Sphaeropthalma arota (Cresson)

Pitts, James P., Wilson, Joseph S., Williams, Kevin A. & Boehme, Nicole F., 2009, Velvet ants (Hymenoptera: Mutillidae) of the Algodones sand dunes of California, USA, Zootaxa 2131, pp. 1-53 : 35-37

Sphaeropthalma arota (Cresson)

Mutilla Arota Cresson, 1875 . Amer. Ent. Soc., Trans. 5: 120. Female. Holotype data: San Diego, California, G.R. Crotch, Type no. 1873 (UMSP).

Mutilla helicaon Fox, 1899 . Amer. Ent. Soc., Trans. 25: 254. Male. Holotype data: Nevada, Type no. 4642 (UMSP). New Synonym.

Photopsis lingulatus Viereck, 1903. Acad. Nat. Sci. Phil., Proc. 54: 737. Male. Holotype data: La Jolla, San Diego Co., California (UMSP). New Synonym.

Sphaeropthalma (Photopsis) carinata Schuster, 1958 . Ent. Amer. 37: 34. Male. Holotype data: Purissima, Baja California (NMNH). New Synonym.

Sphaeropthalma (Photopsis) helicaon coahuilae Schuster, 1958 . Ent. Amer. 37: 34. Male. Holotype lost. New Synonym.

Sphaeropthalma (Photopsis) helicaon diegueno Schuster, 1958 . Ent. Amer. 37: 35. Male. Holotype data: S. Carlos, Arizona, 12–13 May 1918, J. Ch. Bradley (CUIC). New Synonym.

Diagnosis of male. This species is recognized by the tooth on the ventral margin of the mandible having a weak excision and being slightly angulate ( Fig. 102 ), the apical mandibular teeth being at an oblique angle rather than vertical, the clypeus being carinate at base ( Fig. 101 ), but sometimes delicately so or gibbous, the lack of mesosternal processes or a sternal felt line, and the ventral margin of the paramere having dense setae that are directed inward toward the cuspis on the basal 0.5X the parameres free length ( Fig. 100 ).

Diagnosis of female. The female of this species can be recognized by the following combination characters: the mandible has only a weak angulate basal tooth on the ventral margin (e.g., Fig. 40 ), the mesosoma and second tergite of the metasoma are covered in brachyplumose orange setae surrounded by white setae along the margins (Figs. 97, 98), the metasoma is petiolate, and the pygidium is granulate.

Description of female: Coloration and Setal Pattern. Body integument brownish-ferruginous to almost black. Legs and posterior pleural region darker brown. Posterior portion of head, around eyes, clypeus, and antennal scrobe with white plumose setae. Remainder of dorsum of head with silver brachyplumose setae (Fig. 99), sometimes with some orange brachyplumose setae rather than silver located centrally on vertex. Pronotum anteriorly on declivity, pleurae, and vertical portion of propodeum with dense appressed white plumose setae. Dorsum of mesosoma with both erect and appressed brachyplumose orange setae (Fig. 97). Legs with silver brachyplumose setae. T1 with dense appressed as well as longer erect white plumose and brachyplumose setae. T2–T5 and S2–S5 with dense plumose apical fringes (Fig. 98). Disks of metasomal tergites with dense orange setae overlapping plumose fringe medially; part of plumose fringe orange. T2 laterally with only white plumose setae. Sternites with only white brachyplumose setae. Plumose setae with long lateral branches from base to apex.

Head. Head rounded posteriorly, not as wide as mesosoma, densely punctate. Punctures obscured by setae. Eye ovate, distance from posterior mandibular articulation ~ 3X visible length of pedicel. Distance across face in frontal view at genal region slightly wider near eyes than near mandibular base. Clypeus protruding anteriorly, posteromedially produced into distinct triangular tubercle. Antennal scrobe with dorsal carina. Antennal tubercle glabrous. Flagellomere I ~1.5X length of pedicel. Flagellomeres II–III ~1.3–1.5X length of pedicel. Mandible bidentate apically. Dorsal mandibular carina without tooth-like projection at anterior termination of carina. Ventral mandibular margin with slight basal angulation; mandible tapers slightly towards apex. Genal carina absent. Hypostomal carina slightly lamellate medially.

Mesosoma. Mesosoma widest just posterior to pronotal spiracle, as long as or slightly longer than wide. Mesosoma densely confluently punctate on dorsum. Punctures obscured by setae. Propleuron anteriorly, mesopleuron medially running vertically, and propodeal side, except around propodeal spiracle, punctate. Humeral angle dentate. Epaulet prominent. Scutellar scale absent. Mesosternum with low transverse tubercle present medially just anterior to mesocoxa. Metasternum tridentate; middle tooth elongate. Propodeum with distinct dorsal and vertical faces.

Metasoma. Segment 1 distinctly petiolate with segment 2. Punctures obscured by setae. T1 with moderate punctures. T2 with dense moderate punctures anteriorly, almost confluent; posteriorly at least 1 puncture width separates punctures. T2 with felt line, 0.10X length of tergite. T3–5 shagreened. T6 with distinct pygidial area defined laterally by weak carinae; surface weakly granulate. S2 with distinct anteromedian tumid region. S2–5 with punctation similar to tergites.

Length. 5–11 mm.

Material examined. California, Imperial Co., Algodones Dunes : Cahuilla Ranger Sta., 10 km WSW Glamis, 1 male, 22.Sep–15.Nov.2008, E. Dreyfus ( UCDC); Niland-Glamis Rd., 7.4 km NW Glamis, 8 males, 24–28.Mar.2008, Museum Survey Team ( UCDC), 7 males, 3–30.May.2008, S. Heydon and K. Lorenzen ( UCDC).

DNA voucher specimen data. California, Riverside Co., Corn Springs, 10 mi. S Desert Center, 1 male, 29. May.2005, KW07; 1 female, 29. May.2005, K.A. Williams, KW01 ( EMUS).

Distribution. From the Chihuahuan Desert of Texas west to the Sonoran Desert of California and north into the Mojave Desert.

Remarks. Ferguson (1967) first synonymized S. helicaon with Photopsis lingulatus, S. carinata , S. helicaon coahuilae and S. helicaon diegueno . We agree with his synonyms. After careful study of specimens from western Texas, New Mexico, Arizona, California, Nevada, and Baja California, no consistent morphological differences could be found, including genitalic morphology. Specimens, however, do range widely in coloration, sculpturing on the scutellum, and clypeal shape, and this species should be investigated molecularly.

The holotype of S. arota (female) differs from the female associated with the male S. helicaon from the Algodones Sand Dunes. The holotype has long orange brachyplumose setae on the disks of third to the sixth metasomal tergite in addition to short white plumose setae, whereas the female found on the Algodones Sand Dunes only has short white plumose setae. At this time, we believe this only represents intraspecific variation.

Originally, the holotype of Sphaeropthalma (Photopsis) helicaon diegueno was a specimen Schuster had on loan from Cornell University and was labeled “Porter 20; Cornell U., Lot 709, Sub., Arizona; Specimen B 12 F; Holotype Sphaeropthalma helicaon ssp. diegueno Schu.” Schuster discovered that this specimen did not fit his description and he selected a new holotype (label data listed above in synonymy section). This specimen also belonged to Cornell University ( Ferguson, 1967). We have been unable to locate this specimen and believe it is now lost.

Figures

FIGURES 100 – 107. Sphaeropthalma arota, male: 100. genitalia, dorsal view right, ventral left; 101. head, dorsal view; and 102. mandible, lateral view. Photomorphus clandestina, male, 103. genitalia, dorsal view left, ventral right; 104. mandible, lateral view; and 105. mesosternal processes, oblique angle, posterior view. Odontophotopsis bellona, male, 106. mesosternal processes, anterior view; Photomorphus clandestina, male, 107. genitalia, dorsal view left, ventral right.

FIGURES 31 – 46. Lateral view of mandible, 31 – 40 female and 41 – 46 male. 31. O. arcuata; 32. O. inconspicua; 33. O. melicausa; 34. O. obscura; 35. O. parva; 36. O. villosa; 37. Sphaeropthalma blakeii; 38. S. difficilis; 39. S. militaris; 40. S. triangularis; 41. O. ambigua; 42. O. arcuata; 43. O. aufidia; 44. O. melicausa; 45. O. becki; and 46. O. django.