| abstract | The present paper deals with four Chinese ticks of the subgenus Argas. Among them Argus (A.) beijingensis is described as new to science, and A. (A.) vulgaris Filippova [misidentified as A. (A.) reflexus in "Economic Insect Fauna of China," Vol. 15 (Teng, 1978)] and A. (A.) japonicus Yamaguti et al. are recorded for the first time in China. A key to the seven Chinese known species of the genus Argas is provided in the Chinese text.
Argas (Argas) beijingensis, sp. nov.
Adult (figs. 1-4): Rather large, elongate oval in shape, female 8.23-9.39 mm long. 5.99-6.18 mm broad; male 5.34-8.49 mm long, 3.26-5.79 mm broad. Integumemal ridges mostly rather short, stellate. Peripheral ridges short and sinuous. Basis capituli ventrally ca. 2 (♀) or 2.18 (♂) times as broad as long. Fixed digit of chelicera with 2teeth. Dental formula 2/2 (3 rows), 3/3-5/5 (ca. 9 rows). Palpal segments I-IV respective lengths 0.18,0.22,0.16,0.18 (♀) or 0.14,0.16,0.10,0.12 (♂) mm, and setae visible from ventral view numbering 2,1,1,2 plus apical tuft. Anus somewhat posterior from center of venter, bearing 6 setae on each valve. Tarsi each with a prominent dorsal subapical protuberance; setae from lateral view on I-IV, respectively: apicodorsal 1,1,1,1; subdorsal 4 (and 1 unpaired),3,3,2 (♀) or 4,3,2,2 (♂) pr; median 4,2,3,3 (♀) or 3,2,2,2 (♂) pr; apicoventral 5,4,4,5 (♀) or 5,4,4,4 (♂) pr; subventral 5,4,4,5 (♀) or 5,3,3,4 (♂) pr.
Nymph (fig. 5): Body 2.72-5.90 mm long, 1.81-3.78 mm broad. Basis capituli ventrally ca. 1.37 times as broad as long. Palpal segments I-IV respective lengths 0.145,0.198,0.132,0.172mm, and segments II-IV each with 1 ventral seta. Dental formula as in adult. Anus with 3 setae on each palve. Tarsi each with a short dorsal subapical protuberance; setae from lateral view on I-IV, respectively: apicodorsal 1,1,1,1; subdorsal 3 (and 1 unpaired),3,3,3 pr; median 2,1,1,2 pr; apicoventral 3,3,3,4 pr; subventral 4,3,3,4 pr.
Larva (figs. 6-9): Body oval (engorged), 2.79-2.90 mm long, 1.99-2.10 mm broad. Dorsal plate nearly oval, 0.396-0.422 mm long, 0.264-0.304 mm broad, surface pebbled. Dorsal and dorsolateral setae mostly lightly fringed on apical 1/2; 1 pr lateral to dorsal plate, 8 pr in posterolateral quadrants, usually 24-25 pr on dorsolateral margin. Venter with 3 sternal pr, 3 circumanal pr, also 2 pr on each coxa and 1 pr on anus. Basis capituli 0.356-0.370 mm long (hypostome apex to basis posterior margin). Palpal segments I-IV lengths 0.101,0.063,0.081,0.060 mm respectively. Setal numbers on segments I-IV, 0,5,4,12 respectively. Dental formula 2/2, 7-9 denticles in each file exclusive of minute denticles on apex. Tarsus I 0.237-0.250 mm long; setal formula 1 pr A, 2 PC, 3 PM, 1 pr B, 1 pr AV, 1 pr PMV, 1 pr MV, 1 pr BV, 1 pr AL. Haller’s organ open, with elongate trumpet-like sensillum.
Holotypc ♀, allotype ♂, and paratypes 3♀♀ 2♂♂ 4 nymphs and 4 larvae were collected from roost of domestic pigeons (Columba livia) in Beijing, China, in April 1955. All type specimens are deposited in the Institute of Zoology, Academia Sinica, Beijiing.
This new species is allied to Argas (A.) reflexus (Fabricius), but in adult, the latter is oval in shape and markedly broadened in posterior 1/3, the fixed digit of chelicera with 3 teeth, and the setae on tarsi I-IV different in number; and in larva, reflexus is subcircular in shape, its dorsal plate is relatively narrower and longer, and the setae in posterolateral quadrants are 9 pairs in number. This new species is also related to A. (A.) vulgaris Filippova, but the adult of the latter with its anus much more posterior to the center of venter, the peripheral integumental ridges relatively narrower and longer; and the larva is subcircular in shape, and its dorsolateral margin with 19-21 pairs of setae. |