Antrops orbitalis (KITS & MARSHALL, 2013)

KITS, JOEL H. & MARSHALL, STEPHEN A., 2013, <p class = " HeadingRunIn " align = " left "> <strong> Generic classification of the Archiborborinae (Diptera: Sphaeroceridae), with a revision of <em> Antrops </ em> Enderlein, <em> Coloantrops </ em> gen. nov., <em> Maculantrops </ em> gen. nov., <em> Photoantrops </ em> gen. nov., and <em> Poecilantrops </ em> gen. nov. </ strong> </ p>, Zootaxa 3704 (1), pp. 1-113 : 60

Antrops orbitalis group

The Antrops orbitalis group is a clade of 15 species, 13 of which were previously undescribed. This clade was keyed as the Archiborborus orbitalis group by Marshall and Buck (2010), who suggested that it represented an unnamed subgenus. Although this group is highly distinct within the subfamily, the phylogeny of Kits et al. (2013) suggests it belongs within the genus Antrops . Members of the group are small (<3 mm), entirely black to dark brown, and usually almost entirely shiny ( Fig. 9 ). Species occur exclusively in the Andes and the Venezuelan coastal ranges, from approximately 1200 m to over 4000 m ASL. Several species occur in the dry puna of northern Argentina and Chile to Peru, while other species occur in moister páramo and cloud forest habitats from Bolivia north to Venezuela.

The A. orbitalis group is clearly monophyletic. Synapomorphies for the clade (states found in other Archiborborinae in parentheses) include 1) the nearly uniform structure of the male fifth sternite ( Fig. 121 ), broad and parallel-sided at the base with the apical portion narrowed triangularly (various, but never exactly as above); 2) the characteristic ventral tooth of the surstylus ( Fig. 86 ) (surstylus entire, not toothed); 3) entirely brown halter (halter predominately white); 4) interfrontal plates darker than orbital and frontal plates, shiny, and striate (interfrontal plates usually smooth and/or microtomentose, if shiny and striate then paler than orbital and interfrontal plates); 5) gena entirely shiny (gena with at least some microtomentum). The extensively shiny appearance of all members of the group except the male of A. guandera sp. nov. is also distinctive, and combined with the unmarked wings this group is readily recognizable. Within the species group, A. guandera is likely the sister group to the remaining species, based on the plesiomorphic retention of extensive microtomentum and 6 acrostichal rows in the male. The A. nitidicollis complex is derived within the group, with the greatest reduction of microtomentum and partial loss of the microtrichia at the base of the wing ( Fig. 14 ) as derived characters for the clade.

Many specific characters for identification depend in part on the form of the surstylus. Descriptive terms for the parts of the surstylus referred to in descriptions are illustrated in Figure 86 .

Figures

FIGURES 7–12. Archiborborine adults, habitus photos: (7) Antrops truncipennis, female, Bird Island, South Georgia Islands; (8) A. siberia, male holotype, Yungas de la Siberia, Bolivia; (9) A. tetrastichus, male paratype, Quito–Baeza pass; (10) Photoantrops echinus, male holotype, SierrAzul Lodge, Ecuador; (11) Coloantrops daedalus, female paratype, Laraquete, Chile; (12) Poecilantrops psilosternum, female paratype, Nova Friburgo, Brazil.

FIGURES 119–124. Antrops terminalia. A. orbitalis: (119) male, phallus, postgonite, and phallapodeme, lateral view, (120) male, surstylus, anterior view, (121) male, sternite 5, (122) female, tergite 8, epiproct, cerci, (123) female, sternite 8, hypoproct, (124) female, spermathecae.

FIGURES 85–91. Antrops terminalia. A. cochabamba: (85) male, phallus, postgonite, and phallapodeme, lateral view, (86) male, surstylus, anterior view, (87) female, tergite 8, epiproct, cerci, (88) female, sternite 8, hypoproct, (89) female, spermathecae; A. cochinoca: (90) male, phallus, postgonite, and phallapodeme, lateral view, (91) male, surstylus, anterior view. ad, anterodorsal corner of surstylus; mr, medial ridge of surstylus; pc, posterior cleft of surstylus; vt, ventral tooth of surstylus; cr, cercus; ep, epiproct; hp, hypoproct; s, sternite; t, tergite.

FIGURES 13–18. Archiborborine wings: (13) Antrops annulatus; (14) A. nitidicollis; (15) A. tetrastichus; (16) Coloantrops daedalus; (17) Maculantrops hirtipes; (18) Poecilantrops stellans.