Schacontia rasa Solis & Goldstein

Goldstein, Paul Z., Metz, Mark A. & Solis, M. Alma, 2013, Phylogenetic systematics of Schacontia Dyar with descriptions of eight new species (Lepidoptera, Crambidae), ZooKeys 291, pp. 27-81 : 58-61

Schacontia rasa Solis & Goldstein sp. n. Figs 72752-54

Material examined.

(22♂, 32♀).

Type material.

(3♂, 13♀), USNM. Holotype ♂ (Fig. 7). Mexico: Col. Becker 110514; Mexico: Tam San Fernando, 50 m, 28. vi. 1997, V. O. Becker Col.; USNM genitalia slide "JAL 18" Paratypes (2♂, 13♀, 4 sex undet.). Same data as holotype (2♂, 4 sex undet., 13♀ incl.1 with green USNM genitalia slide label "JAL 19."

Other material examined.

Cuba (3♂, 2♀):Col. Becker 72733, Cuba Gtnmo. Imias, 10 m, 17. vii. 1990, V.O. Becker, USNM ENT 00808543, DNA 2012 (1♂); Col. Becker 72409, Cuba: Holquin Mayari, 400 m, 12.vii.1990, V.O. Becker, USNM ENT 00808544, DNA 2012 (1♀); Santiago, Cuba, Collection Wm Schaus, Genitalia slide by DA ♂ USNM 108,096 (1♂); Col. Becker 73068, Cuba: Stgo. Siboney, 20 m, 23.vii.1990, V.O. Becker, genitalia slide by JAL, 16 (1♂, 1♀). Dominican Republic (15♂, 13♀) [CMNH]: Dominican Republic: Pedernales, 14.5 km N Cabo Rojo, 18-03N, 71-39W, 165 m, 19 July 1990, J. Rawlins, C.W. Young, S.A. Thompson (1♂, 7♀); Dominican Republic: Pedernales, 9.5 km N Cabo Rojo, 18-02N, 71-39W, 35 m, 19 July 1990, J. Rawlins, C.W. Young, S.A. Thompson (5♂, 3♀); Dominican Republic: Pedernales, 14.5 km N Cabo Rojo, 10 m, 17-55N, 71-39W 26-27 September 1991, C. Young, B. Thompson, R. Davidson, J. Rawlins Coastal desert (2♂, 1♀); Dominican Republic: Pedernales, 14.5 km N Cabo Rojo, 18-03N, 71-39W, 165 m, 26-27 September 1991, C. Young, S. Thompson, R. Davidson, J. Rawlins, Arid thornscrub (1♂); Dominican Republic: Pedernales, 1 km W Cabo Rojo, 17-55N, 71-39W, 10 m, 30 July 1990, C.W. Young, J.E. Rawlins, S. Thompson (4♂, 1♀); Dominican Republic: Pedernales, Cabo Rojo, Sea level, 17-55N 71-39W, 21 Oct 1991, J. Rawlins, R. Davidson, C. Young, S. Thompson, Edge of salt marsh (1♂); Dominican Republic: La Altagracia, Parque del Este, Caseta Guaraguao, 4.4 km SE Bayahibe, 18-19-59N, 68-48-42W, 3 m, 26-27 May 2004, C. Young, J. Rawlins, J. Fetzner, C. Nunez, semi-humid forest near sea, limestone, UV light. Sample 51114 (1♀); Dominican Republic: La Altagracia, 2 km N Bayahibe, 10-23N, 68-51W, 10 m, 3 July 1992, C. Young, R. Davidson, S. Thompson, J. Rawlins, Dry seasonal forest on limestone, USNM ENT 00808542, DNA 2012 [GenBank Accession #KC789514] (1♂). British Virgin Islands (1♂, 2♀):Virgin Gorda BVI Prickley Pear Id, Vixen Pt, 14.IV.56, J.F.G. Clarke, 33, Genitalia Slide ♂ by JALUSNM 108,872 (1♂); Col. Becker 66649, British Virgin Is., Guana I., 0-80 m. 9-23 vii 1987, V.O. Becker & S.E. Miller, #20, Genitalia Slide ♀ by JAL (1♀); British Virgin Is.,Virgin Gorda Island, V. Gorda Peak, Ca. 400 m, 17-19 July 1986, S.E. Miller & M.G. Pogue, Black light trap in secondary moist forest, 37, Genitalia slide by JAL ♀ USNM 108,876 (1♀).

Diagnosis

(Figs 7, 52-54). Very similar to Schacontia themis (above), particularly with respect to the male genitalia, but lacking the secondary sexual characters enumerated above and the forewing ground color usually mousegray instead of straw colored. Female hind tibia with a single pair of spurs (medial pair absent - diagnostic within the ysticalis-themis group).

Description.

Male (Fig. 7). Forewing length: 7.0 mm– 8.0 mm. Head - Ocelli present; proboscis normal; frons unmodified; labial palpi porrect, extending beyond clypeus. Thorax - Forewing. Medial area gray, unicolorous with basal area and postmedial areas; antemedial and postmedial lines jagged, darker gray. Hindwing. Postmedial line faint if present; outwardly tinged with bronze. Abdomen - Terga unicolorous with wings and thorax; scales arranged in two terminal black dorsal spots in males. Tympanal organs. (Fig. 27). As for ysticalis-themis group, vide supra. Male genitalia (Figs 52, 53) - Teguminal sulcus short, anterior margin of tegumen appears deeply invaginate, two oblong teguminal lobes joined obliquely; uncus trefoil shaped, outermost tip hastate; lateral edges of uncus swollen, appearing re-enforced; uncus with raised, pronounced medial ridge; juxta robust, V-shaped; valvae complex, intrasaccular flange at latero-ventral edge and sclerotized to form a trigger-shaped process; robust, spine-like setae at base of valva; saccular margin angled close to vinculum, not at saccular mid-point; ventro-marginal setae concentrated at saccular ulna; valva with secondary outer, oblong lobe or process below costa; fleshy setose lobe and recurved/decumbent setal plume associated with terminus of costa. Phallus moderately sclerotized; vesica with two large cornuti. Female genitalia (Fig. 54) - Very similar to Schacontia themis but posterior lobe of corpus bursae more pronounced, superficially rugose; both colliculum and sclerotized channel or sleeve of ductus more elongate than in Schacontia themis .

Immature stages.

Unknown.

Etymology.

The specific epithet refers to the absence of male hind tibial and metatarsal structures and epipleural setal tufts (presumably secondary sexual characters) present in other Schacontia species (Table 1).

Biology.

Unknown. Adults active June (Mexico), July (Cuba), and July, September (Dominican Republic).

Distribution.

Mexico, Cuba, Dominican Republic (essentially, vic. Gulf of Mexico).

Remarks.

Schacontia rasa is evidently the sister species of Schacontia themis . Were it not for the characters associated with the forewing ground color, female hind tibia, and male genitalia and given the homoplastic nature of certain male secondary sexual characters comparable to the system described by Ohno (2000) [see discussion], Schacontia rasa would be a more obvious candidate for conspecificity with Schacontia themis . We have treated anomalous specimens with “chimeric” distributions of male secondary sexual chacters under Schacontia themis (above), and considered only those lacking both tibial hair pencils and abdominal coremata (in addition to genitalic features) to be unambiguously Schacontia rasa , recognizing the need for future molecular work to evaluate the degree to which these character systems are functionally and genetically linked. DNA barcode data (meeting the Barcode Data Standard of Genbank, noted in Benson et al. 2012) are limited to three Dominican Republic specimens and do decisively unite two specimens of Schacontia themis to the exclusion of Schacontia rasa . Not enough specimens are sampled to test the variable sites as diagnostic characters and enable their use in the species’ diagnoses ( Goldstein and DeSalle 2011), but the data corroborate (albeit by a distance measure of>7%) the reliability of the morphological characters as consistent with two distinct species.

It was suggested by V.O. Becker (pers. comm., following the submission of this work) that the name Dichogama fernaldi Möschler, 1890, the type material of which has apparently been lost from MNHU, might refer to this species (see Becker & Miller, in prep., for discussion) and that it should be placed in the now monotypic genus Dichochroma , whose description is, in turn, based on a single female (and only known specimen) of the type species, Dichochroma muralis Forbes, 1944. This attribution of the specimens we consider to fall within Schacontia themis (or Schacontia rasa , below) to Dichochroma fernaldi is, however, not well corroborated by any character identified in the original description by Möschler, but only by process of elimination and the report of its being reared on Capparis by Wolcott (1950-1951: 658, cited in Becker and Miller, in prep.). While eliminating a nomen dubium is desirable and the process of elimination by which such an attribution might be reached intriguing, the recognition of two similar co-occurring species ( Schacontia themis and Schacontia rasa ) described here, corroborated at least indirectly by DNA barcode data, precludes any specific attribution. We therefore retain the description of Schacontia themis and Schacontia rasa as such. Further, notwithstanding the superficial similarity of certain female Schacontia genitalia to those of the only known specimen Dichochroma muralis , both phylogenetic placement described in this work and priority of Schacontia would dictate that Dichochroma be sunk were it determined that these species were congeneric, even if male Dichochroma muralis were discovered and or more compelling character data were brought to bear.

The Schacontia nyx complex: Some of these species are not readily diagnosed by a single character; each, rather, is characterized by either an absence of characters (as in Schacontia atropos ) or by combinations of characters, all of them male, both genitalic and external, the latter presumably secondary sexual features.