Aphilodon aiuruocae new species

(Figs 3–4)

Types. Holotype: ♀, from Parque Nacional de Itatiaia, Itatiaia, Rio de Janeiro, Brazil, 03–17/12/2017, V. Calvanese & A. Silva leg., deposited in IBSP 6447 . Paratypes: 2♀ (IBSP 6449) and 3♂ (IBSP 6448), same data as holotype .

Other material examined. 2♀ (IBSP 6450), same data as types .

Etymology. The specific epithet aiuruocae refers to the Aiuruoca river (the genitive form of the Latinized version of the river’s name), that springs in the Serra da Mantiqueira in the Parque Nacional de Itatiaia, the type locality. Aiuruoca, in Tupi language, means “house of parrots”.

Diagnosis. Aphilodon aiuruocae n. sp. resembles A. cangaceiro n. sp. by the presence of coxal pores all grouped along the lateral membranes between the coxopleuron and metasternite (Figs 3B, 4G), but differ from it by having body 7–10 mm long (20–30 mm long in A. cangaceiro n. sp.), 41–43 leg-bearing segments (Fig. 4A) (87–93 in A. cangaceiro n. sp.), and metatergites, pretergites, metasternites and presternites of the walking leg-bearing segments with shape not elongated (Fig. 4D–E) (elongated in A. cangaceiro n. sp.).

Description of holotype. Female (IBSP 6447).

General aspect: 43 leg-bearing segments; body 8 long, maximum width (middle part of trunk) 0.25. Color (preserved specimen in alcohol): head and forcipular segment yellow, leg-bearing segments and post-pedal segments pale yellow (Fig. 4A–G).

Cephalic plate: longer than wide, 0.24 long, 0.2 wide (length/width ratio 1.2), without transverse suture, with setae scattered all over its surface (Fig. 4B).

Antennae: 0.45 long (1.9 times as long as cephalic plate); length/width ratio of articles II–XIII 0.4–0.7; length/ width ratio of last article 2.5. Last article with ca. 12 claviform specialized setae on the external margin and ca. 8 on the internal margin. Morphology and chaetotaxy as in Fig. 4A–B.

Clypeus: 3+3 lateral setae; 2+2 post-antennal setae; 4+4 subclypeal setae.

Mandible: pectinate lamellae with ca. 10 denticles.

First maxillae: left telopodite length 0.034, width 0.024; distal article with 2 subapical sensilla; each medial projection of coxosternite with 4 apical and 1 subapical sensilla.

Second maxillae: 8 little setae distributed in a row along the anterior margin between the telopodites; coxosternite subrectangular, not distinctly shorter in the middle part, length/width ratio 0.6; left telopodite length 0.05 (1.5 times as long as the telopodite of first maxillae), maximum width (basal margin) 0.02; each telopodite with one apical sensillum and two subapical setae on article 3.

Forcipular segment: metatergite subrectangular, slightly wider at the base, length 0.04 (0.16 times as long as cephalic plate), width 0.19 (length/width ratio 0.2), with a row of 10 setae; coxosternite length 0.18, width 0.21 (length/width ratio 0.85); telopodites length 0.14, not reaching the anterior margin of the cephalic plate; trochanteroprefemur+femur with 2 denticles, tibia with 1 denticle, all relatively large; denticle distal of trochanteroprefemur with 1 apical seta, denticle corresponding to the vestigial femur bilobed, with 2 apical setae, denticle of tibia bilobed, with 4 setae; tarsungulum 0.85 times as long as the trochanteroprefemur+femur, with a short denticle (Figs 3A, 4B–C).

Tergites from the first to penultimate leg-bearing segment: metatergites rectangular, with two rows of 6 setae; in segment 18 metatergite length 0.1, width 0.24 (length/width ratio 0.4); in segment 18 pretergite 0.6 times as long as the previous metatergite, with one row of 6 setae (Fig. 4D).

Walking legs: first leg 0.8 times as long as second leg, procoxae extended to the body midline; leg of segment 34 length 0.24 (Figs 3A, 4A–G).

Sternites from the first to penultimate leg-bearing segment: first metasternite oval, other metasternites elongated, with scattered setae; metasternite of segment 27 length 0.12, width 0.11 (length/width ratio 1.1); presternite present throughout body, in segment 27 presternite 0.25 times as long as previous metasternite (Fig. 4E).

Ultimate leg-bearing segment: metasternite wider than long, pentagonal, length 0.11, maximum width 0.14 (length/width ratio 0.8); presternite apparently divided in the middle part (Figs 3B, 4G). Ultimate legs conical, tapering to the anterior part, length 0.56 (2.05 times as long as penultimate leg); each coxopleuron with ca. 8 coxal pores all grouped close to the lateral membranes between the coxopleuron and metasternite; tarsus 2.1 times as long as tibia (Figs 3B, 4F–G).

Postpedal segments: gonopods with 3+3 distal setae (Figs 3B, 4G).

Sexual dimorphism. Male ultimate legs a little thickened, gonopods biarticulated, article 1 with 3–6 setae, article 2 with 6–9 scattered setae.

Variation. N= 8, including 5♀ and 3♂ (from a single locality): total body length: 7–10 mm. Leg-bearing segments: ♀ 41, 43; ♂ 41. Coxal pores in each coxopleuron: 5–10.

Natural history. The specimens were sampled at about 5–10 cm deep, near tree roots, besides streams or in the humid microhabitats of the environment, in high forests, in the low part of the Parque Nacional de Itatiaia.

Distribution. Brazil, state of Rio de Janeiro (Fig. 13).