Sphaerophoria (Sphaerophoria) scripta (Linnaeus)
Sphaerophoria (Sphaerophoria) scripta (Linnaeus, 1758).
Linnaeus, C. (1758) Systema naturae... Ed. 10, Vol. 1. 824 pp. L. Salvii, Holmiae [= Stockholm].
Species of Sphaerophoria have face and scutellum yellow in background colour; anterior anepisternum bare; postpronotum bare; scutum with a sharply defined yellow lateral vitta; abdomen unmargined; subscutellar fringe absent or nearly so on at least median 1/3, present but sparse laterally; metapleuron bare ventrad to spiracle; male genitalia extremely large, globose; tergite 9 as wide as abdomen.
Vockeroth (1969) diagnosed the genus: Very slender, small to medium-sized flies with extremely large hemispherical male terminalia, almost always with bright yellow markings on head, thorax, and abdomen but rarely almost entirely black. Length 5.9 to 10.8 mm.
Eye bare. Face yellow, often with distinct black median vitta, entirely black only in nigra Frey. Face somewhat protruding below, in profile area between antennae and apex of tubercle oblique and scarcely concave and area below tubercle receding only very slightly to anterior oral margin; oral opening about 2.2 times as long as broad. Usually thorax black with bright yellow lateral mesonotal vitta at least presuturally, scutellum bright yellow or rarely brownish on disc, and pleura with bright yellow markings; scutum and pleura entirely black only in nigra Frey. Subscutellar fringe usually absent on median fourth to half of scutellum and very short and sparse laterally, rarely entirely absent. Dorsal and ventral katepisternal pile patches distinctly separated but the former usually triangularly extended ventrally about 3/4 of the distance from dorsal to ventral margin of katepisternum. Metasternum usually with a few hairs, rarely entirely bare. Metafemur in scripta (L.) with posteroventral piles short, stiff, black, and setulose in male and similar, but much weaker, in female; legs otherwise unornamented. Abdomen slender, unmargined, in the male parallel-sided and sometimes extending well beyond the wing apices, in the female usually slightly broadened at mid-length and extending at most very slightly beyond wing apices. Tergum 5 of male with rounded posterior extension on right side. Abdomen entirely black only in nigra Frey, otherwise with yellow markings as follows: terga narrowly to broadly yellow laterally and sometimes posteriorly; terga 2 to 4 with narrow to broad, entire or divided, usually arcuate, transverse fascia which may not reach the lateral yellow margin; tergum 5 usually with yellow fascia extended forward to anterior margin of tergum and sometimes backward to posterior margin so tergum may have a pair of submedian yellow vittae or be mostly yellow with isolated black maculae; tergum 6 in female exposed, usually yellow with one median and a pair of posterior black maculae, sometimes with the maculae fused or only the median present; in male sometimes the black markings of terga as far forward as the second becoming red or orange so abdomen is mostly yellow-orange. Sternites yellow, without distinct markings (adapted from Vockeroth 1969: 132).
Adapted from Knutson (1973).
Face with diffuse brownish medial vitta and narrowly black oral margin. Lateral scutal vitta narrower and darker behind suture but clearly reaching scutellum. Anteroventral corner of anepimeron entirely brown to black or narrowly opalescent yellow. Scutellum yellowish-white haired, sometimes with many black pile scattered over surface. Abdomen elongate, varying from black with paired vittate maculae on terga 3, 4, and 5 to only moderately melanistic with yellow fascia on terga 2 and 4 interrupted medially. Posterior margins of terga 4 and 5 and sometimes 3 narrowly yellow. Coxae and trochanters brown to black. Front and middle femora darkened basally, metafemur darkened from base almost to apex on inner surface, and with dense patch of short, black bristles posteroventrally on apical 3/4; all tarsi darkened and strongly contrasting with yellow tibiae. Wing extending only to base of 5th abdominal segment. The male genitalia have been figured many times (Metcalf 1921, Bankowska 1964, Dusek and Liska 1967, and in great detail by Vockeroth 1969). Posterodorsal lobes of surstyli elongate, with dense, elongate hairs on most of surface; extensive, bare, median triangular area at bases of lobes. Anteroventral lobes very large, flattened, without ventroapical teeth or processes, ventral margin rounded. Inner lobes broad, hook like apically. Superior lobe with relatively longer basal portion than in philanthus, dorsal fringe of apical portion sparser and more restricted to "heel"; apex of apical portion rounded, terminal appendage small, with fine hairs. Ventral surface of aedeagal base not rugulose, with a broad trough and a median ridge. Ventrolateral lobes of distal portion of aedeagus not directed laterally.
Face as in male; midfrontal vitta broad and parallel-sided, weakly trilobate or truncate apically. Lateral scutal vitta as in male. Anepimeron broadly light yellow along anterior margin. Scutellar pile as in male. Yellow fascia on abdominal terga 2-5 rather narrow, broadly interrupted, reaching margins; posterior margins of terga 3-5 very narrowly yellow. Legs much lighter than in male, only tarsi and bases of coxae darkened. Posteroventral bristles of metafemur slightly stronger than other bristles.
In the male, the elongate abdomen and the closely spaced, short, black bristles posteroventrally on the apical 3/4 of the metafemur will easily distinguish scripta from other members of this group. The slightly stronger bristles on the posteroventral surface of the metafemur will distinguish the females.
The only genera likely to be confused with Sphaerophoria are Allograpta (typic subgenus) and Exallandra. Allograpta (sensu stricto) has a complete subscutellar fringe, which is well developed and at least moderately dense, whereas Sphaerophoria and Exallandra have a reduced or no subscutellar fringe.
Length: body: 10.2-11.0 mm, wing: 6.3-6.5 mm (male); body: 7.2-9.0 mm, wing: 5.9-6.2 mm (female).
Ecology and Distribution
S. scripta is a highly migratory species, found in southwest Greenland, Iceland and Fennoscandia south to the Mediterranean, the Canary Isles and North Africa; from Ireland eastwards through much of the Palaearctic to the Pacific coast of Asia; Kashmir and Nepal (Speight 2010).
Adults' referred environment: open ground; grassland up to and including the alpine grassland zone; grassy clearings in dry woodland; heath, garrigue and suburban gardens; salt-marsh; predominantly coastal at the northern edge of its range; further south distinctly anthropophilic, occurring with various crops and along hedges and roadside verges (Speight 2010).
Flowers visited by adults: white umbellifers; Achillea, Campanula rapunculoides, Cirsium arvense, Crataegus, Erigeron, Eschscholzia californica, Euphorbia, Leontodon, Origanum vulgare, Prunus spinosa, Ranunculus, Tripleurospermum inodoratum, Tussilago (Speight 2010).
Larvae of S. scripta have been found feeding on more than 30 genera of aphids (Aphididae), on Psyllidae and onl arvae of Pieris brassicae (Lepidoptera) (see Rojo et al. 2003). They are aphid-feeding on herbaceous plants, including various crop plants e.g. Avena, Brassica, Cichorium, Lactuca, Triticum, Vicia (Speight 2010).
Flight period in Europe from April to beginning November (May/September in more northerly latitudes/higher altitudes and probably all the year round in southern Europe) (Speight 2010).
Adults fly low through grasses etc.; settles on vegetation, including grass stems (Speight 2010).
The larva of S. scripta has been described and figured by various authors (Bhatia 1939; Dixon 1960; Goeldlin de Tiefenau 1974). It is incorporated into the keys provided by Rotheray (1993). Overwintering in this species apparently occurs as a puparium (Kantyerina (1979) in the grass-root zone. Barkemeyer (1994) provides a survey of the literature on the biology of this species. The morphology of the chorion of the egg is figured by Kuznetzov (1988).
Egg (Chandler 1938).
Off-white, turning greyish-brown on development; mean length 888 µ (n = 221, range 800-1100 µ), mean width 373µ; rounded at both ends; surface patterning of opaque plates slightly upstanding, usually about twice as long as wide, but sometimes hunched up laterally and patterning appears crest-like as in Syrphus luniger, although the units are less than 5 times as long as wide. Chorionic sculpturing: as in Sphaerophoria menthastri but sharp demarcation between dorsal and ventral types of sculpturing, axis never present if central area absent. Ecological notes: Common; eggs found from May to October; wide host acceptance range; eggs laid singly, not infrequently on the upper surface of the leaf.
Larva (Dixon 1960).
Average length 8 mm., width 1.5 mm., height 1.5 mm.; green with a wide white dorsal band on either side of the heart line; subcylindrical, tapering anteriorly, truncate posteriorly; dorsolateral longitudinal ridges absent; transversely wrinkled; fleshy projections and prominences absent; prolegs and claws absent; integumental vestiture absent; segmental ornamentation microscopic; external mouth hooks present; aphidophagous. Posterior respiratory process: postero-dorsal; one to one and a half times as long as broad; spiracular plates separated by a median groove; circular plates round, sloping antero-ventrally, displaced towards median line, and anterior to inner ends of spiracles I; dorsal spurs absent;
interspiracular ornamentation of five pairs of openings, two pairs between spiracles I and II; three pairs of straight, wide spiracles mounted on carinae; fringe of microscopic hairs projecting inwards from borders of spiracles.
Evolution and Systematics
Nomenclature and Synonymy
Lepeletier and Serville (1828) described Sphaerophoria as a subgenus of Syrphus. Rondani (1848: 458) designated scripta as the type-species of the genus. Thompson (2010) recognises two subgenera: Sphaerophoria sensu stricto and Loveridgeana.
Sphaerophoria scutellata Portevin, 1909: 25.
Sphaerophoria brunettii Joseph, 1967: 243.
Musca scripta Linnaeus, 1758: 594.
Sphaerophoria strigata Staeger, 1845: 362.
Musca invisito Harris, 1780: 83.
Musca libatrix Scopoli, 1763: 346.
Sphaerophoria violacea Abreu: 1924, 71.
Vockeroth (1969) realted Sphaerophoria with Allograpta and said that "females [of Sphaerophoria] are often difficult to distinguish from those of some species of Allograpta, especially if the latter lack the obliquetergite markings commonly found in that genus." Knutson (1973) made four groups within Sphaerophoria: contigua group, loewii group, scripta group (with scripta section and abbreviata section) and novaeangliae group.
Rotheray and Gilbert (1989) placed the genus Sphaerophoria in the tribe Bacchini based on larval characters and their analysis placed Sphaerophoria as sister group of Baccha, with Platycheirus and Pyrophaena as sister groups of both. In 1999, Rotheray and Gilbert resolved Sphaerophoria as sister group of Allograpta, and Baccha as sister group of these two genera. The sister group was a cluster with Platycheirus, Pyrophaena and Rohdendorfia.
Ståhls et al. (2003) recovered Sphaerophoria as sister group of Baccha using larval morphological characters, but it was placed as sister group of Toxomerus when only adult characters or only molecular characters were used independently.
Hippa and Ståhls (2005) recovered Sphaerophoria as sister group of Toxomerus when only using adult morphology. Mengual et al. (2008a, b) recovered Sphaerophoria within Allograpta clade, and Exallandra was palced as sister group of Sphaerophoria loewii. Mengual et al. (2008b) said that it would be reasonable to synonymise Exallandra under Sphaerophoria.