Basis Capituli

Author(s):  
Heinz Mehlhorn
Keyword(s):  
Parasitology ◽  
1953 ◽  
Vol 42 (3-4) ◽  
pp. 161-186 ◽  
Author(s):  
D. R. Arthur

The palps of all stages of Ixodes trianguliceps are provided with a ventral plate below the basal article; formerly this plate was thought to be the first palpal article. This article in the larva and nymph is produced forward into a spur, but in the female tick this spur is incorporated into the basis capituli as the sella. The hypostomes of I. trianguliceps and I. canisuga are redescribed to clear up existing inaccuracies.Ticks in which the rostrum does not extend beyond the apex of the first palpal article are found on birds, and this probably represents a primitive condition. Those with palpal spurs, which may or may not be fused with the basis capituli, are found on birds (not in Britain) or on mammals of the mouse size group, and those where the rostrum is produced beyond the first palpal article occur on a wide range of large and small animals. The longer and more heavily toothed digits of ticks appear to be associated with a wide host range and vice versa. The structure of the digit may also influence the choice of attachment sites by ticks on their hosts because the microstructure of the skin varies in different parts.Variations in size and form of the scuta of some British ticks are described, and the mean growth rate is ascertained from this data. The information shows that the material of I. ricinus and I. hexagonus is homogeneous, and that specific differences occur in size, shape, the position and type of dermal ducts and in the relation between scutal and alloscutal bristles.The morphology of Gené's organ in I. hexagonus is described. It consists of a basal sac-like portion surmounted by four horns and lined with a cuticle beneath an epithelium. The gland is a proliferation of the epithelium and located near the bifurcation of the base into the horns. A watery refractile fluid, secreted by the gland, accumulates between the epidermis and the cuticle in the horn-like extensions. Proximally the thick endocuticle and epidermis lie close together, and two cuticularized rods penetrate the endocuticle for about half-way along the stalk. The rods arise from the postero-dorsal margin of the basis capituli. Muscles, arising from the free ends of the rods, pass back to near the hind-margin of the scutum; they retract the basis capituli after egg laying and indirectly assist in the retraction of Gené's organ. A suggested mechanism for everting Gené's organ in I. hexagonus is outlined.During feeding the opisthosomatic cuticle of all developmental stages of the tick is much stretched. In the larva, where the cuticle is thin, this is effected by the flattening of the epicuticular pleats, but nymphs and females have, in addition, two longitudinal folds alongside the body which stretch to a far greater extent than do the epicuticular pleats. Similar folds are present between the hard ventral plates and the scutum and between the epimeral and median plates in the male. Coupled with the large size of the male digit, this suggests that morphologically, at least, males can imbibe blood.The growth of the leg segments of I. hexagonus is not constant from stage to stage, and as a result the shortest ‘leg-length’ of the female exceeds the longest ‘leg-length’ of the male.


Parasitology ◽  
1957 ◽  
Vol 47 (1-2) ◽  
pp. 46-59 ◽  
Author(s):  
B. Feldman-Muhsam

The validity of the subgenus Hyalommina is discussed and reaffirmed.Hyalommina is differentiated from Hyalomma by the absence of the subanal plates in the males and by the humped tarsi and the more or less hexagonal basis capituli in both sexes.The male and the female of H. rhipicephaloides Neumann, 1901 are re-described. The larva and nymph of H. rhipicepholoides are described for the first time.The Indian species H. hussaini Sharif, 1928 and H. kumari Sharif, 1928 are re-described. H. hussaini var. brevipunctata Sharif, 1928 is considered as a species inquirenda.H. lewisi Schulze, 1936 is synonymized with Hyalomma truncatum K., 1844 (Feldman-Muhsam, 1954).


1942 ◽  
Vol 74 (8) ◽  
pp. 137-139 ◽  
Author(s):  
J. D. Gregson

FEMALE. Dimensions of unengorged holotype–1.2 mm. (to tip of scapula) x .78 mm. Colour–pale, dirty white, engorged specimens pale and yellowish.Capitulum. Length 340 microns (tip of hypostome io dorsal ridge); width (at cornua) 300 microns. Surface of basis capituli smooth and impunctate. Cornua heavily chitinized but not prominent.


2016 ◽  
pp. 298-298
Author(s):  
Heinz Mehlhorn
Keyword(s):  

Parasitology ◽  
1933 ◽  
Vol 25 (2) ◽  
pp. 269-272 ◽  
Author(s):  
E. Aneurin Lewis

Male: Large, 4·00–7–75 mm. long. Salient features: Inornate; basis capituli nearly twice as broad as long; lateral angles within the anterior third and rather acute. Anterior coxae slightly prominent in dorsal view. Lateral grooves well-marked and including two festoons. Dorsal furrows distinct, the lateral somewhat comma-shaped, the median straight and continued anteriorly beyond the laterals. Punctations very numerous, usually discreet and equal in the median area which appears shagreened; few on the scapulae, lateral folds and festoons, which form a glossy border. Adanal plates with straight external border and broad, rounded posterior border; internal border slightly concave to where it joins the posterior border to form a small point in a number of specimens. Accessory plates distinct. Spiracle short with slight dorsal curve.


Parasitology ◽  
1916 ◽  
Vol 8 (3) ◽  
pp. 294-337 ◽  
Author(s):  
George H. F. Nuttall

Female (Fig. 1): Colour: scutum, basis capituli, coxae, distal parts of femur and proximal portions of tarsi and intervening articles are blackish brown, the remaining hard parts shading to yellowish-brown. (Dorsal aspect) Body (partly gorged) short and broad. Scutum about as long as broad, 0·87 × 0·85 mm., very slightly emarginated, with rounded scapular angles, antero-lateral borders almost straight, lateral angles situated at the anterior third of the length, posterior border rounded; cervical grooves deep, far apart, but slightly concave outwardly and slightly divergent, fading near the postero-lateral borders; surface glossy, somewhat rugose; punctations few, mostly fine. Capitulum with base roughly equilateral-triangular, short pointed cornua and sinuous dorsal ridge; porose areas not depressed, subcircular, near ridge, the interval less than their width and hollowed. Palps slender, article 1 small, articles 1–2 almost fused, broadest at the distal third of article 3 which is rounded distally; (Ventral aspect) hypostome club-shaped, 4|4 merging to 3|3 and 2|2 posteriorly where the median unarmed ridge broadens, teeth sharp, 12 per external file; basis capituli constricted where the short pointed recurved auriculae arise, posterior margin straight with rounded angles. Venter: vulva between coxae II; anal grooves form a small closed ring situate near the posterior border; spiracle ovoid, macula central. Legs slender; coxa I with short internal and stout external spur; stout external spurs on coxae II–IV progressively decreasing in size; trochanters with slight spurs; tarsus 4 tapering gradually, the distal pseudo-article about thrice as long as the basal; pads large but shorter than the claws.


2018 ◽  
Vol 25 (03) ◽  
pp. 43-48
Author(s):  
Jargalan E ◽  
Uurtsaikh Z ◽  
Tserentogtokh B ◽  
Naranbaatar H ◽  
Khatanbaatar I ◽  
...  

The blood sucking 4 species ticks of Haemaphysalis genus were distributed in Mongolia, that an important vectors of diseases transmitting to human and animals and causing economic lost. Newly found Haemaphysalis females in Selenge province was confirmed to H. concinna species based on following features: strong lateral margins of palp article II, heart-shaped scutum with widest at middle, short-wide hypostome, sharpen cornua of basis capituli, posterior margins of basis capituli, ventral surface of basis capituli, latero-anterial I festoon connected with lateral, anterior groove of genital pore and additional spur of leg I trochanter. To confirm morphological description of H. concinna, CoxI sequence analysis was done and results was showed H. concinna CoxI sequences in GenBank with 86-89% identity. The results indicate that the Haemaphysalis concinna tick was distributed in Mongolia and it is announcing that the spread of Haemaphysalis tick in Selenge aimag. Сэлэнгэ аймгийн нутгаас шинээр олдсон Heamphysalis concinna хачгийн хэлбэр зүйн судалгаа Хураангуй: Монгол оронд Haemaphysalis төрлийн 4 зүйлийн хачиг тархан хүн, мал амьтанд шимэгчилж өвчин дамжуулан хохирол учруулдаг. Сэлэнгэ аймгийн нутгаас олдсон хачиг нь хэлбэр зүйн ерөнхий онцлогоороо Haemaphysalis төрөлд хамаарагдаж байлаа. Хошууны пальпын II үеийн хажуугийн нэмэлт хурц ирмэг, бамбайн дунд хэсгээрээ өргөссөн зүрх мэт хэлбэр, богино өргөн гипостом, хошууны суурийн булангийн эвэр, арын ирмэгийн илрэлт, хошууны суурийн доод гадаргуугийн хэлбэр, хачгийн захын I фестон нь зөвхөн биеийн хажуугийн ховилтой холбогдсон байдал, бэлгийн сүвийн урьдах зураасны онцлог, бэлгийн сүвийн хэлбэрийн онцлог, ялгадасны сүвийн арын ховилын онцлог, I хөлийн I үеийн нэмэлт өргөс хэлбэрийн өргөсөлт зэрэг онцлогоороо Haemaphysalis concinna зүйлийн хачиг болох нь батлагдав. Энэхүү хачгийн морфологийн ялган танилтыг CохI генийн нуклеотидын дарааллыг тогтоон баталгаажуулахад ГенБанкинд бүртгэлтэй H. concinna хачгийн нуклеотидын дарааллуудтай 86-89%-ийн адил байлаа. Бидний судалгааны үр дүнд хэлбэр зүйн онцлог, нуклеотидын дараалал тогтоох шинжилгээгээр Монгол оронд H. concinna зүйл хачиг тархсан нь тогтоогдсон тул Монгол орны хачгийн жагсаалтанд оруулж болохыг баталгаажуулж байна. Мөн энэхүү судалгаагаар Сэлэнгэ аймгийн нутгаас Haemaphysalis төрлийн хачиг анх удаа илрүүлэв. Түлхүүр үг: Цус сорогч хачиг, Haemaphysalis concinna, хэлбэр зүй, Сэлэнгэ аймаг


Parasitology ◽  
1927 ◽  
Vol 19 (4) ◽  
pp. 405-410 ◽  
Author(s):  
Cecil Warburton

Adult. Eyeless; camerostome without movable cheeks. In size (largest specimen 14 × 9 mm., Smallest 9 × 6 mm.), configuration, grooves, etc strongly recalling O. coriaceus, and the younger specimens have a suggestion of a similar dorsal pattern, but the whole surface is uniformly mammillate and the hood and the rather long palps are visible from the dorsal aspect. Discs in most specimens inconspicuous. Basis capituli about as broad as long, broadest posteriorly, where there are short, stiff, caducent bristles (? three pairs) directed outwardly. Hypostome lanceolate, with very small corona, followed by 2/2 well spaced teeth, about 6 per row. The leg armature, best understood from Text-fig. 1, is highly characteristic, the most striking feature being a prominent, rather sharp tooth on the proximal false articulation of the tarsus in legs I, II and III, but absent on tarsus IV. All the tarsi bear a prominent dorsal tooth near their distal ends. Legs I and II show characteristic prominences on other articles, notably the penultimate, which has a dorsal tooth at its basal and distal extremities.


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