Pergalumna (Pergalumna) dedzaensis, Ermilov & Starý, 2022

Ermilov, Sergey G. & Starý, Josef, 2022, Three new species of Pergalumna (Acari, Oribatida, Galumnidae) from Malawi, with updated identification key to known species of the genus from the Afrotropical region, Zootaxa 5133 (2), pp. 226-240 : 227-231

Pergalumna (Pergalumna) dedzaensis sp. nov.

( Figs 1A–E ; 2A–G ; 3A–D ; 4A, B )

Diagnosis. Body length: 697–813. Rostrum rounded. Rostral, lamellar and interlamellar setae minute, smooth; bothridial seta long, setiform, smooth. Dorsosejugal suture present. Three pairs (Aa, A1 and A3) of comparatively large, oval porose areas; Aa located between setal alveoli la and lm, equally removed from them. Median pore absent. Lyrifissure im located anterolaterally to A1 and removed from it. Subcapitular seta a longest and thickest, h shortest and thinnest; h removed from anterior edge of mentum. Epimeral and anogenital setae short, setiform, roughened. Circumpedal carina long, reaching pedotectum I. Genital plate with one longitudinal medial ridge. Aggenital seta located between genital and anal apertures, nearer to the former. Adanal lyrifissure located close and parallel to anal plate. Postanal porose area absent. Leg famulus inserted close and anterolaterally to solenidion ω 1; leg solenidion on tibia IV inserted in anterior part of the segment, but close to the middle.

Description of adult. Measurements. Body length: 796 (holotype: female), 697–813 (six paratypes: six females); notogaster width: 614 (holotype), 547–647 (six paratypes).

Integument. Body color dark brown. Body surface densely microfoveolate. Lateral side of body partially with microgranulate cerotegument. Lateral part of epimeres I, II with slight elongate tubercles. Antiaxial side of leg femora I-IV and trochanters III and IV partially with elongate tubercles.

Prodorsum. Rostrum rounded. Lamellar and sublamellar lines thin, parallel, curving backwards. Rostral, lamellar and interlamellar setae (10–12) setiform, thin, smooth; le distinctly removed from L. Bothridial seta (164–176) setiform, smooth. Dorsosejugal porose area elongate oval (53–73 × 8–10), transversely oriented, located posterolaterally to insertion of interlamellar seta. Dorsophragma distinctly elongate longitudinally.

Notogaster. Dorsosejugal suture present, strong. Ten pairs of notogastral setae represented by setal alveoli. Three pairs of oval porose areas (Aa, A1 and A3: 28–41 × 16–28; sometimes A3 up to 16 × 8); A2 absent; Aa located between setal alveoli la and lm, equally removed from them. Median pore absent. Opisthonotal gland opening and all lyrifissures distinct: gla located laterally to A1; im anterolaterally to A1 and removed from it; ip between p 1 and p 2; ih and ips close to each other, anterolaterally to p 3.

Gnathosoma. Size of subcapitulum: 196–213 × 180–192. Subcapitular setae (a: 41; m: 24; h: 12) setiform, slightly barbed; a thickest, h thinnest; h removed from anterior edge of mentum. Adoral seta (16–20) setiform, barbed. Length of chelicera: 225–241; cheliceral setae (cha: 77–82; chb: 49–53) setiform, barbed. Length of palp: 151–155. Postpalpal seta (6) spiniform, smooth.

Epimeral and lateral podosomal regions. Anterior margin of ventral plate smooth. Epimeral setal formula: 2- 0-2-3. Setae (1a, 3c, 4c: 16–20; 1c, 3b, 4a, 4b: 12–14) setiform, thin, roughened. Pedotectum II rounded in ventral aspect. Circumpedal carina long, reaching pedotectum I.

Anogenital region. Genital (g 1: 16–20; g 2 – g 6: 12), aggenital (12), anal (16–20), and adanal (16–20) setae setiform, thin, roughened. Genital plate with one longitudinal medial ridge. Anterior edge of genital plate with three setae. Aggenital seta located between genital and anal apertures, nearer to the former. Adanal lyrifissure located close and parallel to anal plate. Adanal setae ad 1 and ad 2 posteriorly, ad 3 laterally to anal plate; distance ad 1 – ad 2 shorter than ad 2 – ad 3. Postanal porose area absent. Ovipositor (319 × 82) of typical morphology for Galumnidae (Ermilov 2010) , with three blades (135) and longer distal section (beyond middle fold; 184); setae ψ 1 and τ 1 (73) rod-like, smooth; ψ 2, τ a, τ b, and τ c (36) stiff, smooth; six coronal setae (6) spiniform.

Legs. Median claw distinctly thicker than lateral claws, all slightly barbed on dorsal side. Porose area on all femora and on trochanters III, IV well visible; proximoventral porose area on tarsi and distoventral porose area on tibiae not observed. Formulas 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 indicated in Table 1 . Famulus of tarsus I short, straight, slightly swollen distally, inserted close and anterolaterally to solenidion ω 1. Seta s of tarsus I eupathidial, located between pairs of setae u and a. Solenidion on tibia IV inserted in anterior part of the segment, but close to the middle.

Material examined. Holotype (female) and six paratypes (six females): Central Malawi, Dedza District, Dedza Mountain , 14°21’13.4”S, 34°19’36.3”E, 2032 m a.s.l., sifting litter in forest (sample #15), Winkler extraction, 29.XI.2018 (leg. P. Baňař and P. Hlaváč).

Type deposition. The holotype is deposited in the collection of the SMNH; six paratypes are deposited in the collection of the TSUMZ. All specimens are preserved in 70% solution of ethanol with a drop of glycerol.

Etymology. The specific name dedzaensis refers to the place of origin, the Malawian Dedza District.

Remarks. The systematic placement of P. dedzaensis sp. nov. is difficult. The problem is that some specimens have a transverse, slightly pigmented epimeral band located anteriorly to genital aperture. This band partially resembles the generic character in the genus Taeniogalumna Balogh, 1962 ; Pergalumna and Taeniogalumna are generally similar differing only by one generic character: absence versus presence of long, dark, transverse bandlike structure located anteriorly and continuing laterally to genital aperture ( Ermilov & Klimov 2017). On the one hand, the epimeral band in specimens of the new species is absent or only slightly developed, short and brown (not dark brown), therefore, we provisionally include it in Pergalumna . On the other hand, the degree of development of the epimeral band-like structure may vary as was found for Taeniogalumna behanae Ermilov, Sidorchuk & Rybalov, 2010 (see Subías et al. 2021), therefore, if, theoretically, the new specimens of P. dedzaensis sp. nov. with a welldeveloped epimeral band-like structure are found in the future, then it will be more correct to transfer this species from Pergalumna to Taeniogalumna .

Pergalumna dedzaensis sp. nov. is morphologically most similar to P. tanzanica Mahunka, 1984 and P. pietertheroni Ermilov & Khaustov, 2019 from the Afrotropical region in the presence of dorsosejugal suture, setiform bothridial seta, three pairs of oval notogastral porose areas (Aa located between la and lm and equally distanced from them), and minute interlamellar seta. However, the new species differs from P. tanzanica by the larger body length (697–813 versus 416–425) and smooth (versus unilaterally ciliated) bothridial seta; from P. pietertheroni by the larger body length (697–813 versus 315–348), similar length of rostral, lamellar and interlamellar setae (versus ro longer than le and in), long (versus medium-sized) circumpedal carina reaching (versus not reaching) pedotectum I, and the presence (versus absence) of strong longitudinal ridge on genital plate.

Pergalumna dedzaensis sp. nov. is similar to Taeniogalumna tanzanica Mahunka, 1983 from Tanzania in the presence of dorsosejugal suture, setiform and smooth bothridial seta, three pairs of notogastral porose areas, and minute interlamellar seta. However, the new species differs from T. tanzanica by the larger body length (697–813 versus 276–303) and oval (versus triangular) notogastral porose area Aa located between setal alveoli la and lm, equally removed from them (versus located close and anteriorly to la).

Figures

FIGURE 1. Pergalumna (Pergalumna) dedzaensis sp. nov., adult:A—dorsal view; B—anterior part of prodorsum, dorsoanterior view; C—ventral view (gnathosoma, legs and right pteromorph not shown); D—right lateral view (gnathosoma, legs and pteromorph not shown); E—posterior view (left pteromorph not shown). Scale bars 100 μm (A, C–E), 50 μm (B).

FIGURE 2. Pergalumna (Pergalumna) dedzaensis sp. nov., dissected adult: A—subcapitulum, ventral view; B—chelicera, right, antiaxial view C—palp, right, antiaxial view; D—leg I (trochanter not shown), right, antiaxial view; E—leg II (tarsus not shown), right, ventroantiaxial view; F—leg III (trochanter and tarsus not shown), left, antiaxial view; G—leg IV, left, antiaxial view. Scale bars 50 μm.

FIGURE 3. Pergalumna (Pergalumna) dedzaensis sp. nov., adult, SEM micrographs: A—dorsal view; B—ventral view; C— anterior view (rostrum broken); D—right lateral view.

FIGURE 4. Pergalumna (Pergalumna) dedzaensis sp. nov. (A, B), P. (P.) paratsavoensis sp. nov. (C–F) and P. (P.) parafrater sp. nov. (G–I), dissected adult, photo images: A—lamellar seta and partially lamellar and sublamellar lines, anterolateral view; B—right genital plate; C—rostrum, dorsal view; D—inner rostral tooth; E—anterior dentate margin of ventral plate; F— tuberculate sculpturing of leg trochanter IV; G—striate and tuberculate sculpturing of anterior part of pteromorph; H—striate and tuberculate sculpturing of lateral part of pteromorph; I—adanal lyrifissure.