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sum occus in this territory and that he considers the Jarvis statements as "sheer nonsense". It appears, therefore, that earlier
literature records for A. pgmpgsu in Mozambique and Southern Rhodesia are open to question.
Wherever A. Egmfiosu occurs it seems to be present in good nubers. Its dis r1 u ion, so far as Theiler has determined (cor. respondence), is mainly in the Rhodesia Highland Savannah type of vegetation, certainly not in the moist vegetation of the Umtali_ Melsetter district and adjoining Manicaland.
More extensive search for and study of this species is required. Statements regarding damage to cattle and to children by this tick in Southern Rhodesia appear to be questionable.
Sousa Dias (1950) writes concerning A. su, which is com; mon in the Angolan highlands, as fo11ows:_ “It Is considered by breeders to be one of the most harmful ectoparasites of stock for it causes wounds that are nost difficult to heal. It is probable that (this tick) is one of the factors that favors the dispersal of bovine dermatoses so common in Ango1aF. He surmises,that A. pgmfigggm is a heartwater vector in Angola inasmuch as it occurs in eartwater areas in the absence of other recognized vectors. Z-Neitz (1947) showed that A. pgmpgsum is a vector of heartwater;7.
A. osu is close morphologically to A. lepidum and to A. varie-atum. The latter, biologically, is a mast versatile tick’ except that it shuns desert and rainforest areas. A. lepidum is a semiarid country and sav ah species. A. pgmpgsum appears to be chiefly a highlan species. See also remar s on _. superbum in section below.
A gynandromorph of this species has been described by Santos Dias (1954). Schulze (19320) discussed certain features of the ornamentation of_A. pgmposum in relation to other species in this genus.
Both sexes have hemispherical eyes situated in a depression,
and are distinct from A. varie atum and A. lepidu in possessing very coarse scutal pundtations.
Male scutal ornamentation, inside the lateral groove, is like that of A.lepidu except that a small red spot may be present laterally in Z. ~, but no red color is found on A. lepidum.
The female scutum may be variable in length_width ratio, that of some specimens being only as long as wide, of others longer than wide; its rugosity is very distinct; it may be unornamented but usually has a small white or pale spot in the posterior field. Z-Robinson (1926) stated that are unornamented. Nevertheless a nuber of those in the Nutt collection, which comprised his chief reference material, have ornamented spots on the scutum.
These, as well as others similar to them have been observed in different collections.J7
Specimns from the Sudan referable to these characteristics should be checked against authoritatively identified specimens from the known range of A. pgmposum before this name is applied. Char. acters provided here are generalized; an exhaustive survey of the subject is precluded by our uncertainty over variability between this species and A. variegatum, as indicated below.
In some large collections of_A. varie atum, a few robust male specimens, or, more rarely, a few pygmy e specimens, may be sug.. gestive of A. E¥mposum owing to unusually heavy scutal punctations. Associated Te es are also more heavily punctate and may have a wider scutum than normal. Jack (1942) referred to similar males from Rhodesia (see REMARKS above). I have collected a few lots of such specimns in the Sudan and in the mountains of Yemen (Arabia). The most distinctive collection in this category is one recently presented to me by Dr. C. B. Philip, who collected it from a herd of cattle near Kabete in the mountains of central Kenya. The single female has a wide scutum and is heavily punctate but not rugose and the punctations are not confluent. 0f
the males, four are slightly more punctate than is usual for A. varie atum, one is slightly more punctate than the first fou:
E tfie last two are so heavily punctate that, done, there would be little question of their identity as A. sgmpgsum. Such specimens, in addition to various queries alre y men ioned, suggest the possibility that A. sum is a heavily punctate, mountain
or heavy forest subspecies o _. variegatum and that intergradation does occur.
It appears that A. varie atum ovurensis of Santos Dias (l95OB,l954H) is an intermediate form etween the almost nonpunctate A. variegatum and the heavily punctate_A. pgmposum. Santos Dias‘ description adds weight to the concept that A. pompgsum is actually
no more than a variant form or subspecies ofiA. varie atum. Rearing of pogeny from isolated females in lowlands and in highlands and
transporting some of their progeny to different altitudinal levels for development under different ecological conditions may solve this question.
Since the above was written, Santos Dias' (l953E) paper des_ cribing_A. su rbum sp. nov. has appeared. In it ‘A. varie atum vurensis is placed in synonymy under A. pgmposum. A. superhum
chiefly on the basis of size, depth, tribution o punc ations. Even more recently, the same author (l954H) has reaffirmed
the validity of his variety of_A. varie atum, with no indication of what he proposes to do about A. superbum.
On ecological grounds A. su rbum (or A. varie atum ovurensis) might be a useful niche in,whic to rop the Sudan specimen :53 certain other Central African lowland specimens. Variable and
confusing series of specimens still confront us. Unfortunately, however, A. superbum does not answer the problems this material
poses. No recourse offers itself but to maintain the present systematic status of A. varie atum and A. 0 osum, undertake biological studies suggeste in t e paragrap above, and only then judge the presently considered questionable validity of A. su rbum as a real species and the range of variation in_A.
ar egatum and.A. pgmpgsum.
Santos Dias (195313) further refers the Belgian Congo records
of A. sum by Nuttall and Warburton (1916), Schwetz (l927A), Bequaer ) and Schoenaers (l95lA) to A. sufirbum. Since no
adequate descriptions for differentiating Songo specimens were provided by these authors, the validity of this proposed synonymr is highly questionable. Belgian Congo specimens that have been seen in British Museum (Natural History) collections, in Museum of Comparative Zoology collections, and in the HE collection are typically A. om sum by comparison with specimens from everywhere within the range 0 his species.
In conclusion, one may only belabor the point: the status of heavily punctate specimens morphologically intermediate between A. varie atum a.nd _A. sum remains to be ascertained by biolog c s es, not y museum-type studies.
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Figures 81. and 85, d‘, dorsal and ventral views