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ZooKeys 435: 7–23, doi: 10.3897/zookeys.435.8213
Two new species of Pergalumna (Acari, Oribatida, Galumnidae) from Costa Rica, including a key to all species of the genus from the Neotropical region
Sergey G. Ermilov 1, Olman Alvarado-Rodríguez 2, Axel P. Retana-Salazar 2
1 Tyumen State University, Tyumen, Russia
2 Centro de Investigación en Estructuras, Microscópicas (CIEMIC), Ciudad de la Investigación, Universidad de Costa Rica, San José, Costa Rica

Corresponding author: Sergey G. Ermilov (ermilovacari@yandex.ru)

Academic editor: Vladimir Pesic

received 5 July 2014 | accepted 7 August 2014 | Published 15 August 2014
(C) 2014 Sergey G. Ermilov. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
For reference, use of the paginated PDF or printed version of this article is recommended.

Citation: Ermilov SG, Alvarado-Rodríguez O, Retana-Salazar OP (2014) Two new species of Pergalumna (Acari, Oribatida, Galumnidae) from Costa Rica, including a key to all species of the genus from the Neotropical region. ZooKeys 435: 7–23. doi: 10.3897/zookeys.435.8213

Abstract

Two new species of oribatid mites of the genus Pergalumna (Oribatida, Galumnidae), P. elongatiporosa sp. n. and P. striatiprodorsum sp. n., are described from leaf litter of a secondary forest in Costa Rica. Pergalumna elongatiporosa sp. n. is most similar morphologically to P. horvathorum P. Balogh, 1997 and P. sura P. Balogh, 1997, however, it differs from both by the body size, body surface ornamentation and morphology of notogastral porose areas A1 and A3. Pergalumna striatiprodorsum sp. n. is most similar morphologically to P. hawaiiensis hawaiiensis (Jacot, 1934) and P. strigulata Mahunka, 1978, however, it differs from P. hawaiiensis by the length of interlamellar setae and surface ornamentation of the prodorsum; from P. strigulata by the surface of ornamentation of the notogaster, length of interlamellar setae and morphology of bothridial setae. An identification key to known species of Pergalumna from the Neotropical region is given.

Keywords

Oribatid mites, new species, Pergalumna, key, Costa Rica, Neotropical region

Introduction

Pergalumna is a large genus that was proposed by Grandjean (1936) with Oribata nervosa Berlese, 1914 as type species. Currently, it comprises more than 130 species having a cosmopolitan distribution collectively (Subías 2004, updated 2014). The generic characters of the genus are summarized by Ermilov et al. (2013a), an identification key to some species has been presented by Balogh and Balogh (2002).

In the course of taxonomic identification of Costa Rican oribatid mites collected in 2013, we found two new species of the genus Pergalumna. The main goal of our paper is to describe these species. Earlier, only three species were known from Costa Rica (P. Balogh 1997; Schatz 2006, 2007; Ermilov et al. 2014): Pergalumna horvathorum P. Balogh, 1997, Pergalumna silvatica Hammer, 1961 and Pergalumna sura P. Balogh, 1997. An identification key to known species of Pergalumna from the Neotropical region is given in the present work.

Materials and methods

Three specimens (holotype: male; two paratypes: one male and one female) of Pergalumna elongatiporosa sp. n. and nine specimens (holotype: female; eight paratypes: five males and three females) of Pergalumna striatiprodorsum sp. n. are from: Costa Rica, 9°50'24"N, 83°53'17"W, Cartago, Dulce Nombre, Paraíso, Jardín Botánico Lankester, 1400 m a.s.l., in leaf litter in secondary forest, 14.V.2013, collected by O. Alvarado-Rodríguez and A.P. Retana-Salazar.

Holotypes and paratypes were mounted in lactic acid on temporary cavity slides for measurement and illustration. The body length was measured in lateral view, from the tip of the rostrum to the posterior edge of the ventral fig. The notogastral width refers to the maximum width in dorsal aspect. Lengths of body setae were measured in lateral aspect. All body measurements are presented in micrometers. Formulae for leg setation are given in parentheses according to the sequence trochanter–femur–genu–tibia–tarsus (famulus included). Formulae for leg solenidia are given in square brackets according to the sequence genu–tibia–tarsus. General terminology used in this paper follows that of Grandjean (summarized by Norton and Behan-Pelletier 2009).

Taxonomy
Pergalumna elongatiporosa sp. n.

http://zoobank.org/E008B3A2-4238-4C4E-B918-8B9E10E48686

Figs 1–4
Diagnosis.

Body size: 332–352 × 246–266. Body surface and pteromorphs microgranulate. Rostral, lamellar and interlamellar setae well developed, barbed. Bothridial setae setiform, ciliate unilaterally. Anterior notogastral margin not developed. Three pairs of porose areas: Aa and A3 elongate triangular, A1 long, band-shaped, specifically curving, Aa located between notogastral alveoli la and lm. Median pore and postanal porose area absent. Aggenital and ano-adanal setae simple, short. Solenidion φ on tibia IV inserted in proximal part.

Description.

Measurements. Body length: 332 (holotype, male), 340–352 (two paratypes: one male and one female); notogaster width: 246 (holotype), 246–266 (two paratypes).

Integument. Body color brown to black-brown. Body surface and pteromorphs with dense microgranules (their diameter up to 2). Pteromorphs with poorly visible wrinkles.

Prodorsum. Rostrum broadly rounded. Rostral (ro, 24–28), lamellar (le, 49–53) and interlamellar (in, 69–77) setae setiform, barbed. Bothridial setae (ss, 90–102) setiform, densely ciliate unilaterally. Exobothridial setae absent. Lamellar and sublamellar lines distinct, parallel, curving backwards. Insertions of lamellar setae distanced from the lamellar lines. Porose areas Ad small, elongate oval (8–12 × 2–4), located latero-posteriorly to interlamellar setae.

Notogaster. Anterior notogastral margin not developed. Dorsophragmata (D) long. Notogastral setae represented by 10 pairs of alveoli. Three pairs of porose areas well visible, with distinct margins: Aa weakly triangular, transversally oriented (36–57 × 8–12), A1 long, band-shaped, specifically curving (57–69 × 8–13), A3 elongate, narrowly triangular (28–32 × 8–16). Porose areas Aa located between notogastral alveoli la and lm. Median pore absent. All lyrifissures distinct; im and opisthonotal gland openings (gla) located latero-anteriorly to A1.

Gnathosoma. Morphology of subcapitulum, palps and chelicerae typical for Pergalumna (see Engelbrecht 1972; Ermilov et al. 2010; Ermilov and Anichkin 2011). Subcapitulum longer than wide (90–94 × 77–86). Subcapitular setae setiform, slightly barbed; a (14–16) longer than m (10) and h (8). Two pairs of adoral setae (or1, or2, 8) setiform, hook-like distally, barbed. Palps (73) with setation 0–2–1–3–9(+ω). Solenidion attached to eupathidium, both located on dorsal tubercle. Chelicerae (118–123) with two setiform, barbed setae; cha (28–32) longer than chb (20). Trägårdh’s organ distinct.

Epimeral and lateral podosomal regions. Apodemes 1, 2, sejugal and 3 well visible. Six pairs of setiform epimeral setae observed; setal formula: 1–0–2–3. Setae 4a, 4b (4) thin, smooth, shorter than 1b, 3b, 3c, 4c (8–10), slightly barbed. Pedotecta II (Pd II) scale-like, rounded in ventral view. Discidia (dis) pointly triangular. Circumpedal carinae (cp) distinct, directed posterior of setae 3b.

Anogenital region. Six pairs of genital (g1, g2, 8; g3–g6, 4), one pair of aggenital (ag, 4), two pairs of anal (an1, an2, 4) and three pairs of adanal (ad1–ad3, 4) setae minute, thin, smooth. Anterior parts of genital figs with two setae. Adanal setae ad3 inserted laterally or antero-laterally to lyrifissures iad. Postanal porose area absent.

Legs. Morphology of leg segments, setae and solenidia typical for Pergalumna (see Engelbrecht 1972; Ermilov et al. 2010; Ermilov and Anichkin 2011). 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 indicated in Table 1. Solenidion φ on tibia IV inserted in proximal part.

Figure 1.

Pergalumna elongatiporosa sp. n.: dorsal view. Scale bar 100 μm.

Figure 2.

Pergalumna elongatiporosa sp. n.: ventral view (legs not illustrated). Scale bar 100 μm.

Figures 3–4.

Pergalumna elongatiporosa sp. n.: 3 dorso-lateral view of prodorsum and anterior part of notogaster and pteromorph (gnathosoma and legs not illustrated) 4 posterior view of notogaster. Scale bars 100 μm.

Table 1.

Leg setation and solenidia of Pergalumna elongatiporosa sp. n. (same data for Pergalumna striatiprodorsum sp. n.).

Leg Trochanter Femur Genu Tibia Tarsus
I v’ d, (l), bv’’ (l), v’, σ (l), (v), φ1, φ2 (ft), (tc), (it), (p), (u), (a), s, (pv), v’, (pl), l’’, ε, ω1, ω2
II v’ d, (l), bv’’ (l), v’, σ (l), (v), φ (ft), (tc), (it), (p), (u), (a), s, (pv), ω1, ω2
III v’ d, ev’ l’, σ l’, (v), φ (ft), (tc), (it), (p), (u), (a), s, (pv)
IV v’ d, ev’ d, l’ l’, (v), φ ft’’, (tc), (p), (u), (a), s, (pv)

Roman letters refer to normal setae (ε to famulus), Greek letters to solenidia. Single prime (’) marks setae on anterior and double prime (’’) setae on posterior side of the given leg segment. Parentheses refer to a pair of setae.


Type deposition.

The holotype is deposited in the Zoological Institute of the Russian Academy of Sciences, St. Petersburg, Russia; one paratype is deposited in the collection of the Tyumen State University Museum of Zoology, Tyumen, Russia; one paratype is deposited in the collection of the Centro de Investigación en Estructuras, Microscópicas (CIEMIC), Ciudad de la Investigación, Universidad de Costa Rica, San José, Costa Rica.

Etymology.

This specific name “elongatiporosa” refers to the elongate porose areas A1.

Remarks.

In having the setiform bothridial setae, well developed interlamellar setae, absence of anterior notogastral margin and presence of three pairs of porose areas (Aa transversally elongated), Pergalumna elongatiporosa sp. n. is most similar to Pergalumna horvathorum P. Balogh, 1997 and Pergalumna sura P. Balogh, 1997 (see also Ermilov et al. 2014) from the Neotropical region. However, it differs from both by the smaller body size (332–352 × 246–266 versus 394–410 × 295 in Pergalumna horvathorum and 443–498 × 315–377 in Pergalumna sura), microgranulate body surface (versus smooth in Pergalumna horvathorum and Pergalumna sura), band-shaped, specifically curving porose areas A1 (versus elongate oval in Pergalumna horvathorum and triangular in Pergalumna sura) and elongate triangular porose areas A3 (versus absent in Pergalumna horvathorum and oval in Pergalumna sura).

Pergalumna striatiprodorsum sp. n.

http://zoobank.org/2DBFC49F-0502-4A55-AC59-6E1E45C8358C

Figs 5–8
Diagnosis.

Body size: 630–697 × 448–514. Body surface and pteromorphs microgranulate; surface of prodorsum with numerous longitudinal stria. Rostral, lamellar and bothridial setae of medium size, setiform, barbed; interlamellar setae short, slightly thickened, barbed. Anterior notogastral margin not developed. Three pairs of porose areas oval; Aa located between notogastral alveoli la and lm, close to lm. Median pore absent. Aggenital and ano-adanal setae simple, short. Postanal porose area present, elongated.

Description.

Measurements. Body length: 697 (holotype, female), 630–697 (eight paratypes: five males and three females); notogaster width: 514 (holotype), 448–514 (eight paratypes).

Integument. Body color brown to black-brown. Body surface, pteromorphs and subcapitular mentum with dense microgranules (their diameter up to 2). Surface of prodorsum with numerous longitudinal stria. Pteromorphs with poorly visible wrinkles.

Prodorsum. Rostrum broadly rounded. Rostral (41–53), lamellar (57–69) and bothridial (106–114) setae setiform, barbed. Interlamellar setae short (12–16), setiform, slightly thickened, barbed. Exobothridial setae absent. Lamellar and sublamellar lines distinct, parallel, curving backwards. Insertions of lamellar setae distanced from the lamellar lines. Porose areas Ad elongate oval (20–28 × 4–8), located latero-posteriorly to interlamellar setae.

Notogaster. Anterior notogastral margin not developed. Dorsophragmata of medium size. Notogastral setae represented by 10 pairs of alveoli. Three pairs of porose areas well visible, with distinct margins: Aa rounded (14–16) or oval, weakly transversally oriented (14–20 × 12–16), A1 oval, weakly elongated diagonally (24–41 × 12–20), A3 rounded (12–16 )or oval (12–16 × 10–12). Porose areas Aa located between notogastral alveoli la and lm, but clearly closer to lm. Median pore absent. All lyrifissures distinct; im located latero-anteriorly to A1. Opisthonotal gland openings located laterally to A1.

Gnathosoma. Morphology of subcapitulum, palps and chelicerae typical for Pergalumna (see Engelbrecht 1972; Ermilov et al. 2010; Ermilov and Anichkin 2011). Subcapitulum longer than wide (155–159 × 131–143). Subcapitular setae setiform, slightly barbed; a (24) longer than m (16) and h (14–16). Two pairs of adoral setae (12–14) setiform, hook-like distally, barbed. Palps (123–127) with setation 0–2–1–3–9(+ω). Solenidion attached to eupathidium, both located on dorsal tubercle. Chelicerae (196–205) with two setiform, barbed setae; cha (53) longer than chb (32–36). Trägårdh’s organ distinct.

Epimeral and lateral podosomal regions. Apodemes 1, 2, sejugal and 3 well visible. Six pairs of setiform epimeral setae observed; setal formula: 1–0–2–3. Setae 4a, 4b (6–8) thin, smooth, shorter than 3b (20–24) and 1b, 3c, 4c (32–36), slightly barbed. Pedotecta II scale-like, rounded in ventral view. Discidia pointly triangular. Circumpedal carinae distinct, directed posterior of setae 3b.

Anogenital region. Six pairs of genital (g1, 16–18; g2, 12–14; g3–g6, 8–10), one pair of aggenital (6–8), two pairs of anal (6–8) and three pairs of adanal (6–8) setae setiform, thin, smooth. Anterior parts of genital figs with two setae. Adanal setae ad3 inserted laterally to lyrifissures iad. Postanal porose area present, elongate oval (20–28 × 6–8).

Legs. Morphology of leg segments, setae and solenidia typical for Pergalumna (see Engelbrecht 1972; Ermilov et al. 2010; Ermilov and Anichkin 2011). 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 indicated in Table 1.

Figure 5.

Pergalumna striatiprodorsum sp. n.: dorsal view. Scale bar 200 μm.

Figure 6.

Pergalumna striatiprodorsum sp. n.: ventral view (legs not illustrated). Scale bar 200 μm.

Figures 7–8.

Pergalumna striatiprodorsum sp. n.: 7 dorso-lateral view of prodorsum and anterior part of notogaster and pteromorph (gnathosoma and legs not illustrated) 8 posterior view of notogaster. Scale bars 200 μm.

Type deposition.

The holotype is deposited in the Zoological Institute of the Russian Academy of Sciences, St. Petersburg, Russia; seven paratypes are deposited in the collection of the Tyumen State University Museum of Zoology, Tyumen, Russia; one paratype is deposited in the collection of the Centro de Investigación en Estructuras, Microscópicas (CIEMIC), Ciudad de la Investigación, Universidad de Costa Rica, San José, Costa Rica.

Etymology.

This specific name “striatiprodorsum” refers to the striate prodorsum.

Remarks.

In having the striate prodorsum, setiform bothridial setae, absence of anterior notogastral margin and presence of three pairs of oval porose areas (Aa oval, rounded, located close to lm), Pergalumna striatiprodorsum sp. n. is most similar to Pergalumna hawaiiensis hawaiiensis (Jacot, 1934) from the Pacific Islands and Pergalumna strigulata Mahunka, 1978 from Mauritius. However, it differs from Pergalumna hawaiiensis by the short interlamellar setae (versus medium size in Pergalumna hawaiiensis) and striate prodorsum (versus only anterior part of prodorsum with stria in Pergalumna hawaiiensis); from Pergalumna strigulata by the absence of stria on notogaster (versus notogaster striate in Pergalumna strigulata), short interlamellar setae (versus medium size in Pergalumna strigulata) and barbed bothridial setae (versus smooth in Pergalumna strigulata).

Among Neotropical species Pergalumna striatiprodorsum sp. n. is most similar morphologically to Pergalumna decorata Balogh & Mahunka, 1977. However, it differs from the latter by the absence of anterior notogastral margin (versus anterior margin present in Pergalumna decorata), barbed bothridial setae (versus smooth in Pergalumna decorata), absence of stria on notogaster (versus notogaster striate in Pergalumna decorata) and microgranulate body surface and pteromorphs (versus with larger foveoles in Pergalumna decorata).

Key to known species of Pergalumna from the Neotropical region1
1 Bothridial setae with clear head 2
– Bothridial setae setiform 13
2 Anterior margin of notogaster developed 3
– Anterior margin of notogaster not developed 9
3 Surface of prodorsum with numerous longitudinal stria or rugae 4
– Surface of prodorsum without stria and rugae 5
4 Surface of notogaster striate; interlamellar setae of medium size; notogaster with four pairs of porose areas (A2 present); body length: 330–460 Pergalumna striata (Pérez-Íñigo & Baggio, 1980) (see also Pérez-Íñigo and Baggio 1994). Distribution: Brazil
– Surface of notogaster foveolate; interlamellar setae absent; notogaster with three pairs of porose areas (A2 absent); body size: 486–527 × 405–437 Pergalumna complicata Balogh & Mahunka, 1978 (see Fig. 23A–B, not Fig. 24A–E, in Balogh and Mahunka 1978). Distribution: Brazil
5 Centro-anterior part of notogaster with specific ornamentation (longitudinal line with lateral lineate branches); lamellar setae minute; notogastral porose areas Aa elongated transversally, very narrow; body size: 282–298 × 199–215 Pergalumna ornamenta Ermilov, Starý, Sandmann, Marian & Maraun, 2013. Distribution: Ecuador
– Centro-anterior part of notogaster without specific ornamentation; lamellar setae of medium size or long; notogastral porose areas Aa triangular, boot-shaped, rounded or oval 6
6 Interlamellar setae long; notogastral porose areas Aa triangular or boot-shaped 7
– Interlamellar setae minute; notogastral porose areas Aa rounded or oval 8
7 Median pore located posterior to the virtual line connecting porose areas A2; notogastral porose areas A1 and A2 small; lyrifissures im located between setal alveoli lm and lp; body length: 470–600 Pergalumna bryani bryani (Jacot, 1934) (see also Hammer 1973). Distribution: Pacific Islands and Galapagos Islands
– Median pore located little posterior to the virtual line connecting porose areas A1; notogastral porose areas A1 and A2 of medium size; lyrifissures im located laterally to A1; body size: 620 × 430 Pergalumna comparanda (Berlese, 1920) (see also Mahunka 1992). Distribution: Argentina
8 Bothridial setae pointed distally; notogastral porose areas A3 elongated, longer than A1 and A2; body length: 820 Pergalumna andicola Hammer, 1961. Distribution: Peru
– Bothridial setae rounded distally; notogastral porose areas A1, A2 and A3 rounded, similar in size; body length: 730 Pergalumna anellata Hammer, 1961. Distribution: Peru
9 Interlamellar setae long 10
– Interlamellar setae minute or represented by alveoli 11
10 Bothridial head barbed medio-distally, stalk smooth; rostral setae inserted laterally; pteromorphal wrinkles indistinct; body size: 320–400 × 270 Pergalumna numerosa (Sellnick, 1923) (see also see also Pérez-Íñigo and Baggio 1994). Distribution: Brazil
– Bothridial head and stalk barbed; rostral setae inserted ventro-laterally; pteromorphal wrinkles clearly visible; body size: 338–392 × 258–320 Pergalumna bellesii Pérez-Íñigo & Baggio, 1997. Distribution: Brazil
11 Basal part of prodorsum with longitudinal stria; notogaster with four pairs of porose areas; lamellar setae of medium size; body length: 600 Pergalumna montana Hammer, 1961. Distribution: Peru and Venezuela
– Basal part of prodorsum without longitudinal stria; notogaster with three pairs of porose areas; lamellar setae short 12
12 Notogastral porose areas Aa oval; median pore present; bothridial setae well barbed; body length: 492–576 Pergalumna nasica Pérez-Íñigo & Baggio, 1980. Distribution: Brazil and Argentina
– Notogastral porose areas Aa triangular; bothridial setae indistinctly barbed; median pore absent; body length: 468 × 360 Pergalumna cardosensis Pérez-Íñigo & Baggio, 1986. Distribution: Brazil and Peru
13 Anterior margin of notogaster developed 14
– Anterior margin of notogaster not developed 17
14 Surface of prodorsum and notogaster nearly smooth; body size: 520–676 × 502 Pergalumna foveolata Hammer, 1973 (see also Bayartogtokh and Chattarjee 2010). Distribution: Polynesia, India and Brazil
– Surface of prodorsum with longitudinal stria or large foveoles; surface of notogaster striate 15
15 Surface of prodorsum with longitudinal stria; interlamellar setae minute; notogastral porose areas Aa located closer to setal alveoli lm than to la; body size: 637–653 × 469–494 Pergalumna decorata Balogh & Mahunka, 1977. Distribution: Neotropical region
– Surface of prodorsum with large foveoles; interlamellar setae of medium size; notogastral porose areas Aa equal distanced from setal alveoli la and lm 16
16 Rostrum pointed; anal figs striate; body size: 810–860 × 780–810 Pergalumna decoratissima Pérez-Íñigo & Baggio, 1986. Distribution: Neotropical region
– Rostrum rounded, with lateral tooth on each side; anal figs not striate; body size: 780–962 × 630–747 Pergalumna paradecoratissima Ermilov & Kalúz, 2012. Distribution: Ecuador
17 Surface of prodorsum with three striate bands (one basal, transverse and two dorso-lateral, longitudinal striate bands) 18
– Surface of prodorsum without three striate bands 19
18 Rostrum pointed; posterior part of notogaster with striate bands; body size: 415–464 × 282–332 Pergalumna boliviana Ermilov, 2013 (see Ermilov and Niedbala 2013). Distribution: Bolivia
– Rostrum rounded; posterior part of notogaster without striate bands; body size: 278 × 213 Pergalumna passimpunctata Balogh & Mahunka, 1969 (see also Ermilov and Niedbała 2013). Distribution: Brazil
19 Surface of prodorsum with numerous longitudinal stria 20
– Surface of prodorsum without stria 21
20 Whole surface of prodorsum striate; interlamellar setae minute; notogastral porose areas Aa rounded; body size: 630–697 × 448–514 Pergalumna striatiprodorsum sp. n. Distribution: Costa Rica
– Only basal part of prodorsum striate; interlamellar setae of medium size; notogastral porose areas Aa elongated transversally; body length: 750 Pergalumna magnipora magnipora (Hammer, 1961). Distribution: Peru
21 Interlamellar setae of medium size or long 22
– Interlamellar setae minute or represented by alveoli 30
22 Rostrum tridentate; body size: 384 × 360 Pergalumna plumata Pérez-Íñigo & Baggio, 1986. Distribution: Neotropical region
– Rostrum rounded 23
23 Notogastral porose areas A1 of specific structure 24
– Notogastral porose areas A1 rounded or oval 25
24 Body surface microgranulate; notogastral porose areas Aa weakly triangular, A1 long, band-shaped, specifically curving; body size: 332–352 × 246–266 Pergalumna elongatiporosa sp. n. Distribution: Costa Rica
– Body surface smooth; notogastral porose areas Aa elongate oval, A1 with rounded anterior part (with distinct margins) and triangular posterior part (without distinct margins); body size: 448–498 × 315–348 Pergalumna sura P. Balogh, 1997 (see also Ermilov et al. 2014). Distribution: Neotropical region
25 Interlamellar setae longer than bothridial setae 26
– Interlamellar setae shorter than bothridial setae 27
26 Adanal setae of medium size, ad3 inserted posteriorly to lyrifissures iad; surface of prodorsum with small tubercles; body size: 1062–1261 × 713–863 Pergalumna paralongisetosa Ermilov & Kalúz, 2012. Distribution: Ecuador
– Adanal setae minute, ad3 inserted laterally to lyrifissures iad; surface of prodorsum without tubercles; body size: 697–713 × 498–506 Pergalumna ecuadorensis Ermilov & Kalúz, 2012. Distribution: Ecuador
27 Notogastral porose areas A1 clearly larger than other porose areas; body length: 400 Pergalumna melloi Pérez-Íñigo & Baggio, 1994. Distribution: Brazil
– Notogastral porose areas A1 not larger than other porose areas 28
28 Two pairs of notogastral porose areas (A1, A2) observed, A1 very narrowly band-shaped; body size: 394–410 × 295 Pergalumna horvathorum P. Balogh, 1997. Distribution: Neotropical region
– Three or four pairs of notogastral porose areas observed, A1 rounded or oval 29
29 Three pairs of notogastral porose areas (A3 not observed) present; median pore absent; body size: 390–420 × 342–360 Pergalumna pauliensis Pérez-Íñigo & Baggio, 1991. Distribution: Brazil
– Four pairs of notogastral porose areas (including A3) present; median pore present; body size: 410–490 × 315–365 Pergalumna aequalis (Sellnick, 1923). Distribution: Neotropical region
30 Notogastral porose areas Aa rounded 31
– Notogastral porose areas Aa elongated transversally 32
31 Rostrum pointed; notogastral porose areas A1 and A3 oval or rounded; body length: 620 Pergalumna bifissurata Hammer, 1972. Distribution: Polynesia and Galapagos Islands
– Rostrum rounded; notogastral porose areas A1 and A3 elongated; body length: 500–540 Pergalumna australis Pérez-Íñigo & Baggio, 1980. Distribution: Brazil and Ecuador
32 Four pairs of notogastral porose areas present; interlamellar setae represented by alveoli; body size: 276–348 × 228–300 Pergalumna parva Pérez-Íñigo & Baggio, 1986. Distribution: Brazil
– Three pairs of notogastral porose areas present (A2 absent); interlamellar setae represented by microsetae 33
33 Lamellar setae longer than rostral setae; surface of anterior part of prodorsum granulate; body size: 863–1000 × 680–697 Pergalumna silvatica Hammer, 1961 (see also Ermilov et al. 2014). Distribution: Neotropical region
– Lamellar setae shorter than rostral setae; surface of prodorsum not granulate; body size: 468 × 408 Pergalumna aegra Pérez-Íñigo & Baggio, 1986. Distribution: Brazil

1 We did not include two Neotropical species, Pergalumna obvia (Berlese, 1914) and Pergalumna curva ventralis (Willmann, 1931) (sensu Subías 2004, updated 2014), in the key. We consider Pergalumna obvia as representative of the genus Galumna Heyden, 1826 without additional studying of the type material (see Ermilov et al. 2013b). Pergalumna curva ventralis has no lamellar lines (see Hammer 1958, 1961, 1972), therefore we consider this species as representative of the genus Allogalumna Grandjean, 1936 (see generic diagnosis for Allogalumna in Ermilov et al. 2013a).

Acknowledgements

We cordially thank Dr. Elizabeth A. Hugo-Coetzee (National Museum, Bloemfontein, South Africa) and one anonymous reviewer for the valuable comments.

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