Tethina xanthopoda (Williston)

Mathis, Wayne N. & Marinoni, Luciane, 2012, A conspectus on the Canacidae (Diptera) of Brazil, ZooKeys 162, pp. 59-92 : 81-82

Tethina xanthopoda (Williston) Figs 18-20

Anthomyza xanthopoda Williston 1896: 445 [West Indies. St. Vincent; LT ♂ (designated by Foster and Mathis 1998: 620); BMNH]. Czerny 1902: 256 [citation, placement in Rhicnoessa ].

Tethina xanthopoda . Foster 1976b: 3 [generic combination, Neotropical catalog]. Woodley and Hilburn 1994: 54 [citation, Bermuda]. Mathis and Munari 1996: 19 [world catalog]. Foster and Mathis 1998: 620-624 [revision, Caribbean and Gulf of Mexico, lectotype designation, figs. of head and ♂ terminalia]. Munari and Mathis 2010: 66 [world catalog].

Rhicnoessa xanthopoda . Czerny 1902: 256 [generic combination]. Melander 1913: 298 [key]; 1952: 202 209 [key, citation]. Hendel 1934: 51 [citation].

Rhicnoessa seriata Melander 1952: 206 [United States. Florida. Dade: Miami; LT ♂ (designated by Foster and Mathis 1998: 620), USNM]. Foster and Mathis 1998: 620 [synonymy, lectotype designation].

Tethina seriata . Vockeroth 1965: 728 [generic combination, Nearctic catalog]. Mathis and Munari 1996: 18 [world catalog].

Tethina brasiliensis Prado and Tavares 1966: 435 [Brazil. Rio de Janeiro: Ilha do Governador ( Galeão); HT ♂, FIOC (13358); figs. of ♂ and ♀ terminalia]. Foster 1976b: 2 [Neotropical catalog]. Artigas et al. 1992: 127-129 [figs. of puparium]. Mathis and Munari 1996: 15 [world catalog]. Foster and Mathis 1998: 620 [synonymy].

Diagnosis.

This species is distinguished from congeners by the following combination of characters: Body length 1.70-3.10 mm; body with gray microtomentum; setae generally black. Head (Fig. 18): Gena short, less than 0.5 eye height. Thorax: 4 somewhat irregular rows of acrostichal setulae; apex of scutellum with yellowish to reddish spot (sometimes variable in size but always obvious); femora yellow; hindfemora of male similar to or only slightly more swollen than fore- and midfemora; tibiae and basal 4 tarsomeres yellow, apical tarsomere brown. Abdomen: Male terminalia (Figs 19-20): surstylus articulated with and broadly attached to epandrium, broadly spatulate in posterior view, length less than twice width, median margin bearing dense patch of robust setulae along entire length, apex broadly rounded; surstylus in lateral view broadly developed, lateral margin only slightly narrowed posteriorly, apex broadly rounded, lateral surface mostly bare, basal portion only slightly produced anteriorly, bearing moderately dense patch of setulae; aedeagus narrow, ribbonlike.

Specimens examined from Brazil.

RIO DE JANEIRO. Ilha do Governador (22°47.8'S, 43°14.7'W), Nov 1963, H. Souza Lopes (1♂; MZUSP).

SANTA CATARINA. Barra Velha (26°38'S, 48°40.9'W; beach), 29 Apr 2010, D. and W. N. Mathis (12♂; DZUP, USNM).

SÃO PAULO. Ubatuba, Praia do Estaleiro (23°20.5'S, 44°53'W; beach), 30 Mar 2010, D. and W. N. Mathis (3♂; USNM).

Distribution.

Nearctic: Bermuda, Canada (Alberta), United States (Florida). Neotropical:Bahamas, Belize, Brazil (Bahia, Rio de Janeiro, Rio Grande do Norte, Santa Catarina, São Paulo), Guyana, Mexico (Quintana Roo, Yucatan), Panama, Trinidad and Tobago, Turks and Caicos, West Indies (Antigua, Barbados, Barbuda, Cuba, Curaçao, Dominica, Dominican Republic, Grand Cayman, Grenada, Jamaica, St. Lucia, St. Vincent).

Remarks.

This widespread species can easily be distinguished from Tethina cohiba (often collected at the same locality) in having an obvious reddish yellow spot on the apex of the scutellum. Some specimens must be examined with the scutellum oriented to be directly viewed from behind and with good lighting. In most specimens, however, the spot is immediately obvious. Additional external characters include the mostly yellow femora, which are moderately swollen, as in Tethina cohiba .