"H. scupense" by Oswald (1938A). It is characterized by secre MAN: DISEASE RELATIONS "H. scupense" (= H. volgense), harbors Pasturella pestis, the causative organism of plague, for several days after feeding on an infected animal and can transmit the bacteria by biting another animal; its feces also contains virulent organisms. "H. scupense" appears to be of negligible importance in the sustaining of certain Soviet foci of tularemia. H. detritum is considered by Soviet workers to be a possible vector of Uzbekistan hemorrhagic fever (virus). In North Africa and in Uzbekistan, H. detritum is a natural reservoir of Q fever (Coxiella burnetii), and the organism is transmitted from stage to stage of the tick and through the eggs to the subsequent generation. CATTLE: H. detritum is an important vector of theileriasis (Theileria dispar and T. annulata). "H. scupense" is also a vector of theileriasis and a carrier of brucellosis (Brucella spp.). HORSES: H. detritum is a vector of equine piroplasmosis (Nuttallia equi) and possibly of Nuttallia minor. IDENTIFICATION The following remarks are based on typical specimens of H. detritum collected in Morocco, Egypt, the Sudan, Turkey, south eastern Europe, and Russia. Remarks on variations are based on Iranian specimens determined definitely as H. detritum by Delpy, and on Middle and Far Eastern specimens in the Schulze collection. Males: Typical males have the subanal shields directly posterior of the adanal shields; the lateral grooves are clear and uniform, reaching almost to the eyes; scutal punctations are either entirely absent, or number up to twelve superficial, un obtrusive punctations either scattered or more or less localized on the scutal surface; the appearance of the scutum is bright and shiny; the posteromedian groove is narrow and long, extending from the central festoon to the scutal midlength; the paramedian grooves are distinct, wider, and somewhat deeper, either as long as or shorter than the posteromedian groove; the area in which these grooves lie is usually depressed. The size is medium to large, the typical color is intensely black; the legs are red dish or yellowish brown and may be somewhat lighter on the an terior surface. The posterior margin of the scutum is quite rectangular, the scutal surface is usually arched. The specimen illustrated (Figure 158) indicates the maximum amount of punctation found in furrows or on the scutal surface; the punctations in the grooves of this specimen are especially numerous. A parma is either present or absent; if present it is small and inconspicuous. size. Subanal shields vary in size and shape from small to moderate The leg segments may have pale rings but these do not con trast greatly with the basic color of the segments. The following variations have been seen: Lateral groove on one side not so distinct as on the other side; or indistinct on both sides beyond the posterior third (these are most confusing specimens), in which case the lateral grooves continue anteriorly as a row of contiguous punctations. Linear scutal depressions extending anteriorly from the posterior grooves frequently mar the scutal gloss. The scutal color may be various shades of brown. In greatly engorged specimens, the subanal shields are displaced from their typically posterior position to a lateral position, external of the central axis of the adanal shields; such specimens should not be confused with H. dromedarii or H. impeltatum. Females: The genital apron is typically an almost equilateral triangle with slightly convex margins, and the posterior juncture is rounded or narrowly truncate, not narrowly pointed. In profile, it is very gradually sloping (Figure 161,E,F) when unengorged but somewhat more abruptly sloping when engorged; in greatly engorged specimens the central area protrudes (Figure 161,D) sometimes with a very slight concavity centrally. The anterior margin may be straight or slightly concave or slightly convex, and in profile the posterior slope may be more acute than it is in typical fe males; in these cases there may be a very narrow bulge along the anterior margin. The shieldshaped scutum is longer than wide; smooth and shiny; with from four to ten superficial, scattered punctations of large diameter; punctations may be entirely lacking or a very few, shallow, minute punctations may be present. The scutal surface in greatly engorged specimens may be slightly rugose. The cervical grooves are long and wide, and reach the posterior scutal margin. Note: According to Pomerantzev (1950), H. detritum is largest in Middle Asia and gradually diminishes in size towards the west (Algeria). Color differences of various parts of the body do not support division of H. detritum into geographical races. The larva and nymph of H. detritum have been described and compared with those of other Russian species by Bernadaskai a (1939). Feldman Muhsam (1948) also described these stages and compared them with those of Palestinian species. Identification of "H. scupense" The following remarks concerning the biological race "H. scupense" are from Pomerantzev (1950); H. scupense is similar to H. detritum and difficult to distinguish. It is smaller, has shorter legs, and has a more distinct caudal field in the male as well as greater scutal rugosity. The dorsal projection of the spiracular plate is broader and shorter. The capitulum is smaller and the porose areas of the female are more rounded than in H. detritum. The maximum size of the spiracular plate occurs in specimens from Central Asia, where the species is almost indistinguishable from H. detritum. "It may be best to regard "H. scupense" as a winter, single host form of H. detritum".. Schulze collection material labelled H. scupense conforms to the above remarks but is not extensive enough to be of great value. It is difficult to decide what taxonomic disposition should be made of biological entities with slight morphological varia tions, such as "H. scupense" appears to be. It appears that the observations on this form have been carefully done, but the biological and taxonomic principles involved are unusual if not unique in the study of ticks. Pomerantzev's approach appears to have considerable merit. |