Milichiella dimidiata (Wiedemann, 1830)

Brake, Irina, 2009, Revision of Milichiella Giglio-Tos (Diptera, Milichiidae) 2188, Zootaxa 2188 (1), pp. 1-166 : 69-72

dimidiata -group

Species in the dimidiata -group are characterized by the combination of T5 anteriorly silvery microtomentose, middle brown microtomentose, tip shiny; S5 elongate with lateral sides parallel; surstylus with long setulae along anterior margin, line not moving medially.

Distribution: Guatemala east to Suriname, south to middle Peru.

Milichiella cingulata Becker, 1907 (Pl. 12C, E, F)

Milichiella cingulata Becker, 1907: 538 . PERU. Pichis, Puerto Bermudes. LT ♂ SMTD [pres. des.]. Becker 1907: 538 [fig. of male abdomen]. Sabrosky 1973: 4 [Neotropical catalogue]; Brake 2000: 105 [world catalogue].

Diagnosis. Differs from congeners in the combination of ocellar triangle brown microtomentose, mesonotum reddish brown microtomentose, and male T2–5 brown microtomentose except for silvery wide anterior margins of T3–4, which widen laterally on T3–4, T5 silvery anteriorly, middle brown and tip subshiny black.

Description. Body length: 2.3–2.8 mm; wing length: 2.4–2.8 mm. Male coloration and vestiture: frons subshiny black, ocellar triangle and orbital plate brown microtomentose, frontal plate greyish, lunule brown, basoflagellomere black, face dark grey microtomentose, palpus black; thorax with mesonotum densely reddish brown microtomentose, scutellum and pleuron same except for grey microtomentose area around anterior spiracle and base of fore coxa, wing slightly brown grey, veins brown, brown spot at apex of vein R1 absent, calypter brown with dark margin, halter black, legs black except for yellow tips of tibiae, and basitarsi, fore and hind tarsus with conspicuous yellow brush; abdomen with T2–5 brown microtomentose except for silvery wide anterior margins of T3–4, which widen laterally on T3–4, T5 silvery anteriorly, middle brown and tip subshiny black. Female coloration and vestiture: halter yellow, abdomen with T2–5 brown microtomentose.

Head: frons with 2+0.3 orbital and 2 frontal setae, anterior frontal seta medioclinate. In males frons about 2.5x as wide at posterior margin than at base of antenna, arista about 4.1x as long as basoflagellomere width, pubescence on arista very short, posterior eye margin with slight notch (3om) and very slight emargination (1–2om).

Thorax: 2 dc, 1 prsc, 1 pprn, 1 prs, 2 keps setae, posterior prsc as long as posterior dc, seta between posterior prsc and posterior dc small. Wing with veins R 4+5 and M nearly parallel; M-ratio is 2.5. Fore femur normal setulose, tibial organ absent.

Male abdomen: posteromedial triangular projection of T1 into T2 present. Tergal chaetotaxy: T2 anterolateral corner with more than 3 lines of setae, T2–5 with scattered setulae on posterior part, lateral margins with long setae. S5 1.7 x as long as wide, 1.7x as long and 1.9x as wide as S4, posterior margin indented, setulose in hour glass shape (Pl. 12E, F). Male genitalia with apical seta on cercus as long as longest epandrial setae, 1 seta on subepandrial plate, surstylus 0.6x as long as epandrium high, bent posteriorly, dilated apically (1.6x), 3.6x as long as wide, structure of lateral surface smooth, medial surface with row of 4–5 long setae near anterior margin (Pl. 12C).

Lectotype, ♂: PERU. Pasco: Pichis, Puerto Bermudez (10°16'59.88"S 74°55'59.88"W), 20.xii.1903, Schnuse ( SMTD, 3217293), in suboptimal condition, head partly damaged. The type series consists of 3 males from Peru. There are 7 specimens in SMTD that fit the locality and date. One of these bears Becker's identification label and is here designated as the lectotype. Which of the other specimens are paralectotypes cannot be ascertained.

Possible paralectotypes, same data as LT (5 ♂ SMTD, 3217294–7, 3217303), 1–31.xii.1903 (♂ SMTD, 3217298) .

Additional material examined (USNM unless otherwise indicated): BOLIVIA. La Paz: Guanay , 22 km SE, 540 m (15°17.8'S, 68°15.6'W), 17.iii.2001, Mathis (♂, 3218599) ; COLOMBIA. La Combre (4°0'0"N 72°0'0"W), 17.v.1914, Parish (♂, 3216942) ; COSTA RICA. Alajuela: San Mateo, Higuito (9°57'0"N 84°33'0"W), Schild (♀, 3217312). Cartago: La Suiza (9°51'0"N 83°37'.12"W), 12.vi.1926, Schild (♂, 3216940), 24.vi.1926 (4 ♂, 3216937–8), 1–30.vii.1926 (♂, 3216941). San Jose: Farm La Caja (9°58'.12" N 84°7'.12"W), 29.vii.19??, Schmidt (♂, 3217302), 30.vii.19?? (♂, 3217299), 8.viii.19?? (♀, 3218146), 10.viii.19?? (2 ♂ BMNH, USNM, 3217300–1); San Pedro de Montes de Oca (9°55'59.88"N 84°3'0"W), 3.ii.1935, Ballou (2 ♂, 3217311) ; EL SALVADOR. San Salvador: San Salvador (13°40'.12" N 89°10'.12"W), 4.v.1958, Cartwright (♂, 3217316) ; GUATEMALA. Izabal: Quirigua (15°16'.12" N 89°4'59.88" W), 8.v.1926, Aldrich (♂, 3217315); PANAMA. Panama: Ancon, Ancon Hospital Ground (8°58'.12" N 79°33'0" W), 2.vii.1918, Dietz (♂, 3217313); Pedro Miguel (9°1'.12" N 79°37'.12"W), 9.ix.1946, Krauss (♂, 3217314) ; PERU. Huanuco: Cachicoto, 457 m (9°5'S, 76°9'0"W), 16.ix.1965, Hitchcock (3 ♂, 3217304–6). Loreto: Iquitos (3°46'.12" S 73°15'0" W), 1.iii.–30.iv.1931, Shannon (3 ♂, 3217308–10) .

Distribution: Guatemala south to middle Peru.

Remarks. It is possible that Milichiella cingulata is a variety of M. dimidiata as it differs only in the partly brown male T2–5. Milichiella cingulata was collected on Ipomoea tiliacea (Willd.) (Convolvulaceae) .

Pl. 12: A–B. Milichiella dimidiata . A. male genitalia, lateral view; B. Surstylus. C. M. cingulata , male genitalia, lateral view. D–F. Male sternite 4–5. D. M. dimidiata ; E–F. M. cingulata . E. non-type; F. possible PLT. Scale bar: 0.1.

Milichiella dimidiata ( Wiedemann, 1830) (Pl. 12A, B, D)

Chlorops dimidiata Wiedemann, 1830: 597 . Surinam. Cordua. HT ♂ SMF.

Lobioptera dimidiata . Mik 1887: 180 [combination].

Milichiella dimidiata . Becker 1907: 538 [diagnosis, type information]; Sabrosky 1973: 4 [Neotropical catalogue]; Brake 2000: 105 [world catalogue].

Diagnosis. Differs from congeners in the combination of brown microtomentose frons and mesonotum, brown calypter, wing hyaline with brownish tinge and T2–5 silvery microtomentose except for subshiny black tip of T5 and brown microtomentose line between silvery and black part.

Description. Body length: 2 mm; wing length: 2.3 mm. Male coloration and vestiture: frons brown, ocellar triangle and orbital plates brown microtomentose, lunule brown, basoflagellomere black, face greyish microtomentose, palpus black; thorax with mesonotum brown microtomentose, scutellum same, pleuron dorsally brown microtomentose anteroventrally dark grey microtomentose, wing hyaline with slight brownish tinge, veins brown, brown spot at apex of vein R1 absent, calypter brown, halter black, legs black except for orange bases and tips of tibiae, and yellow basitarsi; abdomen with T2–5 silvery microtomentose, except for brown microtomentose middle and black subshiny tip of T5; margin between silvery and brown parts gradual.

Head: frons with 2+0.3 orbital and 2 frontal setae, anterior frontal seta medioclinate. In males frons 2.3x as wide at posterior margin than at base of antenna, arista about 4.8x as long as basoflagellomere width, pubescence on arista very short, posterior eye margin with notch (4om) and emargination (2om).

Thorax: 2 dc, 1 prsc, 1 pprn, 1 prs, 2 keps setae, posterior prsc less than 0.8x as long as posterior dc, seta between posterior prsc and posterior dc absent. Wing with veins R 4+5 and M nearly parallel (1.3); M-ratio is 3.0. Fore femur normal setulose, tibial organ absent.

Male abdomen: posteromedial triangular projection of T1 into T2?. Tergal chaetotaxy: T2 anterolateral corner with 2–3 lines of setae, T2–4 posterior margin with 1 row of setulae, line of long setae along crease. S5 1.8 x as long as wide, 1.7x as long and 1.3x as wide as S4, posterior margin indented, setulose, strongly setulose at posterior margin (Pl. 12D). Male genitalia with apical seta on cercus as long as longest epandrial setae, 1 seta on subepandrial plate, surstylus 0.6x as long as epandrium high, dilated posteroapically (1.3x), 2.3x as long as wide, structure of lateral surface smooth, medial surface with row of 4–5 long setae near anterior margin (Pl. 12A, B).

Holotype, ♂: SURINAME. Cordua (4°0'0"N 56°0'0"W) ( SMF, 3216583), bad condition, head, one wing and some legs missing, thorax damaged, abdomen dissected.

Additional material examined: TRINIDAD & TOBAGO. Trinidad: Saint George Co., Aripe Valley, 152 m (11°13'N, 60°42'W), 29.i.1976, Stubbs (♂ BMNH, 3216927); Curepe, Santa Margarita (10°37'59.88"N 61°24'0"W), 14–16.vi.1972, Pitkin (♂ BMNH, 3216924) .

Material near Milichiella dimidiata : BRAZIL. Santa Catarina: Nova Teutonia , 300–500 m (27°11'S, 52°23'W), 7.iv.1938, Plaumann (♂ BMNH, 3216929), 30.iv.1938 (♂ BMNH, 3216930), 1–30.xi.1966 (♂ CNC, 3217855) .

Distribution. Suriname, Trinidad.

Remarks. The males from Brazil, Nova Teutonia, with hyaline wings and the same shape of the male genitalia but with a sternite shape more similar to Milichiella sculpta probably belong to a separate species. Milichiella dimidiata has been collected in Malaise traps.