Arrhopalites mendoncae

Description. Holotype body about 1.02 mm length. Other measurements presented in Table 1. Coloration in ethanol ranged from white to yellow. Antennae (Figs. 1 – 4). About 1.96 × cephalic length. Mean length ratio of antenna segments I: II, III, IV = 1: 1.6, 3.1, 6.8. Ant. I with six normal chaetae on anterior side, and one small microchaeta in apical part on posterior side (Fig. 1). Ant. II with eight apical chaetae, three medial and three basal, one basal internal much longer (~ 3 ×) than other two (Fig. 2). Ant. III apical organ with two sensilla in separate pits, Ai bigger than Ape, Ape short and bristle-like, Aai minute, rod-like and blunt, other chaetae normal. Ant. III mid-dorsal with two chaetae longer than the other in the segment (Fig. 3). Ant. IV subdivided into five ringed sub-segments. Sub-segment formula as 1 + 3 + 1 = (A + M 1, M 2) + (M 3 – M 5) + (B), A apex with a capitate sense rod. Ant. IV with 13 whorls of chaetae: four on apical sub-segments (A + M 1), five on median sub-segments (M 2 – M 5 + BA) and four on basal sub-segments (BM 1 – BM 3 + BB) (Fig. 4). Head (Figs. 5 – 6). Eyes 1 + 1 unpigmented. Posterior cephalic spines interposed between normal chaetae, posterior dorsal chaetotaxy A, B, C, D as 5,3,4,7, inter-antennal region with four α and three β chaetae; frontal cephalic chaetotaxy a to f as 5,8,8,10,12,12 and with six medial chaetae (Fig. 5). Labral chaetotaxy a, m, p, pl with 4,5,5,6 chaetae respectively (Fig. 6). Leg I (Fig. 7). Precoxae and coxa with one chaetae. Trochanter with three anterior and one posterior chaetae. Femur with 12 chaetae, a 4 turned perpendicularly to the longitudinal axis of the segment. Tibiotarsus with 44 chaetae: whorl I with 9, Ja is slightly curved, whorls II – V with 8, region F with three primary FP chaetae (e, ae, pe), secondary FSa absent. Pretarsus with 1 + 1 chaetae. Unguis 5.25 shorter than tibiotarsus, without tunica, with a small inner medial tooth; lateral or posterior tooth absent. Unguiculus sub-apical filament exceeding unguis tip, with clear corner tooth; 2.66 shorter than unguis. Leg II (Fig. 8). Epicoxae with one and precoxae with two chaetae, pre-coxal process absent; coxa with three primary chaetae, i 2 chaetae absent. Trochanter with trochanteral organ (a 1), three anterior and one posterior chaetae. Femur with 13 chaetae; p 1 and p 3 small and thin. Tibiotarsus with 41 chaetae: whorl I with 8, Ja normal and not curved as in leg I, whorls II, IV with 8, whorls III, V with 7 (Vp absent); region F with three primary FP chaetae (e, ae, pe), FSa absent. Unguis 4.48 × shorter than tibiotarsus, small inner medial tooth present, without tunica. Unguiculus 2.37 × shorter than unguis, with small corner tooth; subapical filament exceeds unguis tip. Leg III (Fig. 9). Epicoxae with two and precoxae with three distal chaetae, coxa with three anterior chaetae, one anterior microsensillum and one posterior chaetae. Trochanter with three anterior chaetae, a metatrochanteral organ, and one posterior chaetae. Femur with 12 anterior chaetae and one short chaetae (p 1) on posterior face. Tibiotarsus with 44 chaetae: whorl I with 9, Ja normal and not curved, whorls II – IV with 8, whorl V with 7 (Vp absent); region F with three primary FP chaetae (e, ae, pe), secondary FSa present. Unguis 5.44 × shorter than tibiotarsus, with a weak tunica and one small inner tooth. Unguiculus 2.31 × shorter than unguis, with a corner tooth, subapical filament short, never reaching the tip of the unguis. Lengths ratio of tibiotarsi I: II, III = 1: 0.97, 1.24. Ratio cephalic: tibiotarsus I = 1.54. Ventral tube 1 + 1 apical anterior chaetae. Rami tenaculum tridentate with a basal finger-like appendix, corpus two apical chaetae. Furca (Figs. 10, 11). Manubrium with 4 + 4 distal chaetae. Dens (23 chaetae): anterior side chaetotaxy I (ae, a, ai): II (ae, a): III (ae, a): V (a): B (a) as 3: 2: 2: 1: 1, all chaetae simple; posterior chaetotaxy Ie, I – IVpe, Ip and IIIp, Ii, II – IVpi heavily spiny (Fig. 10). Mucro gutter-like, both lamellae serrated, constricted at the distal third, with a spoon shaped tip (Fig. 11). Dens 1.54 × as long as mucro. Great abdomen (Figs. 12, 13). All chaetae smooth and acuminated; Th and Abd I chaetae short, dorsal posterior abdominal chaetae long normal. Trichobothrial complex: ABC form an obtuse angle near straight angle (= 167 °), AB smaller than BC (AB = 81.7, BC = 90.5, AC = 171,6, all in m) (Fig. 12). Single p chaetae of p – row on Abd I located below the level of trichobothrium B; chaetae b 1 on same line as BC, closer to C; chaetae c 1 and c 2 below the trichobothrium C. Central dorsal complex with three chaetae arranged in triangular form. Posterior complex lateral with 2 + 3, dorsal with dI = 7, dII = 9 and dIII = 5 chaetae. Furca base complex with nine chaetae. Ventral complex with three chaetae (Fig. 13). Small abdomen of female (Figs 13 – 14). Fifth segment with two chaetae and trichobothrium D in row a, two chaetae in row p. Genital field with 3 + 3 chaetae close to anterior margin of genital opening (Fig. 13). Sixth segment with 2 + 1 + 2 cuticular spines on the upper valve, lower valves with 2 + 2 spines. Chaetae ms 1 slightly curved. Chaetae mps 1 – 3, mpi 1 – 3 broad and winged. Lower valves with aai 1, aai 2 chaetae; sub-anal appendage flattened, gutter-like, and apically serrated.

Figs 1 – 14, Table 1 and 2

Diagnosis. Trichobothria ABC form a very obtuse angle and AB

Brito, Roniere A., Lima, Estevam C. A., Zeppelini, Douglas (2019): Three new species of Collembola (Arthropoda: Hexapoda) from Brazil. Zootaxa 4700 (4): 401-430, DOI: 10.11646/zootaxa.4700.4.1