Allogalumna rugata, Liang & Yang, 2015

Liang, W. Q. & Yang, M. F., 2015, Allogalumna rugata, a new species of oribatid mite from China (Acari, Oribatida, Galumnidae), Acarologia 55 (3), pp. 277-284 : 278-283

Allogalumna rugata n. sp.

( Figures 1-4 )

Diagnosis — Body size 650 – (660) – 720 × 440 – (460) – 475. Body and legs covered by the microgranular cero-tegument. Rostral and lamellar setae setiform, smooth. Interlamellar setae longer than rostral and lamellar setae, setiform, slightly barbed. Bothridial setae slenderly setiform, slightly barbed. Anterior notogastral margin interrupted. Four pairs of porose areas small, oval, Aa largest, A2 smallest. Median pore absent in females and males. Genital plates with some longitudinal stria. Postanal porose area absent. Legs monodactylous.

Measurement — Body length 660 (holotype: female), 650 – 720 (twelve paratypes, eight females, four males); width 460 (holotype), 440 – 475 (twelve paratypes).

Integument — Body colour brown to dark brown. Surface of body smooth, genital plates with dense longitudinal stria.

Prodorsum — Rostrum rounded in dorsal view. Rostral (ro, 40 – 45) and lamellar (le, 30 – 36) setae setiform, smooth; interlamellar (in, 53 – 57) setae setiform, slightly barbed. Bothridial setae (ss, 125 – 130) slenderly setiform, slightly barbed distally, pointed distally in lateral view. Exobothridial setae and their alveoli absent. Porose areas Ad small, elongate oval, transversally oriented (8 – 10 × 28 – 32). Sublamellar (S) lines distinct, curving backwards.

Notogaster — Anterior notogastral margin not developed medially. Dorso-phragmata of medium size. Notogastral setae represented by 10 pairs of alveoli. Four pairs of oval porose areas developed: Aa oval, 14 – 18 × 36 – 40; A1 oval, 18 – 22 × 21 – 25; A2 oval, 8 – 12 × 18 – 23; A3 slightly elongate oval, 8 – 12 × 35 – 38. Lyrifissures im located anterolaterally to A1. Median pore absent in females and males.

Roman letters refer to normal setae (e–famulus), Greek letters refer to solenidia. A prime (′) marks anterolateral setae and a double prime (″) posterolateral setae of the given leg segment. Parentheses refer to a pair of setae.

Gnathosoma — Morphology of subcapitulum, palps and chelicerae typical for Galumnidae ( Engelbrecht 1972 a; Ermilov and Anichkin 2011). Subcapitulum wider than long: 124 – 135 × 115 – 125. Hypostomal setae a, m, h setiform, thin, smooth. h (35 – 40) longer than a (28 – 32) and m (22 – 24). Two pairs of short adoral (5 – 10) setae, setiform, curved. Palp (length 143) with setation of 0-2-1-3-9 (+1 solenidion ω). All setae (except on tarsus) barbed. Chelicera (length 183) with few blunt teeth on fixed and movable digits. Cheliceral setae long, setiform, barbed: cha (56) longer than chb (35).

Epimeral region — Epimeres smooth. Four pairs of epimeral setae visible ventrally; 1a, 3a, 3b and 4a (18 – 26), thin, smooth. Discidia triangular, circumpedal carinae distinct.

Anogenital region — Six pairs of genital setae present, anterior two setae (g1, g2, 18 – 24) longest; genital and anal plates with densely longitudinal stria. Two pairs of anal (an1, an2) setal alveoli, three pairs of adanal (ad1-ad3, 8 – 16), one pair of aggenital setae (ag) short, thin, smooth. Adanal lyrifissures iad short, thin, located anterior to adanal setae ad3. Postanal porose area (Ap) absent.

Legs — Morphology of leg segments, setae and solenidia generally typical for Galumnidae ( Engelbrecht 1972; Ermilov & Anichkin 2011). All legs tridactylous, lateral claws slightly thinner than median claw. Formulae of leg setation 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 as indicated in Table 1.

Material examined — Holotype ♀, China: Qinghai Prov., Mutual Beishan National Forest Geological Park (36°50’59.76"N, 102°04’05.10"E), 2241 m a.s.l., 2 July 2010, coll. Maofa Yang ( GUGC) . Paratypes: 5♀♀ 4♂♂, with same data as holotype ; 3♀♀, China: Qinghai Prov., Three Rivers’ Headwaters Natural Reserve Area of Yushu Tibetan Autonomous Prefecture (32°33’48.65"N, 97°39’55.66"E), 3464 m a.s.l., from soil under the Picea crassifolia , 5 Aug. 2009, coll. Lixia Xie ( GUGC) .

Etymology — The specific name " rugata " is from Latin, and refers to the stria of the genital plates.

Types deposited — The type specimens are deposited in the Institute of Entomology , Guizhou University, Guiyang, Guizhou, China ( GUGC) .

Remarks — In having the combination of main morphological characters (bothridial setae setiform, slightly barbed; interlamellar setae setiform, longer than rostral and lamellar setae; anterior notogastral margin not developed; notogaster with four pairs of rounded porose areas; median pore absent in females and males), Allogalumna rugata n. sp. is similar to Allogalumna ampla Ermilov, 2013 from Ecuador (see Ermilov 2013), however it clearly differs from the latter by the smaller body size (650 – 720 × 440 – 475 versus 448 – 464 × 332 – 365 in A. ampla ), interlamellar setae setiform, longer than rostral and lamellar setae (versus represented by alveoli or minute in A. ampla ), numbers of striae on genital plates (versus one longitudinal stria in A. ampla ) and the absence of postanal porose area (versus present in A. ampla ).

Figures

FIGURE 1: Allogalumna rugata n. sp. (female): A – dorsal view; B – ventral view (legs not shown). Scale bar 100 µm.

FIGURE 2: Allogalumna rugata n. sp. (female): A – dorso-lateral view of prodorsum; B – posterior view of notogaster; C – pteromorph; D – subcapitulum; E – bothridial setae; F – palp; G – chelicera. Scale bar: (A-C) 100 µm, (D-G) 50 µm.

FIGURE 3: Allogalumna rugata n. sp. SEM micrographs of adult, macerated in lactic acid, some cero-tegument removed, some of the setae are broken. A – dorsal view; B – ventral view; C – lateral view.

FIGURE 4: Allogalumna rugata n. sp. SEM micrographs of adult, macerated in lactic acid, some cero-tegument removed, some of the setae are broken. A – detail of prodorsum in dorsal view; B – bothridial seta and part of pteromorph; C – inter-lamellar seta; D – adanal seta; E – detail of genital plates; F – detail of anal plates.