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hosts but the full extent of their importance as hosts remains to be studied. Nymphal preferences may differ from those of adults, although in some species this may not be true. Host size appears to be of some importance, for most larvae parasitize small animals; nymphs attack larger animals; and adults feed on the largest available animals, except carnivores. Immature stages, however, more frequently parasitize carnivores, Cattle and, to some extent, other domestic animals are important adult hosts and wild ante lopes are also frequently parasitized. The African tortoise, rhinoceros, elephant, and buffalo harbor species mostly restricted to themselves. In general, the domestic animal parasitizing species are well represented in study collections; others are seldom collected.

Amblyomma ticks are usually three host parasites and, so far as known in Africa, there is usually only a single generation an nually.



1. Lateral grooves extending anteriorly at

least to middle of scutum...


Lateral grooves absent


2. Eyes small, hemispherical, situated in

a well defined depression (i.e, orbited).....


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4. Scutum with numerous coarse punctations,

and with a red lateral spot. (Rare in

.A. POMPOSUM Figures 80 and 81

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Smaller than A. marmoreum group, maxi-
mm size 5.5 mm. x 4.5 mm. Dark scutal
areas more widely separated by pale
areas than in A. marmoreum (see Figures ).........A. NUTTALLI

Figures 76 and 74

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1. Eyes in a well-defined depression

(i.e. orbited), hemispherical or
strongly convex......



Eyes not in a depression, flat or

slightly convex......
2. Scutal punctations very coarse, uneven,

some confluent; surface rugose poste
riorly; ornamentation absent or con
sisting of only a small pale area in
posterior field; length often no
greater than width. Eyes may be
convex but not hemispherical. (Ex
tremely rare in Sudan).....

.A. POMPOSUM Figures 82 and 83

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Scutum dark centrally, small pale spot
on posterior border, lateral fields
with small pale spots or entirely
dark. Eyes flat. Very narrow pale
rings on legs. (Chiefly from elephant)......... A. THOLLONI

Figures 90 and 91

Scutum pale centrally, lateral fields
with only small pale spots. Eyes
slightly convex. Broad pale rings
on legs. (Chiefly from buffalo).

.A. COHAERENS Figures 66 and 67

*In the Sudan, exceptional specimens of A. marmoreum may have a scutal width of at least 1.3 greater than length (Figure 74), but in these, large punctations are scattered over the entire scutal surface.


Figures 64 and 65, o, dorsal and ventral views, Sudan specimen Figures 66 and 67, 6, dorsal and ventral views, Uganda specimen


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Note: The illustrated is malformed in the following areas: left scutal margin anteriorly and right scutal margin lateral ly deformed, festoons on right side absent, only three legs on left side. Diagnostic criteria are not affected by these malformations.


. 210.

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