Aptilotella umbracatus Luk & Marshall, 2014

Luk, Stephen P. L. & Marshall, Stephen A., 2014, A revision of the New World genus Aptilotella Duda (Sphaeroceridae: Limosininae), Zootaxa 3761 (1), pp. 1-156 : 42-43

Aptilotella umbracatus Luk & Marshall , sp. n.

Figures 4 , 49–51 , and 295–305

Description. Habitus as in Figures 4 , 49 , and 50. Body length 1.0– 1.3 mm. Head ground color yellow. Frons finely rugose, its pale areas uniformly constricted by brown stripes; medial brown stripes broad, each approximately onequarter the width of frons, diffuse along the anterior margin; orbital stripes darker, ending at ocular emargination. Ocellar tubercle slightly raised and overlapping medial stripes; ocellar bristle two-thirds the length of frons. Orbital bristle absent; orbital setulae inconspicuous, in three pairs. Interfrontal setae minute, in two pairs. Facial tubercle, excavation and gena shining. Antenna yellow, first flagellomere brown in distal two-thirds. Scutum and scutellum dark reddish-brown to black, shining. Scutum uniformly, sparsely setose, with minute patch of tomentosity on anterior margin laterally and medially; posterior margin tomentose. Scutellum microtrichose; 2.5 times wider than long, 0.7 times the width of scutum. Apical scutellar bristles 2.5 times as long as basal. Pleuron black; anepisternum sometimes with a faint pruinose stripe. Legs yellow; fore coxa brown, mid and hind coxae dark brown; mid tibia and tarsus darker; mid tibia with two anterodorsal bristles. Wing rudiment yellowish. Abdomen black, shining; tergites distally with a row of evenly-spaced setae, syntergite with 2 rows; sternites finely microtrichose, with rows of longer setae posteriorly. Terminalia reddish-brown; epandrium densely microtrichose; cercus and surstylus yellow.

Male terminalia. Sternite 5 ( Fig. 298 ) irregularly shallowly excised in posteromedial third, with a simple membranous lining. Synsternite 6+7 ( Figs. 51 , 297 ) densely microtrichose, with a field of minute spinules on medial bridge. Cercus ( Figs. 51 , 295, 296 ) 1.3 times as long as basal width; base triangular, with two inner setae; distal half narrow and curved, basally with a long seta half the length of cercus, and a shorter seta below. Surstylus ( Figs. 51 , 295, 296 ) irregularly angular; posteromedially with a large setaceous tubercle, beneath which are four stout setae of which the anterior one is largest; distal margin squared, with a few small sensory setae. Postgonite ( Figs. 51 , 300 ) sinuous posteriorly, descending arm one-third the total length, with a basal sensory seta; articulatory process for pregonite hooked upward and truncate; articulatory process for basiphallus reduced to a small knob. Hypandrium ( Fig. 301 ) with medial rod straight and slightly slanted to the right; hypandrial arms apparently fused to broad base, slender, with the apex rounded and bent back; pregonite minute, triangular, and fused to base. Aedeagus as in Figure 299 . Basiphallus cylindrical; posteroventrally humped, appearing boot-shaped in lateral profile; articulatory process for postgonite rounded and divergent. Ejaculatory apodeme very slender-tipped. Lateral flanking sclerites with dark dorsal and ventral margins, very narrowly fused posterodorsally and more broadly posteroventrally; dorsum densely armed with heavily-sclerotized teeth. Dorsal sclerite very dark; flattened; apex curved upwards and broadly rounded, with a rudder-like ventral keel. Ventral flanking sclerites paddleshaped; the triangular medial article sharply pointed beneath the basal article; the distal article darkest and irregularly ovate.

Female terminalia. Tergite 7 divided medially; distal half densely microtrichose, with several marginal setae. Epiproct semicircular. Each half of tergite 8 ( Figs. 302–304 ) rhomboid, with a weak medial ridge. Cercus three times as long as wide; truncate. Hypoproct a narrow band. Spermathecae ( Fig. 305 ) ridged; collar with two rings of minute stubs; sclerotized ducts very short, less than the diameter of a spermatheca.

Variation. Some series consist of darker and barer individuals. These specimens, while possessing the unmistakable dorsal sclerite which characterises Aptilotella umbracatus , differ by most to all of the following: darker overall colour; legs dull yellow to orange, often paler distally; all coxae dark; scutum lacking anteromedial patch of tomentosity; scutellum lacking microtrichosity.

Etymology. The species epithet is derived from the Latin umbra, “shadow,” and acatus, “a boat or light vessel,” in reference to the starkly contrasting, rudder-like dorsal sclerite of the distiphallus.

Type material. Holotype ♂, DEBU. PANAMA: Chiriquí, 4.5 km E Cerro Punta , 2500 m, 23–28.v.1977, carrion, S. Peck.

Paratypes. PANAMA: Chiriquí, same label as holotype (9♂, 4♀, DEBU) ; 2 km E Cerro Punta , 2200 m, 28.v. – 8.vi.1977, dung traps, S. Peck (2♂, ♀, DEBU) ; same locality as previous label, 1–8.vi.1977, carrion traps, S. Peck (♂, DEBU) ; same locality as previous label, 8.vi.1977, dung, S. Peck (♂, ♀, DEBU) ; Boquete , 5.7 km NE, 1500 m, 19.vi.1995, mixed oak forest, leaf litter, R.S. Anderson (♂, ♀, DEBU) ; Boquete , 5.8 km NE, 14.vi.1996, oak forest, leaf litter, R.S. Anderson (♀, DEBU) ; Volcán Barú National Park , 5.9 km E Cerro Punta, 2400 m, 14.vi.1995, oak ridge-bamboo forest, litter, R.S. Anderson (2♂, ♀, DEBU) ; same as previous label but at 2150 m, riparian alder forest (♀, DEBU); Volcán Barú National Park , 11 km W Boquete, 2150 m, 18.vi.1995, mixed oak forest, leaf litter, R.S. Anderson (3♂, 4♀, DEBU) ; Cerro Pando, 12 km NE Santa Clara, 2120 m, 17.vi.1996, wet cloud forest, leaf litter, R.S. Anderson (♀, DEBU) ; Hartmann’s Finca , 30.7 km W Volcán, 1800 m, 16.vi.1995, mixed oak forest, leaf litter, R.S. Anderson (♂, DEBU) ; La Fortuna area, Finca La Suisse, 1450–1600 m, 11.vi.1995, oak ridge forest, litter, R.S. Anderson (2♂, ♀, DEBU) ; La Fortuna area, Finca La Suisse, 1450 m, 12.vi.1995, wet montane forest, leaf litter, R.S. Anderson (♀, DEBU) . COSTA RICA: Limón, Valle del Silencio, La Estación , 9°6’37”N, 82°57’43”W, 2473 m, 26–27.ii.2005, forest litter, R.S. Anderson (4♂, 2♀, DEBU) .

Comments. Aptilotella umbracatus has a known range occupying the southerly slopes of the Cordillera de Talamanca in Panama and neighbouring Costa Rica. This species is significantly smaller than A. quadrata and not as boldly marked. The scutal tomentosity and rudder-like dorsal sclerite of the distiphallus are diagnostic.

Figures

FIGURE 4. Aptilotella umbracatus Luk & Marshall, sp. n., paratype male.

FIGURE 51. Aptilotella umbracatus Luk & Marshall, sp. n., male terminalia. Abbreviations: CER = cercus, PG = postgonite, SPN = spinules of synsternite 6+7, SUR = surstylus, VFS = ventral flanking sclerites of distiphallus.

FIGURES 49–50. Aptilotella umbracatus Luk & Marshall, sp. n., male: 49—habitus, left lateral; 50—habitus, dorsal.

FIGURES 295–298. Aptilotella umbracatus Luk & Marshall, sp. n.: 295—male terminalia, posterior; 296—male terminalia, left lateral; 297—male synsternite 6+7; 298—male sternite 5.

FIGURES 299–301. Aptilotella umbracatus Luk & Marshall, sp. n.: 299—aedeagus with postgonites removed; 300—left postgonite; 301—hypandrium. Abbreviations: BP = basiphallus, DS = dorsal sclerite, LFS = lateral flanking sclerite, VFS = ventral flanking sclerite.

FIGURES 302–305. Aptilotella umbracatus Luk & Marshall, sp. n.: 302—female terminalia, dorsal; 303—female terminalia, left lateral; 304—female terminalia, ventral; 305—spermathecae. Abbreviation: S8 = sternite 8.