Phthiracarus globosus (C. L. Koch)

Kamill, B. W., 1981, The Phthiracarus species of C. L. Koch, Bulletin of the British Museum of Natural History (Zoology series) 41, pp. 263-274 : 268

Phthiracarus globosus (C. L. Koch)

(Figs 8, 14-18)

Hoplophora globosa Koch , 1841: Heft. 32, t. 12. Regensburg [type series presumed lost]. NEOTYPE (here designated), Burgweinting, Regensburg (ZM, Hamburg, A31/80).

Phthiracarus globosus : Willmann, 1931: 193; Feider & Suciu, 1957: 5; Sellnick, 1960: 131.

Phthiracarus globus Parry , 1979: 341. Holotype, Rydal Water, Westmorland, England (BMNH, London, 1976.2.18.3.) [examined]. Syn. nov.

Adult: Large and strongly sclerotized. The aspis (Figs 15-17) ranges in length from 240-310 µm with a maximum width of 180-250 µm. All the dorsal setae are very long, simple and procumbent. Setae (il) and (la) are more or less equal in length and both pairs of setae reach the rostral bases. The sensilli are 40-55 µm long, lanceolate and serrated marginally. The exobothridial setae (ex) are moderately long. The notogaster (Figs 14, 18), 500-640 µm long and with a maximum depth of 300-160 µm, is rather globular in comparison with other species of the genus. All the setae are long (greater than the distance c1-d1), simple and almost erect. Seta c, is inserted on the posterior margin of the collar and setae c2-3 submarginally. Vestigial f1 is located adjacent and just dorsal to the seta h1, towards the mid-dorsal line. The fissures ip and ips are absent. On each anal plate there are five long setae; an1-2 and ad3 being more or less equal in length and somewhat shorter than setae ad1-2. The chelicerae are 170-190 µm long. The principal segment carries 12-26 sharply pointed spines on the paraxial surface and 22-25 conical spines antiaxially. The leg chaetotaxy is of the 'complete type' and on femur I (Fig. 8) the dorsal seta is long (equal in length to l'), slightly curved and covered in whorls of blunt serrations.

Material: Two specimens from litter under 'broom ( Genista )' [= Sarothamnus ] growing under willows, Burgweinting, Regensburg, 16.viii.1959 (M. Sellnick), deposited in the collections of the Zoological Museum of the University of Hamburg. One of these specimens (A31/80) from sample no. 59059 is hereby designated as the neotype. A further ten specimens were 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. globosus was always recorded in small numbers in the Regensburg samples examined.

Remarks: P. globosus is a very distinctive species being characterized by the 'globular' form of the notogaster. In comparison with German specimens, it was found that the British material examined was considerably larger (notogastral length 570-850 µm) and more heavily sclerotized. It is interesting that Jacot did not regard globosus as a Phthiracarus species, but rather as the male of Hoplophora decumana (= Oribotritia decumana ).