Limnellia itatiaia Mathis 1980

Limnellia itatiaia

DIAGNOSIS.—Externally, specimens of this species appear similar to those of L. stenhammari but may be distinguished from the latter and other congeners by the following combination of character states: Coloration of setose portion of face mostly cinereous, some specimens with faintly evident brown transverse band toward ventral margin just dorsad of cinereous ventral margin; antennal fovea shallowly impressed; wing with 3 darker brown spots in cell R5 closely appressed against vein R4+5; halter and tarsi dark brown; length of surstylus not greater than width; more or less subtriangular, with ventrolateral surface shallowly emarginate.

DESCRIPTION.—Small shore flies, length of allotype 1.72 mm (abdomen of holotype removed before it was measured).

Head: Head width-to-height ratio averaging 1:0.69. Frons mostly dark golden brown to blackish brown with faint metallic luster; parafrons wedgeshaped anteriorly, coloration gray to brownish gray; narrowly gray colored also along posterolateral margins of mesofrons. Face grayish to brownish, thin stripe along oral margin and to a lesser extent antennal fovea grayish, nearly flat, very slightly arched transversely; interfoveal carina brownish; interfoveal carina evident but not distinctly protruding; antennal fovea distinctly impressed but shallow. Eye height-to-width ratio averaging 1:0.91; eye-to-cheek ratio averaging 1:0.08.

Thorax: Legs entirely dark, blackish brown, unicolorous. Maculation pattern of wing as follows: Cell R1 with 4–5 white spots, if apical one present not as evident; cell R3 with 4 white spots, each well developed and evenly spaced along cell; cell R5 with 5–6 poorly defined white spots, each small, apical ones frequently abutting; discal cell with 2–3 white spots, apical one better developed; cell M2 with 2 white spots; cell M4 with 2–3 white areas, generally guttate. Wing length-to-width ratio averaging 1:0.47; costal vein index averaging 1:0.22; M1+2 vein index averaging 1:0.72. Halter blackish.

Abdomen: Male terminalia (Figures 40–42) as follows: Epandrium (Figure 40) higher than wide in caudal view, rounded dorsally, more or less truncate ventrally; surstylus (Figure 40) subtriangular in caudal view, centrolateral margins emarginate, generally setose; aedeagus (Figure 41) in lateral view longer than wide, with shallowly V-shaped notch along dorsum; aedeagal apodeme attached to posterior portion of aedeagus and extending ventrally.

TYPE MATERIAL.—Holotype male, labeled: “Alto Itatiaya (Rio de Janeiro) Serra do Itatiaya S E Brazil Feb 21 1922/Alt 7150 [handwritten]/E G Holt Collector/HOLOTYPE Limnellia itatiaia Mathis [handwritten, red].” Allotype female, labeled: “S[ao]. PAULO Capital Forattini Col IV-60 [handwritten]/COLECAO J. LANE [black bordered pink label]/ALLOTYPE Limnellia itatiaia Mathis [handwritten, red].” The holotype is in the National Museum of Natural History, Smithsonian Institution, Washington, D.C., type number 76066. The allotype is in the Museu de Zoologia da Universidade de São Paulo, Brazil. The holotype specimen is double mounted (glued to a paper point) and is in fair condition. One wing is missing, and the abdomen has been removed and dissected; the structures are in an attached microvial.

GEOGRAPHIC DISTRIBUTION.—This species is known only from the two localities from southeastern Brazil as listed previously.

RELATIONSHIP.—Because specimens of this species closely resemble those of L. stenhammari, I suspect that these two species are related, at least patristically.