Sphecosoma tarsalis (Walker)

Simmons, Rebecca B., 2004, Description of Sphecosoma pattiannae, new species, with comments on its novel male androconia (Lepidoptera: Arctiidae: Arctiinae: Euchromiini), Zootaxa 519, pp. 1-12 : 6-11

Sphecosoma tarsalis (Walker) ( Figs. 1, 3–7)

Glaucopis tarsalis Walker, 1854: 196 .

Glaucopis semihyalina Walker, 1854: 197 .

Pseudosphex vespiformis Herrich­Schäffer, 1850 –1869 [1855]: pl. 74, fig. 425. Pompilopsis tarsalis (Walker) : Hampson, 1898: xii, 161. Sphecosoma tarsalis (Walker) : Simmons & Weller 2004: 69.

Diagnosis. In S. tarsalis , brown wing membrane pigmentation is present on large portions of the fore­ and hindwing, with bright royal blue highlights on the costal and distal portion of the discal cell of the forewing, and apically in the hindwing. Sphecosoma pattiannae possesses the same highlights on the forewing, but lacks them on the hindwing.

Redescription.

Head: Black with some metallic green sheen. Vertex black, rimmed with electric blue. Palpi black dorsally and white ventrally. Antenna bipenctinate, black with metallic green flagellum. Ocelli present with sclerotized rim. Eyes rimmed with white. Proboscis longer than thorax.

Thorax: Prothorax black; patagia black with long white setae. Tegula black. Mesothorax black with metallic green sheen. Scutum black. Legs black, with some scattered white scaling. Metaepisternite without defined striated band.

Wings ( Fig. 3): Hyaline, with brown membrane pigmentation. Forewing costal region, discal cross vein, and portion of hindwing royal blue. Forewing length 18 mm in both male and female (n = 3).

Abdomen: Tympanal hood black with metallic green, dorsal on second segment. Third abdominal segment narrowed, edged in white. Remainder of abdomen black with metallic green sheen.

Abdominal androconia: Dorsal scent pocket present between the seventh and eighth abdominal segments, at base of genital capsule ( Fig. 4 ). Androconium not eversible. Scales within pouch deciduous.

Genitalia. Male ( Figs. 5, 6): Tegumen rounded, bearing fingerlike projections on either side of uncus. Uncus central, setose. Saccus rounded. Valvae unilobed, slightly curved apically. Juxta shieldlike. Aedoeagus: Phallus margin with two spikelike projections. Distal portion of phallus rounded. Vesica membranous, cornuti absent. Female ( Fig. 7): Papillae anales (PA) lightly sclerotized, laterally flattened; anterior apophyses (AA) reduced and thickened; 8th tergum and sternum unmodified; antevagellar plate (AV) unmodified; ostium bursae central; ductus bursae membranous; corpus bursae membranous, signa absent; ductus seminalis arising from accessory bursae; accessory bursa small, arising from ductus bursae.

Early stages: Unknown.

Types: BRAZIL: Pará, 50–45 (BMNH, 1M, holotype of Pompilopsis tarsalis ); Pará, 51–147 (BMNH, 1F, holotype of Pompilopsis semihyalina ).

Additional material examined: BOLIVIA: Buenavista, 750m ( BMNH, 2M); Prov. del Sara, Dep. Sta. Cruz ( BMNH, 1M). BRAZIL: Goiás ( BMNH, 3M); Humayta, Rio Madeira ( BMNH, 1M); Luis Paulo ( NMNH, 1F); Mato Grosso: Cuiabá ( BMNH, 1M); Nivac ( BMNH, 1M); Pará: ( BMNH, 2M); Obidos ( BMNH, 2M; NMNH, 1F); Santa Catharina ( BMNH, 1M); São Paulo, Rio Preto ( BMNH, 1M); Teapa ( BMNH, 1M); Tonantins ( BMNH, 1M); No locality data: ( BMNH, 1M). GUYANA: Georgetown ( FSMC, 1F); No locality data ( BMNH, 1M). FRENCH GUIANA: St. Laurent ( BMNH, 1M; NMNH, 1F); No locality data ( BMNH, 1M). GUATEMALA: Cuyuga ( NMNH, 1M); Teleman, Vera Paz ( BMNH, 1M). SURINAM: No locality data: ( BMNH, 1M). NO COUNRTY DATA: ( NMNH, 1M); ( MNHP, 1F).

FIGURE 8. S.

Phylogenetic placement. Simmons & Weller (2004) place Pompilopsis Hampson as a junior subjective synonym of Sphecosoma Butler because it possesses the six synapomorphies of the latter genus; however, it differs from both Sphecosoma and the Sphecosoma genus group in a number of features. The petiolate waist of S. tarsalis and S. pattiannae is formed by a narrowed third abdominal segment as in the unrelated genus Trichura Hübner (Ctenuchini) (Weller et al. 2000). Within Sphecosoma , the petiolate waist typically is formed by a modified second abdominal segment (Weller et al. 2000). Sphecosoma tarsalis and S. pattiannae have unilobed valves like some Sphecosoma , but the valves differ in shape from those of the latter. The valves of S. cognatum are blunt apically, the valves of S. tarsalis and S. pattiannae taper and curve ( Figs. 5, 8, 10). Male S. cognatum have a ventral, subabdominal pouch between segments 2–4, as described in Weller et al. (2000); however, S. tarsalis and S. pattiannae possess a dorsal pouch of scent scales at the base of the genitalia. Female S. tarsalis have unornamented bursae, while other Sphecosoma have numerous small signa covering a portion or the entire corpus bursae ( Figs. 7 & 11 ). Thus, the taxonomic placement of these two species should be considered tentative; they are in need of further study in the context of larger taxon sampling.

Figures

FIGURE 4. Dorsal view of S. tarsalis / S. pattiannae male abdomen (arrow = location of scent pocket).

FIGURE 11. S. cognatum, female genitalia (cb = corpus bursae), ventral view.