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IDENTIFICATION

Use of the following key should never be attempted without reference to the section on identification for each species men tioned in the text. In the identification section, an attempt has been made to present lucidly all important characters of typical specimens and to indicate the range of variability seen in each species. I am most grateful to Mr. Makram N. Kaiser, Chief Technician in the Department of Medical Zoology at U.S. Naval Medical Research Unit, who has served as a "sounding board" and has given invaluable assistance in grouping the very large numbers of specimens that have been studied and often restudied for this section. Special acknowledgement should also be made of the services of Dr. L. P. Delpy, who initially iden tified many of our early collections of Hyalomma and of Mr. Glen Kohls who has spent several days conferring over specimens in the Schulze collection, now deposited in the Rocky Mountain Laboratory at Hamilton, Montana.

Persons attempting to identify field collected material of Hyalomma should recognize that a certain proportion of specimens in many series will defy final determination of species. These had best be called "Hyalomma species" and sent to a capable specialist in the group or put aside for further study as addi tional information becomes available.

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*In H. excavatum, and sometimes in other species that have en gorged on large animals such as camels, and have considerably stretched their integument, the subanal shields may be laterally displaced. Such excavatum specimens would appear to be H. dromedarii, except for smaller size, fewer and smaller scutal punctations, and differences in the caudal area of the scutum. See also identification of H. impeltatum for superficial varia tion among unfed males, which may cause them to be suggestive of H. marginatum.

3.

Lateral grooves not extending beyond
the posterior third of the scutum.
Scutum with few punctations except
in the caudal area which is depressed
between two lateral ridges and some
times very shagreened. Small ticks,
often frail, maximum overall length
usually less than 5 mm. (Fairly
common on cattle and especially on
horses in central Provinces; also

occurs in Northern Province)....

Lateral grooves extending beyond the
midlength of the scutum (may be obs
cured in very heavily punctate spe
cies; examine by oblique orientation)....

4. Scutum smooth, bright*, with very few,
large, shallow, scattered, punctations;
posteromedian and paramedian grooves
well marked. Legs usually not ringed.
(In northcentral Provinces; rare)..

Scutum densely punctate, or with dense,
contiguous punctations posteriorly...

5. Scutum densely, entirely, and almost always uniformly covered by punctations often obscuring the lateral grooves.

Scutum irregularly punctate, or
punctate only posteriorly..

.H. EXCAVATUM Figures 166 and 167

...4

..H. DETRITUM

Figures 158 and 159

*Do not confuse this with H. truncatum that has a smooth, shiny scutum but also dense punctations in a rectangular field poste riorly.

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..6

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*If small punctations are present in this group of three species, they are extremely shallow, irregular, and non-discrete. Do not confuse in this group exceptionally sparsely-punctate H. marginatum, which in all instances has a large, widely transverse, very strongly bulging genital apron not found in this group of species.

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