Idiops dilatatus, Gomes & Santos & Almeida, 2024

Gomes, João Pedro Costa, Santos, Naila Amanda Sousa dos & Almeida, Marlus Queiroz, 2024, Idiopidae in the Brazilian Amazon: Description of a new species, characterization of an unknown male and expansion of geographic records, EntomoBrasilis (e 1076) 17, pp. 1076-1076 : 2

Idiops dilatatus sp. nov.

Figures 1-2 , 6 urn:lsid:zoobank.org:act:8113C827-DC77-4A3D-9ED0-ED333B5AEBD5

Etymology: the specific name refers to the femur of the third leg that has a dilation in the basal part.

Diagnosis: Females of Idiops dilatatus sp. nov. can be distinguished from other species within the genus by the following sets of characters: Presence of bristles on the ocular tubercle ( Figure 1A, C ); internal dilation of the femur (fe) on the third pair of legs ( Figure 2A ); inferior tarsal claw (ITC) and superior tarsal claw (STC) each with basal teeth on either side ( Figure 2B ); Base of the spermatheca little sclerotized, receptacles with a rounded shape, short ducts and almost as wide as the receptacles, are oppositely curved ( Figure 2C ).

Unknown males.

Holotype ♀ ( INPA-ARA9162 ) Brazil, Amazonas, Manaus, Adolpho Ducke Reserve, 26.VII.1991, H. HÖfer & T. Gasnier

Col.

Description ♀ (INPA-ARA9162) - Carapace and legs light brown, sternum yellowish, abdomen grayish with a small portion on the dorsal region depigmented ( Figure 1 ). Total size 17.6; carapace 7.6 in length and 6.7 in width; procurved fovea; cephalic region with two rows of two spines; arrangement of ocular setae [disposition of ocular arrangement in Figure 1 ; AME with an unpaired and robust bristle, and PME with a pair of small bristles between them; eye sizes: AME 0.2, ALE 0.4, PME 0.2, PLE 0.2; sternum with a length of 2.3 and a width of 1.9, sigilla faintly visible; trapezoidal labium with a rounded upper part and five cusps, three larger subapical and two smaller median; maxillae with 86 cusps distributed sparsely throughout the region, with a small concentration in the anterior prolateral lobe; rastellum present with 16-18 closely grouped spines, all of similar size; cheliceral groove with seven teeth on both sides, presence of four basal denticles; measurements of palp and legs in Table 1; spines: Palp Fe v0- 0-3, Pa v0-1, Ti p2-12-7, r3-12-9, Ta p4-15-7, r5-13-6. I Fe 0, Pa 0, Ti p2-13-6, r3-14-7, Mt p5-10-7, r5-11-3, Ta v0-0-4, p2- 4-3, r4-7-0. II Fe 0, Pa 0, Ti p2-5-4, r0-0-1, Mt p7-8-6, r2-5-4, Ta v0-3, p3-4-4, r2-3-2. III Fe 0, Pa d0-0-3, p3-5-9, Ti p2-2-4, r1-1-4, Mt v0-0-2, d1-9-3, p3-3-2, r3-1-1, Ta v0-5, p0-1. IV Fe 0, Pa d10-6-0, Ti v0-2-2, Mt v0-0-1, p0-2-3, tA v0-1; femur of leg III internally dilated as in Figure 2A ; tarsal claws with basal teeth and presence of inferior tarsal claw (ITC) ( Figure 2B ); short spermatheca with rounded lobes, base almost as wide as the apex ( Figure 2C ).

I II III IV Palp

Femur 1.4 1.4 1.2 0.9 1.3 Patella 0.8 0.7 0.7 0.6 0.8 Tibia 0.9 0.8 0.6 0.7 0.8 Metatarsus 0.5 0.6 0.6 0.6 -

Tarsus 0.3 0.4 0.5 0.4 0.7 Total 3.9 3.9 3.6 3.2 3.6

Figures

Figure 1. (A-F)♀ Idiops dilatatussp. nov. (INPA-ARA9162),A:Cephalothorax.B: Sternum and thighs, ventral view.C: Eye and bristle arrangement, dorsal view. D: Abdomen, dorsal view. E: Labium, chelicerae and palp in ventral view. F: Spinnerets, ventral view. Scale bar A-B: 2mm; C-F: 1mm.

Figure 2. (A-C) ♀ Idiops dilatatus sp. nov. (INPA-ARA9162), A: Left leg III, retrolateral view, fe indicates internally dilated femur III. B: Distal tarsus and tarsal claws of leg II (prolateral), arrows indicate respectively lower tarsal claw (ITC) and upper tarsal claw (STG). C: Spermatheca, ventral and dorsal views, respectively. Scale bar: 1mm.

Figure 6. New record of Idiops petiti (Guérin, 1838) and the respective localities of Idiops dilatatus sp. nov. (white circle) and Neocteniza coylei (Goloboff & Platnick, 1992) (blue circle).