Phthiracarus longulus (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 : 270-273

Phthiracarus longulus (C. L. Koch)

(Figs 25-31)

Hoplophora longula Koch , 1841: Heft. 32, t. 17. Schweighauser Forest, Regensburg [type series presumed lost]. NEOTYPE (here designated), Donaustaufer Forest, Regensburg (RNH, Leiden, P2012-15).

Phthiracarus ferrugineus (Koch) sensu Jacot, 1936: 179 [in part]. Topotypes, Dechbetten Forest, Regensburg (MHN, Geneva, 3119h) [examined].

Phthiracarus tardus Forsslund , 1956:216. Holotype, Västerbotten, Sweden (paratype, BMNH, London, 1964.7.13.78) [examined]. Syn.nov.

Adult: Small and weakly sclerotized. The aspis (Figs 27, 29-30) ranges in length from 220-255 µm with a maximum width of 170-190 µm The interlamellar setae (il) which are inserted on a level with the bothridia, are twice as long as the lamellars (la) and extend almost to the rostral bases (ro). The sensilli.are lanceolate, serrated marginally, and range in length from 30-40 µm. The exobothridial setae (ex) are short. The notogaster (Figs 26, 28) is somewhat elongate and ranges in length from 430-490 µm with a maximum depth of 300-320 µm. All the setae are erect and more or less equal to the distance c1-d1. Setae c1_3 form a row immediately behind the posterior collar margin while vestigial f1 is located just dorsal to the seta h1, and towards the mid-dorsal line. The fissures ip and ips are absent. On each anal plate (Fig. 31) there are three rather short setae, ad3 being the shortest. The chelicerae are 150-200 µm long with 4-14 sharply pointed spines on the paraxial surface of the principal segment and 6-10 conical spines antiaxially. The leg chaetotaxy is of the 'reduced type' (see Parry, 1979) with three setae on femur I (v' absent) and no setae on genu IV (l' absent). Tarsus II bears 12 setae (subunguinial seta present), a feature which is generally associated with 'complete chaetotaxy' species. All the solenidia are moderately long and straight. Solenidion omega2 on tarsus I is coupled with a minute distal seta. On femur I (Fig. 25) the dorsal seta is short, serrated, curved distally and located posterior to the setae l' and v'.

Material: Eight specimens from rotten wood and litter beside a brooklet, Donaustaufer Forest, Regensburg, 27.vi.1961 (L. van der Hammen), deposited in the collections of the Rijksmuseum van Natuurlijke Historie, Leiden. One of these specimens (P2012-15) from sample no. 61 R45 is hereby designated as the neotype.

Remarks: Koch recorded longula in moss in woods, a species he described as being small with long, fine notogastral setae and rather short, round-ended sensilli.

Of the species here described, P. longulus appears to be the most abundant in all the Regensburg samples. The species has been recorded only rarely in the British Isles but in Sweden the author has found it to be extremely widespread.