Efferia stylata (Fabricius),

Aubrey G. Scarbrough & Daniel E. Perez-Gelabert, 2009, Review of the West Indian species of Efferia Coquillett (Diptera: Asilidae) with 13 new species and checklist: Part II. Hispaniola, Puerto Rico, and Lesser Antilles including Tobago and Trinid, Zootaxa 1994, pp. 1-66: 58-63

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http://doi.org/ 10.5281/zenodo.1455810

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scientific name

Efferia stylata (Fabricius)


Efferia stylata (Fabricius) 

Figs. 122–127View FIGURES 122–127, Table 1

Asilis stylatus Fabricius, 1775: 795  ; Wiedemann 1821: 198; Walker 1855: 630; Wulp 1882: 112; Williston 1891: 87; Aldrich 1905: 227; Kertész 1909: 243.

Erax stylatus, Hine 1919: 127  ; Curran 1931: 9; Bromley 1929: 291; Wolcott 1923–1924.

Erax tortola Curran, 1928: 23  . Holotype ♂, Tortola Island, British Virgin Islands ( AMNH). Syn. nov.

Nerax stylatus, Hull 1962: 479  . Comb. nov.

Efferia stylata, Martin and Papavero 1970: 68  . Catalogue; comb. nov.

Redescription, male. Measurements, body 20.0– 24.4 mm; wing 15.6–20.0 mm. Head: Gray to yellowish-gray tomentose, mostly white or yellowish setose. Face mostly white setose, several black bristles dorsally, sparse ventrally and along epistomal margin laterally. Palpi mostly black setose, sometimes narrow base and ventral 1/2 basally whitish. Antennae mostly to entirely black setose, white setae sparse, sometimes scape dorsally entirely white setose; flagellum and scape light to dark yellowish-brown. Frons mixed black and yellowish setose. Ocellar tubercle black setose. Occiput yellowish-gray tomentose with yellowish setae dorsally, gray with white setae ventrally and 4–6 stout black postocular bristles, sometimes sparse black setae and long thin bristles.

Thorax: Pronotum yellowish tomentose with yellowish setae and 6 yellow bristles. Scutum slightly brownish-yellow anteriorly, yellowish-gray posteriorly; vestiture mostly black, setae widespread, mostly short, longest anteriorly and between dorsocentral rows posteriorly, sparse yellow setae laterally, above wing base and along anterior margin narrowly; anterior scutal setae about as long as scape; dorsocentral bristles thin, longest posteriorly, those just before transverse suture about 1/2 as long as those posteriorly, black setae between dorsocentral rows posteriorly mixed thin and thick. Scutellum brownish-gray to yellowish-gray tomentose, setae longer than scape, longest subequal or as long as marginal bristles, entirely black or mixed white and black setose, black setae often concentrated medially, whitish setae along margins; 5–6 marginal scutellar bristles present, mostly or entirely black, sometimes 2–4 bristles slightly thin. Pleura yellowish-gray tomentose, vestiture mostly yellowish, anepisternum, katepisternum, anepimeron and katatergite slightly brownish tomentose with scattered black setae. Halter yellow.

Wing: Brownish, costal cell dark brown. Costal margin moderately dilated. Cell r4 narrow, base well beyond cell d; R4 recurrent vein short, almost absent, much less than diameter of cell base.

Leg: Coxae, trochanters, and femora black, femora in 1 male from Tortola with brownish streak dorsobasally; setae mostly pale yellowish or white, bristles mostly black. Femora with apical 1/3–1/2 black setose. Mesothoracic femora with 3 or 4 thin posterior bristles medially, sometimes black, usually yellowish. Metathoracic femora with anteroventral bristles usually mostly black, sometimes pale yellow. Tibiae mostly yellow, narrow base and apex blackish, bristles and scattered short setae black, thin, long, yellowish setae; dense golden yellow setae laterally. Tarsi black, bristles and scattered setae black; dense golden yellow setae ventrally.

Abdomen: Sternites 1–7 white tomentose with white setae except those along the apical margin of sternite

7 black. Tergites 1–5 with large light brown to blackish spots dorsally, those basally palest and with long yellowish setae laterally, tergites 4–5 darkest and with short black setae; apical 1/3–1/2 of tergite 5, sometimes entirely, and all of 6–7 white tomentose, with white setae; segment 8 black, black setose, apical margin of sternite 8 with long, black setae.

Terminalia ( Figs. 122–125View FIGURES 122–127): Black, black setose. Epandrium 3 times longer than wide, dorsal process truncate posteriorly. Gonostylus narrow, bladelike apically. Gonocoxa with apex round, not pointed. Aedeagus distinctive.

Female. Measurements, body 14.8–20.0 mm; wing 11.3–15.6 mm. Head: Frons usually mostly or entirely yellow setose. Antennae black setose. Face at antennae 3/4 diameter of 1 eye. Thorax: Anterior scutal setae 1/ 2–2/3 as long as scape; posterior scutal setae about as stout as dorsocentrals. Scutellar vestiture variable, setae entirely yellowish, black, or mixed, as long as scape; 2–6 marginal bristles, 4–5 stout, 1–2 lateral bristles shorter and thinner than median bristles. Pleura mostly yellow setose. Leg: Metathoracic femora usually with black bristles, sometimes anteroventral bristles yellowish. Tibiae with sparse long yellowish setae. Abdomen: Wide sides of tergites 2–6 and sternites 1–6 white tomentose with white setae; tergites 1–7 brown tomentose dorsally, basal 3 tergites light brown tomentose with mostly whitish setae, apical 4 tergites and sternite 7 mostly or entirely black setose. Terminalia ( Figs. 126–127View FIGURES 122–127): Black, longer than segments 5–7, 4.0– 4.8 mm, 10–11 times as long as wide medially. Tergite 9 about twice as long as cercus. Spermathecae oval, longer than wide, mostly brownish.

Specimens examined: BRITISH VIRGIN ISLANDS: Guana Island / 1–14.vii.1984 / S.E. & P. M. Miller (1 ♂, 1 ♀, NMNH); Guana Island, 0– 80 m. / 13–26.vii.1986 / S. E. Miller & M. G. Pogue (2 ♀, NMNH); F5138B / Tortola, V. I. /. 18.iii.1925 (1m #, AMNH); Guana Is. 9.v –9.vi /.2000 W.P. Liao / Malaise trap (1 ♂, 1 ♀, NMNH); Guana Is. 9.vii – / 8.viii.2000 W.P. Liao / Malaise trap (2 ♀, NMNH); Guana Is. 8.viii / – 9.ix.2000 W.P. Liao / Malaise trap (2 ♂, NMNH); Guana I., i.2001 / Malaise trap. Liao (1 ♂, 1 ♀, NMNH); Guana I. viii.2001 / W.P. Liao, Malaise / at quail dove gut (3 ♂, NMNH); Guana I. 1–7.x.2001 / B. & B. Valentine. Quail / dove Malaise trap (1 ♂, NMNH); Guana I., i. / 2002 W.-P. Liao / Quail Dove Malaise (1 ♂, NMNH); Guana I., v.2002 / W.-P. Liao / Quail Dove Malaise (6 ♂, 2 ♀, NMNH); Guana I., 2–10.x./ 2002 R.R. Snelling / e. end White Beach (1 ♂, 1 ♀, NMNH); Guana I., 11–20.x./ 2002 R.R. Snelling / E. end White Beach (1 ♂, NMNH); Guana I., 23–30.x. / 2002 B.&B. Valentine / Sand pit Malaise (1 ♂, NMNH); Guana I., i /.2003 W. -P. Liao / Quail Dove Malaise (1 ♂, 1 ♀, NMNH); Guana I., viii.2003 / W. -P. Liao / Quail Dove Malaise (1 ♂, NMNH); Guana I., 26.x.2003 / Sand pit Malaise / B.&B. Valentine (1 ♂, 1 ♀, NMNH); Guana I. xi /.2003 W. -P. Liao/ Quail Dove Malaise (1 ♂, NMNH); Guana I., xi/.2003 W. –P. Liao / Quail Dove Malaise (1 ♂, NMNH); Guana I., iv.2004 W. -P. Liao / Quail Dove Malaise (1 ♂, NMNH); Guana I., vi /.2004 W. -P. Liao / Quail Dove Malaise (1 ♂, NMNH); Guana I., 9.x.05 / @ u / v light. B.D. &/ B.S. Valentine (1 ♂, NMNH); Guana I., viii.2005 / Quail Dove Malaise (1 ♂, NMNH); Guana I., viii.2005 / W.-P. Liao coll./ Quail Dove Malaise (1 ♀, NMNH); Guana I., 5–19.x.2005 / B.D. & B.S. Valentine/ beating (1 ♂, NMNH); Gt. Camonoe Il. / lower bay, 0–550 ft. / 17.x.1994 / M.A. & L.L. Ivie (1 ♂, MAIC); Virgin Gorda / ID. Virgin Pk / 15.iv.1956 / J.F.G. Clarke (1 ♂, NMNH); F5138b / Tortola, V.I. / 18.iii.1925 ~ Erax  / haitensis Macq.  / det. C.H. Curran (1♀, NMNH). PUERTO RICO: San Juan / 9–12, ’14 ~ Am. Mus. Nat. Hist. / Dept. Inv. Zool. / No. ~ OSUC 0 186796 (1 ♂, OSUC). US VIRGIN ISLANDS: (syntype ♀, UZMC); St. John / Lameshur Bay, VIERS / Feb –Mar 1984, in lab / W. B. Muchmore colr (1 ♀, NMNH); St. John, / Great Cruz Bay / 15–19.vi.1996 / B.&B. Valentine coll. (1 ♂, NMNH); F5029 / St. Thomas, V. I. / 11.iii.1925 (1 ♂, AMNH; 1 ♂, NMNH); F5030 / St. Thomas, V. I. / 12.iii.1925 (1 ♂, AMNH); F5030 / St. Thomas, V. I. / 12.iii.1925 (1 ♂, NMNH); VIRGIN ISLANDS, St. John, Caneel / Bay 22.i.33 / Spangler and Muller (1 ♂, NMNH); F5029 / St. Thomas V.I. / 11.iii.1925 ~ C.H.Curran / Collection ~ Acc. 31144 ~ A.M.N.H. / collection (1 ♂, FSCA); F5138bB / St. Thomas V.I. / 18.iii.1925 ~ C.H. Curran / Collection ~ Acc. 31144 ~ A.M.N.H. / collection (1 ♀, FSCA).

Distribution. British and US Virgin Islands, Puerto Rico. Active at sea level to 17 meters in elevation during January through August, October, and November.

Remarks. Efferia stylata  is distinguished by the mostly black setose palpi, dilated wing, usually 2.5, sometimes 2 or 3, white abdominal segments, anterior scutal setae as long as or longer than scape; scutellum mostly or entirely black setose, setae longer than scape and pedicel combined, and 3–6 stout black marginal bristles, and the male and female terminalia ( Figs. 122–127View FIGURES 122–127).

The Fabrician type is a female, in very poor condition, and itself not useful for identification. The eyes are destroyed; the thorax has all femora but only the prothoracic tibiae remain, and the left wing is glued to the label; only segment 1 and parts of segments 2–4 of the abdomen remain. The label bears the hand written name stylatus  .

The identity of Efferia stylata  has been uncertain historically, having been reported from south Florida across the northern Islands in the West Indies and Brazil ( Walker 1855, Johnson 1919, Bromley 1929, Hine 1919, Farr 1964, 1909, Martin & Papavero 1970). At least 4 species ( E. haitensis  , E. rufitibia  , E. caudex and E. invarious Walker 1851  ) have been synonymized with it although 3 of these are now recognized as valid species ( Curran 1928, 1931; Farr 1964). Thus, the confused identity of E. stylata  generated a rather wide distribution of the species in the early literature ranging from southern Florida into the Lesser Antilles ( Curran 1931, Martin & Papavero 1970). However, our study shows that E. stylata  has a more limited range, presently including the U. S. and British Virgin Islands and Puerto Rico. Furthermore, the early dipteran species of Fabricius (1775) were collected in the Virgin Islands, probably St. Croix ( Curran 1931, Zimsen 1964, Scarbrough & Perez-Gelabert 2008, & Thompson 1981).

Curran (1928) described E. tortola  from the British Virgin Islands, separating it from E. stylata  on the basis of 3 white abdominal segments and in the shape of the male terminalia. However, we found 1) that the number of white tomentose segments in the male is variable, ranging from 2–3 with 2.5 segments being the most common, and 2) that the terminalia of the 2 forms are indistinguishable. Thus E. tortola  is here declared a synonym of E. stylata  .


American Museum of Natural History


Smithsonian Institution, National Museum of Natural History


Mediterranean Agronomic Institute of Chania


Oregon State University


Universidad del Zulia


Florida State Collection of Arthropods, The Museum of Entomology














Efferia stylata (Fabricius)

Aubrey G. Scarbrough & Daniel E. Perez-Gelabert 2009

Efferia stylata

Martin and Papavero 1970: 68

Nerax stylatus

, Hull 1962: 479

Erax tortola

Curran 1928: 23

Erax stylatus

Hine 1919: 127

Asilis stylatus

Fabricius 1775: 795