Drosophila (Sophophora) chibcha, Grimaldi, 2024

Grimaldi, David A., 2024, The Drosophila (Sophophora) obscura species group in the Americas (Diptera: Drosophilidae): review, revisions, and three new species, American Museum Novitates 2024 (4015), pp. 1-44 : 22-25

Drosophila (Sophophora) chibcha , new species

Figures 2A , 4B , 7D , 9F–I , 11D , 14D

DIAGNOSIS: Facial carina very thin, small; notum and pleuron light brown; acrostichal setulae in 6 rows; sex comb with 3 slender teeth on ta 1, 2 on ta 2 (specimen from Peru with 1 tooth also on the left ta 3), teeth protrude away from tarsal segments. Inner lobe of ventral epandrial lobe lacking furrows at base; surstylus with row of 9–10 prensisetae; valves of aedeagus unique among New World species, having coarse scales on ventral surface (dorsally with finer ones). Costa Rica to Peru and Venezuela.

DESCRIPTION: Coloration: Frons dark brown, lighter on ptilinal margin; frontal vittae blackish brown, dull; fronto-orbital plates and ocellar triangle faintly shiny, lighter brown; antennal pedicel, flagellomere 1, face, clypeus, cheek light brown, palp dark yellow-tan. Scutum light brown, grading to slightly darker brown posteriad and on scutellum; notum with slight shine; postpronotal lobe, notopleural area, anepisternum, and anepimeron slightly darker, katepisternum same to slightly lighter. Legs tan; halter bulb light (whitish to yellow); abdomen uniformly brown in both sexes, darker in ♂.

Head: Arista with 3–4 dorsal, 2 ventral branches, plus terminal fork; pedicel with 1 stout, longer seta, 3 smaller ones. HD/HW 0.76 (mean of 4♂). Anterior reclinate orbital seta directly lateral to slightly posterolateral of the proclinate orbital; posterior reclinate midway between proclinate and inner vertical setae or slightly closer to proclinate; proclinate 1.7× length of anterior reclinate, posterior reclinate 1.20× length of anterior reclinate. Ipsilateral vertical setae separated only by distance approximately 2× the socket diameter; inner vertical in line with proclinate and posterior reclinate, IV/OV 0.87. Ocellar setae sockets on tangent between median and posterolateral ocelli; postocellars parallel to slightly convergent, length slightly less than ocellars, OC/POC 1.24; 5–6 small setulae in ocellar triangle. Frons with 10–12 setulae near anterior margin. FL/LFW 0.98, UFW/LFW 1.61. Face slightly deeper than wide, frontal W-index 2.89; carina small, narrow, short (0.3–0.4× length of face); vibrissa long, 1st genal seta small, GS1/VL 0.30, gena with row ~7 setae, increasing in length posteriad. Cheek of moderate depth, ED/CD 8.65. Palp with 1 long apical seta, 2–3 shorter setae in middle of ventral margin. Eye broadly oval in lateral view, EW/ED 1.21.

Thorax: Length 0.77 mm (mean of 4♂). Acrostichals in 6 rows between anterior dorsocentrals, lengths slightly increasing posteriad; acrostichals in front of scutellum or anterior dorsocentrals not enlarged. Anterior dorsocentrals 0.61× length of posterior ones; distance between ipsilateral dorsocentrals less than that between contralateral ones. Postpronotum with 2 strong setae, UPS/LHS 0.75; 2 strong notopleural setae near notopleural suture, plus 1 longer one dorsally, another postsutural; katepisternum with 2 large setae, posterior one larger (S-index 0.65), sclerite with 4–5 small setulae. Anterior scutellar setae approximately parallel, posterior ones crossed for about 0.3× their length, anterior pair 0.85× length of posterior pair. Legs: profemur with 3 longer ventral setae (lengths approximately equal to femur width); mid and hind tibiae with stout, ventroapical setae, thinner dorsal-preapical seta; ♂ protarsus with length of ta 1 1.07–1.38× that of ta 2; ta 1 with 3 teeth, ta 2 with 2; teeth long, slender, not touching, projecting away from tarsomeres, tooth lengths 0.1.5–2× width of tarsomeres. Wing of moderate length and width, ThL/WL 0.45, WL/WW 2.33, C-index 1.84, hb-index 3.61, 4V-index 2.49, 5X-index 2.51.

Abdomen: Male terminalia: epandrium height approximately equal to width; cerci somewhat flattened, ventral portion tapered, with small tuft of fine setulae; outer lobes of ventral epandrial lobe broad in lateral view, relatively short; margin of inner lobe of ventral epandrial lobe faintly defined from surstylus; surstylus with row of 10–11 prensisetae; aedeagus and valves very slightly shorter than postgonites; valves uniquely with irregular row ~10–12 coarse scales on ventral margin, additional scales on dorsolateral surface; aedeagal membrane with sparse, finer scales, no microtrichia; hypandrium length ~1.3× the width. Female terminalia: spermathecsa cup shaped, width 1.5× the height; sleeve broad and funnellike, no apical indentation. Oviscapt broad in lateral view, apically blunt, with ~12 small ovisensilla pegs along margins.

TYPE: Holotype, ♂: COSTA RICA: Punatarenas , Las Alturas , 20 km NE San Vito de Hava, 1500 m, 20/VIII/91, Grimaldi and Stark, sweeping forest floor. Dissected ( ASG 05 ), in AMNH.

ETYMOLOGY: In keeping with a tradition of naming American species of the obscura group for indigenous cultures, this species is named for the Chibcha people, as a noun in apposition. The Chibcha (pronounced cheeb’-ka) inhabited Colombia since at least the fifth century BCE; they also settled in Panama, both countries centered within the distribution of this species.

SPECIMENS EXAMINED: Paratypes: COSTA RICA, Prov. San José, Moravia, Zurquí de Moravia , 1600 m, 5–8 Sep 2012, W. Porras, Tp. Malaise #1, ZADBI-1, -84:00:57 10:02:58 #104987, ♂ (dissected, ASG 04) ; 22 Sep 2012 pan light trap, #105059, ♀ (dissected, ASG 17), 24 Sep 2012 Dry MT, ZADBI-60 #165076 ♀ (dissected, ASG 09); San José, Zurqui de Moravia, 1600 m, VII/92, Paul Hanson , Malaise trap ♀ (dissected, ASG18) ( AMNH, MNCR) . PERU: Cusco, Est. Biol. Wayqecha , 13.1845°S 71.58459°W, 2806 m, malaise trap 6, WP532, 8–11/ XII/11, Steck, Norrbom, Sutton, Nolazco, 1 ♂ (dissected, ASG 08) , 1♀ same data, except: WP583, 4–12/VI/12 ( USNM). VENEZUELA: Aragua, Rancho Grande , 26/II/89, D.A. Grimaldi, 1♂ (dissected, ASG 07) ( AMNH) ♀.

DISTRIBUTION: Costa Rica, Venezuela, Peru.

COMMENTS: The Peru specimen has some differences with other specimens of this species: frontal-index 0.81 (vs. 1.00–1.09), cheek deeper (ED/CD 6.66 (vs. 9.2–9.5), frontal-W index 2.6 (vs. 2.85–3.10), but which may not be statistically significant. Most notable is the unique occurrence of a “tooth” on male protarsomere-3. This tooth does not occur on its right ta3, suggesting that the left one is teratological. Slight asymmetries in tooth counts of the sex combs of individual flies is not unusual in various species of the obscura group (e.g., Crumpacker, 1973). For these reasons, and the fact that the male genitalia are identical, I am considering the Peru specimen to be the same species.

All the specimens were collected without bait traps, instead captured in Malaise and light traps, or (in Venezuela) by net sweeping the forest floor. All the collecting localities are cloud forest; a detailed description of the Zurqui, Costa Rica, site is given in Borkent et al. (2018).

Figures

FIG. 2. Heads and thoraces (lateral view) of representative New World species of the obscura group (A–D), and a male midleg of D. cuauhtemoci (E). A. D. chibcha holotype, n. sp. (ASG 05); B. D. maya holotype. C. D. narragansett paralectotype male. D. D. seminole holotype. E. D. cuauhtemoci, male midleg (lateral view), paratype.

FIG. 4. Frontal view of heads of representative species of the affinis subgroup. A. D. affinis, male. B. D. chibcha, n. sp., male holotype (ASG 05); C. D. tolteca, male (ASG 23); D. zapoteca, n. sp., male holotype (ASG 20). Note differences in development of the facial carina compared with faces in figure 3.

FIG. 7. Oviscapts and spermathecae (lateral views) of species in the affinis subgroup, with apical details for three species. A. D. affinis (ASG 28); B. D. athabasca (ASG 30); C. D. azteca (ASG 15); D. D. chibcha, n. sp. (ASG 17); E. D. dobzhanskii (ASG 33); F. D. narragansett (ASG 11); G. D. tolteca (ASG 24).

FIG. 9. Protarsal male sex combs (tarsomeres ta1 and ta2, and ta3 for D. chibcha from Peru) of species in the affinis subgroup. A. D. affinis (ASG 29); B. D. algonquin (ASG 32); C. D. athabasca (ASG 31); D. D. azteca (ASG 13: San Franciso, CA); E. D. azteca (ASG 06: Leticia, Colombia); F. D. chibcha, n. sp. (ASG 04: Zurqui, Costa Rica); G. D. chibcha, n. sp. (ASG 05: Las Alturas, Costa Rica); H. D. chibcha (ASG 07: Rancho Grande, Venezuela); I. D. chibcha (ASG 08: Wayqecha, Peru); J. D. narragansett (ASG 10); K. D. olmeca (ASG 25); L. D. tolteca (ASG 23). All to the same scale.

FIG. 11. Epandria (male tergite VIII) and associated structures in representative species of the affinis subgroup. A. D. affinis (ASG 29); B. D. affinis, detail of A; C. D. azteca (ASG 13); D. D. chibcha, n. sp. (ASG 05).

FIG. 14. Hypandrium, aedeagus and other appendages of representative species of the affinis subgroup (ventral views). The valves of the aedeagal sheath and the pair of hypandrial lobes are highlighted in color; the postgonites are not. A. D. affinis (ASG 29) (hypandrial lobes hidden); B. D. athabasca (ASG 31); C. D. algonquin (ASG 32); D. D. chibcha, n. sp. (ASG 05), with detail of aedeagal valves of ASG 05 (above), and ASG 08 (below). All to the same scale except details of D. chibcha.