Plesioarida Trujano-Ortega & Garcia-Vazquez,

Trujano-Ortega, Marysol, Garcia-Vazquez, Uri Omar, Callaghan, Curtis J., Avalos-Hernandez, Omar, Luis-Martinez, Moises Armando & Llorente-Bousquets, Jorge Enrique, 2018, Two new genera of metalmark butterflies of North and Central America (Lepidoptera, Riodinidae), ZooKeys 729, pp. 61-85: 66-70

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Plesioarida Trujano-Ortega & Garcia-Vazquez

gen. n.

Plesioarida Trujano-Ortega & Garcia-Vazquez  gen. n. Figs 2, 3, 4, 5, 6

Type species.

Apodemia walkeri  Godman & Salvin, 1886 by present designation.


The species of this new genus can be distinguished from other Riodinidae  by a combination of characters (Table 2). Labial palpi are long, slender, pointed apically and projected forward and upward, the second segment is a little more than twice the length of the third segment, the third segment is barely visible from dorsal view (Fig. 2). Radial veins originate near the end of the discal cell, costal vein runs parallel to Sc+R1; these veins get close but never fuse together. Vein R4 reaches wing margin at the apex (Fig. 3). Prothoracic legs of males are slender and trochanter inserts at the middle of the coxa; tibia is as wide as tarsus and smaller than the length of the femur plus the trochanter. Most of the species present two tarsomeres, the second tarsomere is oval-shaped and the apex pointed, except P. hypoglauca  comb. n. which has three tarsomeres with the last one oval-shaped (Fig. 4). Tegumen of male genitalia is typically oval-shaped, narrow and slightly sclerotized, posterior half is a hyaline area that Hall (1999) named ‘windows’ through which the subescafium can be observed; the uncus is rounded and with setae in the posterior margin. The vinculum is a narrow band not covering the whole margin of the tegumen, is mostly straight and convex toward the saccus, a little hump-shaped in the mid region. Valvae are bifurcated, the dorsal process is conical, elongated, and with a sharp end projected forward and exceeding the posterior margin of the uncus, the ventral process is shorter and blunt with many setae. Aedeagus is long and sigmoid, wider in the anterior edge, slender and pointed on the posterior edge, where it opens dorsally. Cornuti are a series of wide, strongly sclerotized spines that originate from individual bulbs (Fig. 5).


Male. Anterior wing length: 10-15 mm. Head. Ringed antennae with 30 to 32 flagellomeres of the same width, with white scales at the base of each flagellomere. Widen abruptly in the apical 10 flagellomeres to form the antennal club, which is dark and iridescent dorsally. Sometimes white or brown scales are present at the sides, ending in a whitish or yellowish tip, with a nudum from flagellomere 20 to the apex. Labial palpi white with black or brown scales mainly in the third segment. Wings (Figs 3, 6) with four radial veins. Three distinct shapes of anterior wings, rounded toward the apex ( P. palmerii  comb. n.), elongated and triangular ( P. walkeri  comb. n.) and triangular with the external margin curved and the apex slightly sickle-like ( P. hypoglauca  comb. n.). Background color in both wings varies from brown to dark gray. Some species present a series of white spots outlined with black in the anterior margins and a series of submarginal black dots, sometimes with white scales and occasionally with reddish scales toward the base of the anterior and posterior wings. In grayish species spots are black. Legs. Prothoracic legs with dense long scales generally whitish, mid and hind legs with multiple short and dense spines in the interior margin of the tibia and tarsus. Abdomen. Dark in the dorsum with reddish or whitish scales outlining each segment. Ventrally with dense scales varying from whitish as in P. hypoglauca  comb. n. to brown-orange as in P. palmerii  comb. n. Genitalia. Genital capsule small, uncus rounded with a groove of variable depth which gives it a lobulated or straight appearance. Tegumen oval-shaped and sclerotized in the anterior region; with large ‘windows’ that reach the gnathi. Gnathi are slender, sclerotized, slightly twisted ending in an upward hook. Vinculum generally is straight or slightly curved near the tegumen, a little wider near the valve, this swelling is weakly sclerotized and hard to notice, curved before the saccus and anteriorly projected. Dorsal processes of the valve conic and membranous toward the transtilla but strongly sclerotized toward the apex, which is a small upward hook, with setae lengthwise. The ventral process is long and blunt, of variable lengths but always with multiple mostly long setae. Aedeagus is slender toward the distal portion with a pointed tip, widening toward the anterior portion, straight or sinuous. Cornuti are thick sclerotized spines apparently each surging from independent bulbs forming a line.


The name comes from the Greek plesios meaning near or close to and the Latin aridus meaning dry, in reference to the desert and semiarid habitats of most of the species.

Distribution and habitat.

This genus is distributed below 1750 m in the Pacific slope from central Arizona and in the Atlantic slope from the south of Texas to the dry forests of Guanacaste in the northeast of Costa Rica ( DeVries 1997) (Fig. 7). In the USA, it has been collected in arid regions, in xerophilic shrubland of Arizona, California, and New Mexico, with isolated records in the south of Texas in Río Grande Valley ( Warren et al. 2017). In Mexico it can be found in deserts and semiarid regions of Baja California Sur and part of Baja California Norte in the Chihuahuan Desert and in the Mexican Plateau, regions were xerophilic shrubland is dominant. It is also distributed in the deciduous tropical forest of the west of Mexico in the Pacific coast and the Balsas Basin, as well as in the east in the coastal plain of the Gulf of Mexico and the Yucatan Peninsula. Its distribution in deciduous tropical forests extends through Central America to Costa Rica. Finally, P. selvatica  comb. n. and some populations of P. walkeri  comb. n. inhabit the tropical forests in the south of Mexico in Veracruz and Chiapas. De la Maza and De la Maza (2017b) mention that P. selvatica  comb. n. probably is present in Guatemala and Belize.

Natural history.

Larvae of the species of Plesioarida  Trujano-Ortega & García-Vázquez gen. n. are associated with the family Fabaceae  , particularly with species of the genera Prosopis  spp. and Acacia  spp. ( Ferris 1985, Austin 1988, DeVries 1997).