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and deeper paramedian grooves. A parma, the color of which me be lighter or darker than the rest of the scutu, may be present, or may appear as a normal median festoon. Two definite pairs of festoons and two more or less fused pairs lie on either side of the parma or median festoon. Delpy states that the scutum is flat, actually it is usually uore or less arched, especially

in males that have fed.

The scutal color varies from dark brown to black; excepn tional specimens, usually very small ones, me be lighter. The leg segments are usually pale anteriorly and posteriorly and darker centrally, but they may be entirely pale yellowish.

Female: The scutum posteriorly and centrally has numerous rather regularly spaced, moderate size, noncontiguous punctations. Scattered among them are several larger and deeper punctations in two parallel rows centrally. The moderate size punctations are usually mostly discrete, but exceptions to this are comon. Anteriorly and in the scapular areas, punctations are large and deep; in the lateral fields punctations are absent or present.

The deeply depessed cervical grooves are more or less rugose,

and the puctations in them are more or less contiguous. The scutum of engorged specimens frequently has less distinct punctations and grooves. The scutum is generally dark brown in color. It is definitely longer than wide, but the ratio may be reduced in some newly molted, misshapen, or greatly engorged specimens.

The genital area is distinctive. The central genital apron is an elongate triangle much like that of H. dromedarii but shorter, wider, and usually not quite so narrowly pointed apically. In profile, it definitely bulges anteriorly and is depressed posteriorly. An important principal additional feature is that, in ummated specimens and in mated but not greatly engorged specimens, this genital apron is bordered on each side by a slight bulge that gives the genital area a trilobed appearance not found in any of the other species with which H. i ltatum may be confused. This characteristic is maintained wigg only slightly less distinctness in greatly engorged females.

Female body size, in all except runts, is always large. The legs are like those of the male.

N01‘E: Very small, rounded, globose, pale runts appear com. monly with typical specimens. Their diagnostic characters are frequently modified. In field collections, such specimens are virtually impossible to identify. They should not be confused with other species or cast into the subgenus Hyalommina. Among collections of reared adults, gradations from ypic males to atypical males closely approximating exceptionally small spec. imens of H. dromedarii are frequently seen. Such atypical spec. imens are_obviousIy poorly nourished in the immature stages and show numerous indications of lack of proper development. If encountered singly, they would be most difficult or impossible to properly identify.

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Figures 174 and 175, d3 dorsal and ventral views
Figure 176, Q, scutum and capitulum, dorsal view

Figure 177, , genital area. A, partly engorged, B to D, outline and pof le; B and C, partly engorged; D, fully engorged.

HHAL£MA nanurmmm
Sddan Specimens

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NOTE: In literature on African ticks various subspecific

designations of H. im essum apply actually to H. rufifis or to £1. truncatum and_are Ereata herein under those_spec1es. The "H.

lum5um 1'm esslml" of Soviet workers is H. rufi s. Koch's -' ~escr1:pt1'ons of _I_i. imgessum and of pgs clearly distinguish these two species.

The H. im ressum mentioned by Adler and Feldman_Muhsam (l9l.6,l9l.'5) for Palestine resulted from mistaken identity of H. rufi es (Fe1dman.Muhsam 1954), as did Delpy's H. im essum _ ~B) from Iran (Delpy l949A,B). The H. 175 ressum o Schulze

1918), from a single specimen collected fiom a Horse in Macedonia, Greece, and presumed to have been carried there as a nymph on a

migrating bird, is questionable; this record was repeated by Panda.zis (1947).


H. imgessum is locally common on" cattle in central Sudan west of e e. Numerous males and fewer greatly engorged fe_ males reach the Khartoum quarantine station on Darfur and Kordo.. fan cattle and many males are still attached when these cattle

reach the Cairo abattoir. The West African hyalomma is not known to be established east of the Nile.

Darfur: Zalingei and Sibdo (common on camels and cattle, also occurs on horses; SVS).

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H. im essum is a West African tick that ranges eastward into the Sudan. It h_as not been found south of the equator, in the

great northern deserts of Africa, or on the Mediterranean littoral.

WEST AFRICA: FRENCH WEST AFRICA (AS 5. 1111 85811111 sp. 11017.8 Koch ~. gyfitium imgessum typica: Ehifize 1919, and S 1


Chodziesner 1991. ressum 1m essum: Schulze and Schlottke 1930, and Kratz ISZU. As _H. savI i intermedia: Girard and Rousselot 1945, and Rousselo . As H. m' gessumz

‘ Rousselot 1953B). NIGERIA (As H. imgessum: Unsworth . Q 6 . .

Material in emu from Katagum; ‘H.

CENTRAL AFRICA: CAMEIOONS (As H. i essum: Rageau 1951, 1%3)~Tmm AFRICA (As g.‘Er‘“_;>;e=sm= Rousselot 1953B .

msr AFRICA: sunm (As 3;. 1Eessum= Hoogstraal 195413. Fel~%4) .

woman and raxrnmn As H. im essum: Wilson (19498) and onelli..Rondelli (l930A). These may refer to I_{. rufifis or to _I_~I. truncatum._7


Domestic cattle are the chief hosts of £1. imgessum, and are mentioned by all authors. No other hosts have previous y been reliably recorded. In Darfur, camels are frequently infested and horses are sometimes attacked.


Unstudied .

Unstudied .

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