Urophora xanthippe species group

Diagnosis. Antenna yellow and rounded apicodorsally; palp yellow, unmodified; mesonotal scutum densely gray mictrichose, its anterolateral margin yellow, concolorous with postpronotal lobe and notopleuron bordering it. Wing either with brown bands (in U. kasachstanica and U. stalker) or hyaline with yellowish pterostigma and apically darkened veins. Aculeus with more or less distinct steps.

Occasional specimens U. terebrans (Loew 1850) have the anterolateral margin of the mesonotum yellow (in most of the specimens is black), although it is conspicuously narrower than in the species of the xanthippe group. To prevent possible confusion, that species is also included in the key.

Description. Head slightly higher than long, Yellowish to brownish, except occiput, ocellar tubercle, and slender part of arista black. Antenna yellow, scape with blackish setulae at dorso-apical margin; first flagellomere yellow, about 2 times as long as wide and distinctly rounded apicodorsally; arista bare. Gena as high as length of first flagellomere. Ocellar, vertical, orbital, frontal and genal setae black and acuminate; two frontal and one orbital setae present. Ocellar seta as long as frontal setae. Frons with black setulae around frontal setae. Labellum moderately long with black setulae.

Thorax. General color black; scutum densely gray microtrichose and black setulose. Thoracic pleura black; postpronotal lobe, dorsal margin of anepisternum, notopleuron and also part of scutum bordering them yellow. Dorsocentral setae usually situated at or slightly anterior of line between supra-alar setae. Scutellum mostly yellow; slightly convex, corners black; with 4 equally long black setae, basal setae inserted in yellow area. subscutellum and mediotergite black. All setae on thorax black. Halter yellow.

Legs. Completely yellow, or in some species fore femur striped black dorsally; and in cold morph of U. impicta basal part of all femora black; all setae and setulae blackish.

Wing. In most species entirely hyaline, except pterostigma yellowish and distal parts of costa and veins R2+3 and R4+5 M black; only U. stalker and U. kasachstanica have 3–4 crossbands. Vein R4+5 without setulae ventrally or dorsally. Cell bcu without short posterodistal lobe.

Abdomen. General color black; covered with sparse gray microtrichia and black setulae. Posterior margin of abdominal tergites 5–6 in female with long black setae. Oviscape shiny black with black setulae, length of oviscape about two times as long as preabdomen. Aculeus narrow and brown. Tergite 5 of males about as long as 2–3 preceding tergites, and with long setae on posterior margin. Male terminalia in most species uniform. Epandrium rounded in caudal view, posterior lobe of lateral surstylus very weakly produced. Phallus elongate and weakly sclerotized in middle.

Key to the species of the xanthippe group

1. Scutum at margins of postpronotal lobe and notopleuron yellow................................................ 2.

- Scutum at margins of postpronotal lobe and notopleuron black................................ other Urophora species

2. Apical section of vein M at least 1.8 (1.8–2.8) times as long as preapical section, apex of aculeus with two pairs of distinct steps. Wing with 3–4 brownish crossbands. Associated with Onopordum spp. and Cirsium spp.......... U. terebrans Loew

- Apical section of M no more than 1.8 (1.1–1.8) times as long as preapical section; apex of aculeus variable. Wing with or without crossbands. Associated with Cousinia, Acroptilon, and Onopordum spp. ( Urophora xanthippe species group)........ 3.

3. Wing with 3–4 brownish crossbands (Figs. 30, 37).......................................................... 4.

- Wing pattern reduced, without brown crossbands (Figs. 1, 10, 21, 25, 41)........................................ 5.

4. Apical and preapical bands separated; subbasal crossband completely lacking; preapical crossband extends from anterior to posterior margin. Aculeus with two pairs of distinct preapical steps (Fig. 34). Smaller: WL♀ <3.8, AL <2.9. Associated with Acroptilon repens ................................................................. U. kasachstanica Richter

- Apical and preapical crossbands connected on anterior margin (if separated, subbasal crossband developed, or preapical band expressed only around dm-cu). Aculeus with distinct proximal and diminished distal steps (Fig. 39). Larger: WL♀> 4, AL> 2.7. Associated with Cousinia ............................................................ U. stalker Korneyev

5. Larger: WL♀> 4mm, if WL♀ <4mm then AL> 3mm ....................................................... 6.

- Smaller: WL♀ <3.8mm, AL <2.5mm .................................................................... 9.

6. All femora black basally; if femora yellow then aculeus with 1 pair of proximal steps; distance between steps 1.3–1.5 times as long as the distance from their level to aculeus apex (Fig. 29). Associated with Cousinia spp.......... U. impicta (Hering)

- Femora yellow, at most only fore femur striped black dorsally; aculeus with both proximal and distal steps; distance between steps as long as the distance from their level to aculeus apex or shorter (Figs. 5, 13)................................. 7.

7. AL <3.4 mm, distance between apices at level of proximal steps clearly greater than that from their level to aculeus apex. With deep notch at apex (Fig. 5). Associated with Cousinia archibaldii Rech. .......................... U. bakhtiari sp. nov.

- AL> 3.4 mm, distance between apices at level of proximal steps almost equal to distance from their level to aculeus apex. 8.

8. AL/WL <0.85, width of aculeus at level of proximal steps>1.75 times as long as distance between proximal and distal steps (Fig. 13). Associated with Onopordum acanthium ............................................. U. dirlbeki sp. nov.

- AL/WL> 0.85, width of aculeus at level of proximal steps <1.75 times as long as distance between proximal and distal steps. Associated with Acroptilon repens and Cousinia sp............................................ U. sp near dirlbeki

9. Aculeus with 1 pair of prominent proximal steps, distance between their apices at level of proximal steps smaller than that from their level to aculeus apex (Fig. 45). Associated with Acroptilon repens ...................... U. xanthippe (Munro)

- Aculeus with distinct proximal and indistinct distal steps, distance between their apices at level of proximal steps greater than that from their level to aculeus apex (Fig. 23). Associated with Cousinia mollis ................. U. iani Korneyev & Merz