have anterior and short
mouthparts, their eyes are small ((Boophilus), Magaropus) or
absent (Haemaphysalis). Coxa 1 has small paired spurs
((Boophilus), Magaropus) or a single spur (Haemaphysalis).
Magaropus occurs mainly on horses in South Africa.
The genus Dermacentor is important to domestic animals mainly
in the Americas, Europe and Asia. Dermacentor marginatus is
found on cattle in North Africa and so is included in this guide.
The unusual species Dermacentor nitens is also included because,
although it does not occur in Africa, it is an important
parasite of horses and could be accidentally imported into new
areas on transported horses, as happened with Otobius megnini.
Two other Dermacentor species found in Africa are Dermacentor
circumguttatus, which infests elephants, and Dermacentor
rhinocerinus, which infests rhinoceroses. These are large robust
ticks, which have conspicuous patterns of white enamel on
the scutum. A similar genus with white enamel and a very large
size is represented by a single species, Cosmiomma
hippopotamensis, which infests hippopotamus.
The six other genera listed in the table below either do not occur
in Africa, or are generally not found on domestic animals.
Only Rhipicentor in central Africa may be found on cattle. Ticks
found on snakes and lizards in the tropics are usually of the
genera Amblyomma and Bothriocroton (the old genus
Aponomma which included these reptile ticks is no longer considered
valid).
Other worldwide genera of ticks rarely or never found on domestic animals.
Genus Some typical features
Anomalohimalaya, similar to Rhipicephalus, occurs in Asia.
Bothriocroton, similar to Amblyomma but small and feed mainly on reptiles, worldwide in distribution.
Carios, argasid ticks which feed on many types of host and are widely distributed.
Nosomma, similar to Hyalomma, occur in Asia.
Step 1 of identification - which genus?
Use the information and drawings of the different genera of ticks
presented in this chapter to identify the genus to which your
tick belongs. First, compare your specimen with the above description
of the ten genera of ticks commonly found infesting
domestic animals in Africa and consult the table that shows the
ten genera placed in five groups with shared features. Select the
genus or group of genera, which shares the same features as
your tick and to which your tick probably belongs. When you
have selected a genus or group of probable genera, compare
your tick with the set of drawings of these tick genera and with
the full lists of character states below the drawings. If it is an
argasid, the sex of your tick does not matter. If it is an ixodid, its
sex is important, so make sure you have identified the sex of
your specimen before comparing it with the drawings on the
genera. When you have identified a genus proceed to Chapter 4
which gives all 48 species in a single alphabetical sequence of
genera and species within each genus. Each genus of argasid
ticks is included within this sequence.
Nuttalliella, in a separate tick family (Nuttallielidae) with features of both argasids and ixodids, feeds on
hyraxes and birds in Africa.
Rhipicentor, similar to Rhipicephalus, all coxae have two long spurs, males have no ventral plates, two species
only, which may be found on cattle in Africa.