Alavesia spinosa Sinclair & Grimaldi 2020, new species
Creators: name: Sinclair, Bradley J.
name: Grimaldi, David A.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Atelestidae
Alavesia
Alavesia spinosa

description: Alavesia spinosa, new species   Figures 1L, 4A, 5C, 7C, 17A  
 DIAGNOSIS: Wing moderately slender (fig. 17A), L/ W 2.88, with distinctly narrowed apex; R 4 +5 and M 1+2 slightly curved; bm-cu and CuA nearly symmetrical; cell dm long and slender. Postpedicel very large, L/ W 4.88, lanceolate. Male genitalia with pair of thick, spinelike setae just anterior to bases of surstyli.   
 DESCRIPTION: Male. Coloration partially visible, much of cuticle with layer of air. Mesoscutum and scutellum dark tan/light brown; postpedicel brown; pleura brown at least in center, perhaps more; halter knob light brown; tarsi entirely dark brown, tibiae and femora lighter; tergites 1–4 dark brown, others yellowish; wing completely hyaline. Head: Scape slender, longer than pedicel; pedicel small, quadrate, setose; postpedicel long, lanceolate (fig. 1L), L/ W 4.88; stylus relatively short, 0.39 × length of postpedicel, with 2 minute basal articles.   
 Thorax: Macrosetae thickened (fig. 5C); acrostichals small and fine, in biserial rows; dorsocentrals similar to acrostichals, ending in pair of long prescutellar setae plus 3 smaller macrosetae per side. Postpronotal setae only slightly larger than acrostichals; 5 notopleural setae of variable lengths; 1 postsutural supraalar seta; 1 postalar seta; 3 pairs scutellar setae, apical pair upright, crossed at tips, only slightly larger than lateralmost scutellars.   
 Legs: Forecoxa setose on anterior surface, longer at apex; forefemur with anteroventral row of ~30 short, spinulelike setae along length of femur; mid and hind femora with such setae only near apex. Tibia with long, apical ventral seta(e): 1-2-2. Hind tibia with short dorsal row of 3–4 thick setae, lengths ~0.7 × width of tibia, posterior surface with brush of fine setulae.   
 Wing: Length 1.7 mm (fig. 4A), vein C terminating slightly beyond M 1+2; Sc nearly reaching costal margin; R 4+5 parallel to M 1+2 but diverging at apices, both veins slightly curved (not straight); crossvein r-m at distal third of cell dm, cell long and slender; apex of M 4 slightly closer to M 1+2 than to CuA+CuP; CuA not aligned with bm-m; apex of cell cua acute, cell cua almost symmetrical with cell bm; CuA+CuP bent slightly in middle.   
 Abdomen: Slightly longer than thorax. Setae short, with little differentiation; sternites 2–4 with slightly thicker, short setulae on posterior and lateral margins. Terminalia (fig. 7C): Epandrium short, broad, dorsally complete, with some setulae and fringe of 5–6 long, fine setae on ventral margins. Cercus small. Surstylus long, slender, digitate, with medial row of 5 fine setulae, apical setula clavate. Phallus short, bifid. Genitalia uniquely with pair of stout, large, spinelike setae near bases of surstyli.   
TYPE MATERIAL: Holotype, male: AMNH KL7-18. The fly is in excellent condition, preserved in clear yellow amber with many microscopic details visible.  
 ETYMOLOGY: The specific epithet is from the Latin spinosus (thorny), in reference to the pair of thick, spinelike setae on the male terminalia.
description: Published as part of Sinclair, Bradley J. & Grimaldi, David A., 2020, Cretaceous diversity of the relict genus Alavesia Waters and Arillo (Diptera: Empidoidea: Atelestidae), pp. 1-40 in American Museum Novitates 2020 (3961) on pages 30-34, DOI: 10.1206/3961.1, http://zenodo.org/record/5370399