Damaeus (Paradamaeus) clavipes (Hermann, 1804) (Figs. 8 B, 9, 10A, 11A, 12–14, 15A) Notaspis clavipes: Hermann 1804; Grandjean 1936, 1954a; Hammen 1952; Sellnick 1960. Oribata clavipes: Oudemans 1900; Kulczyński 1902; Sellnick 1928. Belba clavipes: Willmann 1931; Grandjean 1935; Schweizer 1956. Damaeus (Paradamaeus) clavipes: Bulanova-Zachvatkina 1957a; Marshall et al. 1987; Balogh & Balogh 1992; Pérez-Íñigo 1997; Subías 2004; Miko 2006. Paradamaeus clavipes: Bulanova-Zachvatkina 1967, 1975; Schatz 1983; Siepel 1996. Damaeus auritus ”sensu Nicolet, 1855 ”. Diagnosis. Adults large (910–1050 μm), dark brown. Prodorsum shorter than in D. onustus, notogaster arched, almost spherical (Fig. 9), cerotegument filamentous, thicker in sejugal area. Setae in and ex short. Apophyses P, Sp, Da, Ba and Bp and discidium well-developed, as in D. onustus, but Sp rounded, apophyses Dp and Sa weakly developed. Spinae adnatae smaller in D. onustus, and directed anteroventrally. Bothridium smaller than in D. onustus, and sensillus shorter than seta c 1. Notogastral setae similar, but setae of p -series longer (Figs 10 A, 11A) than in D. onustus, protruding beyond marginal part of posterior body. Coxisternal apophyses E2a and E2a weakly developed, apophyses Va and Vp well-developed, rounded. Formulae of leg setae given in Table 2, dorsal coupled seta d lost on tibiae I and II. Legs monodactylous. Juveniles elongated, slimmer than in D. onustus, unpigmented, legs slightly darker and approximately as long as body. Setae ex and in longer (Table 1), but bothridium smaller than in D. onustus. Gastronotum of larva truncate posterioly, gastronotum of nymphs with well formed posterior excrescence bearing two pairs of setae; long pair h 1, directed posteriorly, and shorter pair p 1, directed laterally. Juveniles with 12 pairs of gastronotal setae, most dorsal setae long, curved, finely barbed, inserted on large apophyses, with flagellate and often twisted distal part. Prodorsum and gastronotum covered with granular cerotegument. Exuviae of previous instars with much scattered debris. Cornicle rather long, between setae lm. Description of juvenile stages. Larva elongated (Fig. 12), unpigmented. Prodorsum triangular, setae ro and le as in D. onustus, seta in shorter than ro, seta ex small. Bothridium rounded, protruding from surface, with funnellike rim, but smaller than in D. onustus; sensillus setiform, usually with cerotegument in distal part. Lateral depression present above leg I. Gastronotum of larva with 11 pairs of setae, including seta h 2 inserted lateral to posterior part of anal opening (Fig. 13 A). Seta h 3 absent, but its vestigial alveolus present medial to anal opening. Central and posterior setae (c 1, c 2, lp and d -series) long (Table 1), lateral setae (c 3, la and lm) shorter; all setae curved, erect, finely barbed, inserted on large apophyses and distally flagellate, with often twisted distal part. Seta c 3 shorter than setae of l -series, but longer than seta h 2; all setae finely barbed. Paraproctal valves (segment PS) with two pairs of alveolar setae. Cupule ia, im, ip and ih, and gland opening (gla) located as in D. onustus. Gastronotum with granular cerotegument. Nymphs slightly slimmer than larva, unpigmented, with relatively longer, and slightly darker legs. Gastronotum of protonymph with 12 pairs of setae, as seta h 3 and three pairs of pseudanal setae (p 1– p 3) appear and remain in successive instars, but setae of d -series absent, leaving central part of gastronotum bare. Other numerical changes of setae in successive nymphs as in D. onustus, but seta ag and epimeral setae longer (Fig. 13 B) than in D. onustus. Gastronotum of nymphs with well formed posterior excrescence bearing two pairs of setae: long pair h 1, directed posteriorly, and shorter pair p 1, directed laterally. Anogenital region with granular cerotegument. Prodorsum of nymphs relatively shorter and slimmer than in larva. Prodorsal setae of tritonymph (Fig. 14) as in larva. Transverse ridges present posterior to seta le, and anterior to bothridium. Lateral depression present above leg I. Bothridium rounded, protruding from surface, with funnel-like rims, but smaller than in D. onustus; sensillus setiform, finely barbed, and covered with cerotegument in distal part. Prodorsum with granular cerotegument. D. clavipes, D. angustipes, Kunstidamaeus tecticola, Metabelba papillipes, Metabelbella longiseta, Protobelba californica, and Subbelba reevesi. Legs Stage D. onustus D. clavipes K. tecticola D. angustipes 1 Leg I LV 0-2-3(1)-4(1)-15(1) 0-2-3(1)-4(1)-15(1) 0-2-3(1)-4(1)-15(1) 0-2-3(1)-4(1)-15(1) PN 0-3-3(1)-4(1)-15(2) 0-2-3(1)-4(1)-15(2) 0-2-3(1)-4(1)-15(2) 0-3-3(1)-4(1)-15(2) DN 1-4-4(1)-5(2)-15(2) 1-4-4(1)-5(2)-15(2) 1-4-4(1)-5(2)-15(2) 1-4-4(1)-5(2)-15(2 TN 1-5-4(1)-5(2)-18(2) 1-4-4(1)-5(2)-18(2) 1-4-4(1)-5(2)-18(2) 1-5-4(1)-5(2)-18(2 AD 1-7-3(1)-4(2)-20(2) 1-7-4(1)-4(2)-20(2) 1-7-4(1)-4(2)-20(2) 1-7-4(1)-4(2)-20(2) TN 1-3-3-4(1)- 12 1-3-3-4 (1)- 12 1-3-3-4 (1)- 12 1-3-3-6 (1)-13 AD 1-5-3-3(1)- 14 1-5-3-4 (1)- 14 1-4-3-3 (1)- 14 1-4-3-7 (1)-15 Legs Stage M. papillipes 2 M. longiseta 3 P. californica 3 S. reevesi 4 Leg I LV 0-2-3(1)-4(1)-16(1) 0-2-3(1)-4(1)-16(1) 0-2-3(1)-4(1)-16(1) 0-2-3(1)-4(1)-16(1) PN 0-2-3(1)-4(1)-16(2) 0-2-3(1)-4(1)-16(2) 0-2-3(1)-4(1)-16(2) 0-2-3(1)-4(1)-16(2) DN 1-4-4(1)-5(1)-16(2) 1-4-4(1)-5(1)-16(2) 1-4-4(1)-5(2)-16(2) 1-4-4(1)-5(2)-16(2) TN 1-6–4(1)-5(1)-18(2) 1-5-4(1)-5(1)-18(2) 1-5-4(1)-5(2)-18(2) 1-5-4(1)-5(2)-18(2) AD 1-10-4 (1)-4(1)-20(1) 1-7-4(1)-5(1)-20(2) 1-7-4(1)-4(2)-20(2) 1-7-4(1)-4(2)-20(2) Leg II LV 0-2-3(1)-3(1)-13(1) 0-2-3(1)-3(1)-13(1) 0-2-3(1)-3(1)-13(1) 0-2-3(1)-3(1)-13(1) PN 0-2-3(1)-3(1)-13(1) 0-2-3(1)-3(1)-13(1) 0-2-3(1)-3(1)-13(1) 0-2-3(1)-3(1)-13(1) DN 1-4-4(1)-4(1)-13(2) 1-4-4(1)-4(1)-13(2) 1-4-4(1)-4(2)-13(2) 1-4-4(1)-4(2)-13(2) TN 1-6-4(1)-5(1)-15(2) 1-4-4(1)-5(1)-15(2) 1-5-4(1)-4(2)-15(2) 1-4-4(1)-5(2)-15(2) AD 1-10-4 (1)-5(1)-17(2) 1-6-4(1)-4(1)-17(2) 1-7-4(1)-4(2)-17(2) 1-6-4(1)-4(1)-17(2) Leg III LV 0-2-2(1)-3(1)-13 0-2-2(1)-3(1)-13 0-2-2(1)-3(1)-13 0-2-2(1)-3(1)-13 PN 1-2-2(1)-3(1)- 13 1-2-2 (1)-3(1)- 13 1-2-2 (1)-3(1)- 13 1-2-3 (1)-3(1)-13 DN 2-3-3(1)-4(1)- 13 2-3-3 (1)-4(1)- 13 2-3-3 (1)-4(1)- 13 2-3-3 (1)-4(1)-13 TN 4-5-3(1)-4(1)- 15 2-3-3 (1)-4(1)- 15 2-3-3 (1)-4(1)- 15 2-3-3 (1)-4(1)-15 AD 4-9-4(1)-5(1)- 17 2-4-3 (1)-3(1)- 17 2-4-3 (1)-4(1)- 17 2-5-3 (1)-4(1)-17 Leg IV PN 0-0-0-0-7 0-0-0-0-7 0-0-0-0-7 0-0-0-0-7 DN 1-2-2-3(1)-12 0-2-2-3(1)- 12 1-2-3-3 (1)- 12 1-2-2-3 (1)-12 TN 2-5-3-4(1)- 12 1-3-3-4 (1)- 12 1-3-3-4 (1)- 12 1-3-3-4 (1)-12 AD 3-9-4-4(1)- 14 1-4-3-3 (1)- 14 1-4-3-4 (1)- 14 1-4-3-3 (1)-14 1—according to Norton (1977a); 2 —according to Ermilov (2010); 3—according to Norton (1978); 4—according to Norton & Ryabinin (1994). Exuviae of previous instars with much scattered (not compacted or humus-like) debris, and well connected with gastronotum (Fig. 15 A). After removal of exuviae, centrodorsal part bare, finely reticulate (14B), and with rather long and thin cornicle, situated midway between setal pair lm. Gastronotal setae rather long, inserted on large apophyses on lateral and posterior parts of gastronotum, leaving centrodorsal part bare except for cornicle; all setae curved, erected, distally pliable, often with twisted distal part. Cupules ia, im, iad, ips and ih, and gland opening (gla) located as in D. onustus, but cupule ip located more posteriorly, between seta h 2 and p 1. Gastronotum with granular cerotegument. Tarsus I of tritonymph long and thin, with two solenidia, ω1 longer and thicker than ω2 (Fig. 8 B). Tibia I with two solenidia, φ1 long, with short coupled seta d, φ2 short. Summary of ontogenetic transformations. Setae ro and le are rather long in all instars, but ro in the juveniles are inserted closer to the rostrum than in the adult. Setae in and ex are short in all instars. The bothridium is rounded in all instars, with a funnel-like rim, but smaller than in D. onustus; the sensillus is long, setiform. The larva has 11 pairs of gastronotal setae; in the protonymph four pairs of setae appear (h 3, p -series) and three pairs are lost (d -series), such that 12 pairs remain in all nymphs (c -, d -, h - and p -series). The adult loses seta c 3, such that 11 pairs of notogastral setae remain. The formula of gastronotal setae in D. clavipes is 11-12-12-12-11 (larva to adult), while those of coxisternal, genital, aggenital, segments PS −AN, and paraproctal setae are as in D. onustus (Table 3). ensis, E. verrucatus, Kunstidamaeus tecticola, Metabelba papillipes, M. glabriseta, and Porobelba spinosa. location of cornicle Anteromedial to la Between lm Between lp Anteromedial to Between h 3 la continued next page Morphological characters D. onustus D. clavipes D. angustipes 1 D. auritus 2 E. kamaensis 3 1—according to Norton (1977a); 2—according to Ermilov et al. (2010), but supplemented with data of adult by Miko (2006) and Mahunka (1982); 3—according to Ermilov & Łochyńska (2010), but supplemented with data of adult by Sellnick (1920, 1926); 4—according to Enami, Y. (1992), but supplemented with data of adult by Enami & Fujikawa (1989); 5—according to Ermilov (2010), but supplemented with data of adult by Miko (2006). Distribution ecology and biology. Damaeus clavipes has been considered Palaearctic occidental (Subías 2004) or Palaearctic (Miko 2006) species. It was recorded from several parts of Poland (Olszanowski et al. 1996). This species occurs in leave litter and mosses (Sellnick 1960), and also in tree bark and rotten wood (Rajski 1967), but has lower requirements for humidity than D. onustus. In Botanical Garden on the campus of the University of Life Sciences in Ås (Norway) it also occurs in Scots pine and shrub litter. Schatz (1983) considered it in forests, arboreal, meso- to hygrophilic, and microphytophagous species, in particular it is fungivorous browser (Siepel 1996). Pauly (1956) investigated the development and biology of this species. Female of D. clavipes feeding on algae from tree bark, laid about 60 eggs in breeding season, and whole development of species lasted 76 days (Pauly 1956), but in subarctic climate (average temperature 5 o C) the development lasted 11–12 months (Block 1965). This species is a host of protozoan Apicomplexa Erhardovina bisphaera, Microspora Nosema acari and Pleistophora oribatei (Geest et al. 2000).

Published as part of Seniczak, Stanisław & Seniczak, Anna, 2011, Differentiation of external morphology of Damaeidae (Acari: Oribatida) in light of the ontogeny of three species, pp. 1-36 in Zootaxa 2775 on pages 14-24, DOI: 10.5281/zenodo.202939