Seira burgersi

Description. Total length (head + trunk) of adult specimens 3.83 ‒ 5.56 mm (n = 4), holotype 5.56 mm. Alive specimens completely black, except Ant II-IV base depigmented, and trochanters to unguis lightly yellow (Fig. 3 B). Specimens in alcohol with similar color pattern, but dark purple pigments on body; eyepatches black (Fig. 3 D). Scales present on Ant I to two basal third of Ant III, ventral and dorsal head, thorax and abdomen dorsally, legs (except empodia), anterior collophore, dorsal and ventral manubrium and dentes ventrally (Figs 39 C ‒ E, 41 A). Ant I ‒ II densely covered by scales heavily ciliated, elongated in spiral-shape with rounded or truncate apex (Fig. 35 A, C ‒ D). Head. Antennae shorter than body length, antennal ratio as I: II: III: IV = 1: 1.6 0 ‒ 1.76: 1.20 ‒ 1.25: 1.81 ‒ 2.16 (n = 3), holotype 1: 1.76: 1.25: 2.16 (Figs 3 B, D, 35 B). Ant IV annulated, with apically bilobed apical bulb retractile and blunt sens (Fig. 36 A). Ant III apical organ with two rod-like sens, 3 guard sens, and several blunt sens of different sizes (Fig. 36 B). Ant I ‒ II enlarged (Figs 35 A ‒ B). Clypeal formula with 4 (l 1 ‒ 2), 3 (f), 9 (pf 0 ‒ 2) ciliate chaetae, l 1 acuminate, l 2 largest, and 2 prefrontal smaller (Fig. 36 C). Four labral papillae large and rounded (Fig. 36 D). Maxillary palp with smooth apical appendage (a. a.) and basal chaeta (b. c.) weakly ciliated, thicker and 0.88 smaller than apical. Eyes A and B larger, G and H smaller, with 3 ‒ 4 interocular chaetae (v, p, r, t), r eventually absent; head dorsal chaetotaxy (Fig. 36 E) with 10 ‒ 12 ‘ An’ mac (An 1, An 2 ‒ 3), 4 ‘ A’ mac (A 0, A 2 ‒ 3, A 5), 4 ‘ M’ mac (M 1 ‒ 2, M 4 i ‒ 4), 8 ‘ S’ mac (S 0 ‒ 6), 1 ‘ Ps’ mac (Ps 2), 5 ‘ Pa’ mac (Pa 1 ‒ 5), 2 ‘ Pm’ mac (Pm 1, Pm 3), 4 ‘ Pp’ mac (Pp 1 ‒ 3, Pp 5), and 4 ‘ Pe’ mac (Pe 2 ‒ 4 plus Pe 3 p). Basomedian and basolateral labial fields with M 1 ‒ 2, R (smaller), E, L 1 ‒ 2. Postlabial ventral chaetotaxy with about 18 ciliate chaetae, postlabial formula 4 (G 1 ‒ 4), 3 (H 2 ‒ 4), 4 (J 1 ‒ 4), basal chaeta (b. c.) largest (Fig. 36 F). Thorax chaetotaxy (Figs 37 A ‒ B). Th II, series ‘ a’ with 4 ‒ 5 mac (a 5 ip ‒ 5 p and one unnamed rarely present); series ‘ m’ with 11 ‒ 14 mac (m 1 ‒ 2 complex, m 4 i ‒ 4 p), 4 mac present or absent; series ‘ p’ with 20 ‒ 24 mac (p 1 ip 4 ‒ 1 p 4 p, p 2 a ‒ 2 ep 2, p 3 i 2 ‒ 3 p, p 5), p 1 ip 4 and p 3 i as mac or mic, p 1 p 5 and p 1 p 4 p eventually absent. Th III, series ‘ a’ with 6 ‒ 7 mac (a 1 i ‒ 6), a 2 rarely absent; series ‘ m’ with 1 ‒ 2 mac (m 1, m 6), m 1 generally as mic; series ‘ p’ with 10 ‒ 12 mac (p 1 ip ‒ 1 p, p 2 a 2 ‒ 2 ea, p 3, p 5 ‒ 6), p 1 ip and p 2 ea mac rarely absent; 2 extra central and 10 lateral psp present. Th ratio as II: III = 1: 0.53 ‒ 0.59 (n = 4), holotype 1: 0.59. Abdomen chaetotaxy (Figs 35 E, 37 C ‒ E, 38 A ‒ B). Abd I, series ‘ a’ with 4 mac (a 1 i ‒ 3); series ‘ m’ with 4 ‒ 5 mac (m 2 i ‒ 4), m 4 i rarely absent, and 11 lateral psp present. Abd II, series ‘ a’ with 2 mac (a 2 – 3); series ‘ m’ with 4 mac (m 3 ‒ 3 e, m 5), and 3 lateral psp present. Abd III, series ‘ m’ with 3 mac (m 3, am 6, pm 6); series ‘ p’ with 1 mac (p 6), and 12 lateral psp. Abd IV with 17 ‒ 18 central mac of series ‘ A’ to ‘ T’ (A 3 a ‒ 6, Ae 7, B 1 ‒ 6, C 1, C 4, T 1 and one unnamed present or absent), and 22 lateral mac of series ‘ E’ to ‘ Fe’ (E 2 ‒ 4 p, Ee 7, Ee 10, F 1 ‒ 3, Fe 2 ‒ 5 and five of uncertain homology); at least 4 sens (as? and ps type I and 2 type II), and posteriorly with 7 mes present. Abd V, series ‘ a’ with 1 mac (a 5); series ‘ m’ with 4 mac (m 2 ‒ 3, m 5 ‒ 5 e); series ‘ p’ with 5 mac (p 1, p 3 ‒ 5, ap 6); one extra sens next to acc. p 4 sens rarely present. Abd ratio as III: IV = 1: 3.9 7 ‒ 5.33 (n = 4), holotype 1: 4.88. Legs. Subcoxa I with 6 chaetae and 2 psp; subcoxa II with an anterior row of 9 chaetae, posterior row with 7 chaetae, 2 posterior chaetae and 8 psp; subcoxa III with one row of 12 chaetae, 5 anterior chaetae in a row and 2 posterior psp (Figs 40 A ‒ C). Trochanter I ‒ II inner side with 9 and 11 spine-like chaetae, respectively, surrounded by ciliate chaetae (Figs 39 A ‒ B; 40 D ‒ E). Trochanteral organ with about 64 spine-like chaetae (Fig. 40 F). Tibiotarsi inner side armed by 18 robust mac finely ciliate and apically acuminate, outer side with one basal largest and one acuminate and elongated chaeta (Figs 39 C ‒ E, 40 G). Unguis with basal and median teeth with the same length, apical tooth smaller. Unguiculus with all lamellae acuminate, pe lamella serrated distally and with small proximal tooth, other lamellae (ai, ae, pi) smooth; ratio unguis: unguiculus = 1: 0.52 (Fig. 40 H). Tibiotarsus III distally with inner smooth chaeta 1.11 larger than unguiculus; and outer tenent hair capitate, discretely ciliate, and 0.78 smaller than unguis. Collophore (Fig. 41 A). Anterior side with 14 ciliate chaetae, including 2 distal mac and 3 proximal long acuminate chaetae; posterior side with 20 ciliate chaetae, of which 2 distal thickest; lateral flap with 3 smooth chaetae (one small posteriorly) and about 29 ciliate chaetae. Furcula (Figs 41 B ‒ C). Manubrium ventrally with formula 1, 0, 0, 0 / 4 (subapical), 20 (apical) ciliate chaetae and approximately 23 elongated apical scales per side; manubrium dorsally with 6 subapical ciliate chaetae; manubrial plate with 8 ‒ 9 ciliate chaetae and 3 psp.

Diagnosis. Body black with legs yellowish (Figs 3 B, D); Ant I ‒ II enlarged and with scales spiral-shaped (Figs 35 A ‒ D); head mac M 4 i, S 4 and Pa 4 present, Pp 6 absent, eyepatches with 3 ‒ 4 interocular chaetae (q absent, r eventually absent) (Fig. 36 E); prelabral inner chaetae smooth (Fig. 36 C); labral papillae large and rounded (Fig. 36 D); Th II with 7 ‒ 11 medio-central mac (m 1 ‒ 2 complex) and PmA ‒ PmC groups with 9 ‒ 12, 3, 7 ‒ 8 mac, respectively (Fig. 37 A); Th III ‒ Abd III with 13 ‒ 17, 8 ‒ 9, 5 and 1 central mac, respectively, plus several psp laterally on these segments (Figs 37 B ‒ E); Abd IV with 17 ‒ 18 central and 22 lateral mac (Fig. 38 A); tibiotarsi with about 18 robust inner mac finely ciliate and apically acuminate (Figs 39 C ‒ E, 40 G); unguis apical tooth present (Fig. 40 H); unguiculus outer edge discretely serrated distally and with one small proximal tooth (Fig. 40 H); manubrium ventrally with 0 / 4 subapical and 20 apical chaetae (Fig. 41 B).

Remarks. In general, S. burgersi sp. nov. is similar to S. pallidipes by body black with legs yellowish and overall dorsal macrochaetotaxy, head with mac M 4 i, S 4 and Pa 4, and Abd I ‒ III with 9, 5 and 1 central mac respectively. However, S. burgersi sp. nov. differs from this species by Th II with up to 11 medio-central mac (up to 10 in S. pallidipes) and 7 ‒ 8 mac in PmC group (9 in S. pallidipes); Th III with up to 17 central mac (15 in S. pallidipes), and Abd IV with 22 lateral mac (19 in S. pallidipes). Other features that differ S. burgersi sp. nov. from S. pallidipes are prelabral inner chaetae smooth (ciliate in S. pallidipes), collophore with 14 anterior and 20 posterior chaetae (9 and 12 in S. pallidipes), and manubrium with formula 1, 0, 0, 0 / 4 (subapical), 20 (apical) ciliate chaetae (0, 0, 2, 2 / 4, 18 in S. pallidipes). The Ant I ‒ II enlarged with elongated spiral-shaped scales present in S. burgersi sp. nov. (Figs 3 B, D, 35 A ‒ D) is an unprecedented characteristic recorded in the genus (probably autapomorphic), as well as in Entomobryoidea, since somehow similar characteristics were observed only in some species of Dicranocentroides Imms (1912) (Paronellidae) (Kim et al. 1999; Hazra & Mandal 2015). Species like S. meyerae (Coates, 1969) comb. nov., S. pectinifera Jacquemart, 1980 (in 1980 b) and S. timiae Jacquemart, 1980 (in 1980 c) also have modified scales in antennae and dorsal macrochaetotaxy smilar to S. burgersi sp. nov., and for that reason these species are closely related. However, in these species (except S. burgersi sp. nov.) the antennal scales have different morphologies (non-spiral) and are associated with modified chaetae (branched in S. pectinifera and spine-like in S. meyerae comb. nov. and S. timiae), plus the dorsal macrochaetotaxy is clearly less dense when compared to the new species. Seira burgersi sp. nov. also differs from these species by another exclusive characteristic, the presence of numerous lateral psp on Th II ‒ Abd III (Figs 37 B ‒ E). Other comparisons among species are presented in Tables 1 and 2.

Etymology. The species was named after André Burgers, who collected the specimens.

Type material. Holotype female on slide (EHL 0004 / MNCN): Spain, Huelva province, Minas de Riotinto municipality (37 ° 39 ' 11 '' N, 06 ° 37 ' 10 '' W), under stones, 445 m, 18. iii. 2014, A. Burgers coll. Paratypes on slides (MNCN), 2 females, same data as holotype. Paratypes on slides (INPA): 3 females and 3 specimens in alcohol: El Campillo (37 ° 40 ' 57.08 '' N, 6 ° 36 ' 25.99 '' W), under stones, 358 m, 19.04.2017, A. Burgers leg.