Hirtodrosophila ordinaria (Coquillett)

Grimaldi, David A., 2018, Hirtodrosophila Of North America (Diptera: Drosophilidae), Bulletin of the American Museum of Natural History 2018 (421), pp. 1-1 : 1-

Hirtodrosophila ordinaria (Coquillett)

Figures 10 , 11 , 16C , 30 , 31 , 32

Drosophila ordinaria Coquillett, 1904: 190 .

Drosophila melanderi Sturtevant, 1916: 337 . Synonymy by Lacy, 1981.

Drosophila magnafumosa Stalker and Spencer, 1939: 112 . Synonymy by Lacy, 1981.

DIAGNOSIS: Coloration sexually dimorphic (males darker), highly variable (darker in individuals from cooler seasons and latitudes), usually with frontal vittae partly to entirely orange; dorsum of thorax yellowish, usually with diffuse, light to dark brown median stripe that is widened posteriad; pleura from light and yellowish with very faint infuscation to mostly dark brown; wing hyaline, legs, and halter light. Arista with relatively short branches, 1 ventral, 4 dorsal; basal flagellomere with setulae short; carina narrow. Male: Ventral portion of cercus curved inward, bearing stout, spinelike setae; surstylus with small dorsal lobe having short row of prensisetae pegs, larger ventral lobe with various prensisetae; hypandrium short and broad; aedeagus with pair of preapical lateral lobes. Female: Oviscapt margin entire (no emargination or differentiation of pegs)

DESCRIPTION: Coloration: Highly variable, from largely yellowish to dark brown, apparently based on temperature during development and sex (males being darker). Head: Frons varying from yellow and orange to brown and orange, always with faint bluish pollinosity on dorsal portion in frontal view; frontal vitta varying from entirely matte orange or orange-yellow, to just anterior portion orange with posterior portion brownish, always with ptilinal margin light, yellowish; ocellar triangle slightly shiny, yellowish to brownish outside of area of ocelli, always dark blackish brown within area of ocelli; frontoorbital plates yellowish to slightly infuscate, shiny. Antenna: Scape, pedicel light; basal flagellomere infuscate brown on anterior half. Face yellowish, light; cheeks slightly lighter, slightly darker at vibrissal angle. Proboscis: Clypeus same color as face or slightly darker; palps light yellowish, labellum slightly darker. Thorax almost entirely and evenly yellow, or like this but with diffuse, light to dark brown median stripe running down scutum and center of scutellum, stripe widened posteriad. Pleura varying from entirely light yellow with very faint brownish infuscation (beneath wing base and notopleural suture, sometimes dorsal portion of katepisternum), to mostly dark brown with some diffuse, lighter areas. Wing entirely hyaline, no markings; halter with knob cream colored, stem slightly darker. Legs entirely yellowish, coxae lighter. Abdomen: Tergites varying from mostly light yellow with faint, light brown infuscation on posterior and lateral margins (lateral margins are darkest), to largely dark brown; males with abdomen more extensively darkened; sternites very light yellow, cerci slightly infuscate.

Head: Antenna: Scape with row of setulae, pedicel setulose with two larger setae; basal flagellomere relatively short, apex reaching to lower level of carina, with short setulae only; arista with relatively short branches, 4 dorsal and 1 ventral branch, plus short apical fork, ventral branch opposite last dorsal branch or between it and apical fork. Eye with short, dense micropubescence; slightly egg shaped in lateral view (dorsal portion larger). Face: Carina narrow, short (not reaching to oral margin), ventral portion deeper. Vibrissa well developed, points forward, one pair present, subvibrissal setae all much smaller. Frons: Fronto-orbital plates matte, very finely striate; orbital plates and ocellar triangle slightly shiny. Fronto-orbital setae: Proclinate slightly shorter than posterior reclinate; anterior reclinate quite small, ca. 0.3× size of other orbitals, slightly differentiated from scattered small setulae on anterior portion of frons; proclinate, posterior reclinate and inner vertical in line, anterior reclinate slightly lateral to this tangent. Ocellar triangle fairly large, anterior point reaching to level of proclinates. Ocellar setae close, within area bordered by ocelli, very long (tips extended past level of proclinate sockets); postocellar setae ca. 0.65× length of ocellars, slightly thicker, parallel. Inner vertical setae strongly inclinate; outer verticals strongly lateroclinate, both pairs about same size. Proboscis relatively short, virtually all withdrawn into oral cavity at rest, labellum small; palp with single, preapical seta.

Head measurements (N = 4): CD/ED 0.19 (0.16–0.22), ED/EW 1.27 (1.22–1.33), FD/FW 1.06 (1.03–1.10), FL/LFW 0.91 (0.88–0.94), HW/ HD 1.43 (1.42–1.44), Ocellar S-index 1.28 (1.21– 1.33), OR1/OR3 0.78 (0.76–0.82), OR2/OR1 0.44 (0.41–0.47), VT-index 1.07 (1.06–1.10).

Thorax: Setation: Acrostichal setae in 6 rows, ones near transverse suture not enlarged; anterior dorsocentral ca. 0.65× size of posterior ones; posterior dorsocentral about midway between anterior dorsocentral and scutellar margin. Anterior scutellars slightly convergent; posterior scutellars crossed for about half their length, slightly longer than anterior scutellars. Postpronotal lobe with two setae; notopleural area with 3 setae, dorsal one largest; 2 supra-alars (posterior one much longer), 2 postalars (one long, one short). Anterior katepisternal ca. 0.7× length of posterior katepisternal, small seta between these ca. 0.5× size of anterior katepisternal. Legs: Forefemur with ventral row of 8 long, fine setae (lengths ca. equal to femur width), lateral row of ca. 4 fine, shorter setae; mid- and hind femora with only short setae; male foretarsus without fine, erect setulae; midtibia with thick ventroapical seta, hind tibia with preapical dorsal seta.

Thorax and wing measurements: ThL 1.15 mm (1.09–1.21), DC-index 0.57 (0.52–0.66), S-index 0.58 (0.51–0.64), 4-V index 1.47 (1.41– 1.52), 5-X index 1.46 (1.23–1.72), C-index 2.89 (2.71–3.01), hb-index 2.05 (1.67–2.40), ThL/WL 0.44 (0.40–0.51), WL/WW 2.23 (2.16–2.29).

Male Terminalia: Epandrium evenly rounded, with row of ca. 6 setae on lateral surface, none dorsally, 12–14 setae on ventral lobe; microtrichia present over most of epandrium, except ventral lobes; ventral lobe of epandrium slender, extended almost to ventral margin of surstylus. Subepandrial sclerite roughly trapezoidal, with pair of short anterolateral arms. Cercus with microtrichia and large setae, ventral surface curved strongly inward and bearing group of ca. 25 stout, sharp, sclerotized, spinelike setae, 2–3 most medial ones largest and interdigitate with such spines on opposite cercus. Surstylus bilobed, with small dorsolateral lobe bearing comb of 5 prensisetae pegs; main lobe of surstylus pendulous, with ca. 15–18 mostly spinelike prensisetae (some peg ones laterally), ventral ones shortest, dorsal ones long, setiform. Hypandrium very short and broad, roughly horseshoe shaped; paraphysis simple, moderately sclerotized, digitiform in full ventral view, with 2 minute and 1 large seta at apex. Aedeagus arched in lateral view, in dorsoventral view bearing pair of hornlike lobes at apex, which are partially sclerotized; aedeagus without hairs or scales. Aedeagal apodeme very short.

Female Terminalia: Oviscapt lightly sclerotized, with apical margin entire (no differentiation of pegs); with 19–20 oviscapt pegs, including short row of 3 small dorsal ones. Oviprovector well developed, apical scales coarse; spermatheca well sclerotized, dome shaped, exterior without striations or other ornamentation, apex slightly flattened, introvert ca. 0.8× length of capsule; small sac where spermathecal ducts meet is slightly sclerotized.

TYPE: Holotype, USA: New Hampshire, White Mountains . In USNM.

OTHER SPECIMENS EXAMINED: USA: Alaska: Anchorage, July 1960, M.R. Wheeler, W.S. Stone, 3000.3, 1♂ ( AMNH, dissected by MRW, genitalia on slide). Montana: 1.5 mi N Fish Creek Campground, Glacier National Park , VII/28– 29/47, 1762.7, M.R. Wheeler, F.A. Cowan, 2♂ (1 dissected, no. 85) ( AMNH). New York: Broome Co., Chenango Valley State Park , 30 August , 1982, D.A. Grimaldi, 1♀ ( AMNH). North Carolina: Highland , banana bait, VIII.62, D.D. Miller, 1♀, 1♂ (dissected, MF-1) ( AMNH). Tennessee– North Carolina: Smoky Mountains National Park , 4000 ft., (holotype male of magnafumosa , in USNM) ; Clingman’s Dome, Great Smoky Mountains National Park IX /11/41, 1275.9, G.B. Mainland, R. Wagner, 2♂ (1 dissected, MF-3, AMNH). Vermont: Orleans Co., nr. Bald Mtn., 1650 ft. 44.793912, -71.987953, D. Grimaldi, 19–21/VI/2016, sweep netted in forest near stream (Mad Brook), 1♂, 1♀ (both dissected, nos. 84, 83 respectively). Mad Brook Farm, E. Charleston, VII/15–25/82, D. Grimaldi, 1♀ ( AMNH). Washington: 10 mi. N. Raymond, 2186.2, VI/31–VIII/1/51, M.R. Wheeler, W.B. Heed, 1♀ ( AMNH) ; Pierce Co., Tacoma, (holotype ♀ of melanderi ) ( USNM) .

COMMENTS: Very widespread across entire North America, principally in the north, and at higher elevations where it extends southerly into Tennessee and North Carolina (e.g., Lacy, 1981). Highly variable coloration seems to correspond to temperature, with darker specimens occurring in more northern latitudes, higher altitudes, and in spring and fall, similar to the situation in Drosophila putrida ( Sabath et al., 1973) . The dramatic color variation probably resulted in ordinaria being described three times.

Wheeler (1954) was the first to recognize that H. ordinaria “is quite similar in appearance to both melanderi and magnafumosa . ” Lacy (1981) examined the types of all three species and confirmed their common identity. He briefly redescribed H. ordinaria and figured the male genitalia for the first time, although he depicted the lower surstylus lobe as just setose instead of with prensisetae. He mentioned his examination of genitalia for specimens from Ithaca, New York, and the Smoky Mountains, Tennessee, that he collected as well as specimens collected by H.T. Spieth in Trinidad, California (on the state’s northern coast). I have not seen specimens from California, but given the distinctive structure of the male genitalia the identification is probably correct. It’s uncertain whether all the distribution records reported by Lacy (1981, i.e., Massachusetts, Minnesota, New Hampshire, Quebec, Washington) were based on specimens that he examined or they were just reports of earlier literature.

It is possible that Hirtodrosophila shaitanensis (Sidorenko, in Toda at al., 1996) is a junior synonym of H. ordinaria ( shaitanensis is a substitute name for neomakinoi Sidorenko, 1995 , which was preoccupied by Hirtodrosophila neomakinoi [Gupta and Singh, 1981]). I suspect this synonymy because Sidorenko’s (1995) description of the external features, and his figures ( Sidorenko, 1995: figs. 1–5) of the male and female terminalia are consistent with ordinaria (though lacking in detail), including aedeagal structure and proportions, the blunt apex of the oviscapt, and the deep spermathecal introvert. Lastly, H. ordinaria occurs north to Alaska, and H. shaitanensis occurs in Primorskii krai, Russian Far East (opposite Hokkaido, Japan) and Irkutskaya oblast (just north of Mongolia), so a Beringian distribution is very plausible. Specimens from eastern Russia need to be directly compared in detail with North American material.

Hirtodrosophila ordinaria belongs to the melanderi species group, all six other members of which are Palearctic ( Wheeler, 1954; Lacy, 1981; Bächli et al., 2004). Hirtodrosophila cameraria (Haliday) , redescribed in detail by Bächli et al. (2004), is widespread throughout Europe, occurring even in northern Africa and the Near East, its most northern record from the vicinity of Stockholm, Sweden ( Bächli et al., 2004), although it is not reported from eastern Russia or Siberia ( Toda et al., 1996). Hirtodrosophila makinoi (Okada) occurs in Japan and the Russian Far East, and H. neomakinoi (Gupta and Singh) was collected in wet conifer forest at 7500 ft elevation in Darjeeling, West Bengal, India. Three species occur in China: H. furcapenis (Zhang and Liang) , H. furcapenisoides (Zhang and Liang) , and H. longifurcapenis (Zhang and Liang) (Zhang and Liang, 1995) . When described from New Guinea, Hirtodrosophila alpiniae (Okada and Carson) was affiliated with the melanderi group (Okada and Carson, 1980), but this is not entirely clear. On the one hand, it has a short, broad, U-shaped hypandrium, a bilobed surstylus, and large spines on the cercus, and was reported as breeding in fungi. On the other hand, it was also breeding in the flowers of a wild ginger (Zingerberaceae), and described as having the arista with “5 lower, very short branches,” the carina “high and long,” and the authors figure the cercus with two large spines on the posterior surface (vs. multiple spines or denticles on the ventral surface). This species also needs to be reexamined.

A preliminary scheme of relationships for the Hirtodrosophila melanderi species group is presented in figure 32 (omitting H. shaitanensis and H. alpiniae ). It is based on seven morphological features, five of which broadly define the species group. Hirtodrosophila makinoi appears to be the most basal species, lacking the pair of slender lateral lobes on the aedeagus so distinctive to the other species.

Life history and host records are largely known for just two species in the melanderi group: H. ordinaria and H. cameraria . Both appear to be rather polyphagous, breeding in an array of fleshy basidiomycetes, though they are rare compared to the common mycophagous species in the Drosophila quinaria and testacea species groups. In North America, Lacy (1981, 1982) reported having reared Hirtodrosophila ordinaria from 16 genera of basidiomycete fungi, comprising some 1520 specimens out of more than 20,000 drosophilids reared in total. I have very rarely encountered H. ordinaria in my rearings of mycophagous drosophilids from the northeastern United States (e.g., Grimaldi and Jaenike, 1984). In Britain ( Basden, 1954; Buxton, 1960), and Switzerland (Burla and Bächli, 1968), H. cameraria has been reported as quite rare in mushrooms, although Shorrocks and Charlesworth (1980, 1982) reported that in Britain it is moderately abundant in certain species, such as Phallus impudicus and Lactarius quietus .

Figures

FIG. 10. Hirtodrosophila ordinaria, darker individual (a male). A. Head, frontal. B. Thorax and head, dorsal. C. Head and thorax, lateral. D. Abdomen, dorsal.

FIG. 11. Hirtodrosophila ordinaria, lighter individual (a female). A. Habitus, lateral. B. Head and thorax, dorsal. C. Head and thorax, lateral. D. Abdomen, dorsal.

FIG. 16. Wings.

FIG. 30. Preliminary scheme of relationships in the Holarctic Hirtodrosophila melanderi species group. Species that are omitted are H. shaitanensis and H. alpiniae (see text).

FIG. 31. Hirtodrosophila ordinaria, C, D female (diss. no. 83). A. Frons, portion. B. Antenna. C. Spermatheca (note slightly sclerotized junction of spermathecal ducts). D. Oviscapt, lateral.

FIG. 32. Hirtodrosophila ordinaria, male terminalia (diss. no. 84). A. Epandrium and associated structures (subepandrial sclerite shown detached, in full ventral view). B. Surstylus. C. Spiny ventral surfaces of cerci, shown in full ventral view. D. Aedeagus and aedeagal apodeme, lateral. E. Hypandrium, aedeagus, aedeagal apodeme, ventral. F.Apex of aedeagus, ventral. G. Aedeagus, full ventral view.