Aptilotella radians 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 : 37-38

Aptilotella radians Luk & Marshall , sp. n.

Figures 43–45 , and 252–264

Description. Habitus as in Figures 43 and 44 . Body length 1.0– 1.6 mm. Head ( Fig. 260 ) ground color yellow. Frons finely rugose except for smooth pale area of interfrontal plate; dark brown stripes each about one-fourth the width of frons; orbital stripes darker and confined to posterior corners of frons. Ocellar tubercle slightly raised; ocelli present; ocellar bristle approximately two-thirds the length of frons. Orbital bristle present; orbital setulae small, in two pairs. Interfrontal setae small, in four pairs. Face and gena shining, with a brown stripe from ventral margin of eye to oral margin between excavation and gena, continuing onto clypeus; clypeus broad. Maxillary palps brown. Antenna yellow, pedicel brown. Occiput dark brown, as well as a narrow strip on gena below the eye. Scutum dark reddish-brown, shining except for pruinose medial half and broken patches of pruinosity along the lateral margins; pruinose area with one medial and two bordering narrow longitudinal vittae, of which only the medial vitta attains the entire length of scutum; uniformly setose; supra-alar strong, subequal to the length of scutum. Scutellum black, convex, bare; twice wider than long, 0.6 times the width of scutum. Apical scutellar bristles 1.7 times as long as basal. Pleuron black; proepisternum and anepisternum mostly orange. Legs dark brown; mid and hind coxae black; fore femur brown; tarsi and distal third of mid and hind femora yellow; mid tibia with two anterodorsal and one distal posterodorsal bristle. Wing rudiment yellowish. Abdomen black, shining; tergites uniformly setose, basal margin microtrichose except for syntergite; sternites finely microtrichose. Epandrium and synsternite 6+7 reddishbrown; cercus and surstylus dull yellow.

Male terminalia. Sternite 5 ( Figs. 45 , 255 ) with two semicircular emarginations at each third of posterior margin, into which the cerci retract; setose and marginally microtrichose in between. Synsternite 6+7 ( Fig. 254 ) with extremely narrow medial bridge, lined interiorly by a broad membrane. Cercus ( Figs. 45 , 252, 253 ) triangular, compressed; apex irregularly truncate and bearing four blunt claw-like spines, and a long seta anterior to them; basal two-thirds of ventral margin forming a curved process extending beyond apex. Surstylus ( Figs. 45 , 252, 253 ) three-sided, each face concave; anterobasally compressed into a truncate lobe; posteroventral face densely setaceous. Postgonite ( Fig. 258 ) broad, 1.5 times as long as wide; posterior margin medially with a truncate hump; apex calloused; articulatory process for pregonite truncate; articulatory process for basiphallus stalked, knobbed with strong ventral tooth; margin slanted between the two processes. Hypandrium ( Fig. 259 ) Y-shaped; medial rod straight and apically dilated and truncate; hypandrial arms curved and apparently fused to medial rod, apex pointed, anterior margin with a basal tooth; pregonite truncate, fused to medial rod. Aedeagus as in Figures 256 and 257 . Basiphallus cylindrical; posteroventrally humped, appearing boot-shaped in lateral profile; articulatory process for postgonite rounded and divergent. Ejaculatory apodeme discoid with four sensory pores, arising on a slender stem. Ventrobasal sclerite very narrow. Lateral flanking sclerite divergent, fused ventrobasally by a broad bridge which has a posteromedial truncate lobe; dorsal margin slightly rolled, basally produced into a triangular tooth; apex round and slightly dilated, its lower margin supporting a wrinkled and lightly membranous sac. Ventral flanking sclerites dark; the slender basal article fused along ventral margin of lateral flanking sclerite, apically elongated into a descending arm; the warped spindle-shaped distal article tapered and converging basally, its dorsal margin roughly following the contour of basal article, laterally with pale, warped, and rounded outer lobe and a larger inclined and triangular inner lobe.

Female terminalia. Epiproct ( Figs. 261, 262 ) very pale, subpentagonal; with a patch of setae and microtrichosity. Each half of tergite 8 ( Figs. 261–263 ) convex; apex drawn out and rounded; dorsal half microtrichose and with several setae. Tergite 7 ( Fig. 261 ) divided; each half densely covered in curled setulae and laterally with four long marginal setae. Cercus 2.5 times as long as wide; with one long apical seta and three preapical setae. Hypoproct ( Figs. 262, 263 ) a semicircular band; margin more sclerotized and weakly microtrichose. Spermathecae ( Fig. 264 ) pear-shaped, finely ridged; apex invaginated, internally with several stubs; collar with a ring of stubs; ducts short, less than the length of a spermatheca, and lightly sclerotized.

Variation. Some darker specimens have a fainter pleural stripe, while often having somewhat broader scutal stripes. The marginal pruinosity may form a complete stripe in boldly marked specimens, giving the scutum a fivestriped appearance.

Etymology. The species epithet is Latin for “beaming, shining,” a reference to its bold thoracic markings.

Type material. Holotype ♂, UNAM. MEXICO: Oaxaca, Valle Nacional , 47.5 km SW, km 100.5, 2125 m, 26.vii.1992, wet oak forest leaf litter, R.S. Anderson.

Paratypes. MEXICO: Oaxaca, same label as holotype (♂, ♀, UNAM) ; same label as holotype but from Berlese (♀, DEBU) ; 48 km E, km 97, 2012 m, 25.vi–2.viii.1983, montane oak flight intercept trap, S. Peck (♀, DEBU) ; 35 mi S, 8000’, 10–12.viii.1970, oak, dense thicket, human dung, A. Newton (2♂, ♀, DEBU) ; 29.7 mi S, 6800’, 11–17.viii.1973, cloud forest dung, A. Newton (♂, DEBU) ; same label as previous but from carrion (♀, DEBU); 13.2 km SW, 17°39’34”N, 96°20’3”W, 1360 m, 11.viii.2009, tropical wet forest, ex. sifted leaf litter, M.G. Branstetter (♀, DEBU) ; 26 km SW, 17°35’12”N, 96°26’58”W, 2160 m, 11.viii.2009, mixed pine-oak forest, ex. sifted leaf litter, M.G. Branstetter (♂, ♀, UNAM) ; 20.5 km SW, 17°36’20”N, 96°23’2”W, 1770 m, 12.viii.2009, mesophyll forest, ex. sifted leaf litter, M.G. Branstetter (♂, 3♀, DEBU) ; 27.4 km SW, 17°35’47”N, 96°28’28”W, 2280 m, 12.viii.2009, mesophyll forest, ex. sifted leaf litter, M.G. Branstetter (8♂, 2♀, DEBU) ; 14.8 km SSW, 17°38’41”N, 96°20’11”W, 1370 m, 13.viii.2009, disturbed mesophyll forest, ex. sifted leaf litter, M.G. Branstetter (2♀, DEBU) ; 22.4 km SW, 17°35’28”N, 96°23’29”W, 1990 m, 13.viii.2009, cloud forest, ex. sifted leaf litter, M.G. Branstetter (♀, DEBU) .

Comments. The pruinose scutal vittae of Aptilotella radians resemble those of the Pterogramma vittatum species group, although these markings are relatively bolder in A. radians . Features of the distiphallus reveal nothing in common between these two taxa, and the similarity in scutal pattern is likely convergent. The colouration of A. radians readily distinguishes it from all other Aptilotella species.

Figures

FIGURE 45. Aptilotella radians Luk & Marshall, sp. n., male terminalia. Abbreviations: CER = cercus, SUR = surstylus.

FIGURES 43–44. Aptilotella radians Luk & Marshall, sp. n., male: 43—habitus, left lateral; 44—habitus, dorsal.

FIGURES 256–260. Aptilotella radians Luk & Marshall, sp. n.: 256—aedeagus with postgonites removed; 257—distiphallus, dorsal; 258—left postgonite; 259—hypandrium; 260—head. Abbreviations: BP = basiphallus, LFS = lateral flanking sclerite, MS = membranous sac, VBS = ventrobasal sclerite, VBA = basal article of ventral flanking sclerite, VDA = distal article of ventral flanking sclerite.

FIGURES 252–255. Aptilotella radians Luk & Marshall, sp. n.: 252—male terminalia, posterior; 253—male terminalia, left lateral; 254—male synsternite 6+7; 255—male sternite 5.

FIGURES 261–264. Aptilotella radians Luk & Marshall, sp. n.: 261—female terminalia, dorsal; 262—female terminalia, left lateral; 263—female terminalia, ventral; 264—spermathecae. Abbreviations: EP = epiproct, HP = hypoproct.