Eupeodes (Metasyrphus) latifasciatus (Macquart)
The species of Eupeodes show an unusual amount of intraspecific variation in color of head, legs, abdomen, and body pile; in some and perhaps in all species, these variations seem to result from differences in temperature during the pupal stage (Dusek and Laska 1974). Eupeodes (Metasyrphus) has face entirely yellow or with brown to black medial vitta; metasternum pilose; vein R4+5 nearly straight; and male genitalia small, scarcely apparent from above.
Adapted from Vockeroth (1992).
MALE.
Head: Frons bright yellow. Face bright yellow, with brown medial vitta of variable width and length; lower facial margin and gena dark brown to black. Eye bare; dorsal postocular margin rather broad.
Thorax: Scutum and pleura with bright yellow pile. Scutellum with bright yellow pile, usually with few to many black pile on disc. Wing extensively microtrichose; cell c entirely trichose or bare on at most basal one-tenth; cell bm usually entirely microtrichose, with small bare area anteriorly near base in some specimens; alula entirely microtrichose. Pro- and mesofemora with about basal one-third brown to black; metafemur with about basal half to three-fifths brown to black; tarsi brownish above; legs otherwise bright yellow.
Abdomen: oval, usually nearly flat above, with strong margin from near middle of tergum 2 to apex of tergum 5. Tergum 2 with pair of yellow maculae of varied size only rarely extending to lateral margins; terga 3 and 4 each with broad yellow fascia extending rather broadly to lateral margins in some specimens; each fascia emarginate posteromedially or, especially in northern specimens, narrowly or broadly divided medially in two large maculae with anterior margins straight or only slightly concave; tergum 4 with moderately broad yellow posterior margin; tergum 5 yellow with anteromedian black macula extending laterally as arcuate fascia almost to lateral margins in some specimens. Sterna yellow with small black fasciae; sternum 4 without black fascia in some specimens. Genitalia: Surstylus short; hypandrium slightly narrowed apically, weakly rugose, with short but rather deep posterior projection on either side of base of aedeagus; aedeagal base with two short bluntly rounded teeth and two longer acute teeth.
FEMALE.
Frons black on upper two-thirds, bright yellow on lower one-third, entirely shining. Face almost without medial vitta in some specimens; oral margin and anterior half of gena yellow in some specimens. Wing usually less extensively trichose than in male; cell bm commonly bare on about anterobasal one-quarter. Legs paler than in male; pro- and mesofemora only narrowly darkened at base, metafemur entirely bright yellow in some specimens. Terga 3 and 4 with yellow fasciae or maculae slightly narrower than in male. Sternum 5 usually bright yellow, rarely with small median black macula.
Body length: 7.0-10.1 mm (Vockeroth 1992).
Rotheray and Gilbert (1999), using larval characters, studied the phylogeny of the European Syrphidae and Eupeodes was recovered as sister group of Scaeva and Ischiodon, with Paragus as sister group of all of them. Mengual et al. (2008), using molecualr characters, recovered Eupeodes (Metasyrphus) and Eupeodes (Macrosyrphus) together, being the sister group of a large clade formed by Lapposyrphus, Dioprosopa, Ischiodon and Scaeva.
Larvae of Eupeodes latifasciatus have been reported feeding on more than 20 different species of aphids (Rojo et al. 2003).
Adults visit flowers of white umbellifers; Caltha, Convolvulus, Euphorbia, Prunus padus, Ranunculus, Salix repens, Taraxacum, Tussilago, Ulex (Speight 2010).
The flight period for European specimens is from May to September, with peaks in June and August (plus April and October in southern Europe) (Speight 2010).
Holarctic species wih a wide distribution. In North America, from Alaska to Newfoundland, south to California, Texas, Delaware and Virginia. In Europe, from Iceland and Fennoscandia south to Iberia, the Mediterranean (including Cyprus), North of Africa and Turkey; from Ireland eastwards through most of Europe into European parts of Russia. But also through Siberia from the Urals to the Pacific coast (Sakhalin and Kuril Isles) and India (Speight 2010; Thompson 2010).
Adults rarely fly more than 2 meters above the ground; usually among low growing vegetation in the vicinity of water (Speight 2010).
Adults inhabits wetland/open ground; fen, humid, seasonally-flooded/poorly-drained grassland, oligotrophic Molinia grassland and along streams in open country, unsown fallow land (including setaside) (Speight 2010).
Larva of E. latifasciatus was described by Dusek and Laska (1960; in German); it is aphid feeding, on root-aphids. This species has been reared in the laboratory on aphids associated with various low-growing plants and shrubs. The available information on rearing in culture is summarised by Barkemeyer (1994).
Egg (from Chandler 1968).
White or cream; deepening to greyish-yellow on development; mean length 933 µ (n = 256, range 770-1040 µ), mean width 360 µ; tapering strongly towards one end; surface patterning often not at all evident dorsally, but traces of sinuous ridges usually discernible at the tips of the egg and faint white plates usually visible laterally. Chorionic sculpturing: dorsally, axis with simple branches rarely contacting those of neighbouring units; branches blunt-ended, essentially confined to 2 dimensions; ventrally, units particulate, margins infolded and some short, straight side-branches. Ecological notes: Frequent; eggs found from May to October; strong preference for Aphis fabae; eggs laid singly.