Although the global human commensal Drosophila funebris (Fabricius) is well known and is the type species of the genus Drosophila Fallén, the four native North American species of the funebris group have been poorly defined morphologically. D. macrospina limpiensis Patterson and Wheeler is newly recognized as a species distinct from D. macrospina, with diagnostic morphological characters provided. The subspecies D. macrospina ohioensis Stalker is synonymized under D. macrospina. Species native to the Palearctic and to the Nearctic are morphologically distinct, each probably a monophyletic group. Detailed descriptions and redescriptions are provided for both sexes of D. macrospina Stalker and Spencer, D. limpiensis Patterson and Wheeler, D. subfunebris Stalker and Spencer, and D. trispina Wheeler, the latter two being very rare species from southern California. Neotypes are designated for D. macrospina and D. subfunebris. A key to the five Nearctic species of the funebris group is provided.
INTRODUCTION
The naming and description 234 years ago of the original species of Drosophila, funebris (originally within Musca), by Linneaus' great student Johann Christian Fabricius (1745–1808), is not merely coincidence. The species is a global human commensal fond of a wide array of human landscapes, including stables, farms, and all sorts of human refuse. Doubtless it was everywhere in Denmark where Fabricius was a professor. Another global commensal, Drosophila melanogaster—equally widespread and in even larger numbers, but preferring decaying fruits—was not described by Johann Meigen until 43 years later, well before it became the darling of experimental biology in the early 20th century. If melanogaster had been described first, then the current taxonomic situation in Drosophila may have been very different.
The genus Drosophila as currently recognized is polyphyletic, the main subgenera, Drosophila and Sophophora, not particularly closely related (Throckmorton, 1975; Finet et al., 2021). If classifications should reflect phylogenetic relationships—which biologists generally agree should be the case—this presents a conundrum. Do we call just the subgenus Drosophila as the genus Drosophila, and melanogaster becomes Sophophora melanogaster? Or do we transfer the name and concept of what is currently the subgenus Sophophora to be the new, revised version of the genus Drosophila? Or do we just continue to use the genus name Drosophila for both of these subgenera, with an understanding that they are not sister taxa? Whatever the outcome, Drosophila funebris as a type species is consequential to any concept of a genus Drosophila. In this regard, an understanding of its close relatives in the funebris group is significant. This study clarifies several aspects of the native North American species of the group, two of which are very rare and hardly known.
METHODS AND MATERIALS
Preserved specimens in the AMNH were studied along with newly preserved material from cultures provided by the Drosophila Species Center (DSC), formerly at the University of California, San Diego (now at Cornell University, Ithaca, New York). Cultures were the following: “macrospina limpiensis,” culture no. 15120-1921.00, from Patagonia, Arizona; “macrospina macrospina,” 12120-1931.02, from Sonora, Mexico; and funebris, 15120-1911.01 from Mexico City, Mexico. Culture no. 15120-1931.03, from Austin, Texas, which was received from the DSC but was misidentified, being actually Drosophila melanica. AMNH material includes the collection of the late Marshall R. Wheeler who was at the University of Texas, Austin, the author's collections, and those of others.
Point-mounted specimens were measured and photographed using a Nikon SMZ1500 stereoscope and Elements® software. Proportions of head and setation used standard measurements and ratios (e.g., Bächli et al., 2004). Male and female terminalia were macerated in 10% KOH, rinsed in water and dilute HAc, disarticulated in glycerine, and slide mounted in glycerin jelly for study at 100-400× using a Nikon Eclipse compound scope.
Repositories of type specimens and sources of cultures are cited under the species treaments, abbreviated as the following:
SYSTEMATICS
THE DROSOPHILA FUNEBRIS SPECIES GROUP
Drosophila funebris group: Sturtevant, 1942: 31 (diagnosis, classification); Patterson and Stone, 1952; Bächli et al., 2004.
Diagnosis: Species with dark brownish to red-brown thorax and head; abdominal coloration dimorphic (tergites in males with more extensive, darker pigmentation). Male: Epandrium and cerci completely lacking microtrichia; ventral epandrial lobe very small, bearing several small, stout setae (these short and thornlike in Old World species; slender, spinelike in New World species); male cerci with stout, heavy spines on ventral portion (most of the mesal margin in funebris).
Immatures and Breeding Sites: Eggs with four fine filaments (known for limpiensis, macrospina, multispina, subfunebris, and trispina). Larval stages and puparia described for D. funebris and D. multispina (Okada, 1968), and the puparia described for D. macrospina and D. limpiensis (Patterson, 1943). Species of the funebris group have been caught at decaying fruits and in vinegar traps, at sap fluxes, on macrofungi, usually in forested habitats (Werner et al., 2020a, 2020b; Miller et al., 2017; see individual species, below).
Mating Behavior: Studied by Spieth (1952) for five of the North American species (Drosophila funebris, limpiensis, macrospina, subfunebris, and trispina) and by Ewing (1979) for all of these except trispina but including the Old World species multispina Okada. Spieth (1952) stated that courtship and copulation among species “is relatively uniform and conforms to the basic pattern found in the subgenus Drosophila,” although courtship is “reminiscent” of the quinaria group and male aggressiveness to that in the virilis group. Ewing (1979) studied the male courtship songs (see below, under limpiensis).
Species Included:
altukhovi Imasheva et al., 1994: Daghestan. Type locality (TL): Makhachkala, Republic of Daghestan.
funebris (Fabricius, 1787): worldwide (originally Palearctic). TL: Copenhagen, Denmark.
limpiensis Mainland, 1941: southwestern North America. TL: Limpia Canyon, Texas.
multispina Okada, 1956: China, Far East Russia, India, Japan. TL: Sapporo, Hokkaido, Japan.
macrospina Stalker and Spencer, 1939: eastern North America. Neotype locality: New Orleans, Louisiana.
pentaspina Parshad and Duggal, 1966: Jammu and Kashmir, India. TL: Srinigar, Kashmir Valley, India.
subfunebris Stalker and Spencer, 1939: California, United States. Neotype locality: Pasadena, California.
trispina Wheeler, 1949: California, United States. TL: near Earp, California.
It is interesting that half the species are poorly known, presumably localized species, while Drosophila funebris is a widespread invasive. Drosophila macrospina, limpiensis, and multispina have larger distributions than the four rare species that are known just from their type localities. Drosophila trispina and subfunebris are among the rarest drosophilids in North America. Okada (1956) originally included Drosophila maculinotata in the funebris group because of the spines on the cercus, but this species is certainly not within this group based on the structure of the spermathecae, female and male internal reproductive organs; deep cheeks, and various other features. Additional species in the group will probably be found in southern China and the Himalayan region; it is unlikely that new species will be found in North America.
The four species native to the Palearctic can morphologically be defined as a monophyletic group based on the short, thornlike setae on the ventral epandrial lobe in the male (Bächli et al., 2004; Imasheva et al., 1994; Okada, 1956; Parshad and Duggal, 1966). The native Nearctic species all have the derived features of serrate preapical lateral lobes on the aedeagus and a very distinctive pair of serrate apical lobes that articulate with the apex of the aedeagus, as described herein. Thus, there appears to be two lineages in the species group, one Palearctic and another Nearctic, each with four species.
Relationships within Drosophila: Molecular and morphological evidence agrees that the funebris group is within the tripunctata radiation sensu Throckmorton (1975), although Throckmorton indicated a relatively isolated position for funebris within the subgenus Drosophila. Morphological features supporting placement in the “tripunctata radiation” are the following: Internally, male ejaculatory bulb with a pair of diverticula, vas deferens with a common stem; and female with ventral receptacle highly coiled (Okada, 1956; Throckmorton, 1962). Externally: anterior reclinate orbital seta between the proclinate and posterior reclinate orbital setae (vs. lateral to proclinate or nearly so); two strong pairs of vibrissae; microtrichia reduced to entirely lost on epandrium and cerci.
There is molecular disagreement as to whether the funebris group is most closely related to the testacea group (Robe et al., 2005; Russo et al., 2013), or to the large Holarctic quinaria group (Robe et al., 2010; Morales-Hojas and Vierera, 2012). Finet et al.'s (2021) molecular analysis indicates that the funebris group is closely related to a group comprised of Drosophila testacea + macroptera + bizonata + histrio, and this collectively is the sister group to the quinaria group. Morphological evidence agrees best with the molecular study by Izumitani et al. (2016), that the funebris group is sister group to the rest of the tripunctata radiation after the immigrans species group. This is based on the plesiomorphic absence in the funebris and immigrans groups of a scoop-shaped “dorsal arch” between and articulating with the two ends of the posterolateral arms of the hypandrium (a distinctive structure present in the quinaria, testacea, tripunctata, and most other groups of the radiation).
Drosophila funebris (Fabricius)
Figure 9A
Musca funebris Fabricius 1787: 345.
Drosophila funebris (Fabricius): Type species of genus Drosophila. Patterson, 1943 (redescription, internal reproductive organs, immature stages, chromosomes, North America distribution); Bächli et al., 2004 (redescription, European distribution); Miller et al., 2017 (redescription, genitalia, eastern North America distribution); Werner et al., 2020a, 2020b (identification, biology).
Diagnosis: Easily distinguished from other Nearctic species of the funebris group by the numerous spines, ∼12, on the male cercus along the mesal margin (vs. 4–6 in native Nearctic species), and by the short, thornlike setae on the epandrial lobe (vs. slender, spinelike setae); female with oviscapt having dorsal knob (vs. without) (fig. 9A).
Description: A detailed description was provided by Bächli et al. (2004) and others (above).
Distribution: A worldwide species found in close association with humans and their domestic animals, and distinct from native North American species by its tolerance of cold; funebris is absent from hot, lowland tropics. The species is present in Iceland and Greenland, and is widespead in Scandinavia, occurring as far north as Longyearbyen, Spitzbergen Island, Norway, 66°19′9.8″ N, no doubt surviving the coldest months within human dwellings (Bächli et al., 2004). It occurs throughout North America, including Texas and northern Mexico, but is more prevalent in cooler climates and higher altitudes (Patterson and Wagner, 1943). Northern limits of its distribution in North America are not well explored, especially the western portion, including Alaska. In the east D. funebris is recorded from southern Québec, Nova Scotia, eastern Newfoundland, and generally in southern Ontario to ∼200 km SW of James Bay at about 52° N (Miller et al., 2017), although it probably occurs even farther north.
Drosophila macrospina Stalker and Spencer, 1939
Figures 1B, 2B, 3A–D, 4B, 5B, C; 6C, D, I; 7A, B, 8B–D, 9C
Drosophila macrospina Stalker and Spencer, 1939: 110. Subsequent refs: Mainland, 1942 (hybrid sterility); Patterson, 1943 (redescription, internal reproductive organs, immature stages, chromosomes); Patterson and Wagner, 1943 (distribution); Patterson and Stone, 1952 (distribution); Miller et al., 2017 (identification, eastern distribution); Werner et al., 2020a, 2020b (identification, biology);
Drosophila macrospina ohioensis Spencer, 1940: 304. NEW SYNONYM.
Diagnosis: Very similar to Drosophila limpiensis. Postocellar setae slightly to strongly convergent to crossing; male with lateral lobes of distiphallus broader and more protruding than in D. limpiensis (especially at the apex); apical lobes with more lateral serrations; large gap between largest (dorsalmost) cercal spine (1) and next one (2) (gap is ∼width of spine 2, vs. with barely any gap); ventral epandrial lobe with 4–5 small setae (vs. 2 thick ones in limpiensis). Female: oviscapt dark, sclerotized as in limpiensis. No distinction between the two species is apparent in the surstyli or female terminalia.
Description: Body size, ThL 1.12 mm (0.92–1.30); wing length, 2.25 mm (1.95–2.74). HEAD: significantly broader than deep HW/HD 1.39; frons short, FL/LFW 0.74 (0.69–0.82), UFW/LFW 1.39 (1.30–1.51). Eye dull, light red, with dense ommatrichia, proportions in lateral view ED/EW 1.26 (1.16–1.34). Frons, face, antennae dull, pollinose, light brown; frontal-orbital plates and ocellar triangle slightly shiny, FOPs (frontal-orbital plates) and carina lighter. Frons with small, scattered setulae on anterior half. Proclinates parallel, shorter than posterior reclinates. Ipsilateral proclinate, posterior reclinate, and inner vertical in line. Anterior reclinate posterolateral to proclinate, closer to proclinate than to posterior reclinate. Posterior reclinates slightly divergent. OR1/OR2 2.32 (1.8–2.8); OR1/OR3 0.69 (0.62–0.82). Inner verticals strongly inclinate, outer verticals strongly pointed posterolaterad; verticals nearly equal in length, VT-index 0.97 (0.92–1.07). Postocellars very strong, slightly convergent to strongly convergent and even cruciate for ∼0.5× their length. Ocellar setae long, tips reaching slightly past ptilinal suture; setal sockets lie between anterior and posterior ocelli. Antennal pedicel with 2 larger setae (1 proclinate, 1 lateroclinate), plus ca. 12 smaller setulae; pedicel without long, fine setae on mesal surface; basal flagellomere with fine setulae short; arista with 4–5 dorsal and 3 ventral branches. Carina narrow, CL/CW 5.33 (3.6–6.5), edge slightly flattened, lying below level of flagellomere 1. Two pairs strong vibrissae present, vibrissa longer than subvibrissa, vibrissa-index 0.77 (0.65–0.88); 7–8 small setae on cheek, anterior margin of cheek darker; cheek shallow, ED/CD 8.90 (6.85–10.8). Clypeus U-shaped, shiny. Palp yellowish, asymmetrical, ventral margin convex, with 2–3 longer setae; dorsal margin flat. Mentum dark yellow, shiny, with ∼10 long, fine setae. Labellum with 8–9 pseudotracheae. Occiput dark yellow and light brown.
Thorax: ThL males 1.06 mm (0.89–1.15mm; N = 9), ThL females 1.29 mm (1.24–1.40 mm; N = 4). Scutum and scutellum light brown (centrally lighter for scutum), faintly pollinose, dull not shiny; pleura slightly lighter, especially katepisternum. Acrostichals in 8 rows between dorsocentrals; anterior to dorsocentral is row of 4–5 acrostichals slightly thicker and longer than others; transverse row of ∼4 acrostichals 1.4–2.0× length of others anterior to transverse suture. 2 postpronotal setae, lower one larger than upper, h-index 0.82 (0.76–1.0), thinner than notopleurals; 3 notopleural setae, 2 at ventral edge of notopleural suture, posterior seta short. Supraalar setae: 1 short, 1 long; 2 large katepisternal setae, anterior one significantly shorter than posterior dc, S-index 0.68 (0.62–0.75), with small seta between them and a vertical row of ∼10 small setulae. Dorsocentral setae: large, well developed, anterior pair significantly shorter than posterior pair, DC-index 0.65 (0.51–0.70); scutellum with anterior pair of setae slightly shorter than posterior, Scut-index 0.91 (0.86-0.94), posterior scutellars slightly to strongly convergent. Legs yellow; fore femur with 3–4 long ventral setae, 1 fine, preapical dorsal seta; male fore tarsus without longer, erect, recurved setulae. Mid tibia with thick ventroapical seta, shorter preapical dorsal seta; hind tibia with 1 fine preapical dorsal seta. Wing: relative to body size, WL/ ThL 2.00 (1.85–2.18); relatively broad, WL/WW 2.19 (2.11–2.23); C-index 2.98 (2.65–3.30); hb-index 1.96 (1.70–2.23); 4V-index 1.53 (1.41–1.62); distance of crossvein dm-cu from wing margin, 5-X-index 1.25 (1.08–1.42). Halter light.
Abdomen: Pigmentation sexually dimorphic; male tergites almost entirely dark blackish brown, shiny, with faint lighter areas in middle of tergites 1–3; epandrium and cerci lighter; sternites light. Female tergites with dark band on posterior half of each segment, anterior half light; dark band on tergites 2–4 with slightly median interruption, tergite 6 with middle of dark band enlarged; tergites 7, 8 light, yellowish, paraprocts slightly darker; oviscapt dark, especially at base.
Male Terminalia: Epandrium lightly sclerotized, devoid of microtrichia, short and somewhat flattened (not capsulate); dorsolateral phragma well developed; ventral lobe small, closely pressed to surstylus, with 4–5 short, stout setae at apex. Cerci well developed, projecting well beyond margins of epandrium, lacking microtrichia, with many long setae; ventral margin with 3 heavily sclerotized spines, 3 smaller ones ventrally (sometimes 2), a large one apically (twice the size of other 2); no gaps between smaller spines; gap between smaller and large spine large, ∼1.5× thickness of large spine. Surstylus well developed, with row of 9–10 peglike prensisetae, 8–14 thick setulae laterally. Hypandrium well developed, lightly sclerotized, anterior end narrowed to ∼0.60× width of posterior end; gonopods (postgonites/paraphyses) with longer seta posteriorly, small seta (∼0.5× the length) mesally; inner lobe of gonopod more sclerotized; pair of narrow sclerites attached to posteromedial corners of hypandrium, not connected in middle. Aedeagus with slender neck of uniform thickness, moderately arched in lateral view; apex with medial lobe (roughly triangular in shape), pair of lateral, winglike lobes, and pair of serrate, apical lobes. Lateral lobes with fine scales/serrations on lateral margins and at base near neck; these lobes hardly sclerotized; “wingspread” 5.0× (mean) thickness of aedeagal neck (range 4.3–6.0). Distal pair of lobes of aedeagus flattened, with irregular teeth/serrations on lateral, mesal and apical margins, ones on apex largest (generally 2–3 very large teeth). Aedeagal apodeme sclerotized, straight, slightly shorter than aedeagus. Ejaculatory apodeme small, bent at right angle, both arms approximately equal in length.
Female Terminalia: Oviscapt heavily sclerotized (especially at base), with ∼30 small, densely spaced marginal pegs, plus 3–4 discal ones; oviprovector membrane with sparse, fine scales. Spermathecal capsule heavily sclerotized, no exterior microtexture, with introvert reaching almost to apex; inserted portion of spermathecal tube sclerotized.
Types: Neotype, male: United States: Louisiana: 0.5mi E Miss. River, New Orleans, VI/12/41, 1112.6, GB Mainland, MR Wheeler/M.R. Wheeler, W.K. Baker/Neotype, Drosophila macrospina, det. D. Grimaldi, 2022. Dissected by D.A.G., in AMNH. Stalker and Spencer (1939) mentioned that the original, type culture, established from a female collected on fungus and from which “type and gonotypes” were made, was from Austin, Texas. As for D. subfunebris (below), no types of macrospina occur in the AMNH, NMNH or other institutions, so a neotype is designated here. Specimens from the published type locality were not available.
Specimens Examined: All in AMNH. United States: Arkansas: Logan Co., Magazine Mtn., 2750 ft., D. Grimaldi, Collected on 9/VI/92 at 2200' with banana bait, 1M (dissected). Georgia: Crooked River State Park, VI/28-VI/29/53, WB Heed, MR Wheeler; Liberty Co., St. Catherine's Is. 11-20/IV/88, D. Grimaldi, 4M, F (1M dissected). Louisiana: .5mi E Miss. River, New Orleans, VI/12/41, 1112.6, GB Mainland, MR Wheeler/MR Wheeler, WK Baker. 7 M, F (1 M dissected). Mississippi: Claiborne Co., VI/5/50, H.D. Stalker, W.P. Spencer (1F). Missouri: Webster Groves, IX/50, H.D. Stalker, W.P Spencer (1M, dissected). New York: Rochester, Highland Park, J. Jaenike, F1 of isofemale culture coll. 16/VI/2016, 4M, 4F (1M dissected). Ohio: Piqua, July 1948, JT Patterson, 1035.3 (4M,F; 3 dissected). Oklahoma: 10 mi NE Tulsa, V/2/41, AB Blair, 996.3 (2F). South Carolina: 2 mi. SW Cross Anchor, VII/13-VII/4/53, W.B. Heed, M.R. Wheeler 2321.8b (1F).
Distribution: Patterson and Wagner (1943) mapped 45 records of macrospina in North America, which was updated by Patterson and Stone (1952). Their westernmost records are from Del Rio, Texas; Moclova, Cuahuila, Mexico; north to the northwest corner of Nebraska and Fort Peck Dam in northern Montana. The record from Albuquerque, New Mexico, may be due to a higher latitude and altitude in that area or to a zone of overlap with limpiensis, but needs to be confirmed. Although it was not recorded from Florida on their maps, records from Georgia and Florida were mentioned, but, regrettably, very few of the specimens from most of their localities were saved. Miller et al. (2017) added eastern records farther north, in southern Québec, Canada, and Rochester, New York. The species is abundant in eastern Texas, the Mississippi valley, Ohio, Michigan, east to coastal Carolinas and New Jersey—essentially encompassing the eastern half of North America from ∼48° N to ∼27° N latitude.
Mainland (1942) used stocks of macrospina for his crossing experiments from the following localities, some series of which are in the AMNH collection (above): United States: Arkansas: Petit Jean St. Park [Conway] (35.1204°, -92.9379°); Florida: Tampa (∼28.0886°, -82.3224°); Louisiana: New Orleans (30.3003°, -90.7120°); Mississippi: Columbus (33.5215°, -88.4060°); Ohio: Overton [Chester Township] (40.8662°, -82.0053°); Texas: Austin (∼30.3109°, -97.8234°), Del Rio (29.3802°, -100.8930°).
Comments: Spencer (1940) made the name D. macrospina ohioensis apparently available as a brief mention within a review article on Drosophila speciation, as an example of “interfertile races/subspecies...” in which “these two subspecies [m. macrospina and m. ohioensis] cross readily and the hybrid offspring are quite fertile.” Types were not designated, though a diagnosis was given. His observations were based on a culture of two males and two females that he collected “6 mi. north of Overton, Ohio” (Overton is a small town ca. 7 mi NW of Wooster, Ohio: 40.8662°, -82.0053°). He distinguished between the two subspecies based on features now known to be quite intraspecifically variable in Drosophila, particularly coloration.
Mainland (1941) did not distinguish these subspecies because he found no sterility in crosses between m. macrospina and m. ohioensis; he reported soon afterward (Mainland, 1942) a slight reduction in fertility between them. Subsuming D. macrospina ohioensis under the species is based not only on the reports of complete hybridization, but also my observations in which no consistent morphological differentiation was found. Fortunately, several specimens of “ohioensis” are in the AMNH collection, from Piqua, Ohio (culture 1035.3, collected by J.T. Patterson), and there is no distinction between the aedeagus of these flies and macrospina from other localities (the apex of the hypandrium is slightly narrowed, but this is quite variable in Drosophila; also, the middle cercal spine is rather small). It would be ideal to compare mitochondrial DNA sequences of flies from these localities.
Stalker and Spencer (1939) mentioned that D. macrospina flies were “subject to ‘catalyptic’ fits when the container is disturbed,” but I did not observe this in the cultures examined. Drosophila macrospina seems to never be particularly abundant in its primary habitat, which is forests; the natural hosts are unknown. It can easily be bred in the lab. Geographic variation in the genetics of D. macrospina and limpiensis would be very useful for examining any zones of overlap and introgression.
FIG. 1.
Heads, frontal views, of native North American species of the Drosophila funebris group. A. D. limpiensis (ex: type locality: Limpia Canyon, Texas). B. D. macrospina (ex: Rochester, NY). C. D. subfunebris (ex: type series: Pasadena, CA). D. D. trispina (ex: type series: Earp, CA). To the same scale.
FIG. 2.
Heads, lateral views, of native North American species of the Drosophila funebris group. A. D. limpiensis (ex: Limpia Canyon, TX). B. D. macrospina (ex: Piqua, OH). C. D. subfunebris (ex: Pasadena, CA). D. D. trispina (ex: Earp, CA). To the same scale.
FIG. 3.
Drosophila macrospina thorax and abdomen (all ex: Rochester, NY). A. Head and thorax, dorsal. B. Thorax, lateral. C. Abdomen, male. D. Abdomen, female.
FIG. 4.
Epandria (male) of native North American species of the Drosophila funebris group; posterolateral views (to same scale). A. D. limpiensis (ex: Limpia Canyon, TX). B. D. macrospina (ex: Magazine Mtn., AR). C. D. subfunebris (ex: Pasadena, CA). D. D. trispina (ex: Earp, CA).
FIG. 5.
Male genitalia of native North American species of the Drosophila funebris group, ventral views (to same scale). A. D. limpiensis (ex: Limpia Canyon, TX). B. D. macrospina (ex: St. Catherine's Island, GA). C. D. macrospina (ex: Rochester, NY). D. D. subfunebris (ex: Pasadena, CA). E. D. trispina (ex: Earp, CA).
Drosophila limpiensis Mainland, 1941, new status
Figures 1A, 2A, 4A, 5A; 6A, B, H; 7C; 8A; 9B
Drosophila macrospina limpiensis Mainland, 1941: 160. Mainland, 1942 (hybrid sterility); Patterson and Wheeler, 1942 (redescription, immature stages, internal reproductive organs, chromosomes); Patterson and Stone, 1952 (distribution); Ewing, 1979 (mating behavior)
Diagnosis: Very similar to macrospina, with differences as noted. Postocellar setae parallel to very slightly convergent (vs. usually strongly convergent to crossing in macrospina); male with lateral lobes of distiphallus in D. limpiensis thinner (especially at the apex), less protruding than in macrospina; apical lobes with fewer lateral serrations; gap between cercal spines 2 and 3 slightly less than width of spine 2 (gap is substantially larger than width of spine 2 in macrospina). Female: oviscapt dark, sclerotized as in macrospina. No distinction between the two species is apparent in the surstyli or female terminalia.
Description: A description was provided by Patterson and Wheeler (1942), to which the following details of the adults are added (N = 4 specimens measured, all from type locality [Limpia Canyon, TX]): Body size: ThL 1.38 mm (1.35–1.44); wing length, 2.21 mm (2.15–2.35). HEAD: proportions HW/HD 1.38 (1.35–1.44); frons short, FL/LFW 0.71 (0.69–0.75), broadened dorsally, UFW/LFW 1.35 (1.30–1.38); vertical setae equal in size, VT-index 0.98 (0.96–1.03); vibrissa slightly larger than subvibrissa, vibrissa index 0.85 (0.65–1.05); ocellar setae significantly longer than postocellars. Eye shape ovoid, ED/EW 1.32 (1.28–1.37); cheek short, ED/CD 7.90 (7.1–8.3); proclinate seta twice the length of anteriorreclinate, OR1/OR2 2.09 (2.0–2.25), proclinate significantly shorter than posterior reclinate, OR1/OR3 0.68 (0.58–0.75); carina narrow, CL/CW 5.3 (4.6–5.8).
Thorax: Postpronotal setae very similar in size, h-index 0.89 0.81–0.95); ant. dorsocentral seta shorter than post. dc, DC-index 0.68; post. katepisternal seta significantly larger than anterior one, S-index 0.59 (0.55–0.68); post. scutellar seta larger than ant. scutellar, Scut-index 0.85. WING of moderate length, WL/ThL 2.02 (1.94–2.09), relatively broad WL/WW 2.14 (2.01–2.21); C-index 2.82 (2.75–2.96); hb-index 1.93 (1.78–2.04); 4V-index 1.54 (1.51–1.60); dm-cu distant from wing margin, 5X-index 1.32 (1.08–1.42).
Types: Holotype, male (label typed): D. macrospina/limpiensis M/Limpia Canyon,/Texas 1939/J.T. Patterson, col./Type. In AMNH.
Specimens Examined: MEXICO: Sonora, DSC stock no. 15120-1931.02 (4M, 4 F, 2 of each dissected) (no further locality data). United States: Arizona: Patagonia, ex DSC stock no. 15120-1921.00 (4M, 4F, 2 of each dissected); Texas: Ft. Davis/Limpia Canyon/MR Wheeler, WK Baker June 1947/1704.5 (3M, 3F; 1 dissected). Field notebooks from the former UT collection contain more detailed locality information for collection lot 1704.5, (recorded as macrospina): “Limpia Canyon, 10 mi W of junction of state highways #17 and #118 near Ft. Davis, Texas and 6.6 mi from Lot 1703. 4 traps.” Coordinates are 30.7775°, -103.7412°. All in AMNH.
Distribution: Patterson and Wagner (1943) mapped 22 records of limpiensis, which was updated by Patterson and Stone (1952). They describe a distribution from northern Mexico (Sonora, central Chihuahua [Loredo]) north to western Texas (Davis Mountains) and portions of New Mexico, most of Arizona and the southwestern corner of Utah. There is a gap in central Texas and northward—in an area that the University of Texas lab sampled very well—where limpiensis ends and macrospina begins more eastward. Regrettably, most of the specimens from these localities were not saved.
Besides the specimens examined and Patterson records cited above, Mainland (1942) used stocks of limpiensis for his crossing experiments from the following localities: MEXICO: Sonora: Hermosillo (29.0745°, -110.9594°), Magdalena (30.6303°, -110.9699°), Punta del Agua (28.4258°, -110.4067°). United States: Arizona: Patagonia (31.5410°, -110.7531°); New Mexico: Silver City (32.7865°, -108.2652°), Radium Springs (32.4819°, -106.9072°); Texas: Limpia Canyon (30.7774°, -103.7412°); Utah: Zion National Park (∼37.2550°, -112.9797°). This material was also the basis for the description by Patterson and Wheeler (1942).
Comments: What were considered eastern and southwestern populations/subspecies of macrospina are now separated into two species, macrospina and limpiensis, respectively.
While the morphological evidence for separating limpiensis from macrospina is subtle, it is consistent as diagnosed above. Also, evidence from Mainland (1941, 1942) indicates substantial hybrid infertility between Drosophila macrospina and D. limpiensis. Flies of the two species readily mate but the F1 hybrids of limpiensis female and macrospina male crosses were “sterile to slightly fertile” (Mainland, 1942). Patterson and Stone (1952) mentioned an east-west gradient in hybrid sterility between macrospina X limpiensis, which may reflect the apparent geographical separation between these species in western Texas and Oklahoma. COII sequences of DSC stocks of macrospina and limpiensis in GenBank (National Center for Biotechnology Information, 2020) have 99% similarity based on BLAST analyses. Assuming the online sequences are correct, this is typically considered minimal identity for species separation (e.g., the sister species Drosophila sechellia and D. simulans have 97% similarity in the COI region). However, and for larger context, COII sequences between D. macrospina and Zaprionus tuberculatus, for example, and species in the Drosophila cardini group have 90% similarity. The close genetic similarity between D. macrospina and limpiensis no doubt reflects the subtle phenotypic differences between the species.
Spieth (1952: 434) mentioned that the mating behavior of macrospina and limpiensis is “identical in all respects,” but this was based on visual observation. He studied two cultures: no. 1897 from Alleghany State Park, New York (macrospina), and no. 1248.1b from San Bernardino, Arizona (limpiensis); specimens from the latter culture were morphologically studied here. Ewing (1979) reported significant differences in the male mating songs, based on two other cultures (numbers were not reported): one from Patagonia, Arizona (for limpiensis, presumably same material studied morphologically here), and one from Albuquerque, New Mexico (for macrospina, material not studied here). According to Ewing (1979) Drosophila limpiensis and macrospina differ in both the primary and secondary songs, limpiensis having longer inter-burst intervals, greater amplitude of sound pulses, and, in the secondary song, the pulses are more condensed.
In addition to morphological, genetic, and behavioral distinctions, Drosophila limpiensis and D. macrospina also appear to be ecologically distinct, the former occurring in hot, dry areas in western Texas, New Mexico, Arizona, and northwestern Mexico. Drosophila macrospina is a resident of forested areas with humid climates from eastern Texas to Florida, north to New England; northernmost records are in Michigan; Rochester, New York; and southern Ontario, Canada (Miller et al., 2017).
FIG. 6.
External details of male terminalia, A–G: Cercal spines, right lateral views; H–K: Surstyli, lateral views. All to same scale. A. D. limpiensis (ex: Limpia Canyon, TX). B. D. limpiensis (ex: Patagonia, Arizona). C. D. macrospina (ex: New Orleans, LA). D. D. macrospina (ex: Piqua, OH), dashed line indicates spine sometimes missing. E. D. subfunebris ex: Pasadena, CA). F. G. D. trispina (ex: Earp, CA), G. showing right cercus with one less spine. H. D. limpiensis (ex: Limpia Canyon, TX). I. D. macrospina (ex: New Orleans, LA). J. D. subfunebris (ex: Pasadena, CA). K. D. trispina (ex: Earp, CA).
FIG. 7.
Aedeagi with aedeagal apodemes, ejaculatory apodemes (B, D, E), lateral views (all to same scale). A. D. macrospina (ex: Magazine Mtn., AR). B. D. macrospina (ex: Rochester, NY). C. D. limpiensis (Limpia Canyon, TX). D. D. trispina. E. D. subfunebris.
Drosophila subfunebris Stalker and Spencer, 1939
Figs. 1C, 2C, 4C, 5D; 6E, J; 7E, 8F, 9D
Drosophila subfunebris Stalker and Spencer, 1939: 108. Subsequent refs: Patterson, 1943 (redescription, internal reproductive organs, chromosomes).
Diagnosis: The most distinctive species of the group that is native to North America: anterior reclinate orbital seta lateral to proclinate or nearly so (vs. posterolateral to proclinate in other species). Male genitalia: aedeagus with broad, winglike lateral lobes; hypandrium distinctly constricted in middle; shaft of aedeagus thick in lateral view; male cercus with 6 (vs. 4–5) spines. Oviscapt lightly sclerotized, relatively thick in lateral view, with ca. 30 small marginal pegs.
Description: (N = 4 specimens, all measured from type series). Largest native funebrisgroup species, ThL 1.39 (1.25–1.48); wing length, 1.96 mm (1.90–2.03).
Head: significantly broader than deep, HW/HD 1.40 (1.38–1.44). Eye dull red, with dense ommatrichia, shape ovoid, ED/EW 1.27 (1.25–1.32). Frons short, FL/LFW 0.60 (0.58–0.63), wider dorsally, UFW/LFW 1.32 (1.27–1.36); frons and face dull, dark yellow, antennae very light brown; frontal-orbital plates and ocellar triangle slightly shiny. Proclinate orbital twice the length of anterior reclinate, OR1/OR2 2.1 (2.0–2.6), proclinate significantly shorter than posterior reclinate, OR1/OR3 0.61 (0.55–0.66); contralateral proclinates slightly divergent, posterior reclinates slightly divergent. Inner vertical slightly lateral to tangent running through ipsilateral proclinate and posterior reclinate. Anterior reclinate directly lateral to proclinate, distance of separation equal to diameter of socket. Vertical setae equal in size, VT-index 0.98 (0.96–1.00); inner vertical strongly inclinate, outer vertical almost directly posterior to inner vertical. Postocellars strong, convergent; ocellar setae significantly longer than postocellars, Ocellar S-Index 1.30 (1.24–1.36). Antennal pedicel with 2 strong setae (1 proclinate, 1 lateroclinate); aristae [broken on all specimens]. Carina broader than in other species, CL/CW 4.39 (3.9–5.4), laterally declivous (not steep as in macrospina and limpiensis), more protruding. Vibrissa significantly longer than subvibrissa, vibrissa index 0.77 (0.71–0.84). Clypeus shiny, short, squared. Palp with apex brown, base yellow; dorsal margin flat, ventral margin convex with 3 strong setae. Labellum with 10 pseudotracheae. Cheek short, ED/CD 7.2 (6.1–8.4); occiput brown.
Thorax: Scutum and scutellum dark yellowish to very light brown, slightly shiny. Acrostichals in 8 rows. Short row of 2–3 acrostichals anterior to anterior dorsocentral are faintly larger than others (similar for acrostichals anterior to transverse suture). Two long postprontal setae, lower seta slightly larger than upper one, h-index 0.88 (0.77–0.93). Three large notopleurals, 2 anterior ones longest. Anterior supraalar seta short, posterior one very long. Two large katepisternal setae, posterior one significantly longer than anterior, S-index 0.60 (0.57–0.63). Dorsocentral setae well developed, anterior seta significantly shorter than post. dc, DC-index 0.61. Scutellar setae nearly equal in length, Scut-index 0.93 (0.91–0.95); anterior scutellars parallel, posterior pair crossing for 0.25 to 0.5× their length. Legs light yellow. Fore femur with 3–4 long, fine ventral setae, 2 lateral ones; male protarsus without longer, curved setulae. Midtibia with long, thick ventroapical seta, smaller dorsal-preapical seta; hind tibia with 1 fine, preapical-dorsal seta.
Wing entirely hyaline, of moderate length relative to body size WL/ThL 1.96 (1.90–2.03), relatively broad WL/WW 2.18 (2.10–2.24); C-index 2.91 (2.80–3.01); hb-index 1.94 (1.78–2.15); 4V-index 1.37; distance of crossvein dm-cu from wing margin nearly equal to length of xvein, 5X-index 1.10 (1.06–1.20).
Abdomen: Pigmentation with moderate sexual dimorphism. Male: tergites 3–6 entirely dark, shiny brown; tergites 1 and 2 with dark yellow medially; tergite 7 light brown, epandrium dark yellowish. Female: tergites 3–4 with dark yellow bands on anterior margin, tergite 5 with paramedian yellow areas; tergites 6 and 7 dark brown; tergite 8, paraprocts and oviscapt dark yellow.
Male Terminalia: Epandrium short, lightly sclerotized, devoid of microtrichia and setae (except 3 short, stiff setae on ventral lobe), dorsolateral phragma very well developed. Cerci projecting, without microtrichia; setae abundant and long (lengths greater than cercal width), posteroventral margin with 6 heavily sclerotized spines: narrow one dorsally, separated by gap from others about 2× width of spine; 5 ventralmost spines adjacent (no spaces between bases), 3 most ventral spines short and stout. Surstylus broadly rounded ventrally, with 9 prensisetae pegs, ∼11 thick setae; no microtrichia on surstylus. Hypandrium lightly sclerotized, slightly longer than aedeagal apodeme, with lateral constrictions. Gonopods lightly sclerotized, each with one larger and one very fine seta. Aedeagus with shaft short, very broad in lateral view; preapically with pair of broad, winglike lobes having finely serrate lateral margins; distal lobes with coarse, spinelike teeth on apical margin and row of fine serrations on mesal margin. Aedeagal apodeme well sclerotized, slightly shorter than aedeagus. Ejaculatory apodeme relatively small, bent at right angle.
Female Terminalia: Oviscapt not heavily sclerotized; short, broad in lateral view (depth 0.3× the length), apex rounded, not pointed. Oviscapt with ∼30 small pegs along margin, plus 3 pegs on dorsolateral portion of valve. Spermatheca faintly pear shaped (narrower at base), sclerotized; introvert long, ∼0.8× length of capsule, apex of introvert with pair of small lobes.
Types: Neotype (designated herein), male (dissected): United States: California/ Pasadena, 1949/Neotype Drosophila subfunebris det. D. Grimaldi, 2022. In AMNH.
Specimens Examined: United States: California: Pasadena, 1949 [no further information]. 5M, 3F (1 of each sex dissected), in AMNH.
Distribution: Known only from the type series.
Comments: Stalker and Spencer (1939) mentioned isofemale cultures of D. subfunebris that were maintained for over a year, originally collected in Pasadena, California (V/1937, and XI/19-28/1936)—from which the “type and gonotypes” were taken—and at “Camp Rincon, San Gabriel Mountains, California (IV/24/1937)” (∼34.4114°, -117.9206°). The Pasadena culture whose behavior was studied by Spieth (1952) and Ewing (1979) presumably was one of those made by Spencer. None of these existed by 2016 in the NDSC when it was at Univ. California, San Diego. The only specimens of this species of which I am aware is a small series of five males and three females in the AMNH from the Pasadena location, from which I am designating the neotype. A thorough search for type holdings of Spencer was made (AMNH, NMNH), including inquiries to the College of Wooster, Ohio, where Spencer was a professor. Typical for species described by Spencer, there are no designated types or other archived specimens. I collected in the San Gabriel Mountains in June 2017 at Wrightwood, California (34.4037°, -117.7243°) but did not find this species.
FIG. 8.
Detail of apices of aedeagi (ventral views) of native North American species of the D. funebris group (all to the same scale). A. D. limpiensis. B. D. macrospina (ex: New Orleans, LA). C. D. macrospina (ex: Piqua, OH). D. D. macrospina (ex: Missouri). E. D. trispina. F. D. subfunebris.
FIG. 9.
Female terminalia (oviscapts, spermathecal capsules, and minutely scaled oviprovector membrane [internal]) of North American species of the D. funebris group (all to same scale). A. D. funebris (introduced). B. D. limpiensis. C. D. macrospina (spermatheca of limpiensis and macrospina is identical). D. D. subfunebris. E. D. trispina.
Drosophila trispina Wheeler, 1949
Figures 1D, 2D, 4D, 5E, 6F, G, 6K, 7D, 8E, 9E
Drosophila trispina Wheeler, 1949: 180.
Diagnosis: Facial carina broad, bulbous, noselike. Aedeagus: lateral lobes short and broadly rounded, not curved posteriad; apical lobe longer and more slender than in other species of group, without large inner spine at apex; distiphallus more slender in lateral view. Male cercus with large gap between spine 1 and 2, with 4–5 spines total. Oviscapt lightly sclerotized, ventral margin with slight emargination; with about 32 marginal pegs; spermathecal capsule with fine papillae.
Description: (N = 4, all measured specimens from type series), body size, ThL 1.10 mm (0.98–1.17); wing length, 2.11 mm (1.91–2.27)
Head: Significantly broader than deep, HW/HD 1.39 (1.32–1.48). Eye dull red, with dense ommatrichia; ovoid, ED/EW 1.31 (1.29–1.43). Frons, face dull, dark yellow (carina lighter), antenna slightly darker (flagellomere 1 with fine, whitish microtrichia); frontal-orbital plates and ocellar triangle slightly shiny. Frons short, FL/LFW 0.72 (0.71–0.74), broadened posteriorly, UFW/LFW 1.32 (1.28–1.38), with fine setulae near ptilinal suture. Proclinates slightly divergent, length more than 2× that of anterior reclinate, OR1/OR2 2.42 (2.21–2.62), proclinate shorter than posterior reclinate, OR1/OR3 0.74 (0.70–0.80). Anterior reclinate posterolateral to proclinate, separated by distance slightly larger than diameter of socket. Posterior reclinates slightly divergent. Inner vertical in line with tangent running through ipsilateral proclinate and posterior reclinate. Verticals nearly equal in size, VT-index 0.96 (0.91–1.04); inner vertical strongly inclinate, outer vertical lateroclinate and almost directly posterior to inner one. Postocellar setae strong, convergent; ocellar setae significantly longer than postocellars, Ocellar S-Index 1.39. Antennal pedicel with 2 strong setae (1 proclinate, 1 lateroclinate); arista with 4–5 dorsal, 3 ventral branches. Carina relatively broad, CL/CW 3.9 (3.2–4.6), protruding, bulbous and noselike. Vibrissa slightly larger than subvibrissa, vibrissa index 0.94 (0.93–0.95). Cheek short, ED/CD 7.5 (6.6–8.6). Palp entirely yellow, asymmetrical, dorsal margin flat and ventral margin convex with 3 strong setae. Labellum with ∼10 pseudotracheae; occiput brown.
Thorax: Scutum and scutellum dark yellowish to faint brownish, dark tan; slightly shiny. Acrostichals in 8 rows; short row of 3 acrostichals anterior to anterior dorsocentral slightly thicker and longer than others (same for transverse row of 4 acrostichals in front of transverse suture). Two long postpronotal seta, lower seta larger than upper, h-index 0.81 (0.80–0.84). Three notopleural setae, longest ones are 2 anterior setae; 1 short, anterior supraalar seta, 1 long posterior supraalar. Posterior katepisternal seta significantly longer than anterior, S-index 0.59 (0.55–0.65). Posterior dorsocentral significantly longer than anterior, DC-index 0.62. Posterior scutellar setae slightly longer than anterior, Scut-index 0.86 (0.83–0.92), anterior pair parallel, posterior pair crossing ∼0.3× their length. Legs light yellow; fore femur with 3 fine ventral setae, 2 lateral ones. Male protarsus without longer, curved setulae; midtibia with long, thick ventroapical seta, smaller dorsal-preapical seta; hind tibia with 1 fine, preapical-dorsal seta.
Wing: Entirely hyaline, of moderate length relative to body size WL/ThL 1.91 (1.89–1.94), wing relatively broad WL/WW 2.12 (2.07–2.18); C-index 2.47 (2.38–2.55); hb-index 1.78 (1.67–1.88); 4-V index 1.28 (1.25–1.31); crossvein dm-cu distant from wing margin, 5X-index 1.27 (1.20–1.38). Halter light.
Abdomen: Pigmentation sexually dimorphic. Male: Tergites 1–3 with most of central area dark yellow; tergites 4–7 entirely dark, shiny brown; epandrium dark yellowish. Female: Tergites more yellow than brown, tergites 1 and 2 all yellow; tergites 3–5 with brown band on posterior margins, each with median gap of yellow; tergites 6 and 7 dark brown, with yellow anterior band; tergite 8, paraprocts, oviscapt light yellow.
Male Terminalia: Epandrium lightly sclerotized, devoid of microtrichia, short, flattened (not capsulate); dorsolateral phragma well developed; ventral lobe very small, with 2 short, thick, stiff setae at apex. Cerci protruding, lobelike, lacking microtrichia, setae dense and long (lengths ∼equal to thickness of cerci). Cercus with 4–5 heavily sclerotized spines; one large, dorsal spine far separated from others (∼3× thickness of spine), group of 3–4 straighter spines ventrally (in one specimen left cercus was missing one of spines in ventral group). Surstylus most distinctive in group of N. American species: ventral margin not broadly rounded, apex of surstylus narrow; with 8 slender prensisetae on inner margin, 10 thick other setae. Hypandrium lightly sclerotized, lateral margins narrowed in middle; posterior width ca. 2× the anterior width; gonopod with 1 long, fine seta and one minute one. Aedeagus with shaft of uniform thickness, apex of aedeagus not as bulbous in lateral view as macrospina and limpiensis; apex with pair of lobes spreading 3.5× width of shaft; lobes short, rounded, partly serrate on margin and neck; distal lobes with coarse serrations, lacking large medial tooth seen in other species. Aedegal apodeme sclerotized, relatively short, 0.7× length of main part of aedeagus (without apical lobes). Ejaculatory apodeme small, bent at right angle, both portions approximately equal in length.
Female Terminalia: Oviscapt not heavily sclerotized, with slight depressions along dorsal and ventral margins in lateral view; apex narrowed; 30–32 pegs along margin, plus 4 slightly longer ones on dorsolateral portion of valve. Spermatheca slighly bulb shaped, sclerotized, introvert long, ∼0.85× length of capsule, with fine papillae on surface of capsule.
Types: Holotype, male: United States: California, Earp/MR Wheeler, June 1948/ [lot]1858.5. In NMNH, not examined. Wheeler (1949) mentioned that the holotype was taken from the same isofemale culture that yielded the paratypes (below).
Specimens Examined: Paratypes, 4M, 2F (1 of each dissected), in AMNH: USA: California, Earp/MR Wheeler, June 1948/ [lot]1858.5. Field notebooks from former UT collection contains more detailed locality for this lot: “Traps set in brushy, woody grove along Colorado River, at Kinders' Camp, at 4 mi [6.4 km] NW Earp, Calif., Coll. 6-14-48” (∼34.2777°, -114.2326°).
Distribution: Known only from the type series.
Comments: Wheeler (1949: 181–182) mentioned that D. trispina can hybridize with D. limpiensis, but they produce sterile male offspring; when the female parent is trispina this yields offspring with reduced viability or that are inviable. The type locality of this species along the Colorado River, separating Arizona and California, is low, hot desert of approximately 120–150 m elevation.
KEY TO NEARCTIC SPECIES OF THE DROSOPHILA FUNEBRIS GROUP
1a. Male with ∼12 spines on each cercus; thornlike setae on ventral epandrial lobe; oviscapt (female) with tubercle on dorsal margin, base of spermatheca with neck (fig. 9A) (introduced species) funebris
1b. Male with 4–6 spines on each cercus (fig. 4); ventral epandrial lobe with 2–5 thick setae (none thornlike); oviscapt without tubercle on dorsal margin, spermatheca without neck (fig. 9B–E) (native species) 2
2a. Male generally with 5–6 spines on cercus (fig. 6E–G), oviscapt not sclerotized (fig. 9D, E) (California) 3
2b. Male with 4 cercal spines (fig. 6A–D); oviscapt noticeably sclerotized and dark (fig. 9B, C) (southwestern US, northern Mexico, eastern North America) 4
3a. Carina not bulbous, noselike (fig. 1C); aedeagus (male) with large, flangelike lateral lobes (figs. 5D, 8F), cercus with 6 spines (fig. 6E); oviscapt with slight emargination on dorsal margin (fig. 9D) subfunebris
3b. Carina bulbous, noselike (fig. 1D); aedeagus with much smaller lateral lobes (figs. 5E, 8E), cercus with 4–5 spines (fig. 6F); oviscapt dorsally and ventrally slightly emarginate (fig. 9E) trispina
4a. Aedeagus with broader lateral lobes (“wingspread” ∼5× the thickness of aedeagal neck) (figs. 5B, C; 8B–D); gap between largest cercal spine and closest small one ∼1.5× thickness of largest spine (fig. 6C, D) (eastern North America) macrospina
4b. Aedeagus with lateral lobes narrow, ∼3.5 –3.7× thickness of neck (figs. 5A, 8A); gap between largest cercal spine and closest small one </= to width of thickest spine (fig. 6A, B) (western Texas, Arizona, New Mexico, northern Mexico) limpiensis
ACKNOWLEDGMENTS
It is a pleasure to acknowledge the help of John Jaenike, who provided a culture of Drosophila macrospina from Rochester, New York; the Drosophila Species Center for providing several cultures of funebris-group species; to Steve Thurston (AMNH) for help with the graphics; and to Shane McEvey (Australian Museum) and an anonymous reviewer for their careful reviews.
