Holotype female on slide. South Africa: Western Cape, Cape Town, Table Mountain National Park, 10/03/2009, native broadleaved forest, sieving of litter and extraction on Berlese funnel, Louis Deharveng and Anne Bedos leg (SAF-141).

8 paratypes on slides (3 males, 4 females, 1 juvenile) and more than 50 in alcohol, same data as holotype — 1 male on slide, ibid, Table Mountain, collapse of New Year cave system, 07/03/2009, native forest, litter, Berlese extraction, Louis Deharveng and Anne Bedos leg (SAF-129) — 1 male and 1 female on slides, ibid, Table Mountain, in a collapse, 10/03/2009, native forest, soil, Berlese extraction, Louis Deharveng and Anne Bedos leg (SAF-139) — 1 male and 1 female on slides, 5 specimens in alcohol, ibid, Table Mountain, Inchuk cave entrance, 10/03/2009, native forest, litter, Berlese extraction, Louis Deharveng and Anne Bedos leg (SAF-144).

Holotype, 6 paratypes on slides (3 males, 3 females) and 25 paratypes in alcohol in IM; 7 paratypes on slides (3 males, 3 females, 1 juv.) and 25 paratypes in alcohol in MNHN.

1 male on slide, 7 specimens in alcohol. South Africa: Western Cape, Stellenbosch, Jonkershoek Nature Reserve, Sosys trail, 12/03/2008, forest litter, Berlese extraction, Louis Deharveng and Anne Bedos leg (SAF-071) — 1 juvenile and 2 females on slides, ibid, Jonkershoek Nature Reserve, Sosys trail, 12/08/2010, litter, Charlene Janion leg (RSA10_JNK026 and RSA10_JNK032, 33°59.758'S, 18°57.156'E) — 1 male, 1 female and 1 juvenile on slides, about 130 in alcohol, ibid, Fish Hoek, Kalk Bay, Echo Valley forest, 05/11/2010, decaying wood of yellowwood, Berlese extraction, Louis Deharveng and Anne Bedos leg (SAF-196).

Length 0.82 – 1.1 mm (males) and 0.75 – 0.85 mm (females). Colour white in alcohol, yellow alive (SAF-196 sample). Eyes 2+2, unpigmented, small (diameter about 1.5–1.8 times that of Ocm socket, Fig. 3A). Habitus similar to Paleonura (Fig. 2A). No cryptopygy. Secondary granules rather large (the size of a mesochaeta socket). Dorsal tubercles visible but poorly delimited except on Abd. V-VI, indicated by secondary granules enlarged and irregularly arranged, without clearly developed tertiary granules. No reticulations. No plurichaetosis. Most ordinary dorsal chaetae are macrochaetae of similar length and morphology, basally swollen, straight, cylindrical, long, thick, covered in their 2/3 distal of numerous minute scales, distally sheathed, rounded apically (Figs 2A, 3A, B, C). Some dorsal mesochaetae shorter, bent, acuminate, smooth or weakly rugose on the lateral area of head, on tubercles L of tergites and on Abd. VI. No dorsal microchaetae. S-chaetae thin, 2/3 as long as or slightly shorter than closest macrochaeta (Figs 2A, 3B).

Ant. I with 7 chaetae, Ant. II with 11 chaetae, Ant. III with 16 or 17 chaetae (chaetae d4 and d5 or only d4 absent). Ant. IV organite as a short thick rod; apical bulb simple, low and fused to Ant. IV tip (Fig. 2B). Buccal cone moderately elongated. Maxilla styliform, mandible thin and bidentate with distal tooth subdivided in 2 or 3 minute cilia. Labrum elongate, rounded apically, with ventral sclerifications arc-like. Labral formula 0/2, 4. Labium with 4 basal, 3 distal and 3 lateral chaetae, and 2 minute sphaerical x papillae (as in Ectonura barrai sp. n., Fig. 5B).

Head chaetotaxy as in Table 1A and Fig. 2A. Head with 6 chaetal groups: CL, 2 (½ Af + Oc), (2 Di, 2 De), 2 (DL, L, So). Central area with B, F, G, Ocm and Ocp. Macrochaeta Ocm internal to ocular line, equally distant to omma or slightly closer to anterior omma; Ocp macrochaeta internal to and at level of posterior omma; Oca absent (Fig. 3A). Posterior area with a very faint tubercle and only 2+2 macrochaetae (Di1 and De1). Five chaetae Vi ventrally on head (Vi5 absent).

Tergite chaetotaxy as in Table 1B and Fig. 2A. Chaeta Di absent on Th. I. Tubercles De and DL separate on Abd. IV. Tubercle L of Abd. IV shift ahead the tubercle line Di-De-DL. Tubercles Di, De and DL fused on Abd. V on each side of axis. Tubercle Di of Abd. V with Di1 macrochaeta, Di2 and Di3 absent. Abd. VI not or hardly bilobed, with strong secondary granules, present even on the axis. S-chaetotaxic formula: 2+ms, 2/11111. Ventral chaetotaxy similar to that of Ectonura barrai sp. n., except the furcal rest in some specimens (Fig. 4C). Secondary sexual characters well developed in the adult male consists of chaetae Ag1 and Ag2 of Abd. V strongly thickened and serrated (Figs 2E, 3F), and chaetae of furcal rest, some Ve of Abd. IV (Fig. 3D), sometimes Ag3 of Abd. V (Fig. 3F), and 3+3 Ve of Abd. VI serrated but less strongly. In a male juvenile from Jonkershoek, chaetae Ag1 were bifid (Fig. 3E).

Microchaetae of furcal rest smaller than secondary granules, often unconspicuous (Fig. 2D). Leg chaetotaxy given in Table 1C. Tita without chaeta M and with chaetae B4-B5 short, not longer than other long chaetae of Tita (Fig. 2C). Claw untoothed, not striated in its basal part, and devoid of secondary granulation.

The species name refers to its reduced chaetotaxy of dorso-internal tubercles of tergites, which bear only one chaeta from Th. II to Abd. IV (2 or 3 in other species of the genus).

All known localities of Ectonura monochaeta sp. n. belong to the Southern Afrotemperate Forest vegetation type. The species is common in this habitat, typically found in the Western Cape, but absent in shrub formations of the fynbos. The distribution ranges from Table Mountain National Park to Jonkershoek Nature Reserve, Stellenbosch. The species is mixed in Stellenbosch with another undescribed species of Ectonura.

The new species Ectonura monochaeta is unique in the genus by the lateral shift of dorso-internal chaetae on Abd. V and their integration in the tubercles (De+DL). Such a lateral shift is only know in Ectonura paralata Deharveng, Weiner & Najt, 1997 from New Caledonia, but less marked and without integration of Di chaetae in (De+DL). By other chaetotaxic characters (Di2 and De2 present on head and on tergites of Th. II-Abd. IV; D, E, OcA present on head) and tubercle arrangement (tubercle Di not developed, others as large flat plates), Ectonura paralata is however only remotely related to our species. Ectonura monochaeta is also distinct from other species of the genus Ectonura by the strong reduction of its chaetotaxy: absence of several chaetae on head (A, O, C, D, E, Oca), absence of Di2, De2 and DL2 on tergites, only 2+2 dorsal chaetae on Th. I, and only 6+6 chaetae on Abd. VI.

The lateral shift of Di on Abd. V is one of the characteristic feature of two genera, the monotypic genus Zelandanura Deharveng & Wise, 1991 from Campbell Island and Pronura Delamare Debouteville, 1953 which is highly diversified in Africa and in Asia. Zelandanura differs from Ectonura by the fusion in one plate of all tubercles of the central area of head, and by the fusion of Di tubercles on the axis on Abd. IV. Contrary to Ectonura, chaetae of the central area of head are not separated in two groups on both side of the axis in Pronura.

Holotype male on slide. South Africa: Western Cape, Grootvadersbosch Nature Reserve, Heidelberg, 24/08/2010, Southern Afrotemperate Forest vegetation, in litter, extraction on Berlese funnel, Charlene Janion leg (RSA10_GVB009, 33°59.167'S, 20°48.639'E).

1 male paratype on slide, same data as holotype — 2 paratypes on slides (1 male, 2 juveniles) and 5 paratypes in alcohol, ibid, Grootvadersbosch Nature Reserve, Heidelberg, 24/08/2010, same habitat, extraction on Berlese funnel, Charlene Janion leg (RSA10_GVB008, 33°58.964'S, 20°48.524'E)

Holotype and 4 paratypes (1 male and 1 juvenile on slides, 2 in alcohol) in IM; 5 paratypes (1 male and 1 juvenile on slides, 3 in alcohol) in MNHN.

Length 1.1–1.3 mm (males). Colour white in alcohol. Eyes 2+2, unpigmented, rather large (diameter about 3 times that of Ocm socket, Fig. 5A). Habitus similar to Paleonura (Fig. 4A). No cryptopygy. Secondary granules rather large (the size of a mesochaeta socket). Dorsal tubercles not clearly delimited, only indicated by secondary granules irregularly arranged, without tertiary granules. No reticulations. No plurichaetosis. Ordinary dorsal chaetae differentiated in macrochaetae, mesochaetae and microchaetae (Figs 4A, 6). Dorsal macrochaetae basally swollen, straight or slightly bent, subcylindrical, long, moderately thick, with minute scales sparsed apparently unilaterally, in their distal half, distally sheathed, rounded apically (Figs 5C, D, 6). Dorsal mesochaetae shorter, acuminate to blunt, smooth or weakly rugose. Dorsal microchaetae thin, smooth, less than 1/5 of macrochaetae, present on all tergites (Di2 from Th. II to Abd. V, De3 on Th. II-III, and De2 on Abd. I-V). S-chaetae thin, smooth, acuminate, 2/3 as long as or slightly shorter than closest macrochaeta (Figs 5C, 6).

Ant. I with 7 chaetae, Ant. II with 11 chaetae, Ant. III with 18 chaetae (chaetae d4 and d5 present). Ant. IV organite as a very short thick rod; apical bulb feebly trilobed, fused to Ant. IV tip (Fig. 4B). Buccal cone moderately elongated. Maxilla styliform, mandible thin and bidentate with distal tooth subdivided in 2 or 3 minute cilia. Labrum elongate, rounded and finely denticulated apically, with ventral sclerifications arc-like distally. Labral formula 0/2, 4. Labium with 4 basal, 3 distal and 3 lateral chaetae, and 2 minute sphaerical x papillae (Fig. 5B).

Head chaetotaxy as in Table 2A and Fig. 4A. Head with 9 chaetal groups: CL, 2 (½ Af + Oc), 2 DL, 2 (L, So), 2 (Di, De) on very faint tubercles hardly separated on axis. Central area with A, B, D, F, G, Oca, Ocm and Ocp (alternatively, Oca might be homologous of chaeta E). Macrochaeta Ocm internal to ocular line, equally distant from omma; Ocp macrochaeta internal to and at level of posterior omma; Oca antero-internal to Ocm (Fig. 5A). Five chaetae Vi ventrally on head (Vi5 absent).

Tergite chaetotaxy as in Table 2B and Figs 4A and 6. Chaeta Di present on Th. I. Tubercles De and DL fused on Abd. IV. Tubercle L of Abd. IV slightly shift ahead the tubercle line Di-De-DL. Tubercles De and DL fused on Abd. V, separated from Di. Tubercle Di of Abd. V with Di1 macrochaeta, Di2 microchaeta and Di3 absent. Abd. VI not or hardly bilobed, with 1+1 areas of slightly enlarged and irregularly arranged secondary granules. S-chaetotaxic formula: 2+ms, 2/11111. No modified chaetae in male (Figs 4E, 5E).

Microchaetae of furcal rest minute and thick, smaller than secondary granules (Fig. 4D). Leg chaetotaxy given in Table 2C, similar to that of Ectonura monochaeta sp. n. (Fig. 2C). Tita without chaeta M and with chaetae B4-B5 short, not longer than other long chaetae of Tita. Claw untoothed, not striated in its basal part, and devoid of secondary granulation.

This species is named in honour of Jean-Auguste Barra, for his important contribution to the knowledge of South African Collembola.

This species was collected in the yellowwood forest leaf litter of Grootvadersbosch Nature Reserve. This is a remnant forest of the larger Tsitsikamma Forest Reserve situated 300 km to the south. The forest consists of indigenous trees such as yellowwood, ironwood and stinkwood.

Ectonura barrai sp. n. is similar to Ectonura natalensis in its relatively complete chaetotaxy, but different in several details of chaetal arrangement. Based on the redescription of Coates (1968), Ectonura natalensis has a more reduced chaetotaxy than Ectonura barrai sp. n.: absence of meso/microchaetae D, Di2 and De2 on head, absence of De2 on Th. I, absence of De3 and DL3 on Th. II-III, absence of Di2 on Abd IV-V. Conversely, chaetae Di2, De2 and DL2 on Abd. I-III of Ectonura natalensis are much larger than homologous chaetae of Ectonura barrai sp. n. (macrochaetae or large mesochaetae versus short mesochaetae). Chaetal groups De and DL of Abd. IV are separate in Ectonura natalensis versus fused in Ectonura barrai sp. n., and chaetal groups Di of Abd. V are fused on axis in Ectonura natalensis versus separate in Ectonura barrai sp. n. The unusual arrangement of S-chaetae on Ant. IV figured by Coates (1968) is probably an erroneous interpretation, and not considered here as a valid differential character.