Species very similar to other European species of the scutatus group, P.aurolateralis, P.speighti and P.splendidus. The female of this species cannot at present be separated from the other species of this group.
Speight et al. (2004) provided a key to separate the European species. P. scutatus has tarsomeres 2 and 3 of the proleg each more than 3 times as wide as long; mesocoxa with an apical, finger-like process anteriorly; ventral surface of mesotibia (excluding lateral margins) almost bare, any scattered white pili much shorter than the maximum width of a tibia; probasitarsus 1.5 times as long as its maximum width; tarsomere 4 of proleg slightly less than 2 times as wide as long; face entirely or predominantly pale pilose; frontal triangle not inflated; wing with 2nd basal cell varying in microtrichial coverage from 90% -50% (frontal triangle covered in pollinosity that varies in colour from silver-grey to mid-grey; pale marks on terga whitish and well-defined).
A further potential complication is P. atlasi Kassebeer, described from North Africa (Kassebeer, 1998), which might occur in Mediterranean parts of Europe.
Synonyms:
Syrphus scutatus Meigen, 1822: 333.
Platychirus scutatus var. pygmaeus Frey, 1907: 69.
Syrphus quadratus Macquart, 1829: 230.
Syrphus sexnotatus Meigen, 1838: 134.
Adapted from Vockeroth (1992).
MALE.
Similar to male of Platycheirus albimanus, differing as follows:
Basoflagellomere extensively orange below at base, orange on lower half in some specimens. Scutum and scutellum with at most very few black pile. Lower katepisternal pili soft, white, very short. Wing with small bare areas at base of cell c and along anterior margin of cell bm. Protrochanter near apex of ventral surface with dense cluster of about 12 rather long stiff pale setae; profemur with basal pale tuft ofabout five pili, with two succeeding black tufts more compact, of at least 10 pili each, and sharply bent preapically, and with many long strong uniform black pili on rest of posterior surface decreasing in length towards apex of femur; protibia gradually widened on basal five-sevenths, then strongly widened posteriorly with posteroapical angle broadly rounded; posterior margin of protibia with dense soft mostly black pili about twice as long as tibial width at three-quarters tibial length; first protarsomere with anterior margin straight, with posterior margin oblique at apex, slightly wider than protibia; second protarsomere as wide as first and one-sixth its length; third and fourth protarsomeres each slightly longer than second and successively slightly narrower. Mesocoxa with slender anteroapical spur, projecting ventrally; about three-quarters as long as base of coxa and yellow to black; mesofemur with black anteroventral setae finer and less regular, followed by three or four very slender curved black pili, with row of long rather strong black posteroventral pili; mesotibia slightly arcuate, slightly broadened on middle half, with very short dense erect fine pale pili on basal two-thirds of ventral surface and rather long fine dense suberect black pili on most of posterior to posteroventral surface. First tarsomere of metaleg moderately swollen, about 3.5 times as long as greatest depth. Maculae of terga submetallic to yellowish; maculae of terga 2 small and irregular in outline or obsolete in some specimens; maculae of terga 3 and 4 subquadrate but slightly longer laterally, about half as long as terga; terga 3 with dense silvery pollinosity anteromedially; terga 4 with dense silvery pollinosity on most of surface.
FEMALE.
Not distinguishable from females of several similar species.
Platycheirus (Platycheirus) scutatus (Meigen, 1822).
Meigen, J.W. (1822) Systematische Beschreibung der bekannten europaischen zweiflugeligen Insekten. Dritter Theil. Schulz-Wundermann, Hamm. x + 416 pp., pls. 22-32.
Body lenght: 6.8-8.7 mm (Vockeroth 1992).
Adults visit flowers of white umbellifers; Achillea millefolium, Aster, Berberis, Campanula rapunculoides, Euphorbia, Geranium robertianum, Leontodon, Ranunculus, Rosa, Salix repens, Silene dioica, Stellaria, Taraxacum, Tripleurospermum inodorum (Speight 2010).
The flight period for European specimens of P. scutatus is from April to October, with peaks in June and August and occasional specimens on into November (Speight 2010).
Its range requires review due to potential for confusion of this species with the recently-described scutatus group species, but supposedly widespread.
Holarctic species ranging from Alaska to Ontario and Maine, south to British Columbia in North America; and from Iceland, the Faroes and Fennoscandia south to Iberia and the Mediterranean; from Ireland eastwards through northern, central and southern Europe (Italy, the former Yugoslavia, Greece) into Turkey and European parts of Russia; Afghanistan; through Siberia to the Pacific coast (Sakhalin Is., Japan) (Speight 2010).
Adults are found in clearings, tracksides, hedges etc., and they fly up to 3 m from ground; the males hovering at from 1-3 m, beside hedges, in woodland glades etc (Speight 2010).
Preferred environment for adults: forest; most types of deciduous forest, especially scrub woodland; anthropophilic, occurring also along field hedges, in fruit and olive orchards, in suburban gardens and parks and in young conifer plantations (Speight 2010).
Larvae can be found aphid feeding, on low-growing plants, bushes, shrubs and small trees.
The larva of P. scutatus is described and figured by Bhatia (1939), who also describes the egg; the larva is illustrated in colour by Rotheray (1994). Larval biology was described by Dusek and Laska (1974) and they mentioned that larvae of P. scutatus overwinter as diapausing larva, with pupation ocurring in April and the emergence of adults taking place in middle May.
unless otherwise stated