Differentiation of external morphology of Oribatulidae (Acari: Oribatida) in light of the ontogeny of three species Author Seniczak, Stanisław Author Seniczak, Anna text Zootaxa 2012 3184 1 34 journal article 45499 10.5281/zenodo.208456 7f4288f8-f0c3-423f-9f26-2415f0039141 1175-5326 208456 Phauloppia lucorum ( C. L. Koch, 1841 ) ( Figs. 1 , 2 A, 3A, 4A, B, 5–8, 9A, 10A, B) Phauloppia lucorum : Grandjean 1948 , 1950 ; Travé 1958 , 1961 ; Sellnick 1960 ; Marshall et al . 1987 ; Pérez-Íñigo 1987 ; Subías 2004 , 2011; Weigmann 2006 . Zetes lucorum C. L. Koch, 1841 . Notaspis lucorum : Michael 1888 . Oppia conformis Berlese, 1895 . Eremaeus schneideri Oudemans, 1900 . Lucoppia ( Phauloppia ) conformis : Berlese 1908 ; Sellnick 1928 . Oribata geniculatus (L.) sensu Willmann (1931) . Phauloppia longiporosa Mahunka, 1982 . Diagnosis. Adult rather large (600–900 µm), drop-shaped ( Fig. 1 ), brown. Males usually smaller than females. Most prodorsal and notogastral setae long, curved, and barbed. Prodorsal lamellae ( Lam ) weakly developed, sensillus ( ss ) rather short, clavate, with barbed head. Notogaster arched in lateral aspect ( Fig. 2 A), with 14 pairs of rather long setae ( c 3 lost), and well formed porose areas; Aa elongated, A1–A3 oval. Four pairs of genital setae, two pairs inserted in anterior part, and two pairs in posterior part of genital plates. Three pairs of small setae of ad -series, seta ad 3 located anterolateral from anal opening, far from seta ad 2 ( Fig. 3 A). Solenidion ω1 on tarsus I thicker than ω2 ( Fig. 4 A), porose areas on tarsus I–IV ( Fig. 4 B), and other segments of legs (trochanter III–IV, femur I–IV, tibia I– IV). Formulae of leg setae (and solenidia): I – 1-5 -3(1)-4(2)-20(2); II – 1-5 -3(1)-4(2)-15(2); III – 2-3 -1(1)-3(1)-15; III – 1-2 -2-3(1)-12. Tarsi tridactylous. Juveniles oval in dorsal aspect, light-brown, with darker legs. Most prodorsal and gastronotal setae long, curved, and barbed, sensillus clavate, with barbed head. Gastronotum arched in lateral aspect, with 12 pairs of setae in larva, and 15 pairs in nymphs. Some gastronotal setae with excentrosclerites ( c 2, l -series and h 1 in larva, c 2, l -, h - series and p 1 in nymphs), small excentrosclerites also at nymphal setae c 1 and d -series. Description of juvenile stages. Larva oval in dorsal aspect ( Fig. 5 ) after hatching, and egg-shaped, when distended, and light-brown, with darker legs. Prodorsum trapezoid. Seta ro rather long, seta le shorter than ro , seta in longer than ro ; pair ro inserted closest, pair in inserted widest; all setae slightly curved, and barbed; seta ex short and smooth. Bothridium rounded, sensillus rather short, and clavate, with barbed head. Gastronotum arched in dorsal aspect, with 12 pairs of setae, including seta h 3, inserted lateral to medial part of anal opening ( Fig. 6 A). Setae c 3, dp and lp approximately as long as seta in ( Table 1 ), other setae shorter. Seta c 1 approximately as long as le , seta c 2 shorter, setae of d -, l - and h -series increasing in size from anterior to posterior; all setae slightly curved and barbed, seta h 2 distinctly shorter than h 1, and barbed, seta h 3 small and smooth. Basal parts of setae c 2 and l -series and h 1 with excentrosclerites, other setae without excentrosclerites. Cupule ia posterior to seta c 3, cupule im posterior to seta lm , cupule ip between setae h 1 and h 2, cupule ih lateral to anterior part of anal opening. Gland opening gla anteroventral to seta lp . Paraproctal valves (segment PS) with two pairs of small setae. In freshly hatched larva gastronotum with transverse stria, and anal region with longitudinal stria, in distended larva cuticle smooth. Nymphs slimmer than larva, light-brown, with darker legs, and relatively shorter prodorsum than in larva. Protonymph with 15 pairs of gastronotal setae, including three pairs of p -series ( Fig. 6 B), which appear in this stage first time and remain in deuto- and tritonymph ( Figs. 7 A, B); length increasing from anterior to posterior. In protonymph setae p 3 and p 2 smooth, seta p 1 barbed; in other nymphs setae p 3 and p 2 distinctly longer, and barbed. In deutonymph small setae of ad -series ( ad 1– a d3) and pair ag appear and remain in tritonymph. Paraproctal valves of proto- and deutonymph glabrous, those of tritonymph with two pairs of small setae. Prodorsal setae of tritonymph (Fig. 8) relatively longer than in larva, especially seta le ; length increasing from ro to in ; all setae barbed, seta ex rather short and smooth. Bothridium rounded, sensillus clavate, with barbed head, but slimmer than in larva. All gastronotal setae long ( Table 1 ) and barbed, except shorter seta c 2. Setae c 2, l -, h -series and p 1 with rather large excentrosclerites, setae c 1 and d -series with small excentrosclerites; seta c 3 without excentrosclerite. Cupules ia and im as in larva, cupule ip between setae h 2 and p 2 ( Figs. 7 B, 9A), cupule iad lateral to anterior part of paraproctal valves, cupule ips pushing lateral, and cupule ih pushing anterolateral to cupule iad . Gland opening gla posteroventral to seta lm . In freshly hatched tritonymph gastronotum with transverse stria, and anal region with longitudinal stria ( Figs. 9 A, 9B), in distended tritonymph cuticle smooth. Tibia I and tarsus I of tritonymph ( Figs. 10 A, B) similar as in adult, but lack setal pair l on tarsus. Summary of ontogenetic transformations. Prodorsal seta le shorter than ro and in in the larva, but becomes longer in the nymphs, and remains so in the adult. The bothridium is rounded in all instars, and the sensillus is clavate, with barbed head, which is more slender in the nymphs and adult than in the larva. The larva has 12 pairs of gastronotal setae, the nymphs have 15 pairs (gained p -series), while the adult losses seta c 3, and 14 pairs remain. Lyrifissure ia is located lateroventral to seta c 2 ( Fig. 2 A). The formula of gastronotal setae is 12-15-15-15 -14 (larva to adult), those of coxisternal setae are: 3-1-2 (larva), 3-1-2-1 (protonymph), 3-1-2- 3 (deutonymph) and 3-1-3-3 (tritonymph and adult). The formula of genital setae is 1-2-3-4 (protonymph to adult), and that of aggenital setae is 1-1-1 (deutonymph to adult). The formula of segments PS–AN is 23333-0333-022. All formulae are consistent with those described by Grandjean (1949) . Distribution and ecology. Phauloppia lucorum is considered to be a Palaearctic species ( Subías 2004 , 2011; Weigmann 2006 ). It is classified as arboricolous, lichenicolous, muscicolous and xerophilous ( Travé 1958 , 1963 ; Pérez-Íñigo 1987 ; Schatz 2008 ; Gerecke et al . 2009 ; Perlinger & Schatz 2009 ), but was also recorded from the bird feathers ( Krivolutsky & Lebedeva 2002 ). In this study it was rather abundant in mosses on roofs of old houses in Górzyskowo Quarter in Bydgoszcz ( Poland , N53 o07.24 , E18 o00.30 ; 90 m a. s. l.), where in the late spring the juveniles were more abundant than the adults. FIGURE 1. Phauloppia lucorum , adult, female. (A) Dorsal aspect, legs partially drawn, scale bar 100 µm; (B) apical part of seta le . FIGURE 2. Lateral aspect of adults, females, legs partially drawn, scale bars 100 µm. (A) Phauloppia lucorum ; (B) Lucoppia burrowsi . FIGURE 3. Adults, females, anogenital region, legs partially drawn, scale bar 100 µm. (A) Phauloppia lucorum ; (B) Lucoppia burrowsi . FIGURE 4. Tarsus and part of tibia of adults, females, scale bars 20 µm. (A) Phauloppia lucorum , antiaxial aspect; (B) Ph. lucorum , part of tarsus, dorsal aspect; (C) Lucoppia burrowsi , part of tarsus, dorsal aspect; (D) L . burrowsi , antiaxial aspect; (E) Oribatula tibialis , antiaxial aspect. FIGURE 5. Phauloppia lucorum , larva, dorsal aspect, legs partially drawn, scale bar 50 µm. FIGURE 6. Phauloppia lucorum , legs partially drawn, scale bars 100 µm. (A) Anal region of larva; (B) anogenital region of protonymph. FIGURE 7. Phauloppia lucorum , anogenital region, legs partially drawn, scale bars 100 µm. (A) Deutonymph; (B) tritonymph. FIGURE 8. Phauloppia lucorum , tritonymph. (A) Apical part of seta le ; (B) dorsal aspect, legs partially drawn, scale bar 100 µm; (C) basal parts of setae c 1 and c 2.