Chilelimnophila lyra (Alexander, 1952)

Ribeiro, Guilherme Cunha, 2007, A review of the monotypic genus CHILELIMNOPHILA Alexander (Diptera: Tipulomorpha: Limoniidae), Papéis Avulsos de Zoologia 47 (18), pp. 203-211 : 204-208

Chilelimnophila lyra (Alexander, 1952)

( Figs. 1-13 )

Chilelimnophila lyra (Alexander 1952) : 108-109 (original description); 118, figure 7 (male terminalia). Alexander (1968): 24, figures 2 (wing) and 7 (male terminalia). Alexander & Alexander (1970): 4.93 (catalogue citation). Oosterbroek (2007) (catalogue citation).

Redescription

Coloration (male and female): Head brownish yellow, generally darker than thorax; thorax and legs light brown-yellow; abdomen brownish, darker than tho-

rax, with tergum darker than sternum; last abdominal segment darker than previous segments.

Dimensions (male; maximum lengths and widths in millimeters): Head length, 0.40-0.60; head width, 0.35; wing length, 5.87-6.25 (5.87 in holotype); wing width, 1.62-1.70 (1.70 in holotype); gonocoxite length, 0.28-0.31 (0.28 in holotype); clasper of gonostylus length, 0.21-0.24 (0.24 in holotype); lobe of gonostylus length, 0.14-0.17 (0.14 in holotype).

Morphology (male and female): Head and appendages ( Figures 1-2 , 4-5 ): Flagellum 14-segmented; scape cylindrical, ca. 1.75 X longer than wide; pedicel ovoid, ca. 1.2 X longer than wide; scape and pedicel similar in length; first flagellomere ovoid, constricted at base; first three to four flagellomeres as long as wide and partially fused in the male, ovoid and not fused in the female; flagellomeres length/width ratio gradually increasing toward tip of antenna, with last flagellomere longer than preceding; maxillary palpus 4-segmented; first palpomere more or less cylindrical, ca. 2.2 X longer than wide; other palpomeres ovoid, shorter than the first; compound yes widely separated dorsally, meeting at median line ventrally; rostrum (including labella) ca. 0.4 X the length of head capsule. Thorax ( Figure 3 ): almost as long as high; pleural sclerites as figured. Leg ( Figure 8 ): tibial spurs (1:2:2) ca. 0.66 X the width of distal part of tibia, covered with tiny hairs; tarsal claws simple, smooth. Wing ( Figure 6 ): h vein situated between the origin and the fork of M+Cu; Sc ending on C at the level of bifurcation of Rs and A 1; position of sc-r variable, more or less near the tip of Sc; r-r linking R 1 to R 2 faint or lacking; Rs almost straight, originating well proximally to the level of the tip of A 2; Rs three branched; R 2+3 ca. 0.46 X the length of R 3; R 2 running more or less parallel to R 3 in most of its length, turning upwards abruptly at tip; section of R 4+5 between its origin and point of contact with r-m curved; section of R 4+5 distal to point of contact with r-m almost straight; r-m straight, similar to m-cu in length; M four branched; M 1+2 long, ca. 3 X the length of M 2; M 1 ca. 1.37 X the length of M 2; M 3 sinuous; M 4 almost straight; m-m ca. 0.20 to 0.40 X the length of r-m; m-cu attached to M 3+4 near mid-length of discal cell; A 1 almost straight; A 2 slightly curved at tip. Male terminalia ( Figures 7 , 9 , 10-12 ): posterior margin of tergite 9 produced into two small lobes; gonocoxite conical, gradually narrowed toward tip, bearing a ventromedial extension; gonostylus terminal; lobe of gonostylus ca. 3.25 X longer than wide, gradually narrowed toward tip; clasper of gonostylus ca. 5.6 X longer than wide, glabrous, bifid (largest and distalmost bifurcation serrated); aedeagus relatively long, reaching the level the gonostylus insertion; lateral process of aedeagal sheath long, narrow and acute, strongly sclerotized, twisted at apex; interbase blade-like, rounded at apex, bearing a stout lateral extension articulating with paramere, and a longer, more slender medial extension. Female terminalia ( Figure 13 ): tenth tergite ovoid, ca. 2 X longer than ninth tergite; hypogynial valve with a more or less ovoid and less sclerotized internal area ranging from its midlength to its apex; apex of hypogynial valve reaching midlength of cercus, bearing slender bristle-like filaments. Pilosity: antenna with verticils longer than individual flagellomeres; wing with macrotrichia all along longitudinal veins.

Remarks: The rounded structure indicated by Alexan- der (1952: 118, figure 7; 1968: 24, figure 7) as the ninth tergite is actually the ninth sternite: the posterior margin of the ninth tergite is not rounded, but produced into two small lobes. The three dimensional structure of the clasper of gonostylus is relatively complex. Although some variation may occur in the relative lengths of its two apical extensions, in flattened slide mounted specimens ( Figure 9 ), the apex of the clasper may be distorted in different ways, giving a false impression of variation. Such a distortion has probably driven Alexander’s (1968: 23) description of the apical part of this structure as “expanded into a triangular blade”. Sexual dimorphism is noticeable in structure of the antenna. In the male, the first three to four flagellomeres are partially fused ( Figure 4 ), while in the female, they are more ovoid than in male and not fused ( Figure 5 ).

Distribution: As far as known, Chilelimnophila lyra has a restricted geographical distribution in Chile, ranging latitudinaly from ca. 37°S (northernmost limit at the Cordillera de Nahuelbuta) to 42°S (southernmost limit at Chiloé Island) within the Subantarctic Biogeographical Province in South America.

Figures

FIGURE 3: Chilelimnophila lyra, male thorax, lateral view. Abbreviations: anepm, anepimeron; anepst, anepisternum; anepst cleft, anepisternal cleft; aprn, antepronotum; cerv scl, cervical sclerite; cx, coxa; kepm, katepimeron; kepst, katepisternum; ltg, laterotergite; mtepm, metaepimeron; mtkepst, metakatepisternum; mtanepst, metanepisternum; mr, meron; mtg, mediotergite; pltr2, mesothoracic pleurotrochantin; pltr3, metathoracic pleurotrochantin; pprn, postpronotum; sct, scutum; sctl, scutellum.

FIGURE 6: Chilelimnophila lyra, wig venation.

FIGURE 7: Chilelimnophila lyra, photograph of male terminalia, dorsal view. Abbreviations: aed, aedeagus; cgonst, clasper of gonostylus; goncx, gonocoxite; interb, interbase; lgonst, lobe of gonostylus; lp, lateral process of aedeagal sheath; pm, paramere; t9, ninth tergite.

FIGURE 13: Chilelimnophila lyra, female ovipositor. Abbreviations: cerc, cercus; hyp vlv, hypogynial valve; s8, eighth sternite; t8-10, eighth to tenth tergites.

FIGURES 1‑2: Chilelimnophila lyra, male head. 1, lateral view. 2, ventral view. Abbreviations: comp eye, compound eye; lbl, labella; plp, maxillary palpus.

FIGURES 4‑5: Chilelimnophila lyra, antenna. 4, proximal part of male antenna, showing partial fusion of first four flagellomeres (I-IV). 5, proximal part of female antenna. Abbreviations: ped, pedicel.

FIGURE 8‑9: Chilelimnophila lyra, male. 8, articulation of tibia with tarsus (foreleg) showing tibial spur (arrow). 9, dorsal aspect of gonostylus in flattened, permanent slide mounted specimen. Abbreviations: cgonst, clasper of gonostylus; lgonst, lobe of gonostylus.

FIGURES 10‑12: Chilelimnophila lyra, male terminalia. 10, general aspect of terminalia, dorsal view. 11, aedeagus and associated structures, dorsal view. 12, general aspect of terminalia, lateral view. Abbreviations: aed, aedeagus; aed apod, aedeagus apodeme; cgonst, clasper of gonostylus; goncx, gonocoxite; interb, interbase; lgonst, lobe of gonostylus; lp, lateral process of aedeagal sheath; pm, paramere; s9, ninth sternite; t9, ninth tergite.