Onespa Steinhauser, 1974

Austin, George T. & Warren, Andrew D., 2009, New looks at and for Onespa, Buzyges, and Librita (Lepidoptera: Hesperiidae: Hesperiinae), with new combinations and descriptions of a new genus and six new species, Insecta Mundi 2009 (89), pp. 1-55 : 2-3

Onespa Steinhauser, 1974

Type species: Onespa nubis Steinhauser, 1974 , by original designation.

Onespa has remained an apparent outlier among hesperiines since its description (along with its sole included species, Onespa nubis Steinhasuser, 1974 ). Steinhauser (1974) offered little on its potential relationships except that it “belongs in the Hesperia sub-group of the Hesperia group (Group M of Evans [1955]) of the sub-family Hesperiinae .” He compared Onespa with several genera having little resemblance in several superficial and genital traits. Steinhauser (1974) correctly noted an overall absence of knowledge of female genitalia among hesperiids in general with the implication that these may be of particular import in resolving relationships among species. As such, Onespa is herein reevaluated indicating it as a polytypic genus with the proposal of a new combination and descriptions of two new species. This first requires a refinement and elaboration of its original description. For this, Steinhauser’s (1974) description of Onespa is reproduced verbatim below with our additions in bold font to augment that description and to encompass the species included within the genus herein.

Description. Palpi quadrate to subquadrate, shaggy, third segment slender, slightly porrect (about mid-way between porrect and erect), hidden in hairs of second segment. Antennae about 1/2 costa (49-53%); club stout, about 1/3 shaft, bent to constricted apiculus beyond thickest part; nudum 5/7 (varies from 11 to 15 segments), subequally divided between club and apiculus (about 4-6 segments on club, 6-9 segments on apiculus) which is about 1.0 to 1.5 times club width; shaft black above, usually not checkered yellow and black above, black and checked with yellow, yellow-orange, or white below; nudum red- brown.

Wings somewhat produced; forewing apex 1.3 - 1.4 times length along vein 2A; hindwing longest at veins 2A and Cu

1

; 3A=Sc+R

1

. No secondary sex characters in male. Hindwing origin Rs nearer to cell end

than base. Forewing origin Cu 2 mid base and origin Cu 1. Sexual dimorphism prominent or minor. Wings brown with yellow-orange or ochreous (male), yellow-orange or ochreous and white (female) maculation.

Mid and hindtibiae smooth (spined on one new species) with long, dense fringes on both tibia and femur; midtibiae with one pair spurs, hindtibiae two pairs; outer spur in each pair 1/2 or less (to about 3/4) length of inner spur.

Male genitalia with gnathos bifid, arms slender and connivent, uncus narrow, slightly bilobed at end, same width as or somewhat narrower than gnathos in dorsal view, slightly longer than gnathos; separation of gnathos and uncus in lateral view shallowly to moderately deep. Tegumen flaring cephalad, ventral arm with dorsal arm of saccus combining into a curved structure, anterior arm of saccus long to very long, narrowing to a pointed cephalic end in ventral view. Valvae remarkably simple and unarticulated, with costa/ampulla relatively straight and undifferentiated between themselves and harpe, ampulla with small dorsal triangular process caudad, harpe with caudal end produced. Aedeagus broad and elongate (1.1-1.7 times length of valva), with complex cornuti consisting of at least one often large pointed spike and a spinulose pad (scouring pad of Burns 1994b), but lacking terminal caudally directed processes (titillators of Burns 1987) common in Poanes and Paratrytone , although lateral triangular keel-like titillators may be present on the right side caudad.

Female genitalia characterized by long (2.5 [2.7-3.6] mm), straight, complexly and heavily striated (=wrinkled) ductus bursae, as long as or longer than corpus bursae. Lamella antevaginalis broad and moderately to deeply indented U-shaped or V-wise; lamella postvaginalis with smooth U-shaped indentation; ostium bursae broad and shallow, twice as broad as deep; cephalic end of ductus bursae wrinkled and expanded with heavily sclerotized nodular pouch-like structure on its left side. Corpus bursae lightly or more prominently striated (=wrinkled) longitudinally cephalad, no signa.

Distribution and richness. As delineated below, the four species included in Onespa are known to occur in northwestern Mexico (Sonora-Sinaloa), the Eje Neovolcanico of south-central Mexico, in cloud forests from the Sierra de Juarez, Oaxaca (southern Mexico) through Chiapas and Guatemala, and in El Salvador and Costa Rica. Onespa occur in montane habitats, from about 1600 m in northwestern Mexico, to about 2400 m in Central America.

Further discussion and diagnosis of the genus is deferred until after the included species are described.