Aphilodon rectitibia new species

(Figs 7–8)

Types. Holotype: ♀, from Parque Nacional de Itatiaia, Itatiaia, Rio de Janeiro, Brazil, 03–17/12/2017, V. Calvanese & A. Silva leg., deposited in IBSP 6467 . Paratypes: 2♀ (IBSP 6468), same data as holotype and 1♂ (IBSP 6469), Parque Nacional da Serra do Cipó, Santana do Riacho, Minas Gerais, Brazil, 01–11/09/2018, V. Calvanese & A. Silva leg.

Other material examined. BRAZIL. Rio de Janeiro: Itatiaia, 14/11/1945, O. Schubart leg., 1♂, 1♀ (MZSP 3061) . São Paulo: Eldorado (24º31’12”S, 48º06’29”W), 09/2015, 1♀ (MZSP 3437); Salesópolis, 09–10/07/1992, 1♂ (MZSP 0739); 09–10/07/1992, 1♂, 1♀ (IBSP 4081); Estação Biológica de Boracéia (23°37’51”S, 45°52’11”W), 26/11/1968, Rabelo leg., 1♂ (MZSP 921) .

Etymology. The epithet rectitibia refers to the straight shape of the forcipular tibia, from the Latin tibia (structure) + rectus (straight).

Diagnosis. Aphilodon rectitibia n. sp. resembles A. micronyx and A. foraminis n. sp. by having a cephalic plate wider than long and with a visible transverse suture (Fig. 8B), but differ from them by having the forcipular tibia straighter, parallel to the basis of tarsungulum (Figs 7B–C, 8C). Also, Aphilodon rectitibia n. sp. differ from A. micronyx by the tarsungulum that is longer than the trochanteroprefemur+femur (Figs 7B–C, 8C) (longer in A. micronyx). From A. foraminis n. sp., Aphilodon rectitibia n. sp. also differ by having 51–55 leg-bearing segments (Fig. 8A) (39–43 in A. foraminis n. sp.), coxosternite of the second maxillae distinctly shortened in the middle part (Fig. 7A) (not distinctly shorter in the middle part in A. foraminis n. sp.), 20–35 coxal pores (Figs 7D, 8G) (5–8 in A. foraminis n. sp.), denticles of tarsungulum evident (Fig. 7B–C) (not evident in A. foraminis n. sp.), and tarsus of ultimate legs with a terminal foraminal process small (large in A. foraminis n. sp.).

Description of holotype. Female (IBSP 6467).

General aspect: 53 leg-bearing segments; body 27 long, maximum width (middle part of trunk) 1. Color (preserved specimen in alcohol): head and forcipular segment ferruginous, leg-bearing segments and post-pedal segments dark yellow (Fig. 8A–G).

Cephalic plate: wider than long, 0.8 long, 0.9 wide (length/width ratio 0.9), with evident transverse suture, with scattered setae (Fig. 8B).

Antennae: left antenna 2.2 long (2.75 times as long as cephalic plate); length/width ratio of articles II–XIII 0.4–0.8; length/width ratio of last article 2.1. Last article with ca. 30 claviform specialized setae on the external margin and ca. 22 on the internal margin. Morphology and chaetotaxy as in Fig. 8B–C.

Clypeus: 4+4 lateral setae; 2+2 post-antennal setae; 10+11 subclypeal setae.

Mandible: pectinate lamellae with ca. 35 denticles.

First maxillae: left telopodite length 0.06, width 0.055; distal article with 2 subapical sensilla; each medial projection of coxosternite with 3 subapical sensilla (Fig. 7A).

Second maxillae: 16 short setae distributed in a row along the anterior margin between the telopodites; coxosternite rectangular, shortened in the middle part (ca. 0.4 times as long as lateral margins), length/width ratio 0.54; left telopodite length 0.11 (1.8 times as long as the telopodite of the first maxillae), maximum width (basal margin) 0.05; each telopodite with one apical sensillum and two subapical setae on article 3 (Fig. 7A).

Forcipular segment: metatergite trapezoidal, length 0.3 (0.35 times as long as cephalic plate) and width 0.9 (length/width ratio 0.3), with short scattered setae; coxosternite length 0.67, width 0.70 (length/width ratio 0.95); telopodite length 0.76, reaching the anterior margin of the cephalic plate, with 2 denticles in the trochanteroprefemur+femur and 1 denticle in the tibia, distal denticle of trochanteroprefemur reduced and denticle corresponding to the vestigial femur and denticle of tibia moderately developed; distal denticle of trochanteroprefemur with 1 short apical seta, denticle corresponding to the vestigial femur bilobed and with 2 apical and 2 subapical setae, denticle of tibia bilobed with 2 apical and 2 subapical setae; tarsungulum 2.15 times as long as trochanteroprefemur+femur, with a reduced denticle (Figs 7B–C, 8B–C).

Tergites from the first to penultimate leg-bearing segment: metatergites rectangular, with scattered setae; in segment 23 metatergite length 0.35, width 1 (length/width ratio 0.3); in segment 23 pretergite 0.3 times as long as previous metatergite, with scattered setae (Fig. 8D).

Walking legs: first leg 0.8 times as long as second leg, procoxae not extended to the midline of the body; leg of segment 40 length 0.9 (Fig. 8A–G).

Sternites from the first to penultimate leg-bearing segment: first metasternite semicircular, other metasternites rectangular or subquadratic, with many scattered setae; in segment 23 metasternite length 0.33, width 0.43 (length/ width ratio 0.75); presternite present throughout the body, in segment 35 presternite 0.14 times as long as previous metasternite, with 10 setae (Fig. 8E).

Ultimate leg-bearing segment: metasternite wider than long, trapezoidal, length 0.23, maximum width 0.26 (length/width ratio 0.9); presternite evident only in the sides of the metasternite (Fig. 8G). Ultimate legs straight, length 1.55 (1.6 as long as penultimate leg); each coxopleuron with ca. 30 scattered coxal pores; tarsus 1.75 times as long as tibia (Fig. 8F–G).

Postpedal segments: gonopods with 3+3 distal setae.

Sexual dimorphism. Males with ultimate legs thickened (Fig. 7D), male gonopods biarticulated, article 1 with 8–10 setae, article 2 with 13–14 scattered setae.

Variation. N= 11, including 6♀ and 5♂ (from four localities): total body length: 20–50 mm. Leg-bearing segments: ♀ 53, 55; ♂ 51, 53, 55. Coxal pores in each coxopleuron: 20–35.

Natural history. The specimens were sampled in the humus or under logs or rocks, at about 1–3 cm deep, in the high forests or in small forest fragments in open areas, in the high and low part of the Parque Nacional de Itatiaia and Parque Nacional da Serra do Cipó.

Distribution. Brazil, states of Minas Gerais, Rio de Janeiro and São Paulo (Fig. 13).