Lamnacarus Balogh and Mahunka, 1963

Jagersbacher-Baumann, Julia & Ebermann, Ernst, 2016, Support for the underrepresented sex: new descriptions of scutacarid males (Acari, Heterostigmatina), Zootaxa 4179 (3), pp. 371-409 : 380-384

Genus Lamnacarus Balogh and Mahunka, 1963

Type species Lamnacarus ornatus Balogh and Mahunka, 1963 , by original designation

Lamnacarus ornatus Balogh and Mahunka, 1963 ( Figs. 1 , 3 , 8 , 9 )

MALE. Idiosoma length 130–150, n = 4.

Gnathosoma ( Fig. 1 c) extended, tube-shaped. One pair of finger-shaped solenidia, two pairs of dorsal setae ch 1 and ch 2, thin, smooth, one ventral pair of ventral setae su, shorter, thinner, smooth. One pair of short tube-like accessory setigenous structures distally.

Dorsum ( Fig. 8 a). Idiosoma with four sclerotized, very finely dotted plates. Most posterior plate forms dorsal cover for genital capsule. Length of dorsal setae: v about 9, sc 1 13, sc 2 31, c 1 52, c 2 24, d 25, e 29, f 45, h 1 6. Setae v, sc 1, sc 2, c 1, c 2, d, e, f barbed, c 1 only sparsely. Seta v pointed, all other setae blunt-ended; h 1 and h 2 spine-like, h 2 small. Distance between dorsal setae: v–v about 4, sc 1 –sc 1 15, sc 2 –sc 2 22, c 1 –c 1 18, c 2 –c 2 63, d–d 57, e–e 47, f–f 17, h 1 –h 1 26, h 2 –h 2 21.

Genital apparatus ( Figs. 3 c, 8a). Segments H and PS fused, form genital capsule. Length of genital plate (tergite H) about 40. Posterior edge of plate narrowed, short genital plate (ratio length: width of genital plate = 1: 0.65). Small area posterior of h 1 with roundish- hexagonal, sucker-like structures or cavities. Aedeagus like in I. dispar .

Venter ( Fig. 8 b). Sternal plates finely dotted. Ap1 limited to region of gnathosoma, prosternal ap continuous from ap1 to sejugal ap, strongly sclerotized; sejugal ap weakly sclerotized at central part, stronger near legII; ap2, ap5 strongly sclerotized; ap3, ap4 complete, weakly sclerotized, poststernal ap between ap3 and ap5 complete, strongly sclerotized. Length of ventral setae: 1 a about 7, 1 b 8, 2 a 9, 2 b 9, 3 a 11, 3 b 10, 3 c 9, 4 a 8, 4 b 7, 4 c 10, ps 1 2, ps 2 7. All setae smooth, short, pointed. Distance between ventral setae: 1 a –1 a about 13, 1 b –1 b 37, 2 a –2 a 17, 2 b – 2 b 39, 3 a –3 a 19, 3 b –3 b 32, 3 c –3 c 56, 4 a –4 a 19, 4 b –4 b 4, 4 c –4 c 47, ps 1 –ps 1 11, ps 2 –ps 2 13.

Leg I ( Fig. 9 a). Setal formula: Tr1–Fe3–Ge4–Ti6(2)–Ta13(2). Ta with one padded claw. Sol ω1 thick and finger-shaped, sol ω2 thin, sol ϕ1, thick, club-shaped, sol ϕ2 thin. Length of solenidia: ω1 about 24, ω2 10, ϕ1 7, ϕ2 12. Eupathidia tc’, tc’’ and ft’’, setae pl’’, dTi, k, l’’Ge, dFe, v’’Fe and v’’Tr sparsely barbed, all other setae smooth; Eupathidion tc’, setae s and pl’’ blunt, all other setae more or less pointed.

Leg II ( Fig. 9 b). Setal formula: Tr1–Fe3–Ge3–Ti4(1)–Ta7(1). Ta with two claws and small empodium. Sol ω 19, thick, ϕ 8, baculiform. Eupathidion tc’’, setae u’, u’’, v’Ge, l’Fe, l’’F e and v’Tr smooth, all other setae barbed, most only sparsely; all setae pointed.

Leg III ( Fig. 9 c). Setal formula: Tr1–Fe2–Ge2–Ti4(1)–Ta7. Fe with a fine suture, Ta with two claws and small empodium. Sol ϕ 7, slightly club-shaped. Eupathidion tc’’, setae u’’, pv’’, v’Ti, v’’Ti and l’Fe smooth, all other setae sparsely barbed; all setae pointed.

Leg IV ( Fig. 9 d, Table 1 ). Setal formula: Tr1–Fe1–Ge1–Ti4(1)–Ta6. Distal Ta with two adhesive pads of differing size. Tarsal setae tc’, tc’’ are longest, length tc’ about 38, tc’’ 22. Sol ϕ, l’Ti and dTi thick, cone-shaped, l’ <d <sol ϕ; sol ϕ 7; dFe thick. Setae v’’Ti, u, pv’, pv’’ and tc’’ smooth, all other setae barbed.

Differential diagnosis. The males of L. ornatus can be differentiated from all other known males by the setation of its leg IV ( Table 1 ), and mostly the cone-shaped form of the sol ϕ is characteristic. The claws on legs I– III are larger and stronger than in all other known males.

Material examined. 5 males from laboratory cultures based on females from a composting facility; AUSTRIA: Petzendorf, 46°55’26’’N, 15°22’18’’E; 2010, leg. Jagersbacher-Baumann.

Deposition of material. 2 males: Natural History Museum Vienna, Austria ( NHMW 27.640 ) ; 2 males: Institute of Zoology , University of Graz, Austria ; 1 male: Museum of Natural History of the City of Geneva, Switzerland .

Figures

FIGURE 1. Dorsal view of the male gnathosoma: a. Heterodispus foveatus, b. Imparipes dispar, c. Lamnacarus ornatus, d. Scutacarus acarorum, e. S. deserticolus, f. S. ellipticus, g. S. longipes, h. S. longitarsus, i. S. tackei, j. S. tyrrhenicus. Abbreviations: ass = accessory setigenous structures.

FIGURE 3. Dorsal view of the genital plates of: a. Heterodispus foveatus, b. Imparipes dispar, c. Lamnacarus ornatus, d. Scutacarus acarorum, e. S. deserticolus, f. S. ellipticus, g. S. longipes, h. S. longitarsus, i. S. tackei, j. S. tyrrhenicus large male (idiosoma length 200 µm), k. S. tyrrhenicus small male (idiosoma length 140 µm).

FIGURE 8. Lamnacarus ornatus male: a. dorsal view, b. ventral view.

FIGURE 9. Lamnacarus ornatus male: a. leg I, b. leg II, c. leg III, d. leg IV.