Mesembrinella xanthorrhina ( Bigot, 1887 )

Whitworth, Terry L. & Yusseff-Vanegas, Sohath, 2019, A revision of the genera and species of the Neotropical family Mesembrinellidae (Diptera: Oestroidea), Zootaxa 4659 (1), pp. 1-146 : 107-108

Mesembrinella xanthorrhina ( Bigot, 1887)

( Fig. 469 )

Calliphora xanthorrhina Bigot, 1887: 619 . Lectotype female (OUMNH), examined. Type locality: Mexico.

Mesembrinella xanthorrhina: Guimar „es (1977: 35); Peris & Mariluis (1984: 260); Kosmann et al. (2013: 78); Wolff (2013: 121); Marinho et al. (2017: tab. 1); Velásquez et al. (2017: 109).

Mesembrinella xanthorrhina: Cerretti et al. (2017 : tab. 2).

Diagnosis. A medium-sized fly, the two specimens examined measured 11 mm each. A dark-colored fly, normal color likely bluish with pale tomentum [the specimens examined were faded and discolored]; ppn with 3x 3 setae; subcostal sclerite bare; legs dark reddish brown, apex of femora orange; anterior spiracle yellow-brown, posterior spiracle darker brown; acrostichal setae 2:1; upper calypter with tan disc and dark brown rim with short dark setae; lower calypter with disc darker brown, rim reddish brown with long reddish-brown setae.

Redescription. [Based only on the lectotype female ( Fig. 469 ) and a female paralectotype.] Female. Head. Frons 0.245 (0.240 –0.250 /2) of head width at narrowest. Fronto-orbital and upper 2/3 of parafacial yellow-orange, lower 1/3 of parafacial dull orange; frontal vitta reddish below, black above; gena dull orange; postgena with long golden setae and silvery tomentum over dark vestiture; occiput with silvery tomentum and weak yellow setae; palpus and antenna typical; eye with median facets about 3x size of lateral facets; frontal setae ending just before ocellar triangle; ocellar triangle small, with ocelli similar in size; supravibrissal setae dark brown, ascending about 1/5 of distance to antennal base.

Thorax. Dorsum and pleura blackish, subshining, with faint presutural stripes; chaetotaxy: ac 2:1, dc 2:3, ia 0, ph 0, ppn 3x 3, kat 2:1, meral setae typical, in an inverted L shape with long black setae, 1 pair converging ap [remaining scutellar chaetotaxy not noted]; subscutellum weakly developed; anterior spiracle yellow-brown, posterior spiracle brown; legs dark reddish-brown, apices of femora orange. Wing hyaline with some darkening at base; section IV 0.20 of section III; disc of upper calypter tan, rim dark with dark setae; disc of lower calypter brown, rim reddish with reddish-brown setae; subcostal sclerite bare; basicosta dark orange, tegula orange.

Abdomen black, T4 subshining with complete row of marginal setae; T5 without posterior row of setae; disc of T5 with irregular stout setae, rest of disc with sparse, fine setae. [Terminalia and sternites were not dissected because of the fragile condition of the specimens.]

Male. Unknown.

Type material examined. LECTOTYPE ♀ ( Mexico; OUMNH; Fig. 469 ), labeled: C. xanthorhina ♀ / So- momyia / Mexique [= Mexico] J. Bigot; Brauer / WIEN. CVIII / (No. 230); Mesembrinella id / syn M. cruciata Townsend / of Aldrich 1922.; CALLIPHORA ♀ / XANTHORHINA Bigot / LECTOTYPE -1974 / J. H. Guimarães det.; LECTO- / TYPE [round label with purple border]; Huascaromusca / xanthorrhina / S.R. Bonatto det. 2001.

PARALECTOTYPE: ♀, Brauer; Wien., CVIII, (No. 230); Calliphora xanthorrhina Bigot , paralectotype 1974, J.H. Guimar„es det.; Huascaromusca xanthorrhina S.R. Bonatto det. 2001 ( OUMNH).

Remarks. Both specimens are in poor condition. They are discolored, faded and covered with hyphae from fungal growth and with many setae missing ( Fig. 469 ). The lectotype has its right wing broken off, but it is with the specimen on a piece of card; the left posterior thoracic spiracle is damaged and several legs are damaged or missing. The paralectotype has a fracture on the dorsum of the thorax from the left lateral side along the transverse suture, but the thorax is still intact.

Remarks. Only two females are known from Bigot’s (1887) type series. Though he listed five syntypes, no other specimens from the type series have been located. Bigot wrote the species name as “xanthorhina” on a label pinned under the lectotype, but he spelled it with two r’s in the text of his paper. Guimar„es (1977) followed this label when he wrote the lectotype label with only one r. Bonatto (2001) added a label to the specimen when he transferred this species to Huascaromusca , writing the name with two r’s. Based on the spelling used in the text of his paper, we have concluded that Bigot intended the species name to be spelled with two r’s and have listed H. xanthorrhina as the correct name.

Guimar„es (1977) placed this species in Mesembrinella and synonymized Mesembrinella spicata with it based on examination of the lectotype and paralectotype. Bonatto & Marinoni (2005) considered this an error, resurrected M. spicata and placed it in a new genus, Henriquella . My examination of the M. xanthorrhina types confirmed their conclusion: they resemble M. spicata but differ in several characters (see key).

The identity of M. xanthorrhina remains a puzzle. Males are unknown and the exact locality of collection of the two remaining type specimens is unknown, the only information being “ Mexique [ Mexico]”. The type specimens are in very fragile condition and it seemed unwise to dissect the terminalia, which might have helped match it with another known species; however, no other female or male specimens with the exact same combination of characters noted for the types have been found. Females of both M. mexicana sp. nov. and M. spicata found in Mexico resemble these specimens, but neither are an exact match for the types of M. xanthorrhina . The most notable difference is that the M. xanthorrhina types have a row of stout discal setae on ST5 placing them in M. aeneiventris species-group, whereas species in the M. spicata group lack discal setae in the male and have only a few irregular discal setae in some females. Marinho et al. (2017) retained M. xanthorrhina in the genus Mesembrinella rather than transferring it to Huascaromusca as Bonatto (2001) suggested, because that recommendation was contained in his dissertation, which is widely available but unpublished. Bonatto (2001) described and illustrated a male of “ xanthorrhina ” from in Peru. However, the specimen he illustrated does not match any known mesembrinellid species and likely belongs to an undescribed species. He did not match any female specimens from Peru to that male. He also listed this species from Colombia, Mexico and Panama. In our opinion, the male of this species is still unknown. No specimens were barcoded.

Distribution. Mexico. Guimar„es (1977) listed it from Panama; Bonatto (2001) also listed it from Colombia and Peru. We consider only the Mexico record as valid and the other records as uncertain, as we believe there has been some confusion about the identity of this species.

Figures

FIGURES 465–469. Lateral habitus and labels of types. 465. Mesembrinella purpurata Aldrich (holotype; USNM). 466. M. semiflava Aldrich (holotype; USNM). 467. M. uniseta Aldrich (holotype; USNM). 468. M. violacea sp. nov. (holotype; INBIO). 469. M. xanthorrhina (Bigot) (lectotype; OUMNH).