Pergalumna amorpha Mahunka, 2008

Zheng, Qianfen, Liang, Wenqin, Ren, Guoru & Yang, Maofa, 2019, A new species and two newly recorded species of the subgenus Pergalumna (Pergalumna) (Acari, Oribatida, Galumnidae) from China, Zootaxa 4647 (1), pp. 407-423 : 419-423

Pergalumna amorpha Mahunka, 2008

( Figs. 26‒35 )

Diagnosis. Body size: 348‒440 × 264‒335. Dorsosejugal suture absent. Body surface smooth. Rostral, Lamellar and Interlamellar setae setiform, barbed bilaterally. Bothridial setae setiform, thick throughout the length densely barbed bilaterally. Bothridial setae bs longest, in second, le longer than ro. Porose area Ad absent. Dorsosejugal suture absent. Pteromorphs ornamented by radiate sculpture. Three pairs porose areas not clearly visible on the punctate notogastral surface. Median pore (mp) and postanal porose area (Ap) absent. All legs tridactylous.

Descriptions. Measurements. Body length: 348‒440, Body width: 264‒335.

Integument. Brown to dark brown. Notogastral setae scarcely seen, only the setal pores visible. Pteromorphs ornamented with radiate sculpture.

Prodorsum ( Figs. 26 , 28 ). Prodorsum surface smooth. Rostral part wide, conical. Lamellar (L) and sublamellar line (S) developed, curving backwards. Rostral seta ro (32‒40), lamellar seta le (70‒79) and interlamellar seta in (120‒131) setiform, barbed bilaterally. Bothridial seta bs (135‒147) setiform, thick throughout the length densely barbed bilaterally. Porose area Ad absent.

Notogaster ( Figs. 26 , 28, 32‒33 ). Dorsosejugal suture absent. Ten pairs of notogastral setae, minute or indis- tinct, only the setal pores visible. Pteromorph ornamented with radiate sculpture. Three pairs of porose areas not clearly visible on the punctate notogastral surface, area Aa (8‒12 × 35‒39) elongate oval, large, transversally ori- ented, area Aa located between setal alveoli la and lm, area A1 (4‒6 × 14‒18) and A3 (4‒6 × 14‒18) oval, similar in size. Lyrifissure im located posteriorly to la. Opisthonotal gland openings (gla) located lateral-posteriorly to h 3. Median pore (mp) area absent.

Gnathosom a ( Figs. 29‒31 ). Subcapitulum size: 55 × 68, three pairs of setiform, smooth, curved subcapitular setae h (9‒11), m (10‒14), a (2‒4). Two pairs of setiform, smooth adoral setae, or 1, or 2 (4‒8). Length of palp: 76. Palp with setation 0-2-1-3-9 (+1 solenidion ω). All setae barbed except on tarsus. Length of chelicera: 159. Two setiform, bilaterally barbed cheliceral setae cha (48), chb (32). Trägårdhʼs organ (Tg) elongate triangular.

Epimeral region ( Fig. 27 ). Discidium (dis) triangular, circumpedal carinae distinct. Epimeral setal formula: 1- 0-1-3. Five pairs of epimeral setae (1a, 3b, 4a, 4b, 4c), setae 1a (10‒15) longest, setiform, smooth, setae 3b, 4b and 4c minute (3‒6), seta 4a indistinct, only the setal pore visible.

Anogenital region ( Figs. 27‒28, 32 ). Subcapitulum wider than long. Six pairs of setiform, smooth genital setae, g 1 ‒g 6 (2‒6). One pair of minute, setiform, smooth aggenital setae ag (2‒4), two pairs of setiform, smooth anal setae an 1 (2‒4), an 2 (3‒6) and three pairs of adanal setae (ad 1, ad 2, ad 3), ad 1 (48‒53) very long, erect, seta ad 2 (7‒10) and ad 3 (5‒8) minute, simple. Lyrifissure iad located posterior to anterior margin of anal aperture, postanal porose area (Ap) absent.

Legs ( Figs. 34‒35 ). All legs tridactylous. Median claw distinctly thicker than laterals, all barbed on dorsal sides. Formulas of leg setaetion and solenidia: I (1-4-3-4-20) [1-2-2], II (1-4-3-4-15) [1-1-2], III (1-2-1-3-15) [1-1-0], IV (1-2-2-3-12) [0-1-0]; homology of setae and solenidia indicated in Table 1 .

Material examined. 5♂♂ 1♀, Labahe National Nature Reserve (102°30’N, 30°5’E), Sichuan Province, China, 25 Jul. 2012, Wenqin Liang & Qiuxiao Tang, in soil ; 8♂♂ 5♀♀, Tengchong Town (98°32’N, 24°54’E), Baoshan City, Yunnan Province, China, 25 Jul. 2012, Wenqin Liang & Qiuxiao Tang, in soil .

Remarks. This species was originally described by Mahunka (2008) from Thailand but the description lacked important information therefore a detailed redescription is given herein. Apart from the lacking characteristics, the Chinese specimens differ by the well-developed adanal setae ad 1 (48‒53) from the specimens from Thailand which show only minute and simple adanal setae ad 1 ( Mahunka 2008).

Figures

FIGURE 26. Pergalumna amorpha Mahunka, 2008, adult, dorsal view. Scale bar 100 μm.

FIGURE 27. Pergalumna amorpha, adult, ventral view. Scale bar 100 μm.

FIGURES 28–33. Pergalumna amorpha, adult: 28—lateral view; 29—subcapitulum; 30—palp, right, antiaxial view; 31—chelicera, right, antiaxial view; 32—posterior view; 33—pteromorpha. Scale bars 100 μm (28, 32), 50 μm (31, 33), 25 μm (29- 30).

FIGURES 34–35. Pergalumna amorpha, adult: 34—leg I, right, antiaxial view; 35—leg IV, left, antiaxial view. Scale bars 50 μm.