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Sudan records and several others in my collections are all from altitudes above 3000 feet. In the Sudan and frequently elsewhere, these hills are more humid than the surrounding plains.

DISEASE RELATIONS

Unstudied.

REMARKS

The only other tick recorded from Africa that has palpal characters more or less similar to those of H. parmata is H. bispinosa Neumann, 1897, an Asiatic species that is said to be found rarely on domestic animals in Kenya. Males of H. bispinosa can be distinguished by their more narrow and elongate scutum, long lateral grooves, and abrupt tapering of tarsus IV. Females of H. bispinosa have a scutal outline that is slightly longer than broad, converging cervical grooves, and a shorter, wider basis capituli. In addition, the distal tapering of tarsus IV is more abrupt. Nuttall and Warburton (1915) recorded a few specimens of H. bispinosa from Kenya, but Lewis' specimens under this name are actually H. parmata (Hoogstraal 19540).

With respect to the tapering of tarsus IV, the Noli Hills female specimen from Equatoria Province is like H. bispinosa. In all other characters, however, it appears to equal H. parmata and it is therefore assigned to the latter species, though with some hesitation. Students of Haema physalis ticks believe that such tarsal characters are constant within a species, but because of the dearth of comparative material it is impossible to arrive at a satisfactory conclusion concerning this variation.

The material described by Santos Dias (1954F) from Mozambique appears to differ somewhat from that known from the rest of Africa.

In a formidable discussion, Schulze (1938A, figure 310) has illustrated the palpi of H. parmata as data for his theories con cerning generic and specific indicators resulting from pressure of the body within the developing nymph of ticks.

DENTIFICATION

Males are easily recognized by the pointed dorsal projection from the basal margin of palpal segment 3; peculiarly shaped palpi; short and broad scutum; very short cervical grooves; lateral grooves that reach only midlength of scutum; numerous, medium size, deep scutal punctations; coxae with short but distinct basal spurs, and tarsus IV gradually tapering. Palpal characters alone are enough to quickly separate H. parmata from other African species. Males are very small; they measure from 1.3 mm. to 1.8 mm. long and from 0.75 mm. to 1.1 mm. wide.

Females have the same distinctive palpal features as do males. The subcircular scutum measures from 0.64 mm. to 0.70 mm. long, and from 0.75 mm. to 0.90 mm. wide; it has broad, shallow, parallel cervical grooves extending to its midlength and medium size punctations that are more shallow than those of the male. Coxa I has a rather wide, short posterior spur but other coxal spurs are replaced by broad posterior ridges. Female palpal characters are as distinctive as those of the male among the African fauna.

Theiler (1945C) has redescribed and illustrated both sexes and the immature stages of H. parmata. Dr. Theiler identified the larvae and nymphs from the forest guineafowl from the Sudan.

H Y AL OM MA

INTRODUCTION

The genus Hyalomma is a complex of a few species exhibiting an almost endless variety of facies. Its original center of dis persal was probably Iran or southern Russia. Genetic instability may in part account for the wide morphological differences found in many specimens. Environmental vicissitudes are undoubtedly important additional factors in modifying size, color, and over. all appearance in this genus. These are tough, hardy ticks that survive under conditions in which all other species are incommon or entirely absent; they may even thrive in such environs. They inhabit country where humidity is frequently low, seasonal climatic conditions are extreme, favorable niches for development away from the host are rare, smaller animals for immature-stage feeding are sparse, and larger-size hosts are frequently poorly nourished and wander widely among inhospitable situations.

Owing to their medical and economic importance and the pressing need to clarify the relationships of all presently recognized spe cies in the genus Hyalomma, the plan of this section has been mod ified to include a key to all species and illustrations of non Sudanese species. Further research will somewhat modify present concepts but this compilation of information will provide a firmer foundation for subsequent revision than is now available without considerable background study. The presently recognized species of continental Africa are, however, fairly well stabilized and the disconcerting prospect of further nomenclatorial changes and addition of new species applies chiefly to populations from the Near East to the Far East.

NOMENCLATORIAL BACKGROUND

HISTORY

It is hardly surprising that criteria for identification of Hyalomma species have long been in a chaotic state. The thir. teen species described by Koch (1844), when he erected the genus,

in addition to three previously described species, remained mostly unrecognized by subsequent workers. The genus was reduced to four species, including a single new one, and four subspecies by Neu mann (1911). H. aegyptium was used as a "catchalli name by most persons until the 1920's. During the early twentieth century, British workers in Africa, depending on Nuttall and Warburton at Cambridge for identification of their collections, developed a group of names that are herein referred to those in contemporary usage after having studied the Nuttall collection in British Museum (Natural History).

Between 1919 and 1950, Schulze and a few of his students and followers seized upon the apparently unlimited opportunities for providing dozens of species names for variants in this genus. Scarcely a single one of the some eighty species and subspecies proposed by Schulze and colleagues has withstood the test of comparison with reared progeny from a single female tick. After having studied parts of Schulze's collection, now housed in Rocky Mountain Laboratory, one can understand, from the small series and poor labelling, how misconceptions regarding species identity developed among persons eager to tag each variation with a spe cies name. Schulze even went so far as to name the progeny of a single female as different species (H. delpyi Schulze and Gossel, 1936) (Delpy 1946A).

RECENT REVISIONAL AND SUPPORTING STUDIES

During the last twenty years a certain amount of cosmos has begun to evolve from this nomenclatorial chaos, although it is obvious that additional modifications in species concepts and names are yet to come. The careful, tedious, and time-consuming pioneer work of Delpy, who secured specimens from many areas where hyalommas occur and reared the progeny from single fe males, enabled him to determine the range of variation within a single species and to show that characters proposed for many so-called species were due merely to multiformity of appearance within a few species. In a few instances, however, Delpy in cluded species that we now know to be distinct genetic entities worthy of species rank.

Shortly afterwards, Adler and Feldman_Muhsam commenced rear. ing Palestinian species in the same manner as Delpy. They corro borated Delpy's species definitions but not his species names. In their 1948 paper these authors provided a potash clearing method for females by which they established constant species characters for the unmated female genital aperture. Delpy expanded this finding to mated females, thus making it of greater value for identification of fieldcollected material. Neverthe_ less, some questionable specimens inevitably crop up in routine collections.

Unfortunately, as stated above, Delpy and Adler and Feldman Muhsam arrived at different conclusions regarding which name from the scores available should be applied to individual species. Re cently Feldman_Muhsam (1954), after study of Koch's (1844) type specimens for several species in the genus, has corroborated some of Delpy's earlier decisions and proposed a few changes. Although Koch's material is badly damaged and its labels have been inexcus ably tampered with, these studies probably represent the final word on these species; therefore this terminology is accepted with certain reservations as noted in the appropriate places.

Delpy's chief morphological and taxonomic contributions to Hyalomma have been his notes on the genus (1936,1946A), descrip tion of H. schulzei (1937A), description of the immature stages of H. dromedarii (1937B), generic revision by experimental methods (1977D and 1949A, especially the latter), and a synoptic list and discussion (1949B), besides studies on bovine theilerosis and tick transmission (19370,1946B, 1947A,1949 and 1950). Adler and Feldman Muhsam presented their chief overall findings in their 1948 paper; subsequent reports by the latter author are listed in the bibliography.

Whenever possible, Delpy's (1949B) synonymy has been followed in the present work. Some changes have been necessary, however, on the basis of the kind of proof that Delpy himself advocated: rearing of progeny from single, known females. A few other changes have been necessary due to Feldman Muhsam's study of Koch's types. It is impossible to decide whether Delpy or Pomerantzev (1950) should be followed for the synonymy of certain Russian species, Pomerantzev's ideas, whenever they differ, have been included as notes under the names indicated by Delpy.

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