Aptilotella gracilis 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 gracilis

description: Aptilotella gracilis Luk & Marshall, sp. n.
Figures 15–18, and 97–110
Description. Habitus as in Figures 15 and 16. Body length 1.3 mm. Head (Fig. 110) ground color orange. Frons finely rugose; with three silvery stripes that are most conspicuous from behind—a very narrow medial stripe from the anterior margin to ocellar tubercle, and a pair of broader lateral stripes not attaining either margins; ocular margin darkened between eye and lateral stripe; ocular emargination with a large silvery spot. Ocellar tubercle raised; ocelli present; ocellar bristle approximately two-thirds the length of frons. Orbital bristle present; orbital setulae minute, in five pairs. One pair of interfrontal setae. Face shining; lower corners of facial excavation diffuse brown; gena paler, weakly shining. Antenna yellow-orange. Scutum orange with diffuse brownish medial stripe and lateral margins, shining, finely rugose; uniformly setose. Scutellum brown, lightly microtrichose, finely rugose; twice wider than long, 0.7 times the width of scutum. Scutellar bristles subequal in length. Pleuron dull orange, with diffuse yellow stripe running through middle; katepisternum and meron dark brown. Legs yellow ochre; coxa dark brown; fore tibia and first fore tarsomere dark brown; fore tarsus off-white; mid tibia with three anterodorsal and one distal posterodorsal bristle. Wing (Figs. 17, 105) paddle-shaped, setaceous. Abdomen black, shining; tergites finely rugose, uniformly densely microtrichose, each with two rows of setae; sternites setose and finely microtrichose.
Male terminalia. Sternite 5 (Figs. 18, 101) concave in posteromedial third and with three scalloped emarginations; the outer two flanked by regular setae and four long marginal setae, one of which is borne on a slender tubercle; the area between the emarginations projecting beyond margin and bearing a pair of hoof-shaped processes, joined by a membrane lining the middle emargination. Synsternite 6+7 (Figs. 18, 99) giving rise to a pair of large, heavily sclerotized, asymmetrically curved processes on either side of medial bridge. Tab-like piece (Fig. 100) resembling half of a hollow cone with foot-like extensions from its basal corners; the top of the cone articulates neatly with the hoof-shaped processes. Cercus (Figs. 18, 97, 98) 3.5 times as long as wide, uniform in thickness except for toothed base and tapered apex; medially slightly bent inward, with long outer seta; apex sloped inward, with two sensory setae; clothed in setulae; outer surface with scattered small setae. Surstylus (Figs. 97, 98) extremely long, nearly twice the length of cercus; base conical; slender portion compressed, twisting and tapering to a point; basally with scattered sensory setae. Postgonite (Fig. 103) broad; descending arm short, slightly curved forward and tapering, with several marginal sensory setae; articulatory process for pregonite truncate; articulatory process for basiphallus short-stalked, knobbed. Hypandrium (Fig. 104) broad; medial rod apically dilated to the right; posteromedial fork divergent and webbed; hypandrial arms curved, the left arm slightly longer; pregonite short, irregularly triangular. Aedeagus as in Figure 102. Basiphallus compressed, squared; anterior margin weakly arched; articulatory process for postgonite apically dilated, directed anteriorly. Ejaculatory apodeme indistinct, with two sensory pores. Ventrobasal sclerite divided. Lateral flanking sclerite not fused ventrobasally; dorsal margin rolled, straight then diverging, tapering to a sharp point with ventral margin. Ventral flanking sclerites very dark; the bilobed basal article originating along but separate from ventral margin of lateral flanking sclerite, projecting an equal length beyond and apicodorsally densely clothed in suspended minute denticles, the inner medial lobe parallel, its dilated apex extending beyond even the distal article; the very dark medial article as long as lateral flanking sclerite, needle-tipped, its base dilated and articulating with ventral margin of lateral flanking sclerite below basal article; the depressed distal article originating from below midpoint of medial article, apex slightly lobed inward. Medial paired sclerites originating between medial and distal articles; dorsally with a posteriorly directed tooth; twisting inward and terminating in a spade-shaped apex.
Female terminalia. Epiproct (Figs. 106, 107) very pale, triangular; apically finely hairy. Each half of tergite 8 (Figs. 106–108) convex, its margins straight, rounded apically; upper two-thirds setaceous. Cercus three times as long as wide; with one long apical seta and several preapical setae. Sternite 8 (Figs. 107, 108) triangular; with four preapical setae. Spermathecae (Fig. 109) simple; length of sclerotized ducts approximately twice the diameter of a spermatheca.
Variation. The scutum and scutellum occasionally have a more uniform orange wash. The facial excavation is entirely orange in some specimens.
Etymology. The species epithet refers to the unusually slender surstyli.
Type material. Holotype ♂, UNAM. MEXICO: Tamaulipas, Joya de Manantiales, 23°0’30”N, 99°17’6”W, 1430 m, 22.viii.2009, mesophyll forest, ex. sifted leaf litter, M.G. Branstetter.
Paratypes. MEXICO: Tamaulipas, Gomez Farias, Rancho del Cielo, near Cabins, 23°6’4”N, 99°11’32”W, 1200 m, 17.vii.2006, mixed oak forest, ex. sifted leaf litter, R.S. Anderson (♀, DEBU); El Cielo, near Alta Cima, 23°3’55”N, 99°12’16”W, 980 m, 21.viii.2009, riparian wet forest, ex. sifted leaf litter, L. Sáenz (♂, DEBU); same label as holotype (4♂, ♀, DEBU); same label as holotype but collected by L. Sáenz (♂, UNAM); El Cielo, 1.8 km NW La Gloria, 23°3’31”N, 99°15’48”W, 2030 m, 23.viii.2009, mesophyll forest, ex. sifted leaf litter, M.G. Branstetter (♀, DEBU); Querétaro, Pinal de Amoles, Huasquilico, 21°9’39”N, 99°34’27”W, 1750 m, 28.vii.2006, hardwood forest, ex. sifted leaf litter, R.S. Anderson (♀, DEBU); Pinal de Amoles, 2 km W San Pedro Escanela, 29.vii.2006, ex. sifted leaf litter, R.S. Anderson (2♂, DEBU); Pinal de Amoles, 1.9 km NE, 21°8’59”N, 99°36’57”W, 2250 m, 18.viii.2009, oak-pine forest, ex. sifted leaf litter, M.G. Branstetter (♂, UNAM); Pinal de Amoles, 7 km NE, 21°10’34”N, 99°34’24”W, 1700 m, 18.viii.2009, disturbed mesophyll forest, ex. sifted litter, M.G. Branstetter (♀, UNAM); Pinal de Amoles, 4.6 km SW, 21°9’53”N, 99°35’39”W, 1960 m, disturbed mesophyll forest, ex. sifted litter, M.G. Branstetter (♂, 3♀, DEBU; 2♀, UNAM); San Luis Potosi, Xilitla, 7.2 km NE, 21°25’42”N, 98°56’28”W, 180 m, 19.viii.2009, disturbed tropical forest, ex. sifted litter, M. Vásquez-Bolaños (♂, ♀, DEBU).
Description. Aptilotella gracilis and A. gladia are among the most distinctive Aptilotella; males especially are unmistakable, with extremely slender surstyli and a broad hypandrium with curved arms and triangular pregonites. Male A. gracilis also possess asymmetrical posterior prongs on synsternite 6+7. These somewhat elongate Aptilotella have reflective silvery stripes along the interfrontal sutures and a large silvery spot in the rather pronounced ocular emargination. The lower half of the pleuron is dark brown. In both sexes, the off-white fore tarsus contrasts boldly with the dark brown fore tibia and first tarsal segment. The abdominal tergites are weakly rugose. Aptilotella gracilis is one of the northernmost species in the genus.
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 21-22, DOI: 10.11646/zootaxa.3761.1.1, http://zenodo.org/record/4909057