Gonomyia (Paralipophleps) cultriformis Alexander 1970

Gonomyia (Paralipophleps) cultriformis

Coloration of body and wings as in the subgenus; male hypopygium with bastistyle unequally bispinous; dististyle relatively narrow, fasciculate setae nearly terminal, below these with a group of small darker setae; phallosome with gonapophysis relatively slender, tip slightly dilated and recurved; ventral plate elongate-oval, apex obtuse, without lobes or spines.

MALE.—Length about 5.5–6 mm; wing 3.3–4 mm.

FEMALE.—Length about 6.5 mm; wing 4 mm.

Rostrum and palpi black. Antennae with scape and the enlarged pedicel yellow above, more darkened below; proximal 2 flagellar segments yellow, the outer ones brown; flagellar segments 3 to 7 with exceedingly long verticils that are six or more times the length of the segments, as common in the subgenus, verticils of remaining segments abruptly shorter, subequal to the segments. Head light yellow, posterior vertex with a brown discal area.

Pronotum, pretergites and narrow lateral border of praescutum light yellow, the last bordered internally by a dark brown line, remainder of praescutum and scutal lobes light cinnamon brown; median region of scutum and most of scutellum obscure yellow, the latter on posterior border and as a central area narrowly brown; mediotergite yellow, base restrictedly patterned with brownish black. Pleura and pleurotergite conspicuously striped with very pale yellow or yellowish white, bordered both above and below by brownish black to form subequal stripes. Halteres with stem weakly darkened, knob slightly infuscated. Legs with fore coxae light yellow at bases, comprising the anterior end of the pleural stripe, apex blackened, being part of the pleural darkening; midcoxae yellow, base narrowly blackened, hind coxae uniformly yellow, all trochanters more obscure yellow; femora brownish yellow with a vague brown nearly terminal ring, extreme tip pale; tibiae and tarsi light brown. Wings very weakly darkened, prearcular and costal fields more yellowed; stigma short-oval, dark brown, with pale areas before and beyond and less evidently on either side of the cord; veins light brown, cord darker brown, anterior branch of Rs slightly darker and more apparent against the ground than in Gonomyia (Paralipophleps) wirthiana. Venation: Sc1 ending a distance before origin of Rs about equal to two-thirds to three-fourths of this vein; m-cu at or shortly before fork of M.

Abdominal tergites obscure yellow, posterior and lateral borders blackened, median region weakly infuscated; sternites, base of hypopygium, and much of the basistyle yellowed. Male hypopygium (Figure 57) with the basistyle, b, bispinous, including a large stout outer spine and a slender curved inner one; fleshy lobe very pale, with long setae. Dististyle, d, relatively narrow, the fasciculate setae nearly terminal, below these with a group of small darkened setae. Phallosome, p, with gonapophysis, g, relatively narrow, tip dilated and recurved; aedeagus longer, relatively narrow; ventral plate elongate-oval, with long setae but without terminal lobes or spines, apex obtuse, in cases slightly more narrowed and darkened.

Holotype, male, Clarke Hall, Dominica, 11–20 February 1965 (Wirth). Paratopotypes several males, 8 January-31 March 1965 (Wirth), 13–17 October 1966 (Gurney). A further broken female is considered to belong here but may pertain to one or another of the other regional members of the subgenus, since it was not found associated with the male.

Other members of the subgenus having 2 apical spines include Gonomyia (Paralipophleps) diplacantha Alexander, G. (P.) latistyla Alexander, and G. (P.) pleuralis (Williston), all having the details of the phallosome quite distinct, particularly the ventral plate and gonapophyses. Other species have the apex of the ventral plate with 2 points or lobes and the gonapophyses terminating in acute spines, not cultriform as in the present fly. G. (P.) dikopis, new species, similarly falls in this general group but has the hypopygial details even more distinct. It should be noted that the species determined as being G. (P.) pleuralis still remains not fully settled since the type cannot be located in any of the various collections where the Williston 1896 materials have been preserved. What has been identified as this over the past several years is the commonest and best known member of the subgenus, with a vast range in the Americas, from Georgia, Florida, and the Bahamas south to Bolivia. The immature stages were described by Rogers and the male hypopygium by the writer (Alexander, 1964a, p. 79, fig. 87). I believe that the name G. (P.) pleuralis should be restricted to this species.