Alavesia pankowskiorum, Sinclair & Grimaldi, 2020

Sinclair, Bradley J. & Grimaldi, David A., 2020, Cretaceous diversity of the relict genus Alavesia Waters and Arillo (Diptera: Empidoidea: Atelestidae), American Museum Novitates 2020 (3961), pp. 1-40 : 29-30

Alavesia pankowskiorum , new species

Figures 1I–K , 3C–F , 7A–B , 8B , 10B , 15C–F

DIAGNOSIS: Relatively small species (fig. 15C–F), wing length 1.0 to 1.4 mm. Males with postpedicel lanceolate to slightly narrow-triangular L/ W 4.3 –3.4x, arista ~0.43 × length of postpedicel; cell cua slightly acute to truncate; M 1+2 and R 4+5 parallel (but slightly curved), diverging slightly at wing margin; M 1+2 and M 4 widely divergent; acrostichals in uniserial (vs. biserial) row; 2 (vs. 3) pairs scutellar setae.

DESCRIPTION: Male. Coloration: notum, abdominal tergites, terminalia evenly light brown, without bold markings; legs and postpedicel lighter. Head: Scape elongate, about as long as width of broadest portion of pedicel. Postpedicel lanceolate to slightly narrow-triangular, gradually and evenly tapered (fig. 1I–K), L/ W 4.3 –3.4x; stylus ~0.43 × length of postpedicel, with two basal articles. Palpus short and narrow (fig. 8B).

Thorax: Macrosetae thickened: acrostichals fine, short, in uniserial row; dorsocentral setae similar to acrostichals, ending in pair of long prescutellar dorsocentral setae; 1 anterior and 1 posterior postpronotal seta; 4 anterior notopleural setae of variable lengths, 1 posterior notopleural seta; 1 postsutural supraalar seta; 1 postalar seta; 2 pairs of scutellar setae.

Legs: Forecoxa with short erect anterior setae; anteroapical setae longer and stouter. Forefemur with anteroventral row of short, spinulelike setae; shorter rows near apex of mid and hind femora. Mid and hind coxae with 2–3 stout lateral setae on apical half. Tibiae with biserial row of short, stout ventral setae; apex of tibiae with long, apical ventral seta(e): (1-2-2). Hind tibia with dorsal row of stout setae, length about half width of tibia.

Wing: Length 1.0– 1.4 mm (fig. 3C–F). Costa terminating slightly beyond M 1+2; Sc nearly reaching costal margin; R 4+5 parallel to M 1+2, diverging slightly near wing margin, veins straight to slightly or obviously curved; crossvein r-m at midlength to apical quarter of cell dm; M 4 straight to wing margin; apex of M 4 approximately equidistant between M 1+2 and CuA+CuP; M 1+2 and M 4 widely divergent; CuA slightly convex; apex of cell cua slightly convex to virtually truncate, length of cell cua slightly shorter than cell bm; CuA+CuP mostly straight, slightly curved subapically to wing margin. Anal vein present; anal lobe very narrow.

Abdomen: Setae short, posteromarginal setae of tergites and sternites hardly differentiated. Segments 1–5 broad, remaining segments retracted with segment 5. Terminalia (fig. 7A,B): cercus finely setose; truncate apically. Epandrium U-shaped with broad dorsal bridge anterior to cerci; long setae along posterior margin, half length of epandrium. Surstylus very narrow and elongate, projecting nearly vertically from epandrium, as long as apical epandrial setae. Phallus slender, sclerotized projection; strongly and evenly (vs. abruptly) bent subapically, hooklike, with apex arched ventrally, apex minutely feathered, probably bifid. Female terminalia like that of Alavesia sp. (JZC Bu-1729: fig. 10C) and A. zigrasi (AMNH Bu-KL9-21: fig. 10D).

TYPE MATERIAL: Holotype, male, AMNH Bu-1554 (other 2 males, 2 females paratypes) . Paratypes, male AMNH Bu-888; male AMNH Bu-KL7-19; male USNM PAL 726869 .

ETYMOLOGY: The specific epithet is named in honour of Pankowski family who donated several specimens used in this study.

Figures

FIGURE 3. Wings of three species of Alavesia in Burmese amber. All are to the same scale. Specimens: A. USNM PAL 726872. B. USNM PAL 726873. C–E. A. pankowskiorum, see figure for specimen numbers. F. Undetermined species.

FIGURE 7. Male terminalia of three species of Alavesia in Burmese amber, shown in various views, to the same scale. A. A. pankowskiorum, AMNH Bu-KL7-19, lateral view. B. A. pankowskiorum, USNM PAL 726869, anterolateral view. C. A. spinosa, AMNH KL7-18, ventrolateral view, with detail of surstylus tip showing clavate setula. D. A. zigrasi, JZC Bu-281. For abbreviations see figure 6.

FIGURE 8. Heads and antennae of Burmese amber Alavesia. A. A. lanceolata, head and antennae, dorsolateral view, holotype, USNM 726868. B. A. pankowskiorum, head and antennae, lateral view, paratype, AMNH Bu-KL7-19. C. A. magna, left antenna, lateral view, holotype, AMNH Bu-KL2-7. D. A. magna, left antenna detail, lateral view, holotype, AMNH Bu-KL2-7. E. A. brevipennae, lateral view, AMNH Bu-494. Note the longer microtrichia on the postpedicel. F. A. longicornuta, holotype, stylus tip, lateral view, JZC Bu-556.

FIGURE 10. Features of Alavesia spp. A. A. magna, holotype, AMNH Bu-KL2-7, wing base. B. A. pankowskiorum male terminalia, right ventrolateral view, USNM PAL 726869. C. Female terminalia, Alavesia sp., lateral view, JZC Bu-1729. D. A. zigrasi female terminalia, lateral view, AMNH Bu–KL9–21.

FIGURE. 1. Antennae of Burmese amber Alavesia species, lateral views. All are males except N, O, P. Some antennae were reversed in direction for optimal comparison; longicornuta and longistylata are slightly reconstructed to account for curvature of the stylus. All are to the same scale. Specimen numbers: A. USNM PAL 726867. B. AMNH Bu-494. C. AMNH Bu-496. D. USNM PAL 726868. E. AMNH Bu-KL2-7. F. AMNH Bu-1476. G. JZC Bu-556 (AMNH). H. USNM PAL 726872. K. USNM PAL 726869. L. AMNH Bu-KL7-18. M. JZC Bu-282. N. Undetermined species. O. A. zigrasi. P. A. zigrasi.