Spalangia subpunctata Förster, 1850

Gibson, Gary A. P., 2009, 2259, Zootaxa 2259, pp. 1-159 : 148-153

30. Spalangia subpunctata Förster, 1850

(Figs 193, 194, 435–450)

Spalangia subpunctata Förster, 1850: 516–518 ; lectotype ♀ (NHMW, not examined) designated by Bouček (1963: 473). Type data: [ Germany], near Aachen [lectotype: ♀ Or. Ex., Germania, Collect. G. Mayr].

Spalangia leptogramma Förster, 1850: 511–512 ; lectotype ♀ (NHMW, not examined) designated by Bouček (1963: 473). Type data: [ Germany], Cologne, bank of Rhine [lectotype: ♀. Or. Ex. Coeln, Collect. G. Mayr]. Synonymy by Bouček (1963: 473).

Description. Female. Length = 1.2–3.0 mm. Legs dark with tarsi uniformly brownish-yellow to black. Head in anterior view (Fig. 435) about 1.1–1.3x as high as wide; in dorsal view about 1.7–1.8x as wide as long; in lateral view (Fig. 436) with malar space about 0.8–1.0x as long as eye height and about 1.2–1.4x eye width. Head capsule (Figs 435–437) smooth and shiny except for setiferous punctures as follows: with complete median sulcus extending ventrally to elongate-triangular scrobal depression, otherwise upper face and parascrobal region with widely spaced, small but distinct punctures, and with setae extending over smooth inclined surface of scrobal depression and often originating from tiny bumps ventrally toward torulus; scrobal depression with finely coriaceous to coriaceous-granular scrobes on either side of more finely coriaceous to smooth and shiny interantennal region; gena (Fig. 436) rugulose-roughened near oral margin and with linear malar sulcus, but otherwise smooth except for setae originating from very shallow, pinprick-like depressions or tiny bumps; temple mostly smooth, with only a few pinprick-like setiferous punctures. Antenna (Fig. 444)

Figs 435–443. Spalangia subpunctata Förster. 435–437, head: 435, anterior view ♀, 436, lateral view ♀, 437, lateral view ♁; 438, ♀ pronotum and mesoscutum, frontodorsal view; 439, ♁ thorax, dorsal view; 440 & 441, mesopleuron: 440, ♀, 441, ♁; 442 & 443, frenum – petiole, dorsal view: 442, ♀, 443, ♁.

with scape about 6.7–8.1x as long as wide, the outer surface (Fig. 447) punctate-rugulose to rugulose-roughened and inner surface (Fig. 446) usually more finely sculptured, more or less coriaceous-alutaceous; pedicel about 2.1–2.9x as long as apical width and about 1.7–3.0x as long as fu 1; funicle of smaller specimens sometimes with fu 1 slightly wider than long (up to about 1.2x) and all subsequent segments, including fu 2, transverse (up to about 1.4x as wide as long), but usually with fu 1 oblong, about 1.1–1.7x as long as wide, and subsequent segments quadrate to distinctly oblong basally and quadrate to transverse apically, with fu 7 about 0.7–1.0x as wide as long; clava about 2.0–2.8x as long as wide.

Figs 444–450. Spalangia subpunctata Förster. 444 & 445, ♀ antenna; 446 & 447, ♀ scape: 446, inner view, 447, outer view; 448, ♁ antenna; 449 & 450, ♁ scape: 449: inner view, 450, outer view.

Pronotal collar in lateral view only very low convex behind neck and with circumpronotal band anterolaterally, but smoothly rounded to neck; without cross-line posteriorly and with setae at most originating from tiny bumps or very shallow, pinprick-like punctures, but uniformly coriaceous, including within mediolongitudinal bare region (Fig. 438). Mesoscutal median lobe (Fig. 439) with anterior convex region smooth and shiny anteriorly and finely coriaceous to transversely alutaceous posteriorly; internotaular region smooth and shiny to distinctly coriaceous lateral to median punctate-rugose region extending virtually to transscutal articulation, the sculptured region usually divided by irregular median carina. Axillae (Fig. 439) smooth and shiny except for setae. Scutellum (Figs 439, 442) low convex, shiny and variably extensively but sparsely setose with setae originating from at most pinprick-like setiferous punctures; frenum with frenal line rarely consisting of only 1 or 2 similar punctures laterally, but usually of several progressively smaller and shallower punctures forming an almost straight or slightly curved, tapered, variably complete punctate-crenulate line (Figs 439, 442). Mesopleuron (Figs 440, 441) mostly with distinct sculpture as follows: pectal region smooth, shiny and bare except for 1 seta ventrally; acropleuron longitudinally striate-carinate, the ridges extending posteriorly onto alar shelf; subalar scrobe not distinctly differentiated from upper mesepisternum, the combined region strigose-rugose or strigose-reticulate anteriorly but more extensively mesh-like coriaceous to very finely, obliquely alutaceous posteriorly; episternal scrobe quite a distinct depression connected to subalar scrobe by a shallow, linear furrow; upper and lower mesepimeron shiny but upper mesepimeron finely, obliquely alutaceous to similarly longitudinally carinate as acropleuron, and lower mesepimeron obliquely alutaceous anteriorly to coriaceous or coriaceous-granular posteroventrally; upper and lower mesepisternum differentiated primarily by a partial or complete line of ventral setae, though sometimes with carinate transepisternal line over at most anterior half below strongly strigose portion and/or with fine sulcus ventral to setal line. Fore wing hyaline or sometimes slightly embrowned; mediocubital fold almost always with 1–7 setae though rarely bare and basal cell sometimes also with several setae distally, but setae extending at most to level of most distal setae on mediocubital fold (Fig. 193). Propodeum (Figs 442, 443) with distinct postspiracular sulcus; callus completely reticulate-rugose to transversely strigose-rugose posteriorly or smooth medially; plical region with narrowly V- shaped paramedian crenulate furrows delineating median carina, the carina in lateral view usually distinctly convex except is small specimens; supracoxal bands continuous with paramedian crenulate furrow; panels smooth and shiny.

Petiole (Fig. 442) about 1.3–2.0x as long as medial width; punctate-reticulate between longitudinal carinae; with or without 1 seta laterally. Gaster shiny with fine coriaceous sculpture on at least Gt 2 and Gt 3.

Male. Length = 1.2–2.3 mm. Antenna (Fig. 448) with scape about 5.6–7.2x as long as wide, the inner (Fig. 449) and outer (Fig. 450) surfaces often more finely sculptured than for female; pedicel about 1.4–1.8x as long as wide; flagellum with setae much shorter than width of respective segment; funicle with fu 1 about 1.3–2.2x as long as wide and about 1.0–1.8x as long as pedicel, and basal funicular segments sometimes quadrate in smaller specimens but usually all variably distinctly longer than wide, with fu 7 about 1.1–1.4x as long as wide. Otherwise similar to female except as follows. Head in anterior view about 1.0–1.1x as high as wide; in lateral view (Fig. 437) with malar space about 0.7–0.8x eye height and about1.0–1.1x eye width. Fore wing with 4–11 setae on mediocubital fold and sometimes with line of setae in basal cell extending beyond level of most distal seta on mediocubital fold, but not in two distinct lines (Fig. 194). Petiole (Fig. 443) about 1.8–2.2x as long as medial width.

Material examined. Nearctic (579 specimens). CANADA: Alberta, Aden, Gilchrist Ranch, 28.VI.56, O. Peck (1♀). Coleman, 7, 26.VII.61, K.R. Depner (135 specimens). Lethbridge — 1961, K.R. Depner (6♀, 8♁); 1997, K. Floate, Physiphora demandata (Fab.) (30♀, 5♁); Research Centre, 13-25.V.97 (3♀, 3♁), 27.V. 97 (1♀), late May-early June, ex cow pats in pasture (2♀), K. Floate. Magrath, 16 km. S, McIntyre Ranch, 24- 31.V.90 (1♁), 26.VIII-9.IX.90 (2♀), D. Griffith. Medicine Hat, 20.VI.61, K.R. Depner, Haematobiae irritans (3♀, 4♁). Menaik — 26.VII.61 (2♀, 1♁), 15.VIII.61 (2♀), K.R. Depner, Haematobiae irritans ; 24.VII.61, 10, 15, 22.VIII.61, K.R. Depner (176 specimens). Midnapore, 22.VIII.61, K.R. Depner (7♀, 3♁). Rocky Mountain House, 10, 28.VIII.61, K.R. Depner (109 specimens). Stavely, 28.IX.60, K.R. Depner, Haematobiae irritans (5♀, 6♁). Schuld̓s Farm, 10.VI.87, K. Floate (1♀). Tod Cr., 6.IX.60, K.R. Depner (1♁). Writing-on-Stone Prov. Pk., 6-12.VI.94, D.B. McCorquodale (1♁). New Brunswick, St. Léonard-Parent, Beaupré farm, 3.VII.03, T. Levesque (1♀). Ontario, Alfred, coll. 12.VI.02 manure pit, em. 6.VIII.02, Gibson & Lachance (2♀)․ Almonte, 5 km. NW, 27.V-3.VI.86, H. Goulet (1♀). Carter Bay, 45º37'N 82º10'W, 180 m., 22-23.VII.97, H. Goulet (2♀ UCDC). Ottawa, Prince of Wales Dr., McEwen farm, 13.IX.01 (dissected 13.XI.01), Stomoxys calcitrans, G. Gibson & L. Bartels (1♀). Styles Side Rd NW West Carleton, Clarence farm, 45º26.622'N 76º10.296'W, G. Gibson & L. Bartels — 4.IX.01 (1♀), 9.X.01 (4♀), 16.X.01 (1♁), Stomoxys calcitrans ; 16.X.01,? Physiphora demandata (1♀); 9.X.01 16.VIII.01 (dissected 15.X.01),? Physiphora demandata (1♀), (dissected 7.II.02), Stomoxys calcitrans (1♀). St-Anne de Prescott, Clermont farm, 4.XI.02 (1♀), 2.VII.03 (1♀), Gibson & Lachance. Prince Edward Island, Harrington, 20.VI-10.VIII.89 (1♀), 24.VII.89 (1♀), 31.VII-8.VIII.89 (1♁), M.E. Smith. PEI Nat. Park, Stanhope Cmpgd, 13.VIII.91, D.S. Chandler (1♀ DENH). Quebec, Gatineau Pk., 2 km. W Chemin Pilon, 7.VII.92, J. Heraty (1♁ UCRC). Quyon, Mackechnie farm, 45º31.89'N, 76º17.26'W, coll. 16.VIII.01, dissected pupa 15.X.01,? Physiphora demandata (Fab.) , G. Gibson & L. Bartels (1♀). USA: California, Inyo Co., 6 km. E Big Pine, 37º10'N 118º13'W, 24.V.94, S.L. Heydon (1♀ UCDC). Marin Co., 1 mi. SW Pt. Reyes Station, 29.VI.69, J.B. Heppner (1♀ FSCA). Modoc Co., Likely Mill, 1972 (1♀ USNM). San Benito Co., Conconi Ranch, 1 mi. NW Dunneville, 27.V.57, R.F. Smith & K.S. Hagen (1♀ EMEC). Santa Clara Co., Olivera Egg Ranch, 14.III.73, D. Whitman (1♀ EMEC). Siskiyou Co., Gazelle, 24.VI.58, J. Powell (1♀ EMEC). Solano Co., 8 km. W Winters along Putah Creek, 30.III.91 (1♀, 3♁ UCDC), 3.IV.91 (1♀ UCDC), S.L. Heydon. Sonoma Co., Zupon Ranch, 8.VIII.63, Ophyra sp. (1♀ USNM). Stanislaus Co. — Miniear Day Use Area, 23 km. W Patterson, 5.IV.96, L.A. Baptiste (1♁ UCDC); Patterson, 1.IV.54, K.S. Hagen (1♀ EMEC); 5 mi. N Turlock Lake, NW LaGrange, Stanislaus PG&E power plant, 9, 10, 16.III.76, J. Collins (6♁ EMEC). Tuolumne Co., 3 mi. E Chinese camp, 20.V.52, E.I Schlinger (1♀ UCDC). Yolo Co. — Fazio Wildlife Area, 3 km. E Davis, 11.VI.99, S.L. Heydon (1♁ UCDC); Rumsey, 2.VI.29, N.J. Smith (1♁ UCDC), 19.V.79, S.A. Begin (1♁ UCDC). Oregon, Alkali Lk, 21.VII.94, S.L. Heydon (2♀ UCDC).

Distribution. Spalangia subpunctata likely is transcontinental in Canada but apparently is limited to west of the Rocky mountains over most of the USA (Fig. 451). In addition to the Nearctic region, S. subpunctata is also known from the Palaearctic region, including Europe, Asia as far east as Uzbekistan, and North Africa ( Noyes 2003).

Fig. 451. Distribution of Spalangia subpunctata Förster.

Biology. Noyes (2003) lists only six host species in Anthomyiidae , Calliphoridae , Muscidae , Otitidae , Sarcophagidae , and Syrphidae . Regional hosts include the previously reported species Physiphora demandata (Fabricius) , plus H. irritans , S. calcitrans and Hydrotaea (= Ophyra ) sp. Interestingly, S. subpunctata has been reared from the stable fly and horn fly in the Nearctic region, but not from the house fly, the only muscid host listed for the species in the Palaearctic region by Noyes (2003).

Recognition. I include S. subpunctata along with S. erythromera , S. fuscipes , S. haematobiae and S. imitator in the subpunctata species group. The five species of this group have a comparatively smooth pronotum, sometimes being quite distinctly coriaceous but at least lacking punctures or a cross-line posteriorly, and always having a median carina on the propodeum. Morphological limits of the species of this group are the least well resolved and correct identification to species for some specimens is problematic. Furthermore, individuals of drosophilae -group species with only a very slender, more or less carinate-like median propodeal band can be mistaken for subpunctata -group species, though most drosophilae -group species have a less shiny, more strongly sculptured mesopleuron. In addition to the supplemental features given in couplet 43 to help distinguish such drosophilae -group specimens, drosophilae -group species lack a petiolar seta whereas subpunctata -group species, particularly those with a widely separated frenal line, often have a petiolar seta. Species assigned to the subpunctata -group also have quite a distinct, smooth inclined lateral portion of the scrobal depression (Figs 147–149, 183, 209, 222, 435), whereas those drosophilae -group species that sometimes have a more carinate-like median propodeal band typically have the sculpture of the scrobes extending over the inclined surface of the depression so as to partly obscure the sculpture of the parascrobal region near the torulus (Figs 114, 174, 176, 387, 389). Finally, other than S. fuscipes (Fig. 188), even small subpunctata - group specimens have the petiole quite distinctly longitudinally carinate (Figs 157–159, 214, 215, 227, 228), whereas drosophilae -group species have the petiole more or less uniformly punctate-reticulate over at least its posterior half (Figs 56, 57, 120, 394).

Structure of the scutellar frenal line forms a continuum within the subpunctata -group. Spalangia erythromera always has a complete, uniformly developed frenal line formed by a short, almost longitudinal lateral portion that is abruptly recurved from a transverse part across the scutellum. The frenal line therefore has a very strongly transverse ∩-like appearance (Figs 153, 157). Both S. haematobiae (Fig. 211) and S. imitator (Fig. 224) always have a broadly separated frenal line, composed of only 1–3 punctures laterally, and therefore both species are readily distinguished from S. erythromera . However, the frenal line of S. subpunctata is variably complete. When more or less complete the frenal line resembles that of S. erythromera , but the punctures forming the line are widest laterally and narrowed toward the median so that the line is tapered and often quite obviously shallower or effaced medially (Figs 439, 442). Much less commonly, the frenal line is composed of just a few widely separated punctures in S. subpunctata and then is more similar to S. haematobiae , S. imitator and S. fuscipes . Of the five species assigned to the subpunctata group, S. erythromera usually is quite readily identified by structure of its frenal line in combination with basally yellow tarsi (see further under S. erythromera ). Individuals of S. imitator , particularly males, are also relatively easy to identify because of a unique sculpture pattern (see under S. imitator ), but morphological limits of S. haematobiae , S. subpunctata and S. fuscipes are not well resolved. Bouček (1963: 473, 476) was uncertain whether S. haematobiae was a valid species or only a North American form of S. subpunctata and further stated that variation in S. subpunctata is “very wide” (p. 475) and “in a few smaller specimens it is difficult to draw a firm line” (p. 476) between S. subpunctata and S. fuscipes . I include in S. haematobiae females that have a bare mediocubital fold and a pronotum that is almost or completely smooth and shiny mediolongitudinally within the bare region. Females I assign to S. subpunctata have the pronotum more uniformly coriaceous, including medially (Fig. 438), and except for the single female from Gazelle, California, at least 1 seta on the mediocubital fold. I include this female in S. subpunctata because it has a frenal line consisting of 4 distinct punctures extending over the lateral third of its scutellum and the upper mesepisternum mostly finely coriaceous except for the subalar scrobe. Specimens I assign to S. haematobiae do not have such an extensive frenal line. Furthermore, even though most individuals of S. haematobiae are smaller than most S. subpunctata , the upper mesepisternum is slightly more coarsely sculptured, being more obliquely alutaceous-strigose or reticulate-strigose (Figs 212, 213) rather than mostly coriaceous-alutaceous as in S. subpunctata (Figs 440, 441). I am even less certain of reliable features to differentiate S. subpunctata from S. fuscipes because I have seen very few specimens of either species from Europe (see under S. fuscipes ).