Myrmecotypus dacetonoides Silva-Junior & Bonaldo 2024, comb. nov.
Creators: name: Silva-Junior, Cláudio J.
name: Bonaldo, Alexandre B.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Corinnidae
Myrmecotypus
Myrmecotypus dacetonoides

description: Myrmecotypus dacetonoides (Mello-Leitão, 1948) comb. nov.
Figs 9A–G, 10A –IE, 11A–I, 12A–N
Apochinomma dacetonoides Mello-Leitão, 1948: 182, 23 (holotype, ♀, Forest near Camp I, Upper Curuyuni, BRITISH GUYANA: 13.IV.1933, leg. J.S. Carter, in Natural History Museum, London, NHM 1933.11.27.2, examined)
Myrmecotypus iguazu Rubio & Arbino, 2009: 66, 1–12 (holotype, ♂, ARGENTINA: Iguazu National Park, Misiones Province, in Museu Argentino de Ciências Naturales, Argentina, MACN-Ar 19708; examined by photos) syn. nov.
Note. Other than the fact that no consistent differences were recorded in the genitalic morphology among the examined specimens, the synonymy of Myrmecotypus iguazu with M. dacetonoides comb. nov. is justified by the following lines of evidence. The female holotype of Apochinomma dacetonoides (Fig. 9), as in the female paratypes of M. iguazu syn. nov. (Fig. 11), has two promarginal and two retromarginal teeth (Rubio & Arbino, 2009, fig. 10) and a V-shaped epigynal transverse ridge with sclerotized corners (Fig. 9B; Rubio & Arbino 2009: figs 8, 9). In the original description of M. dacetonoides comb. nov., Mello-Leitão (1948) describes the tibia I ventral spination as 3- 3 (2-2-2). However, this is a lapsus, as that specimen presents a 1p-2-2 (3-2) pattern (Fig. 9G). The tibia I spination of M. iguazu is reported to be 3- 3 in both sexes (Rubio & Arbino 2009). Most males and females here attributed to M. dacetonoides comb. nov. have a tibia I ventral spination 3-2 (Figs 12D–E, I–J), with the exception of a female specimen (MZUSP-7779, from Caraguatatuba, state of São Paulo, southeastern Brazil) that presents a ventral tibial spination with 3-3 spines on the right and 3-2 on the left leg I (Figs 10D–E). Likewise, almost all specimens of M. dacetonoides comb. nov. have translucent-white coxa II, except the female holotype and two additional female specimens (MZUSP-7779 cited above and MNRJ-07601, from Bahia state, northeastern Brazil), in which that coxa is darker, with only the proximal region white (Figs 9E, 10C). The vial MZUSP-7779 also contains a male with translucent-white coxae II and tibia I with 3-2 spines. Since both tibia I spination patterns were observed to occur in the same individual and both coxae II patterns can occur in the same population (with the dark coxae II pattern apparently occurring only in females), these variations are here considered as intraspecific. Therefore, M. iguazu is here considered as a junior synonym of M. dacetonoides comb. nov.. Similar variations in coxal coloration are also observed in M. tahyinandu and M. atratoides spec. nov. Both types of M. dacetonoides comb. nov. and M. iguazu syn. nov. bear rows of robust hairs on the tibiae and metatarsi of leg IV, differing in the density of these hairs, as the former appears to have fewer of these hairs than the latter. Significantly, the male holotype of M. iguazu (MACN-AR-19708) has fewer hairs on leg IV than the female paratype (MACN-AR-19709) (Figs 11B, E). We consider this difference to be an artifact of different preservation conditions of these specimens, since the female specimen MZUSP-7779, with all coxae dark, has the dense hairs on leg IV preserved (Fig. 10A). Regardless the density of these modified hairs, its mere presence on tibia and metatarsus, as well the slight lateral depression of these segments, could prove to be a further diagnostic character for M. dacetonoides comb. nov. The variation observed in both coxae coloration and in the leg spination and hair covering suggests this species as an interesting subject for future phylogeographic studies.
Diagnosis. Males of Myrmecotypus dacetonoides comb. nov. resemble M. pilosus by the coxae II translucent white (Fig. 11C, D), but they differ by the presence of a RTA, sperm duct long, five-folded, embolus short, with proximal area wider than the distal (Figs 11G, H, 12K, L) vs. RTA present, sperm duct short, with one fold, and embolus long, with the proximal area as narrow as the distal (Reiskind 1969: fig. 247); females differ from those of M. pilosus by the V-shaped epigynal transverse ridge, placed medially on the epigynal surface (Figs 11I, 12M), whereas the epigynal transverse ridge is sinuous in M. pilosus (Reiskind 1969: fig. 245).
Description. Male (UFMG-5538). Total length 6.83. Carapace 3.75 long, 1.57 wide. Sternum 1.74 long, 0.83 wide. Abdomen 2.66 long, 1.77 wide. Eye diameters: AME 0.13, ALE 0.07, PME 0.07, PLE 0.08. Eye inter-distances: AME-AME 0.15, AME-ALE 0.04, ALE-PLE 0.18, PME-PME 0.27, PME-PLE 0.18, AME-PME 0.16. Carapace brownish-black, somewhat narrowed in head region, with moderate constriction in cephalic region, anterior margin truncated. Feathery hairs cover carapace. Endites and labium brownish-black, prolateral margin yellowish. Chelicerae brown, two promarginal teeth of different sizes and two retromarginal teeth equal. Sternum brownish-black, shield-shaped and covered in sparse feathery hairs (Fig. 12A–C). Abdomen with dorsal scute brownish-black, covered by feathery and long hairs, ventral scute brownish-black, quadrangular-shaped and tracheal scute brownish-black (Figs 12A–B). Coxae II translucent white, the rest black. Trochanters following pattern of coxae, femora I and II white, with one black ventrolateral longitudinal line and dorsal surface with medial black line tapering distally, patellae, tibiae and metatarsi yellow, with black pro- and retrolateral lines. Tarsus I brown and II yellow. Legs III and IV with femora, tibiae and metatarsi brownish-black, patellae yellow with dorsal surface brownish-black, tarsi yellow. Leg IV with row of robust hairs (Fig. 11B). Leg measurements: I—femur 1.84 / tibia 1.90 / metatarsus 1.44; II—femur 1.71 / tibia 1.63 / metatarsus 1.48; III—femur 1.86 / tibia 1.49 / metatarsus 1.63; IV—femur 3.13 / tibia 2.42 / metatarsus 2.48. Spination: I-femur do 1-0-1-1, pl 0-0-0-1; tibia ve 2-2-2 (3-3); metatarsus ve 2-2/ II-femur do 1-0-1-1, pl 0-1-0-1, rl 0-1-0-1; tibia ve 2-2; metatarsus ve 2-2/ III-femur do 0-0-1-1; pl 0-1-1, rl 0-1-1; tibia do 0-0-1, pl 0-1-1, rl 0-1-1, ve 2-2; metatarsus pl 1-1-0-1, rl 1-1-0-1, ve 2-2-2-1/ IV-femur do 1-0-1-1, pl 0-0-0-1, rl 0-0-0-1; tibia do 0-0-1, pl 1-0-1, rl 1-0-1, ve p 1-0-1; metatarsus pl 1-1-0-1, rl 1-1-0-1, ve 2-2. Tibia with proximal area blunt, with small spiniform RTA. Palp with globose genital bulb drawn into long neck with twisted end, embolus short and sclerotized, wide, tip smooth (Figs 11G, H, 12K, L).
Female (UFMG-320). Total length 8.93. Carapace 4.79 long, 2.00 wide. Sternum 2.22 long, 1.57 wide. Abdomen 3.56 long, 2.86 wide. Eye diameters: AME 0.12, ALE 0.03, PME 0.07, PLE 0.06. Eye inter-distances: AME-AME 0.12, AME-ALE 0.04, ALE-PLE 0.17, PME-PME 0.26, PME-PLE 0.16, AME-PME 0.17. Carapace, as in male. Endites and labium brownish-black. Chelicerae brown, two promarginal teeth of different sizes and two retromarginal teeth equal and equidistant. Sternum brownish-black, shield-shaped, covered in sparse feathery hairs (Fig. 12D–F, 13F–H). Abdomen globose, with moderately small, brownish-black dorsal scute, golden and feathery hairs covering abdomen, as in male (Fig. 11F). Coxae II translucent white. Leg measurements: I—femur 2.40 / tibia 2.36 / metatarsus 1.66; II—femur 2.36 / tibia 2.34 / metatarsus 1.65; III—femur 2.31 / tibia 1.89 / metatarsus 1.82; IV—femur 4.01 / tibia 1.62 / metatarsus 1.68. Spination: I-femur do 1-0-0-1, pl 0-0-0-1; tibia ve 1p-2-2 (3-2); metatarsus ve 2-2/ II-femur do 1-0-1-1, pl 0-1-0-1, rl 0-1-0-1; tibia ve 2-2; metatarsus ve 2-2/ III-femur do 0-0-1-1; pl 0-1-1, rl 0-1-1; tibia do 0-0-1, pl 0-1-1, rl 0-1-1, ve 2-2; metatarsus pl 1-1-0-1, rl 1-1-0-1, ve 2-2-2-1/ IV-femur do 1-0-1-1, pl 0-0-0-1, rl 0-0-0-1; tibia do 0-0-1, pl 1-0-1, rl 1-0-1, ve p 1-0-1; metatarsus pl 1-1-0-1, rl 1-1-0-1, ve 2-2. Epigyne with V-shaped epigynal transverse ridge, copulatory openings small, laterally oriented. Vulva with small globose spermathecae followed by short neck. Copulatory ducts hidden under STII (Figs 11J, 12M, N).
Variation. Rubio & Arbino (2009) documented variation in the refractory pubescence of the carapace and abdomen, which can be gray or golden. In addition, variation in the coxa II coloration of females (dark or completely translucent) is reported here, as well as variation in the ventral spination of tibia I (3-3 or 3-2) in both sexes (Figs 9E, 10C, 11F, 12H).
New records. BRAZIL: Amazonas: Manaus, Lago do José [04°05’43.0’’S, 41°43’51.6’’W], 1♂, 9.VIII.1978, J. Adis leg. (IBSP, IB-17089); Manaus, Estação Experimental de Silvicultura Tropical, 02°37’S, 60°02’’W, 1♀, 11.VIII.1980, P.S. Oliveira leg. (IBSP-151321); Pará: Benevides [03°02’01.0’’S, 59°58’56.1W’ ’], 1♂, 18–22. III, D.R. Santos-Souza leg. (MPEG (ARA)-003136); Gurupi, Rio Gurupi [17°53’41.5’’S, 51°43’41.4’’W], 1♂, V.1963, B. Malkin leg. (MZUSP-3297); Mato Grosso: Chapada dos Guimarães, 1♂, 12.VII. 2011, R.C. Francisco leg. (MCTP-34445); Tocantins: Sandolândia, Margem Direito do Rio Araguaia, 12°15’S, 50°07W, 1♂, 5–13.VII.1997, L.S. Rocha leg. (IBSP, IB-12014); Bahia: Prado, Fazenda Furado, 1♀, 12.IX.1970 (MNRJ-07601); Goiás: Jataí [01°22’27.2’’S, 48°15’45.9’’W], 1♂, 1995, Carrera leg. (MZUSP-4338); Minas Gerais: Presidente de Morais, Fazendo do Sapé, rodovia MG-424, 19°28’06.18’’S, 44°14’29.78’’W, 1♀, 1.XII.2000, E.S.S. Álvares leg. (UFMG-320); São Lourenço [22°07’30.7’’S, 39°45’33.2’’W], 1♀, 14–17.XI.2009, M.A. Ulyssia & F.F. Alberto leg. (IBSP-156967); Lagra Santa [19°32’48.3’’S, 43°58’30.2’’W], 1♂, 26.XI.1960, B. Malkin leg. (MZUSP-7961); São Paulo: Caraguatatuba [23°37′13’’S, 45°24′47’’W], 1♂ 1♀, 29. III.1962, C.D.Z. leg. (MZUSP- 7779); Rio de Janeiro: Itamaraju [17°02’08.9’’S, 39°45’33.2’’W], 1♂, 22.XII.1969, (MNRJ-07600); Rio Grande do Sul: Machadinho, 10 km before Machadinho Dam, 27º29’42’’S, 51°48’57’’W, 1♂, 5.II.2008, M.O. Gonzaga & A.J. Santos leg. (UFMG-5538).
Distribution. South America (Fig. 26)
description: Published as part of Silva-Junior, Cláudio J. & Bonaldo, Alexandre B., 2024, A revision of the South American species of the ant-mimicking spider genus Myrmecotypus O. Pickard-Cambridge, 1894 (Araneae: Corinnidae: Castianeirinae), pp. 451-496 in Zootaxa 5555 (4) on pages 466-472, DOI: 10.11646/zootaxa.5555.4.1, http://zenodo.org/record/14594905