Aptilotella macula Luk & Marshall 2014, sp. n.
Creators: name: Luk, Stephen P. L.
name: Marshall, Stephen A.
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Sphaeroceridae
Aptilotella
Aptilotella macula

description: Aptilotella macula Luk & Marshall, sp. n.
Figures 1, 58–60, and 337–347
Description. Habitus as in Figures 1, 58, and 59. Body length 1.1–1.4 mm. Head ground color orange. Frons finely rugose, with five silvery spots: one before each ocular emargination, one diffusely at each hind corner and slightly on occiput, and one on interfrontal plate before tubercle. Ocellar tubercle scarcely raised, with minute medial seta; ocellar bristle greater than the length of frons. Orbital bristle absent; orbital setulae inconspicuous, in four pairs. Interfrontal setae in three pairs. Face shining; lunule with silver spot; gena finely rugose, posterior margin black. Antenna yellow, distal half of first flagellomere brown, scape black. Scutum and scutellum black, with metallic sheen. Scutum uniformly, sparsely setose; posterior dorsocentral bristles as long as scutum. Scutellum bare; three times wider than long, 0.8 times the width of scutum; margins carinate. Scutellar bristles subequal in length. Pleuron black, weakly shining; upper anepisternum and anepimeron with pale pruinose stripe. Legs brown; mid and hind coxae black; front and mid femora and distal half of hind femur orange; hind tarsus light brown; mid tibia with two anterodorsal bristles. Wing rudiment black. Abdomen black, with metallic sheen; tergites setose, densely microtrichose; sternites finely microtrichose. Cercus and surstylus brown.
Male terminalia. Sternite 5 (Fig. 339) lunate; posteromedial third weakly dilated, concave and polished, flanked by a patch of setae and four strong marginal setae, medially with four marginal setae. Synsternite 6+7 as in Figure 340. Cercus (Figs. 60, 337, 338) stout, triangular, apically truncate; inner margin setulose. Surstylus (Figs. 60, 337, 338) basally swollen and divergent, bending at a nearly right angle at midpoint, then rounded and upwardly curved apically; base setulose; inner margin with scattered rows of sensory setae before the bend. Postgonite (Figs. 60, 342) 1.8 times as long as wide; posterior margin medially with large tooth-like projection; preapically with three sensory setae; articulatory processes rounded, each with an internal tooth; margin shallowly concave between the two processes. Hypandrium (Fig. 343) with medial rod pinched in distal three-fifths and apically dilated to the right into a rounded fan; posteromedial fork indistinct but swollen; hypandrial arms irregularly triangular, partially fused to base; pregonite inconspicuous. Aedeagus as in Figure 341. Basiphallus stout, cylindrical; articulatory process for postgonite short, divergent; articulation with distiphallus dorsally projected. Ventrobasal sclerite weakly divided. Lateral flanking sclerites very narrowly fused ventrobasally; dorsal margin slightly curved, diverging beyond basal two-fifths and descending, then hooked upward and cradling a membranous sheet in between; the sheet laterally lobed and studded with numerous round or elongate sclerotized scales. Ventral flanking sclerites darker; the basal article fused along ventral margin of lateral flanking sclerite, medially bearing a dorsal arm; the triangular medial article articulating with basal article, its inner corner sharply pointed, its top corner rising to just beneath the hooked portion of lateral flanking sclerite; the membranous distal article with a darker, sickle-shaped ascending arm. Curved dorsal sclerites dark, originating from within hooked portion of lateral flanking sclerite, curving inward and converging, their slightly swollen apices protruding between membranous sheet.
Female terminalia. Epiproct (Figs. 344, 345) semicircular. Each half of tergite 8 (Figs. 344, 345) triangular with broadly rounded apex, convex; dorsal half with several long setae. Cercus 2.5 times as long as wide; with two long preapical setae. Sternite 8 (Figs. 345, 346) divided; each half boomerang-shaped, apically microtrichose and with one preapical seta. Spermathecae (Fig. 347) finely ridged; sclerotized ducts extremely long, six to seven times the diameter of a spermatheca.
Variation. The reflectiveness of the silvery spots varies from faint to very strong. Infrequently, the hind femur is more or fully orange. Teneral specimens have a brownish body but retain the metallic sheen.
Etymology. Aptilotella macula is named for the unique patterning of the frons.
Type material. Holotype ♂, CBFC. BOLIVIA: La Paz, Coroico, Cerro Uchumachi, 16°12’43”S, 67°42’49”W, 2550 m, 5–16.iv.2001, elfin forest, dung pans, S.A. Marshall.
Paratypes. BOLIVIA: La Paz, same label as holotype (21♂, 13♀, DEBU; 4♂, 5♀, CBFC); same label as holotype but 28.i.2001, cloud forest, leaf litter, R.S. Anderson (♂, DEBU); same label as holotype but 5–6.iv.2011 (6♂, 4♀, DEBU).
Comments. Aptilotella macula and A. macta are the southernmost members of the genus; their type localities in the Bolivian Altiplano are over 2,100 km southeast of the described Ecuadorian Aptilotella species, although undescribed species are known from Peru. These two species are probably very recently diverged from each other, and are found just 50 km apart. Both are readily recognized by the spotted frons and very shiny metallic and squat body. The cercal chaetotaxy is simple, and the surstyli are boomerang-shaped. The male distiphallus is distinctive for the scale-studded membranous sheet between the lateral flanking sclerites, and the claw-like fused medial and distal articles of the ventral flanking sclerites. Aptilotella macula differs from A. macta by the five-spotted frons, larger size, and robust male surstylus.
description: Published as part of Luk, Stephen P. L. & Marshall, Stephen A., 2014, A revision of the New World genus Aptilotella Duda (Sphaeroceridae: Limosininae), pp. 1-156 in Zootaxa 3761 (1) on pages 46-47, DOI: 10.11646/zootaxa.3761.1.1, http://zenodo.org/record/4909057