Phthiracarus crinitus
Creators: name: Kamill, B. W.
Publisher: name: Zenodo
Year: 1981
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Sarcoptiformes
Phthiracaridae
Phthiracarus
Phthiracarus crinitus

description: Phthiracarus crinitus (C. L. Koch)
(Figs 1-7)
Hoplophora crinita Koch, 1841*: Heft. 32, t. 8. Regensburg [type series presumed lost]. NEOTYPE (here designated), Schweighauser Forest, Regensburg (ZM, Hamburg, A30/80).
Phthiracarus crinitus: Jacot, 1936: 172 [in part]. Topotypes, Dechbetten Forest, Regensburg (MHN, Geneva, 3119h) [examined]; Willmann, 1931: 130.
*The dating for the various Hefte follows Sherborn (1923).
Adult: Large and strongly sclerotized. The aspis (Figs 1, 4-5) ranges in length from 255-330 µm with a maximum width of 220-270 µm. All the dorsal seiae are long, simple and procumbent. The interlamellar setae (il) which are inserted just posterior to the bothridia, are about 1.5 times the length of the lamellars (la) and extend to the rostral bases. Setae (ro) almost reach the anterior aspal margin. The sensilli are 60-100 µm in length and expanded basally—the distal portion is slender, serrated and blunt terminally. The exobothridial setae (ex) are short. The notogaster (Figs 2-3), 480-550 µm long (measured along a line through c1-ps1 and with a greatest depthof 330-390 µm, is elongate in lateral aspect. All the notogastral setae are long (greater than the distance C1-d1,)and simple, the c and d series being erect while those in the e, h and ps series are recurved. Seta c, is situated on the posterior margin of the collar and setae c2-3 submarginally. Vestigial f1 is located just dorsal to the seta h1 while the fissures ip and ips are situated between setae h2 and h3 and between setae ps3 and ps4 respectively. On each anal plate (Fig. 6) there are three setae of more or less equal length (an1-2 and ad3). The nine genital setae are arranged in two rows, an anterior marginal row of five setae (g1-5) and a posterior submarginal row of four (g6-9). A single aggenital seta ag is located antiaxially in the genital furrow. The genital papillae are typically phthiracaroid in form, the anterior pair being considerably smaller than the two posterior pairs. The chelicerae are 180-210 µm long with about 20 sharply pointed spines on the paraxial surface of the principal segment and about 25 conical spines antiaxially. The leg chaetotaxy is of the 'complete type' (see Parry, 1979) with four setae on femur I and a single seta on genu IV. All the solenidia are long and more or less straight. On tarsus I the seta coupled with solenidium omega2 is short and barely discernible. Setae (tc) and (u) on this segment, and (tc), (u), (p) and s no tarsi II-IV are ribbon-like, hooked distally and covered with whorls of spicules in the middle third. The four setae on femur I (Fig. 7), d, (v) and l', are all located at about the same level as the segment. Seta d which is the shortest of the four (about two-thirds as long as l'), is thickened, bluntly serrated and somewhat curved.
Material: Three specimens from a sample (no. 59015) of moss and bilberries (Vaccinium myrtillus), Schweighauser Forest, Unterkaulhausen, Regensburg, 19.vii. 1959 (M. Sellnick, deposited in the collections of the Zoological Museum of the University of Hamburg. One of these specimens (A30/80) is hereby designated as the neotype. Other material was examined from rotten wood and litter beside a brooklet (sample no. 61 R45), Donaustaufer Forest, Regensburg, 27.vi.1961 (L. van der Hammen) (RNH, Leiden). P. crinitus was not widespread in the Regensburg material, being present only in small numbers in the above two samples.
Remarks: Koch recorded crinita predominantly in mosses, Regensburg. Although the original description of the species was rather incomplete, crinita appeared to be characterized by unusually long notogastral setae - a feature which was noted by Jacot (1936) in his description of specimens which he considered to be conspecific with H. crinita. Jacot's specimens are for the most part conspecific and in good condition. However, as mentioned above, they have not been considered for neotype designation. A neotype was selected from amongst Sellnick's spirit specimens which were found to be conspecific with the m? described by Jacot.
description: Published as part of Kamill, B. W., 1981, The Phthiracarus species of C. L. Koch, pp. 263-274 in Bulletin of the British Museum of Natural History (Zoology series) 41 on pages 263-266