Argentinomyia huitepecensis Montoya sp. nov. Figures 4, 5, 16

Differential diagnosis.

Second tergum with a broad macula reaching apical 1/2. Third tergum with a short rounded basal fascia. Metacoxa black pilose. Argentinomyia huitepecensis sp. nov. is similar to A. puntarena sp. nov., but differs from it by having the antenna oval, longer than wide, orange ventrally; alula and costal cell bare; pro- and mesofemur yellow; metafemur orange on basal 1/5 and apical 3/5; pro, meso- and metabasitarsomere I-II yellow. Argentinomyia huitepecensis sp. nov. is also similar to A. talamanca sp. nov. a species with the antenna brown; alula and costal cell extensively microtrichose; femur extensively brown; the second tergum with a pair of small maculae on basal 1/5 (see 'diagnostic features’ under each species or key).

Type locality.

México, department of Chiapas, San Cristóbal municipality, L.C. Huitepec 16°41.252'N, 92°35.979'E, 2520 m a.s.l.

Description.

Male. Head (Fig. 4A, C). Black, covered with white pollinosity, oral tips, ocellar triangle, and a large triangular macula on the front, brown pilose, pile on front black, on gena and face white pilose, on ocellar triangle black pilose, on the occiput white except the dorsal pile, which are black, frontal triangle golden metallic. Antennae brown, orange-red ventrally, oval, longer than wide pedicel and the lower basal corner of basoflagellomere, long, ratio 1.0:1.2:3.0, arista orange, dark brown toward the tip. Thorax (Fig. 4C). Black, the scutum opaque, shining, with iridescent to opaque reflections, with two median brownish pollinose vittae on anterior half. Wing (Fig. 4C). Slightly smoky, the stigma brown, membrane microtrichose, except for extensive bare areas on basal half (cells, c, sc, r1, dm and bm); tegula black pilose, basicosta yellow pilose, alula bare, calypter whitish, border whitish, fringe yellow, plumula yellow, halter yellow, knob white. Legs (Fig. 4C). Yellow, pro- and mesofemur yellow; metafemur orange on basal 1/5 and apical 3/5; pro- and mesotibia orange with a brown macula on posterior medial edge, metatibia extensively brown, only orange brownish on basal 2/3; metacoxa black pilose; pro, meso- and metabasitarsomere I-II yellow, the pile yellow, black on the metatibia and above on the tarsi. Abdomen (Fig. 4B). Elongate, black, first tergum shining black, second tergum with a pair of broad maculae, reaching apical 1/2, third tergum with a short rounded basomedial fascia. Pile orange on the sides basally, black down the middle and on the apical terga, as well as in the maculae. Male genitalia as Fig. 5.

Female. (Fig. 4D-F). Similar to male except for normal sexual dimorphism. Abdominal maculae on tergum third comparatively shorter than in the male and restricted to the center of the tergum, no reaching the lateral margin, maculae on fourth and fifth tergum absent.

Length (N = 5). Body 12.5-12.8 mm; wing 11.4-11.7 mm.

Etymology.

The specific epithet huitepecensis (noun in the genitive case) is derived from the Mixtec (native language spoken in México) word " Huitztli " which means: thorns, " Tépeltque " means: hill, combined with the Latin suffix - ensis, meaning from a place. The name is given in reference to the Huitepec Ecological Reserve where the species was collected.

Distribution.

Argentinomyia huitepecensis sp. nov. (N = 7) is the northernmost distributed species of the larger Argentinomyia, recorded on the western slope of the Chiapas-Guatemalan Highlands, and inhabiting cloud forest at an elevation between 1800 to 2400 m. a.s.l. The species is exclusively known from the province of Chiapas Highlands (Fig. 16).

Type material.

Holotype. MÉXICO ♂, Chiapas, San Cristobal, L.C. Huitepec. Original label: "Mexico, Chiapas, San Cristóbal, L.C. Huitepec / 16°41.252'N, 92°35.979'E, 2520 m a.s.l., 5.x.2010 / wpt 12, P. Sagot, no 6, collect #4301, ECO-SC-E 4925 ". "HOLOTYPE / Argentinomyia huitepecensis / Montoya 2020" [red, handwritten except the first line]". The holotype is in good condition and deposited at the ECO-SC-E, Chiapas, México . "Identified as Argentinomyia sp. 16 by P. Sagot". Paratypes. MÉXICO • 1 ♂ same data as for holotype (ECO-SC-E) but differs on: 16°41.255'N, 92°35.979'E, 2450 m a.s.l., 20.xi.2009, wpt 30, P. Sagot, no 16, collect #2504 (ECO-SC-E 24471), sp. 16; 1♂, 2450 m a.s.l., 13.i.2010, wpt 25, P. Sagot, no 8, collect # 2950. 1♀, 2400 m a.s.l., 20.xi.2009. wpt 30, no 16, collect #2504 (ECO-SC-E 24472); 1♂, 12.x.2010, wpt 13, P. Sagot, no 48, collect #2504 (ECO-SC-E 24471), sp. 16; 1♂, 2560 m a.s.l., 12.x.2010, wpt 13, P. Sagot, no 48, collect #4413 (ECO-SC-E), sp. 16; 1♂, 2310 m a.s.l., 4.i.2011, wpt 34, P. Sagot, collect #4925 (ECO-SC-E), sp. 10; 1♀, 2390 m a.s.l., 31.x.2010, wpt 9, P. Sagot, no 6, collect # 4539 (ECO-SC-E) sp. 10.