Rounded membranous area from which antenna protrudes; acetabula can be separated from each other by extension of facial
sclerotization [medial sclerotized stripe (Hippa & Ståhls 2005)], which can reach lunule; acetabula can be only partially separated or
completely fused, in this case being referred to as the antennal fossa (in narrow sense of Sorkin & Herman 2018).
Apical part of tarsomere 5, including arolium, empodium, unguitractor, claws and pulvilli (McAlpine 1981).
Anterior sclerite on sternum II, clearly separated by a membranous area from posterior sclerite (McAlpine 1981).
aedeagal apodeme (McAlpine 1981; Speight 1987)
aedeagal apodeme of Microdontinae (Thompson 1972; Vockeroth & Thompson 1987)
see lateral strips
aedeagal projections; apex; ventromedial projection; baso-ventral projection; apico-ventral flange (see van Steenis et al.
see ejaculatory process
aedeagus (Metcalf 1921; Cumming & Wood 2017)
aedeagus, stem of (van Steenis et al. 2016)
Supra-alar area, slightly elevated part of the scutum just posterodorsal from the wing base and anterior to the postalar callus,
often with short black setae (after Knight & Laffoon 1970).
A basal lobe along the posterior margin of the wing, located between the calypter and anal lobe (Cumming & Wood 2017).
alveolus (pl. alveoli)
Socket from which macrotrichia arise; sometimes the alveoli give a granulate aspect or "granulate alveoli" to the exoskeleton,
like in many Cerioidini (McAlpine 1981).
anal cell (Speight 2020)
see cell cua; vein CuP
anal lobe (McAlpine 1981; Speight 2020)
see cell a1
anatergite (Cumming & Wood 2017),
Posterodorsal plate of the mesothoracic pleuron, posterodorsal to the katatergum; with pile tuft in Allobaccha; part of the
lateral postnota of Speight (1987); (Thompson 1999).
Plate ventral to the wing base, with three distinguishable areas in many species: anterior, posterior and dorsomedial; anterior
area always pilose, posterior area sometimes and dorsomedial area pilose in Eristalinus (Thompson 1999).
Anterodorsal plate of mesothoracic pleuron, consisting of a flat anterior part and a convex posterior part in many species,
although its division is not always clear, see Nausigaster (Thompson 1999).
The angle of meeting point of two lines, often used in the wing veins or in the eye contiguity (angle of approximation), indicated
by the exact digit or the adjectives right-, acute- or obtuse-angle (Merriam et al. 2022).
In dorsal view, angle of eyes in holoptic males (Dusek & Laska 1973).
anteclypeus (McAlpine 1981)
antecoxal piece (Shannon 1922b)
antenna (pl. antennae)
Sensory organ, anterodorsally placed on the head; formed by the scape, pedicel, postpedicel and arista (Thompson 1999).
Fused, or partially fused, membranous acetabula (Sorkin & Herman 2018).
Figs9D,10A, B,11A, C
antennal pit (Shannon 1922a)
antennal pits (Speight 1987)
antennal process (Vockeroth 1971)
antennal prominence (Curran 1925)
see frontal prominence
antennal sockets (Cumming & Wood 2017)
Anterodorsal extension of head, anterior to frontal prominence, on which the antennae is placed, e.g. Cerioidini; differing from
an extended frontal prominence in that the antennifer has the lateral margins parallel both in lateral and dorsal views (Thompson 1999).
Anterior part of pronotum, sclerite just above the proepisternum; unpaired anterior sclerite of the prothorax, visible in thorax
in frontal view (Speight 1987).
Figs23A, B,24,B–E,25A, B, D,26A–C,28A,29,30A
anterior (adv. anteriorly)
Towards the head end of the fly; opposite of posterior (Thompson 1999).
Figs1B–D,2,38B,42A, B, F, G,54B
Anterior part of the plate ventral to the wing base, always pilose (Thompson 1999).
The anterior, often flat, part of the anterodorsal plate of mesothoracic pleuron (Thompson 1999).
anterior cervical sclerite
Most anteriorly positioned sclerite of the cervix (Martin 1916; Michelsen 1996).
anterior mesanepisternum (Speight 2020)
see anterior anepisternum
anterior mesocoxite (Speight 1987)
anterior mesonotal collar
Transverse row of long erect pile on the anterior border of scutum, e.g. Allobaccha, Asarkina, Hybobathus,
Ocyptamus (Vockeroth 1969).
Single, anteriorly placed simple eye on ocellar triangle (Thompson 1999).
anterior sclerite on sternum II (Speight 1987, Reemer & Ståhls 2013a).
Respiratory opening on the anterior part of the pleuron; mesothoracic spiracle (McAlpine 1981).
anterior surstylar lobe
Anterior portion of a bilobed surstylus (Metcalf 1921).
anterior tentorial pit
An invagination of the exoskeleton on the head that serves as an internal attachment site for muscles; visible externally on the
boundary between the gena and mala (Thompson 1999).
Figs10B,11D,12A, D,13A, B,14A, B,16D,17C
antero- and posterolateral rows of stout spines (Grkovićet al. 2015)
see setose carina
Anteroventral extension of the coxa; on the metacoxa (Neocnemodon) or on the eucoxa (Platycheirus scutatus) (after
antetergite (Hippa & Ståhls 2005)
The median sclerite at the anterior margin of tergum I (Hippa & Ståhls 2005).
Figs43A,44B–D,45B, C,46C, D
Dorsomedial part of head capsule, bordered laterally by eyes, anteriorly by transverse frontal sulcus, posteriorly by transverse
vertical sulcus, (Lejogaster metallina). Needs further investigation, might be homologous with vertical rugae in female Lejogaster
metallina (Harbach & Knight 1980; Sorkin & Herman 2018).
Transverse sulcus on dorsal part of head capsule bordering the antevertex and the vertex, between the compound eyes, anterior to
the ocellar triangle; e.g. male Lejogaster metallina.
The end of a structure, most apical point (Thompson 1999; Merriam et al. 2022).
apical (adv. apically)
On, or towards, the apex of a structure; opposite to basal (Thompson 1999).
Apical section of vein A1 (Vockeroth & Thompson 1987)
see vein CuA+CuP
apically rounded anterior process of mesotarsus (Vockeroth 1990)
see tarsal lamina
apicoposterior lamina of metafemur (Van Steenis et al. 2017)
see femoral discus
apicoventral projection (Hippa 1978a)
see tibial spina
apodemes of epiproct
Basolateral internal extensions of the epiproct; absent in some Syrphini (Miranda & Moran 2017).
appendage of upper process of hypandrium (van Steenis & Lucas 2011)
see hypandrial process
Small additional vein, arising from another vein or crossvein without connecting to other veins (Thompson 1999); spur (Vockeroth
& Thompson 1987).
Figs35B, C,36B, C,37B, C
appendix of crossvein dm-m
Extra longitudinal vein from crossvein dm-m into cell dm, so far only known to be present in Nephentosyrphus capitatus
appendix of crossvein r-m
Additional vein from crossvein r-m into cell r4+5 found in Stilbosoma (after Thompson 1972).
appendix of vein M1
Additional vein from vein M1 towards wing margin1 like in Eumerus, and some Eristalinus
species (Ssymank et al. 2021).
appendix of vein M1+2
Additional short vein from vein M1+2 into cell r4+5; anterior appendix R4+5. Found in
Mixogaster and Aristosyrphus (after Reemer & Ståhls 2013a).
appendix of vein R2+3
Additional vein from vein R2+3 into cell r2+3, in some species of Oriental Sphegina
(Asiosphegina) (Hippa et al. 2015).
appendix of vein R4+5
Additional vein from vein R4+5 into cell r4+5; posterior appendix R4+5 (Thompson et al.
2010; Reemer & Ståhls 2013a).
Laying, almost, flat to the body surface, most often used of recumbent pile (Merriam et al. 2022). In Fig. 4 the scale is
Slightly curved, forming an arc; an adjective commonly used for maculae or fasciae (Thompson 1999).
Macrotrichia-like structure on postpedicel, derived from modified flagellomeres; in e.g. Psarus abdominalis and
Pelecocera) incrassate; in other species positioned apically (Stuckenberg 1999).
Figs18A, E,19A–C,20,21A, C
aristomere (pl. aristomeres)
Separate segments of the arista (McAlpine 1981).
All kinds of expansions or projections from the exoskeleton; e.g. spina, lamina, dens etc (Thompson 1999).
Median membranous plate on tarsomere 5, bearing the empodium, connecting the unguitractor with the empodium (McAlpine
auxiliary vein (Cumming & Wood 2017)
see appendix of R4+5
auxillary vein in Eumerus (Ssymank et al. 2021)
see appendix of M1
auxillary vein in Lyneborgymyia (Ssymank et al. 2021)
see crossvein r-m1
axillary lobe (Hull 1949)
axillary plates (Sorkin & Herman 2018)
see axillary sclerites
Irregularly shaped plates at wing base, between the thorax and the basal veins, the first three plates are hypothesised to be
detached portions of the base of the veins, while the fourth is supposedly mesonotal in origin (McAlpine 1981; Dessì 2016).
bacilliform sclerite (Sorkin & Herman 2018)
see subepandrial sclerite
band (Sorkin & Herman 2018)
bar (Sorkin & Herman 2018)
Surface lacking vestiture, including the wing; if surface lacks macrotrichia but with microtrichia, it should be stated as
non-pilose and not bare (narrower specification of Thompson 1999).
On, or towards, the base of a structure; opposite to apical (Thompson 1999).
One of two sclerotized areas at wing base, basalare is anterior and subalare is posterior. The basalare is often only visible as a
tuberculate part of the posterior anepisternum (Snodgrass 1935; Crampton 1942).
basale (Speight 1987)
Part of a structure that is attached to another more central structure of the body; most proximal point (McAlpine 1981; Merriam
et al. 2022).
Anterobasal sclerite of wing, lateral to tegula (McAlpine 1981).
basicostale (Cumming & Wood 2017)
Dorsobasal part of the eucoxa in the mesoleg (McAlpine 1981).
Basal part of two-segmented phallus (Cumming & Wood 2017).
basipulvillus (pl. basipulvilli)
Paired connecting membrane between fifth tarsomere and pulvillis (McAlpine 1981).
In frontal view of prothorax, plate between the procoxa (Crampton 1942).
Figs23B,25A,26A, C, D
First/proximal tarsomere of each tarsus (after Speight 1987).
basitarsus (Sorkin & Herman 2018; Cumming & Wood 2017)
basoflagellomere (Thompson 1999)
basotarsomere (Thompson 1999)
beaded (Shannon 1926b).
see premarginal sulcus
Length of the fly from base of antenna to apex of abdomen (Thompson 1999).
see arrowed lines in Fig.1A.
bristle (Sorkin & Herman 2018)
buccal arm of tentorial sulcus (Speight 1987)
see subcranial sulcus
buccal cavity (HAO 2010)
see subcranial cavity
A blister-like, round shiny swelling, found on abdominal terga in some Afrotropical Phytomia (De Meyer et al.
calcar (pl. calcars, adj. calcarate)
Elongate articulated spine-like extension of the exoskeleton, longer than broad. In Syrphidae no articulating extensions of the
exoskeleton were found so far. The term as used in Thompson (1999) is here referred to as spina (Sorkin & Herman 2018). Calcar is used in some
calyptrate families to refer to a more distinct postero-dorsal seta situated at the metatibia (Cumming & Wood 2017).
not in Syrphidae
callus (Ssymank et al. 2021).
see facial tubercle
callus of 1st tergite of abdomen (van Steenis et al. 2016)
see lateral tubercle of tergum I
callus of sternite I (van Steenis et al. 2016)
see metapostnotal “protuberance”
calypter (pl. calypteres)
A membrane connecting base of wing with thoracic wall, basal to alula; forming two lobes: dorsal calypter (dorsal lobe) and
ventral calypter (ventral lobe, thoracic squamula); the calypters fold over each other when the wing is at rest (Thompson 1999).
Figs23C, D,27B,29B,30B,32A, D
capitellum (Harbach & Knight 1980)
capitulum (pl. capitella)
Apical and bulbous part of the halter; knob (Sorkin & Herman 2018).
carina (pl. carinae, adj. carinate)
Sharp low ridge, longer than high, found on the face, legs and genitalia (Harris 1979; Thompson 1999).
Any area of the wing enclosed by veins, crossveins or the wing margin, named after the vein that forms its anterior margin,
written in lowercase (Thompson 1999).
Area of the wing posterior to vein A1; first anal cell. In the old system anal lobe or cell a2 (McAlpine
1987; Saigusa 2006; Wootton & Ennos 1989).
cell a1; first anal cell (McAlpine 1981)
see cell cup
cell a2; second anal cell (McAlpine 1981)
see cell a1
Area of the wing enclosed by vein C anteriorly, crossvein h apically, and vein Sc posteriorly; basal-costal cell (Cumming &
Area of the wing enclosed by vein M anteriorly, M4 base and m-cu apically, and vein CuA posteriorly; basal medial cell
(Cumming & Wood 2017).
Area of the wing enclosed by vein Rs anteriorly, crossvein r-m apically, and vein M posteriorly; basal radial cell (Cumming &
Area of the wing enclosed by crossvein h basally, vein C anteriorly, and by vein Sc apically and posteriorly; costal cell (Cumming
& Wood 2017).
Area of the wing enclosed by vein CuA anteriorly and apically, and vein CuP posteriorly; anterior cubital cell. Cell cup in the
old system (McAlpine 1987; Saigusa 2006; Wootton & Ennos 1989).
cell cua1; first anterior cubital cell (McAlpine 1981)
see cell m4
Area of the wing between veins A1 and CuA+CuP; posterior cubital cell. In the old system cell a1 (McAlpine
1981; Saigusa 2006; Wootton & Ennos 1989).
cell cup; posterior cubital cell (McAlpine 1981)
see cell cua
Area of the wing enclosed by M4 base basally, the anterior branch of vein M anteriorly, crossvein dm-m apically, and
vein M4 posteriorly; discal medial cell (McAlpine 1981; Cumming & Wood 2017).
Area of the wing delimited by crossvein m-cu basally, vein M4 anteriorly, and vein CuA posteriorly; the cell is open
apically; fourth medial cell. In the old system cell cua1 (McAlpine 1981; Saigusa 2006; Wootton & Ennos 1989).
Area of the wing delimited by vein R1 anteriorly and vein R2+3 posteriorly; might be open or closed (when
vein R1 joins R2+3 forming a petiole) before the wing margin; first radial cell (McAlpine 1981; Cumming & Wood
Area of the wing delimited by vein R2+3 anteriorly, and vein R4+5 posteriorly; second + third radial cell
(McAlpine 1981; Cumming & Wood 2017).
Area of the wing enclosed by crossvein r-m basally, vein R4+5 anteriorly, vein M1 apically, and the anterior
branch of vein M posteriorly; some groups have a posteroapical appendix on the cell, which is vein M2; fourth + fifth radial cell
(McAlpine 1981; Cumming & Wood 2017).
Area of the wing delimited by vein Sc anteriorly, and vein R1 posteriorly; in some groups might be closed apically by a
crossvein sc-r; subcostal cell (Cumming & Wood 2017).
cercus (pl. cerci)
Single-segmented pair of appendages, connected to epandrium, lateral to anus; derived from proctiger; may be strongly developed
and/or bearing lobes e.g. Mimocalla (Cumming & Wood 2017).
Figs48D,51B,54A,55A, D,56A, C, E,57A, C, D
cercus (pl. cerci)
Pair of single segment structures lateral to the anus; membranous or slightly sclerotized, position in relation to epiproct varies
among taxa (Miranda & Moran 2017).
The neck; primarily membranous area between thorax and head (Knight & Laffoon 1970; McAlpine 1981).
The disposition of setae/pile on the body surface, especially on the costal vein of the wings (McAlpine 1981).
Usually spherical structure at the base of the phallus in Microdontinae; Metcalf (1921) used this term to refer to the basal
portion of the phallus in general (Thompson 1969).
chitinous box sensu Metcalf (1921)
cicatrix (pl. cicatrices)
Sulcus or ridge-like scar on the femur and tibia of many genera within Microdontinae (Hull 1949, see also Harris 1979).
cilium (pl. cilia)
Special thick pile found on the occiput in some species, e.g., Ceriogaster. Narrower defined than Thompson (1999).
Paired gripping structure, apico-lateral to fifth tarsomere (Thompson 1999).
Tubercle formed by postclypeus, seen in lateral view, dorsal to subcranial cavity and ventral to facial tubercle. Not present in
Pipizinae and several Microdontinae. Adjusted from Thompson (1972) and Hippa & Ståhls (2005).
Baso-anterior sclerite of proboscis, located between apical margin of buccal cavity and labrum; divided into postclypeus and
anteclypeus in some Syrphidae (e.g. Syrphus); clypeus commonly used as synonym of anteclypeus (Speight 1987).
comb (Sorkin & Herman 2018)
compound eye (Sorkin & Herman 2018)
copulatory pocket (Hippa 1986)
see genital chamber
cornea (Sorkin & Herman 2018)
coronal sulcus (in part, Nayar 1964)
see occipital sulcus
coronal suture (in part, Harbach & Knight 1980)
see occipital sulcus
costagium (Doczkal & Pape 2009)
see basicosta. Costagium (Séguy 1941; McAlpine 1981) is the base of vein C, between basicosta and crossvein h. In recent
Diptera manuals this region is not differentiated from the rest of costa and thus costagium is not a term used in Syrphidae.
(pl. coxae, adj. coxal)
First, or most basal, segment of the leg, with prefix pro- meso- or meta- (Thompson 1999).
Figs23A, C,25C,26C,27A, C,28A,29A,30A,31,32B, C,38A, C, D,39A, C,40A, C,42C, F
coxal spur (Thompson 1972)
see anterocoxal spina
The sclerotized cuticle of the head, indicated in one figure only (Snodgrass 1947).
crescent-shaped (Thompson 1999)
A short vein connecting major longitudinal veins, referenced with lowercase letters of the main veins it connects separated by an
hyphen (exception: crossvein h), e.g., crossvein dm-m and crossvein m-cu (Thompson 1999).
Apical crossvein between M4 and M. In the old system crossvein dm-cu (McAlpine 1987; Saigusa 2006; Wootton & Ennos
Short crossvein between veins C and Sc; humeral crossvein (McAlpine 1981; Cumming & Wood 2017).
Crossvein between veins CuA and M4; medial-cubital crossvein, bm-cu (McAlpine 1981; Saigusa 2006; Wootton & Ennos
Crossvein between veins R4+5 and anterior branch of M; radial-medial crossvein (McAlpine 1981; Saigusa 2006; Wootton
& Ennos 1989).
Crossvein on apical part of vein R2+3 to vein R1, found in some Oriental Sphegina
(Asiosphegina) species, not always entirely reaching vein R1 (Hippa et al. 2015).
vein dividing cell r4+5 in two parts, running from vein R4+5 to vein M1, found in the genus
Lyneborgimyia (Doczkal & Pape 2009).
Crossvein between veins Sc and R1; subcostal-radial crossvein (McAlpine 1981; Cumming & Wood 2017); stigmal
crossvein (Reemer & Ståhls 2013a).
ctenidial lobe (Hippa & Ståhls 2005)
ctenidion, especially on the postgonite (Hippa & Ståhls 2005)
ctenidium (pl. ctenidia)
Closely set row of short spinae, comb-shaped; might be applied to a specific structure in some male genitalia (Thompson 1999;
Hippa & Ståhls 2005).
(pl. dentis, adj. dentate)
A pointed, short, non-articulating extension of the exoskeleton, as long as, or shorter than, broad (Thompson 1999).
dentate carina (Hippa 1978a)
see setulate carina
Eyes do not meet each other dorsally between antennal base and vertex; condition seen in all females and some males (Cumming &
discal cell; cell d (Speight 2020)
see cell dm
Sclerotized strengthening on the labellum, together with the epifurca, furca and paraphysis (Schiemenz 1957).
Apical/ventral part of the eucoxa of the mesoleg (McAlpine 1981).
Apical part of two-segmented phallus (Cumming & Wood 2017).
dorsal (adv. dorsally)
On the upper side of a structure; opposite to ventral (Thompson 1999).
Figs1C, D,2,54A, B
Most dorsal part of the occiput directly posterior to the ocellar triangle (in part Thompson 1999), often of different texture and
chaetotaxy than rest of occiput, see further under occiput.
Dorso-medial part of the plate ventral to the wing base, pilose in Eristalinus (Thompson 1999).
dorsoventral bulge (Doczkal & Pape 2009)
see postcranial tubercle
Bodyparts or markings that are not shiny, often covered in microtrichia. Although dull has a wider definition than matt(e), dull
is the preferred term (Merriam et al. 2022).
Unpaired sclerotized structure of the sperm pump; not articulated to other sclerites of the genitalia; its shape varies among
groups (Cumming & Wood 2017).
Tube connecting the vasa deferentia to the sperm pump; not to be confused with the old term 'ejaculatory duct' used in
Microdontinae, see phallus (Cumming & Wood 2017).
ejaculatory hood (Metcalf 1921)
Apically placed processes of the phallus “ejaculatory sac” in Microdontinae (Reemer & Ståhls 2013a) and possibly also
homologous in Cerioidini (van Steenis et al. 2016).
elongated anterior tentorial pit (authors)
see facial sulcus
emarginate (Vockeroth 1969).
see premarginal sulcus
emargination on posterior eye margin
Angulation of the posterior eye margin, seen from lateral view of the head, in genera like Phytomia and Toxomerus
(Thompson 1999; Ssymank et al. 2021).
Long, seta-like, median process of the arolium (McAlpine 1981).
Internal seminal duct of the phallus that extends basally into the sperm sac; only visible in some Microdontinae (Cumming &
Lateral extremities of the apical cleft of the epandrium (Claussen 1991); in several Pipizella species distinctly
differentiated; rarely the epandrial arms fuse together, fully enclosing the cerci apically e.g. Victoriana parvicornis.
A border on the apical part of the epandrium in Pipizella and Ceriana (van Steenis & Lucas 2011; van Steenis
et al. 2016).