Myrmecotypus atratoides, Silva-Junior & Bonaldo, 2024

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), Zootaxa 5555 (4), pp. 451-496 : 488-489

Myrmecotypus atratoides spec. nov.

Fig. 23A–E

Type material. Holotype, ♀, BRAZIL: Amazonas , Manaus, Reserva Ducke, IX.1995, T. Gasnier leg. ( IBSP, IB-14493 ).

Paratypes: EQUADOR: Napo: 20km E. Puerto Napo, Alinahui , 01°00’S, 77°25’W, 150 m, 1♀, XI–XII.1995, E.S. Ross leg. (CASENT-9036802) . COLOMBIA: Meta Restrepo, Vod Tarey , 29.X.1989, A. Arevalo leg. (ICN-Ar- 288) .

Etymology. The specific name derives from the combination of the specific epithet of the ant species Cephalotes atratus and the suffix “-oīdēs” (Latin), referring to the superficial similarity of this species with members of the atratus -clade of this genus of ants.

Note. Unlike all other described species of Myrmecotypus , M. atratoides spec. nov. has a different color and constriction pattern on the carapace, resembling ants from the genus Cephalotes Latreille, 1802 (Tribe Attini ), while, according to Cushing (1997) and Perger & Rubio (2020), several other species of the genus resemble ants from the Tribes Camponotini and Dolichoderini.

Diagnosis. Females of this species resemble those of M. tahyinandu and M. rapaxoides spec. nov. by the presence of recurved transverse ridge with a large marginal sclerotized area but differs from these and all other Myrmecotypus by the wide constriction on the carapace over legs I and II ( Fig. 23B ), whereas the constriction is only over leg II or between I and II in other species.

Description. Female (holotype). Total length 12.76. Carapace 6.91 long, 2.57 wide. Sternum 3.20 long, 1.15 wide.Abdomen 5.09 long, 4.51 wide. Eye diameters:AME 0.20, ALE 0.09, PME 0.09, PLE 0.08. Eye inter-distances: AME-AME 0.12, AME-ALE 0.17, ALE-PLE 0.30, PME-PME 0.41, PME-PLE 0.31, AME-PME 0.26. Carapace dark, cephalic region red, yellow hairs over entire carapace surface ( Fig. 23A ). Endites dark, with promargin white, labium dark, with anterior margin white. Chelicerae brown, two promarginal teeth of different sizes and two retromarginal teeth equal and equidistant. Sternum dark, covered by feathery hairs. Abdomen globose, dark gray, with moderately small, dark dorsal scute ( Fig. 23A, B ). Ventral scute absent and tracheal scute present ( Fig. 23C ). All coxae and femora black. Tibiae I and II brownish; metatarsi yellowish, with proximal area brownish; tarsi brown, with proximal area yellowish; tibiae, metatarsi and tarsi III and IV darker. Leg measurements: I—femur 2.50 / tibia 2.39 / metatarsus 1.76; II—femur 2.65 / tibia 2.35 / metatarsus 1.72; III—femur 2.88 / tibia 1.99 / metatarsus 1.76; IV—femur 4.65 / tibia 3.14 / metatarsus 2.81. Spination: I-femora do 0-1-1-0, rl 0-0-0-1; tibiae ve 2-2-2 (3-3); metatarsi ve 2-2/ II-femora do 0-1-1-0, rl 0-0-0-1; tibiae ve 2-2-2; metatarsi ve 2-2/ III-femora do 1-1-1; pl 1-0-1, rl 1-0-1; tibiae do 0-0-1, pl 0-1-1, rl 0-1-1, ve 2-2; metatarsi pl 1-1-1, rl 1-1-1, ve 2-2-2-/ IV-femora do 1-0-1-1, pl 0-0-0-1, rl 0-0-0-1; tibiae do 0-0-1, pl 1-0-1, rl 1-0-1, ve p 1-0-1; metatarsi pl 1-1-0-1, rl 1-1-0-1, ve 2-2. Copulatory openings under fine sclerotized and continuous ridge, posterior in relation to secondary spermathecae, CD curved at 90-degree angle, STII larger than ST I ( Fig. 23D, E ).

Variation. One of the paratypes (ICN-Ar-288) presents yellowish coloration on the cephalic region as well as on the legs, and pale yellow on the abdomen. Coxa II is yellowish-white with darkened distal margins ( Fig. 23F ).

Other material. Only the types.

Distribution. Known from three localities in Brazil, Ecuador and Colombia ( Fig. 27 ).

Figures

FIGURE 23. Myrmecotypus atratoides spec. nov. A–C, G–H; holotype female (IBSP, IB-14493); D–F, paratype variation forms (ICN-Ar-288). A female, dorsal view; B same, lateral view; C same, ventral view; D female, dorsal view; E same, lateral view; F same, ventral view; G, female epigyne, ventral view; H same, dorsal view.Abbreviations: CO, copulatory opening, CD, copulatory duct; ST II, secondary spermathecae; ST I, primary spermathecae; FD, fertilization duct. Scale: 1 mm.

FIGURE 27. Distribution records of species of Myrmecotypus.