Symphoromyia Frauenfeld

Kerr, Peter H., 2010, 2592, Zootaxa 2592, pp. 1-133 : 100-102

Genus Symphoromyia Frauenfeld

Figs. 24–25, 31, 63, 84, 106, 123, 132, 150, 165–166, 177–178, 186, 189.

Symphoromyia Frauenfeld 1867: 496 . Type species Atherix melaena Meigen 1820 , by original designation.

Sympheromyia Schiner 1868: 910 (lapsus).

Parapheromyia Becker 1921: 42 . Type species Atherix crassicornis Panzer 1806 , by original designation. See notes below.

Paraphoromyia Becker 1922 (incorrect subsequent spelling). See notes below.

Axinicera Turner 1974: 861 . Type species Symphoromyia johnsoni Coquillett 1894 , by original designation.

Pogonaria Turner 1974: 861 . Type species Symphoromyia pachyceras Williston 1886 , by original designation.

Ochleromyia Turner 1974: 862 . Type species Symphoromyia kinkaidi Aldrich 1915 , by original designation.

Diagnosis. The autapomorphic development of the enlarged scape of Symphoromyia provides support for the monophyly of the genus. Desmomyia also has an enlarged scape, however, the distant phylogenetic placements of this genera indicate that this character state has evolved independently. Another autapomorphy for the genus is the shape of the aristate flagellomere, which is produced ventrally and is often kidney-shaped in profile.

Symphoromyia species are stout bodied flies, moderately sized (4.7 to 9 mm), with black, gray or goldgray thorax, and abdomen colored gray, black, mixed black and yellow, black terminating with yellow, or entirely yellow. Wings hyaline or lightly infuscate; male holoptic, eyes separated in female; antenna aristate; first flagellomere kidney-shaped or subcircular, expanded ventrally; laterally compressed; mandibles present; laterotergite bare; M 3 present; tibial spur formula 0:2:1; hind tibia without macrochaetae; tergite 9 with ventrolateral arms, extending posteriorly, surrounding and fusing to sternite 9 laterally; female spermathecal ducts with accessory glands. Symphoromyia is restricted to the Holarctic Region and reaches its greatest diversity in North America. Symphoromyia may be confused with local Tabanidae and Athericidae since females of some species are known to be bloodfeeders and can be a nuisance. Symphoromyia may be distinguished most easily from both Athericidae and Tabanidae by the absence of a scale on the postspiracular sclerite and in addition to this, from Athericidae by an elongated scape and R 2+3 meeting the margin at some distance away from R 1; and from Tabanidae by having an aristate antenna and R 4 not sinuate, and nearly parallel to R 5. Symphoromyia is similar in form and color to several species of Ptiolina , but may be distinguished by the elongate scape (that is clearly larger than pedicel), the ventrally expanded first flagellomere, and setose laterotergite. Symphoromyia may be distinguished from Chrysopilus and Rhagio by the large size of the scape, the two-segmented palp, and presence of mandibles. Additionally Symphoromyia may be separated from Rhagio by having a bare proepimeron and a single hind tibial spur; and from Chrysopilus by the absence of scale-like thoracic setae.

Description. Head. Clypeus bulbous. Scape clearly larger than pedicel. First flagellomere of antenna laterally compressed, enlarged bearing terminal or anterodorsal arista. Eyes inconspicuously setulose; in male, often flattened dorsally, holoptic or dichoptic, ommatidia split into dorsal and ventral areas and smaller ventrally. Parafacials in male swollen slightly or not swollen. Labella with pseudotracheae, length variable. Theca short and stout, with medial suture. Palpus two-segmented, distal segment longer than proximal segment. Stipes surrounded by membrane above theca, directed posteriorly. Lacinia present, longer than palpus, with serrated tip. Mandibles present. Cibarial pump long, clearly not as wide as long. Cornu nearly as long as or longer than cibarial pump, extending beyond pharyngeal pump. Pharyngeal pump anteriorly broad, forming cup-like structure, approximately same length as cibarial pump.

Thorax. Mesonotum with vittae. Dorsocentral bristles absent; all dorsal setae of equal length. Anepisternum setulose throughout posterior half. Laterotergite setose. Proscutellum present. Subscutellum inconspicuous. Wing hyaline, without markings or membrane lightly to moderately infuscate, brownish. Lower calypter reduced. Upper calypter well developed, with broad curvature, lobe-like, width twice length or less. Costa extends to wing tip (between R 4 and R 5). Humeral crossvein well developed. Sc-r crossvein weakly developed, positioned distal to h by approximate length of h. R 1 and R 2+3 separated at wing margin. Dorsal side of R 1 setulose, ventral side bare. All other wing veins without setulae. R 2+3 sinuous, apical third of R 2+3 ultimately bends anteriorly slightly, toward leading edge of wing margin. Length of R 2+3 shorter than R 5. Base of R 4 –R 5 fork proximal or directly above distal end of cell dm. R 4 nearly straight apically. R 5 posterior or anterior to wing tip, clearly longer than R 4+5 (r-m to R 4 origin). R-m crossvein at proximal one-third to near halfway of discal cell. M 3 present. M-cu crossvein present. Origin of CuA 1 at cell bm near discal cell. M 3 cell at margin convergent. CuA 2 length between 1/2 and 2/3 the length of posterior vein of cell bm. Alula with broad, evenly rounded curvature. Anal lobe well developed. Cell cu p open. Halter knob approximately 1/2 length of stem. Tibial spur formula 0:2:1. Hind coxal tubercle absent. Hind tibial macrochaetae absent. Postmetacoxal bridge absent.

Abdomen. Abdominal segments evenly tapered. In female, last 3 abdominal segments telescoped; tergite 7 much wider than long; intersegmental membrane between segments 7 and 8 especially long; sternite 8 as wide as long or wider than long. Male terminalia with epandrium simple, not containing hypandrium ventrally. Epandrium wider than long, strongly notched anteriorly. Tergite 10 present, divided medially, setose. Hypoproct present. Cercus base held underneath epandrium or directly adjacent to epandrium. Cerci partially displaced from one another, separation distance approximately half width of single cercus. Cerci, in posterior view cupped, forming circular outline medially. Hypandrium fused entirely to gonocoxites. Gonocoxite with sinuous dorsal ridge, leading to gonocoxal apodeme. Gonocoxal apodemes short, usually not long enough to reach anterior margin of hypandrium. Sperm sac forming separate, distinct lobes ventrally. Lateral ejaculatory processes present, not part of sperm sac posteriorly. Ejaculatory apodeme short or long. Ejaculatory apodeme laterally compressed. Aedeagal tines absent. Endoaedeagal process present. Female terminalia with tergite 9 entire, with narrow anteriorly-directed ventrolateral projections, enveloping sternite 9. Spermathecae three, spherical, moderately to well sclerotized. Spermathecal ducts more than three times but less than five times length of sternite 9, inflated at base of spermathecae. Spermathecal duct accessory glands arise at approximately the distal third of the spermathecal ducts, thickened and lightly sclerotized, with furrows, near junction with common spermathecal duct. Spermathecal ducts furrows at base present. Common spermathecal duct thickened, long, clearly longer than longest diameter of genital chamber. Genital chamber teardrop shaped, moderately sized. Accessory gland posterior to genital chamber inconspicuous, easily overlooked even after staining, common duct as long or shorter than sternite 9, with short paired extensions posteriorly. Sternite 9 anterior end rounded, posterior end with broad extensions posteriorly. Posterior end of sternite 9 joined together in horizontal plane centrally, held in vertical plane laterally. Tergite 10 entire, short, length less than half width. Sternite 10 split into two sclerites. Cercus two-segmented. First segment of cercus not elongate, without ventral process. Basal cercal segment adjacent dorsally. Ventral lobes of first segment of cercus sometimes curve ventrally towards one another to form ring, usually are flat and compressed medially. Second cercal segment not elongated, with apical sensory pits.

Larva. Body with 11 segments (not including head segment), smooth ventrally. Head capsule not folded within second thoracic segment, composed of a single, undivided plate (dorsal plate), less than 4.5 times longer than greatest width, not cone-shaped, with hole in dorsal shield around each antenna. Mandibular brush present, associated with simple fold of cuticle. Mandibular hook with external groove on adoral surface, serrate, otherwise smooth. Dorsal ridge of mandibular hook without anteriorly-directed microsetae. Labral teeth developed, sclerotized, in two rows, converging anteriorly. Maxilla sclerotized. Saw sclerite of mandibular base absent. Maxillary palpus soft, three-segmented, poorly differentiated. Antenna apparently one-segmented, bifurcated. Unpaired salivary pump absent. Posterior tentorial expansion fused to each other, with thin extension produced anteriorly.

Biology. Perhaps the most well known rhagionids are Symphoromyia whose adult females take blood meals from vertebrate hosts. In various areas throughout its range, Symphoromyia has been regarded as a bothersome pest, particularly in mountainous or high latitude regions ( Cockerell 1923; Frohne 1953a, 1953b, 1959; Knab & Cooley 1912; Shemanchuk & Wintraub 1961; among many others, see Turner 1979), and in some cases, the bite of Symphoromyia species has caused inflammation, swelling, and even severe allergic reaction ( Chvála 1983; Knab & Cooley 1912; Turner 1979). Some Symphoromyia species , however, and even perhaps most of the species of this genus seem not to attack people ( Sommerman 1962; Turner 1979; Turner & Chillcott 1973). Symphoromyia adults tend to be most active during the summer months, however, occasionally may be seen in flight during early spring. Despite the fact that species of Symphoromyia and Spaniopsis may be pestiferous, they are not considered medically or economically important. None serve as vectors of disease. In general, larval rhagionids are thought to be predators of other insect larvae ( Foote 1991). However Sommerman (1962) noted that Symphoromyia larvae are slow moving and apparently are not predaceous; their association with moss indicates that they may be at least partially herbivorous ( Sommerman 1962).

Literature. Aldrich (1915) gives a key to North American species, but there are numerous undescribed species in the region. Narchuk (1969) gives a key to eastern European species. Turner (1974) proposes species-groups within the genus. Sommerman (1962) provides natural history information for the larval stages.

Notes. Previous authors have referenced the genus name of Parapheromyia to Becker (1921: 59). However, the original article spans three issues with separate dates, hence the disjunct pagination (pp. 41–48, 15 August 1921; pp. 54–64, 15 November 1921; pp. 69–72, 15 January 1922). Since the new genus name is published in the first installment of the article, even though the type species designation and full description is given on page 59 in November, 1921, the name Parapheromyia was initially validly established in the key on page 42 in August, 1921 and this is the date and pagination which should be referenced. Becker (1921: 59) states that the type species for Parapheromyia is Symphoromyia crassicornix Panzer. This was a lapsus for Atherix crassicornis Panzer.

Turner (1974: 859) explains that Becker used the name Paraphoromyia in subsequent publications in place of Parapheromyia and the subsequent spelling was followed by other workers. Furthermore, Symphoromyia is what he calls the “coordinate taxon” of Parapheromyia and therefore, should be similar in spelling (besides, he notes, Paraphoromyia is euphonious). Therefore, he concludes, the name Parapheromyia was introduced by Becker as a lapsus or perhaps by a copier’s or printer’s error. However, Parapheromyia is used consistently throughout the paper (in the key (p. 42), the generic description (p. 59), and twice in the discussion (p. 72)) and the name Paraphoromyia is never proposed. Therefore, there is no clear indication that Parapheromyia Becker was used in error in the original publication and the proposed emendation of Turner (1974: 859) does not satisfy article 32.5.1 of the code (ICZN 1999). Furthermore, Becker makes no note of a spelling change in the original paper, nor in corrigenda published by the author or the publisher and therefore, the proposed emendation also fails to satisfy article 33.2.1 of the code (ICZN 1999). Since Becker’s original publication, most authors have used Paraphoromyia as an incorrect subsequent spelling (article 33.3 of ICZN 1999). Therefore the name Paraphoromyia Becker may be validated by prevailing usage (ICZN 1999: article 33.3.1). This matter needs to be resolved by the ICZN.