Arthropeina melanochroma, sp. nov.

(Figs. 6, 38–49, 58, 64, 74–75, 82, 88)

Diagnosis. Body color including the scutum, mostly black (Figs. 82, 88). Postpronotal lobes and notopleural strip whitish yellow, strongly contrasting with scutum color (Fig. 64). Spermathecal capsule biconcave (Figs. 46–47).

Material examined. HOLOTYPE, ♂, ECUADOR, Napo, Res. Ethnica, Waorani, 1 km S. Okone Gare, Camp. Trans. Ent. 00º39’25.7”S 076°27’10.8”W, 261m, Insectidal fogging, terre firme forest, Lot. 964, Transect 4, Station 8, 10.x.1994, T.L. Erwin et al. (USNM). PARATYPES: 1 ♀ (antennae and right wing slide–mounted), BRAZIL, Rondônia, Monte Negro, Reserva Legal/Loteamento, 10º16’35”S 63º20’40”W, 187m, Malaise, 03–15.xii.2011, Amorim, Ament & Riccardi col. (MZUSP). 1 ♀, ECUADOR, Napo, Tiputini, Biodiversity Station, nr Yasuni National Park, 00º37’55”S 076°08’39”W, 220–250m, Insectidal fogging, terre firme forest, Erwin Transect T/2, Lot. 2017, Transect 2, Station 8, 09.ii.1999, T.L. Erwin et al. (USNM). 1 ♀, PERU, Madre de Dios, Avispas, 1-15.x.1962, L. Pena, 400m (CNC).

Description. Male. Length: body, 6.5 mm; wing, 6.0 mm. Head. Vertex reddish yellow, setation yellow. Upper frons yellow to reddish yellow. Antenna with scape brown, whitish yellow distally; pedicel whitish yellow, setation light yellow; flagellomeres l–3 brownish yellow on outer margin, pale ventrally on inner margin; flagellomeres 4–8 dark brown; eighth flagellomere more than three times length of seventh (Fig. 6). Palpus (Fig. 75) whitish yellow, elongate; basal segment cylindrical, sclerotized distally, length 1.8 times its width; apical segment oval, sclerotized basally, length three times its width, twice length of basal segment; pale hairs. Proboscis whitish yellow, at least dark brown on distal half; pale hairs. Thorax (Fig. 64). Black, with postpronotal lobes and notopleural strip whitish yellow, strongly contrasting with the color of scutum. Scutum and scutellum entirely black, except subalar callus and postpronotal lobes; pilosity yellowish. Pleura black except for posterior half of anepisternum whitish. Legs. Mostly whitish yellow, except for coxae, trochanters, fore and mid femora at extreme base and apex, hind femora on basal two thirds and apex, hind femora almost entirely (except at extreme basal) and all tarsomeres, dark brown to black. Wing as in Fig. 74. Halter pale, knob yellow whitish. Abdomen. Whitish yellow, with black transverse bands on segments; black color covering nearly all segments. Male genitalia. (Figs. 38–42) Distal margin of gonocoxite strongly pointed (Fig. 38); inner plate with three projections distally (Fig. 39), medial one narrower and longer than lateral ones. Gonostylus with three projections (Figs. 40–41), distal one clearly longer than others. Ejaculatory apodeme rounded basally (Fig. 38). Distal margin of lateral projections of phallus gradually narrowing towards apex (Figs. 38–39). Cercus wider on distal half (Fig. 42).

Female. Differs from male as follow. Length: body, 7.0 mm; wing 7.0– 7.5 mm. Legs. Fore femora entirely whitish yellow or with extreme base and apex, dark brown to black. Female genitalia (Figs. 43–49). Tergite 8 wide, more or less rectangular, rounded anteriorly. Sternite 8 elongate (Fig. 48), more slender basally than distally; gonapophyses sclerotized, strongly bilobed, gradually tapering towards apex. Tergite 9 wider basally than distally (Fig. 44). Genital fork with anterior arm rounded basally (Figs. 43–45), as wide as posterior arm; membranous lobes of genital fork rounded, wider distally; projection of posterior margin slightly pointed distally; margin between posterior projection with a moderately circular incision medially; genital opening more or less oval, gradually narrowing towards apex, with numerous microtrichia on bursa. Three spermathecae present (Fig. 58), lateral ones with long ducts, strongly sclerotized posteriorly, with distinct circular valve medially; spermathecal capsules biconcave, more sclerotized basally (Figs. 46–47). Tergite 10 limited to two lateral triangular plates in dorsal view. Cercus with first segment compressed, wider basally than distally; segment 1 of cercus about two times length of segment 2.

Etymology. The species name is feminine, and the specific epithet comes from the Greek roots melanos, meaning black, dark, and chroma, color, as a reference to dark body surface of the species.

Geographic distribution. Ecuador, Peru and northern Brazil (State of Rondônia) (Fig. 92).

Comments. This species presents variation on intensity leg as well as areas that in some specimens are dark brown to black. Occasionally, the hind femur may be almost entire black, except for distal whitish annulus, and the mid tibia may have the distal two-thirds dark brown to black, as well as the fore tibia may be brownish apically. In the other hand, the dark color of the hind femur may be restricted to the basal and distal extremes.