Plega mixteca Ardila, Cancino, Acevedo & Contreras, sp. n.

Figs. 1–3, 13a

Material examined. Type material. Holotype ♂: Mexico: Jalisco, Chamela, 5-VII-1985, R. Ayala [pinned, genitalia dissected] (CNIN).

Paratypes: Oaxaca, Huatulco, Parque Nacional Huatulco, Estación El Sabanal, 15°48’10.7” N, 96°11’39.4” W, 109 m, 31-V-2005, S. Zaragoza, F. Noguera, E. Ramírez, E. González, 1♂ [alcohol] (CNIN); same data but 02-VI- 2005, 1♂ [pinned, genitalia dissected] (CNIN) .

Diagnosis. This new species is included within the P. signata group due to the discoidal basal flagellomeres on the antennae. Plega mixteca sp. n. has 10–13 apical spines on gonocoxite 9, unlike other species of the P. signata group ( P. signata: three, P. duckei: four, P. banksi: seven, P. fumosa: eight). Additionally, the new species may be separated from P. dactylota because its brush-like arrangement of the apical spines of gonocoxite 9. Such structures are elongated, thickened, slightly expanded basally and curved dorsally, with distal half curved laterodorsally, with apical spines of different sizes, subparallel and brush-like arranged. The male ectoproct is trapezoidal in lateral view, ventrally with a thickened sclerotized ovoid lobe with the inner zone arched; the gonarcus has a semicircular window between the differentiated dorsal and ventral parts.

Description. Body length: 12–17 mm. Forewing length: 10.1–15.8 mm. Hind wing length: 7.2–12 mm.

General coloration: pale with brown areas.

Head. Mostly pale with dark areas. An irregular brown pattern from frons to occiput; a bump area between the antennae; frons and vertex covered by pale setae; antenna with a pale scape, brown pedicel, flagellum completely brown; 54 to 57 antennomeres, basal ones wider than long (Fig. 2a); clypeus anterior half pale, posterior half pale brown; labrum pale brown; mandibles dark brown; maxillary and labial palpi brown, paler apically.

Thorax. Pronotum mostly pale brown, with brown suffusions; with three rows of thick uneven setae on transverse outgrowths (Fig. 2a); mesonotum pale with brown areas on sclerites, with stout brown setae; metanotum pale with brown areas and a pale zone on scutum, glabrous; pleural region pale with brown spots.

Legs. Foreleg with coxa brown; trochanter pale brown; fore femur outer side pale, with brown suffusions adjacent to row of minor spines, and amber apically (Fig. 2b), inner side mostly brown, pale basally (Fig. 2b), spines amber with dark apex; fore tibia with dark bands (Fig. 2b). Mid- and hind leg pale brown.

Wings. Forewing hyaline with most of the crossveins brown, amber areas surrounding M fork and posterior wing margin between CuP apex and first CuA branch (Fig. 1); pterostigma brown with pale at middle, longitudinal veins alternate brown and pale; 10–12 costal crossveins posterior to humeral vein; three or four veins arising from rarp1 cell, two or three from rarp2 cell; five or six gradate veins on RP; hind wing hyaline with crossveins brown, wing margin dashed with brown and pale; six costal crossveins, pterostigma brown with a preapical area pale; three or four veins arising from rarp1 cell, one or two from rarp2 cell; four gradate crossveins on RP.

Abdomen. Mostly pale with brown areas; pleural membrane dark.

Male genitalia. Tergite 9 dark brown, dorsally narrower than laterally; ectoproct trapezoidal in lateral view (Fig. 2c), rounded on posteroventral margin, with numerous fine and long setae; ventrally with a thickened ovoid lobe, mostly sclerotized with an arched, concave inner zone (Fig. 2d); sternite 9 pentagonal in ventral view with posterolateral sides rounded (Fig. 2d), trapezoidal in lateral view with a pointed posteroventral process, setose, posteroventrally swollen; mediuncus elongate, slightly expanded basally (Fig. 3a), thickened, subparallel sided, with two median lateral short, blunt, and curved processes (Fig. 3b); pseudopenis thickened at base, long, strongly coiled, forming two loops, apex protruding from the abdomen (Fig. 3a); a pair of hypomeres elongated and thin (Fig. 3c); the base of pseudopennis and distal half of mediuncus protected by a dorsal semimembranous dome (Fig 3a), ventrally connected to hypomeres; gonarcus median lobe with two differentiated parts: dorsal one with apical region bent dorsad (Fig. 3a), narrower medially and expanded laterally, forming a rounded lobe in caudal view; ventral part with a short bulging, and a short ventral curved projection, between these parts a semicircular window is present (Fig. 3b); gonarcus arms elongated, straight, basally slightly curved (Fig. 3a); gonocoxite 9 elongated, thickened with distal half curved laterodorsally (Fig. 3a), slightly expanded basally and curved dorsally, apically with 10–13 spines of different size, subparallel, pectinately arranged (Figs. 3, 13a).

Geographical distribution. Mexico: Jalisco (Estación Biológica Chamela), and Oaxaca (Huatulco, Parque Nacional Huatulco).

Etymology. This species is named after the prehispanic mixtecan culture, that lived in part of the Pacific coast and central Mexico, in the current states of Guerrero, Oaxaca, and Puebla.

Biological notes. This species was found in a tropical dry forest, at 109 m a.s.l. Adults were collected during May and June, which corresponds to the beginning of the rainy season.