Leucozona lucorum (Linnaeus, 1758):592

The subgenus Leucozona s. str. differs by having abdomen oval, marginated; 2nd tergum mainly white, grey or pale yellow, with a medial lack vitta; 3rd and 4th terga black (sometimes anterior margin of 3rd tergum whitis); and wing with a medial dark macula. The subgenus Ischyrosyrphus has abdomen parallel-sided, mostly unmarginated (sometimes with very weak margin on terga 4th and 5th); tergum 2 black with pair of large subbasal subquadrate pale maculae, medially joined or not; 3rd and 4th terga with small pale maculae; wing without dark macula, except dark stigma.

Leucozona (Leucozona) lucorum (Linnaeus, 1758).

Linnaeus, C. (1758) Systema naturae... Ed. 10, Vol. 1. 824 pp. L. Salvii, Holmiae [= Stockholm]. [1758.01.01]

Synonyms:

Leucozona differens Frey, 1946: 158.

Musca lucorum Linnaeus, 1758: 592.

Syrphus asiliformis Fabricius, 1781: 306.

Conops praecinctus Scopoli, 1763: 357.

Leucozona nigripila Mik, 1888: 140.

Musca asiliformis Gmelin, 1790: 2871.

Musca lucorum Houttuyn, 1768: 488 [Subsequent combination of Musca lucorum Linnaeus].

Adapted from Vockeroth (1992).

Species robust with rather long pile, with anterior oblique brown macula at mid length of wing, and with abdomen oval and whitish yellow to submetallic gray on basal half.

Head: Face densely pruinose, dull yellow with dark shining medial vitta, almost half as wide as face, yellow pilose; gena and epistoma black, yellow pilose. Eye with long dense pile. Antenna and arista black.

Thorax: Scutum black; in some specimens with brownish or bluish tinge, subshining, yellow or gray pollinose laterally. Scutellum dull yellow to dark brown, darkened anterolaterally or anteriorly. Ventral scutellar fringe long and dense. Pleura black, with obscure or distinct grayish pollinosity on about dorsal half. Anterior anepisternum, meron, and katatergum bare. Dorsal and ventral katepisternal pile patches narrowly joined posteriorly, otherwise broadly separated. Metasternum bare. Wing with moderate bare areas on basal one-third, with oblique brown anterior macula at mid length. Calypters, their fringes, and knob of halter dark brown. Legs: entirely black except pro- and mesotibiae yellow on basal half, metatibia yellow on basal 2/5, and all femora yellow very apically, black pilose except yellow pilose on yellow areas. Metacoxa with posteromedial apical pile tuft.

Abdomen broadly oval, with strong margin from base of tergum 3rd to apex of tergum 5th; tergum 1st black, gray pollinose; tergum 2nd (except for narrow anterior black medial vitta) and usually narrow base of tergum 3rd whitish yellow to submetallic gray; remaining terga shining black; entirely yellow pilose except 3rd tergum dorsally and laterally black pilose on black areas. Sterna 1st and 2nd yellow, otherwise black, all yellow pilose.

GenBank accession number for this species are: protein-coding COI gene (EF127346), rRNA 28S gene (EF501965) and 18S gene (EU431548).

Leucozona lucorum resembles L. americana Curran. Leucozona americana differs from L. lucorum by having basoflagellomere a little shorter; facial tubercle longer, less prominent; pile of the scutum and scutellun wholly pale yellow; abdomen wholly black pilose beyond the second tergum; 1st and 2nd terga yellow, yellow pilose; 3rd tergum black, yellow pilose on anterior 2/3, black pilose on posterior 1/3; 4th-9th terga black pilose. L. lucorum has scutum yellow pilose, but rather tawny on the lateral margins and scutellum; terga are yellow pilose, except 3rd tergum dorsally and laterally black pilose on black areas, and sometimes, in the male, a few black pile on 4th tergum. The result is that the shining apical terga appear metallic black in L. lucorum, while in L. americana they are deep solid black.

Body length: 9.8-13.0 mm.

Rotheray and Gilbert (1989) resolved Leucozona as sister group of a clade formed by Chrysotoxum, Eriozona, Scaeva, Eupeodes, Megasyrphus, Didea and Dasysyrphus. But later, they resolved Leucozona in a different phylogenetic position, as sister group of Didea, Megasyrphus, Eriozona, Dasysyrphus, Paragus, Eupeodes, Scaeva and Ischiodon (Rotheray and Gilbert 1999).

Mengual et al. (2008) included in their analysis one species of each subgenus of Leucozona and they were resolved together as sister group of the two major groups of Syrphini sensu stricto, with the genera Dideoides, Eriozona, Dideopsis, Megasyrphus, Didea, Epistrophella, Xanthogramma, Chrysotoxum and Epistrophe forming one of those major groups. The second wass formed by Melangyna, Fagisyrphus, Meligramma, Dasysyrphus, Parasyrphus, Syrphus, Eupeodes, Lapposyrphus, Dioprosopa, Simosyrphus and Scaeva.

Adults visit flowers of white umbellifers; Acer pseudoplatanus, Centaurea, Cirsium palustre, Euphorbia, Filipendula, Polygonum cuspidatum, Rubus, Sorbus aucuparia, Taraxacum.

Larvae of L. lucorum have been collected from Rumex sp. in June and July from Britain (Dixon 1960). Larvae have been reported feeding on Brevicoryne brassicae and Lipaphis erysimi (Aphididae) and associated with arboreal and ground layer aphids in Great Britain (Rotheray and Gilbert 1989).

The flight period for L. lucorum is from May to July and on into August in western Europe (stragglers in September).

European species known from Fennoscandia south to the Pyrenees and northern Spain; from Ireland eastwards through Eurasia to the Pacific coast (Sakhalin and Kuril Islands), and Japan (Speight 2010). Some authors considered the Eastern populations as a different species (Thompson pers. com.). Specimens from North America referred as Leucozona leucorum belong to another species, Leucozona americana Curran.

Adults inahbit: clearings, tracksides etc., and they fly through bush-level and scrub vegetation.

Adults' preferred environment: deciduous forest, including scrub woodland and hedgerows, normally in
relatively humid regions and up to the upper altitudinal limit of Fagus; unimproved montane grassland.

Larva (from Dixon 1960).

Average length 10-15 mm., width 3.5 mm., height 2 mm.; brown with yellow-orange chevrons; dorsoventrally flattened, tapering anteriorly, cuspidate posteriorly, scalloped in outline; transverse wrinkles present; fleshy projections and prominences absent; ventral sole present; integumental vestiture absent; body papillose; segmental ornamentation of single spines each mounted on a papilla, twelve spines on segments 4-11, eight on segment 12; external mouth hooks present; aphidophagous.
Posterior respiratary process: postero-dorsal ; one and a half times as long as broad at the base, basal two-thirds parallel-sided, nodular; apical one-third rounded, smooth, a constriction separating basal and apical parts; entirely sclerotized; spiracular plates separated by a pronounced median groove; hind margin of circular plates just posterior to inner end of spiracles II, circular plates towards median groove; apices of well-developed triangular dorsal spurs between inner ends of spiracles II; interspiracular ornamentation of large prominences, an inner opening between spiracles I and II; three pairs of straight spiracles mounted on slight carinae curving over edge of spiracular plates when viewed from above, spiracles radiating on each spiracular plate.

Egg (from Chandler 1968).

Shining white, turning grey-brown on development; mean length 1375 µ (n = 113, range 12801470 µ), mean width 493 µ; rounded at both ends; surface lightly "dusted ", patterning of small irregularly-shaped, ill-defined units tightly packed together. Chorionic sculpturing: dorsally, short branching units irregularly orientated with no contact between neighbours; ventrally, sharply defined groups of characteristic shape, comprising densely-packed dots and rods. Ecological notes: Common spring species; eggs found from May to July, notably on plants infested with Aphis spp.; laid singly.