Pergalumna microtuberculata, Bayartogtokh & Akrami, 2014

Bayartogtokh, Badamdorj & Akrami, Mohammad Ali, 2014, The soil mite family Galumnidae of Iran (Acari: Oribatida), Journal of Natural History 48 (15), pp. 881-917 : 909-912

Pergalumna microtuberculata sp. nov.

( Figures 11 and 14 )

Diagnosis

With typical characters of Pergalumna ; rostrum with small triangular central tooth, lateral carina absent; rostral and lamellar setae thin, finely barbed; interlamellar seta long, thin, finely barbed; sensillus medium long, with finely barbed, slightly dilated head; porose area Aa large, nearly elongate triangular, its lateral part wide, but medial part narrowed, A 1 small, round, A 2 and A 3 elongate oval, subequal in size; median pore present, consisted of single pore; notogastral lyrifissure im positioned far anterior from seta lp; postanal porose area large, elongate oval.

Measurements

Holotype: body length 552 µm, width of notogaster 400 µm, length of notogaster 464 µm; paratypes (n = 2): body length 545–570 (558) µm, width of notogaster 380– 470 (425) µm.

Description

Integument. Body colour dark brown. Cuticle of body and legs with minute granules; humeral region, posterior part of notogaster and epimeral region with few small tubercles.

Prodorsum. Rostrum with small triangular central tooth, which is easily seen in dorsofrontal view, lateral carina absent ( Figure 11B and C ). Rostral seta thin, 71– 76 µm long, finely barbed, inserted ventrally and clearly visible in dorsofrontal view. Lamellar seta thin, 82–88 µm long, finely barbed. Interlamellar seta thin, 86–93 µm long, finely barbed. Sensillus 82–86 µm long, with finely barbed, slightly dilated head (one specimen showed finely barbed setiform sensillus). Lamellar and sublamellar lines well developed ( Figure 14A and B ). Dorsosejugal porose area large, elongate oval, located posterolaterad of seta in.

Notogaster. Notogaster widened posteriorly, dorsosejugal furrow well developed. Pteromorph nearly smooth, with small granules. Notogastral setae vestigial, their alveoli well discernable. Porose area Aa large, nearly elongate triangular, its lateral part widened, but medial part narrowed; A 1 round, A 2 and A 3 elongate oval; median pore present, consisting of single pore. Lyrifissures ia, im, ih, ip, ips and opisthonotal gland opening well developed ( Figures 11E–H and 14 ).

Gnathosoma . Subcapitulum longer than wide, with few microtubercles; hypostomal setae a, m and h 8–11 µm long, smooth ( Figure 14D ). Palp typical for family, all setae except on tarsus finely barbed, formula of setation: 0-2-1-3-10 including solenidion ω on tarsus. Chelicera with few heavily sclerotized blunt teeth on fixed and movable digits; setae cha and chb long, barbed; Trägårdh’ s organ well developed, its proximal part well discernable.

Epimeral region. With large granules and longitudinal striations; apodemes apo.1, apo.2, apo.sj, apo.3, circumpedal carina and discidium well developed. Six pairs of short epimeral setae of 12–18 µm length observed, setal formula: 2-0-2-2 ( Figure 14D ).

Ano-genital region. Anal aperture 110 µm long, 131 µm wide; genital aperture 77 µm long, 86 µm wide for holotype. Genital and aggenital setae well developed, 14–19 µm long, thin, smooth; anal and adanal setae vestigial; adanal lyrifissure situated in paranal position, at level little posterior to seta ad 3 ( Figure 14D ). Postanal porose area large, elongate oval, narrowed bilaterally ( Figure 14E ).

Legs. Structure and setation of legs typical for family as shown in the description of Allogalumna dentirostrata sp. nov. Formula of setation, including famulus: I (1-4-3-4- 20), II (1-4-3-4-15), III (1-2-1-3-15), IV (1-2-2-3-12), formula of solenidia I (1-2-2), II (1-1-2), III (1-1-0), IV (0-1-0).

Material examined

Holotype (female): Babol, Mazandaran province, Northern Iran, 36°35 ʹ N, 52°40 ʹ E, approximately at the sea level, 28 September 2004, Col. M. A. Akrami; two paratypes (females): same data as holotype. The holotype and paratypes are deposited in the collection of the Department of Plant Protection , College of Agriculture, Shiraz University, Iran.

Remarks

Pergalumna microtuberculata sp. nov. is unique among the known species of Pergalumna by the combination of following features, namely: large, nearly elongate triangular porose area Aa, the outer part of which is widened, but inner part is narrowed; very slightly dilated head of sensillus; presence of small central tooth of rostrum; dense granules and longitudinal striations on epimeral region; far anterior position of notogastral lyrifissure im, and microtubercles on humeral region and posterior part of notogaster.

Among the known species of Pergalumna , Pergalumna altera (Oudemans, 1915) , Pergalumna comparanda (Berlese, 1920) , Pergalumna formicaria (Berlese, 1914) , Pergalumna minoricana Pérez-Iñigo, 1990 and Pergalumna nervosa (Berlese, 1914) are similar to the new species in the structure of porose area Aa and sensillus. However, two common species in the Palaearctic region, P. altera and P. nervosa are different from the new species in the slightly widened outer part of porose area Aa; round porose area A 2; reticulate structure of pteromorph; smoothly rounded rostrum, and far larger body size.

Two other species, P. comparanda and P. formicaria , are distinguishable from the new species by the different size of interlamellar seta (seta in is far longer in P. comparanda , but much shorter in P. formicaria ); swollen head of sensillus; relatively posterior position of notogastral lyrifissure im, and smoothly rounded rostrum.

The Mediterranean species, P. minoricana differs from the new species in the structure of porose area Aa, conspicuously widened in both inner and outer parts; relatively longer interlamellar seta, extending well beyond tip of rostrum; relatively posterior position of notogastral lyrifissure im; smoothly rounded rostrum, and much larger body size.

Etymology

The specific epithet “ microtuberculata ” refers to the presence of small tubercles on humeral region and posterior part of notogaster.

Ecology

This species is an inhabitant of the lowland pasture soil, and the specimens were found under graminoid grasses ( Poaceae ).

Figures

Figure 11. Morphological characters of different species. (A––D) Galumna iranensis Mahunka et Akrami, 2001. (A) Lateral view of proterosoma (arrow indicates dorsosejugal porose area Ad); (B) dorsal view of prodorsum (arrow indicates central carina of rostrum); (C) lateral part of notogaster; (D) lateral view of sensillus. (E–H) Pergalumna microtuberculata sp. nov. (E) Posterior view of notogaster showing porose areas A3 and Ap; (F) porose area Aa; (G) posterior part of notogaster; (H) pteromorph.

Figure 14. Pergalumna microtuberculata sp. nov. (A) Dorsal view of idiosoma; (B) dorsofrontal view of prodorsum, partial; (C) ventral view of idiosoma; (D) posterior view of notogaster, partial.