Hoverfly terminology

Part

explanation/ synonym terms

Figures

Abdomen

Abdomen

Posterior division of the body (Thompson 1999).

Figs 1 A, B, 3A, C, D, 32 B, C, 43–51

acetabulum (pl. acetabula)

Head

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).

Figs 10 C, D, 11 A

acropod

Leg

Apical part of tarsomere 5, including arolium, empodium, unguitractor, claws and pulvilli (McAlpine 1981).

Fig. 42 A, B

acrosternum

Abdomen

Anterior sclerite on sternum II, clearly separated by a membranous area from posterior sclerite (McAlpine 1981).

Figs 47 A, B

aedeagal apodeme (McAlpine 1981; Speight 1987)

Male terminalia

see phallapodeme

aedeagal apodeme of Microdontinae (Thompson 1972; Vockeroth & Thompson 1987)

Male terminalia

see lateral strips

aedeagal projections; apex; ventromedial projection; baso-ventral projection; apico-ventral flange (see van Steenis et al. 2016).

Male terminalia

see ejaculatory process

aedeagus (Metcalf 1921; Cumming & Wood 2017)

Male terminalia

see phallus

aedeagus, stem of (van Steenis et al. 2016)

Male terminalia

see phallapodeme

alar callus

Thorax

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).

Figs 28A, 29B, 30 B, 32 A

alula

Wing

A basal lobe along the posterior margin of the wing, located between the calypter and anal lobe (Cumming & Wood 2017).

Figs 34 B, 36 D

alveolus (pl. alveoli)

General

Socket from which macrotrichia arise; sometimes the alveoli give a granulate aspect or "granulate alveoli" to the exoskeleton, like in many Cerioidini (McAlpine 1981).

Figs 4 , 53 C

anal cell (Speight 2020)

Wing

see cell cua; vein CuP

anal lobe (McAlpine 1981; Speight 2020)

Wing

see cell a₁

anal segment

Male terminalia

see proctiger

anatergite (Cumming & Wood 2017),

Thorax

see anatergum

anatergum

Thorax

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).

Fig. 28A

anepimeron

Thorax

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).

Figs 23C, 28B, 29A, 30

anepisternum

Thorax

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).

Figs 28, 29B, 30 A

angle

General

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).

Figs 5 , 6 C

angle of approximation

Head

In dorsal view, angle of eyes in holoptic males (Dusek & Laska 1973).

Fig. 6 C

anteclypeus (McAlpine 1981)

Head

see clypeus

antecoxal piece (Shannon 1922b)

Thorax

see metasternum

antenna (pl. antennae)

Head

Sensory organ, anterodorsally placed on the head; formed by the scape, pedicel, postpedicel and arista (Thompson 1999).

Figs 1 A, 18–21

antennal fossa

Head

Fused, or partially fused, membranous acetabula (Sorkin & Herman 2018).

Figs 9 D, 10 A, B, 11 A, C

antennal pit (Shannon 1922a)

Head

see acetabulum

antennal pits (Speight 1987)

Head

see sacculus

antennal process (Vockeroth 1971)

Head

see antennifer

antennal prominence (Curran 1925)

Head

see frontal prominence

antennal sockets (Cumming & Wood 2017)

Head

see acetabulum

antennifer

Head

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).

Figs 3A, 6 C, 9 C, 12D

antepronotum

Thorax

Anterior part of pronotum, sclerite just above the proepisternum; unpaired anterior sclerite of the prothorax, visible in thorax in frontal view (Speight 1987).

Figs 23A, B, 24,B–E, 25 A, B, D, 26 A–C, 28A, 29, 30 A

anterior (adv. anteriorly)

General

Towards the head end of the fly; opposite of posterior (Thompson 1999).

Figs 1 B–D, 2 , 38 B, 42 A, B, F, G, 54 B

anterior anepimeron

Thorax

Anterior part of the plate ventral to the wing base, always pilose (Thompson 1999).

Figs 29A, 30

anterior anepisternum

Thorax

The anterior, often flat, part of the anterodorsal plate of mesothoracic pleuron (Thompson 1999).

Figs 28, 30 A

anterior cervical sclerite

Thorax

Most anteriorly positioned sclerite of the cervix (Martin 1916; Michelsen 1996).

Figs 23B, 25 B, D, 26 C

anterior mesanepisternum (Speight 2020)

Thorax

see anterior anepisternum

anterior mesocoxite (Speight 1987)

Leg

see disticoxa

anterior mesonotal collar

Thorax

Transverse row of long erect pile on the anterior border of scutum, e.g. Allobaccha, Asarkina, Hybobathus, Ocyptamus (Vockeroth 1969).

Fig. 53 D

anterior ocellus

Head

Single, anteriorly placed simple eye on ocellar triangle (Thompson 1999).

Figs 6 D, 12B

anterior sclerite on sternum II (Speight 1987, Reemer & Ståhls 2013a).

Abdomen

see acrosternum

anterior spiracle

Thorax

Respiratory opening on the anterior part of the pleuron; mesothoracic spiracle (McAlpine 1981).

Figs 23B, 25 D, 26 D, 28B, 30 A

anterior surstylar lobe

Male terminalia

Anterior portion of a bilobed surstylus (Metcalf 1921).

Fig. 54 A

anterior tentorial pit

Head

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).

Figs 10 B, 11 D, 12A, D, 13A, B, 14A, B, 16D, 17C

antero- and posterolateral rows of stout spines (Grković et al. 2015)

Leg

see setose carina

anterocoxal spina

Leg

Anteroventral extension of the coxa; on the metacoxa (Neocnemodon) or on the eucoxa (Platycheirus scutatus) (after McAlpine 1981).

Fig. 42 G

antetergite (Hippa & Ståhls 2005)

Abdomen

see antetergum

antetergum

Abdomen

The median sclerite at the anterior margin of tergum I (Hippa & Ståhls 2005).

Figs 43A, 44 B–D, 45 B, C, 46 C, D

antevertex

Head

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).

Fig. 9 B

antevertical sulcus

Head

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.

Fig. 9 B

apex

General

The end of a structure, most apical point (Thompson 1999; Merriam et al. 2022).

Fig. 2 B

apical (adv. apically)

General

On, or towards, the apex of a structure; opposite to basal (Thompson 1999).

Fig. 1 B

Apical section of vein A₁ (Vockeroth & Thompson 1987)

Wing

see vein CuA+CuP

apically rounded anterior process of mesotarsus (Vockeroth 1990)

Leg

see tarsal lamina

apicoposterior lamina of metafemur (Van Steenis et al. 2017)

Leg

see femoral discus

apicoventral projection (Hippa 1978a)

Leg

see tibial spina

apodemes of epiproct

Female terminalia

Basolateral internal extensions of the epiproct; absent in some Syrphini (Miranda & Moran 2017).

Figs 52A–C

appendage of upper process of hypandrium (van Steenis & Lucas 2011)

Male terminalia

see hypandrial process

appendix

Wing

Small additional vein, arising from another vein or crossvein without connecting to other veins (Thompson 1999); spur (Vockeroth & Thompson 1987).

Figs 35B, C, 36 B, C, 37 B, C

appendix of crossvein dm-m

Wing

Extra longitudinal vein from crossvein dm-m into cell dm, so far only known to be present in Nephentosyrphus capitatus (Hippa 1978b).

Fig. 37 D

appendix of crossvein r-m

Wing

Additional vein from crossvein r-m into cell r₄₊₅ found in Stilbosoma (after Thompson 1972).

Fig. 36 B

appendix of vein M₁

Wing

Additional vein from vein M₁ towards wing margin₁ like in Eumerus, and some Eristalinus species (Ssymank et al. 2021).

Figs 35C, 37 B

appendix of vein M₁₊₂

Wing

Additional short vein from vein M₁₊₂ into cell r₄₊₅; anterior appendix R₄₊₅. Found in Mixogaster and Aristosyrphus (after Reemer & Ståhls 2013a).

Fig. 37 C

appendix of vein R₂₊₃

Wing

Additional vein from vein R₂₊₃ into cell r₂₊₃, in some species of Oriental Sphegina (Asiosphegina) (Hippa et al. 2015).

Fig. 35B

appendix of vein R₄₊₅

Wing

Additional vein from vein R₄₊₅ into cell r₄₊₅; posterior appendix R₄₊₅ (Thompson et al. 2010; Reemer & Ståhls 2013a).

Figs 35C, 36 C

appressed

General

Laying, almost, flat to the body surface, most often used of recumbent pile (Merriam et al. 2022). In Fig. 4 the scale is appressed.

Fig. 4

arcuate

General

Slightly curved, forming an arc; an adjective commonly used for maculae or fasciae (Thompson 1999).

Figs 5 , 44 B, 46 D

arista

Head

Macrotrichia-like structure on postpedicel, derived from modified flagellomeres; in e.g. Psarus abdominalis and Pelecocera) incrassate; in other species positioned apically (Stuckenberg 1999).

Figs 18A, E, 19 A–C, 20 , 21 A, C

aristomere (pl. aristomeres)

Head

Separate segments of the arista (McAlpine 1981).

Fig. 18B

armature

General

All kinds of expansions or projections from the exoskeleton; e.g. spina, lamina, dens etc (Thompson 1999).

Fig. 4

arolium

Leg

Median membranous plate on tarsomere 5, bearing the empodium, connecting the unguitractor with the empodium (McAlpine 1981).

Fig. 42 A

auxiliary vein (Cumming & Wood 2017)

Wing

see appendix of R₄₊₅

auxillary vein in Eumerus (Ssymank et al. 2021)

Wing

see appendix of M₁

auxillary vein in Lyneborgymyia (Ssymank et al. 2021)

Wing

see crossvein r-m₁

axillary lobe (Hull 1949)

Wing

see alula

axillary plates (Sorkin & Herman 2018)

Wing

see axillary sclerites

axillary sclerites

Wing

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).

Figs 23D, 29B, 30 B

bacilliform sclerite (Sorkin & Herman 2018)

Male terminalia

see subepandrial sclerite

band (Sorkin & Herman 2018)

General

see fascia

bar (Sorkin & Herman 2018)

General

see macula

bare

General

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).

Figs 19 A, 20 B, 34 B, 36 A

basal (adv. basally)

General

On, or towards, the base of a structure; opposite to apical (Thompson 1999).

Figs 1 B, 2 B

basalare

Thorax

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).

Fig. 30 B

basale (Speight 1987)

Male terminalia

see epandrium

base

General

Part of a structure that is attached to another more central structure of the body; most proximal point (McAlpine 1981; Merriam et al. 2022).

Fig. 2 B

basicosta

Wing

Anterobasal sclerite of wing, lateral to tegula (McAlpine 1981).

Figs 23D, 33 D, 34 A

basicostale (Cumming & Wood 2017)

Wing

see basicosta

basicoxa

Leg

Dorsobasal part of the eucoxa in the mesoleg (McAlpine 1981).

Fig. 42 F

basiphallus

Male terminalia

Basal part of two-segmented phallus (Cumming & Wood 2017).

Figs 55 C, D

basipulvillus (pl. basipulvilli)

Leg

Paired connecting membrane between fifth tarsomere and pulvillis (McAlpine 1981).

Fig. 42 E

basisternum

Thorax

In frontal view of prothorax, plate between the procoxa (Crampton 1942).

Figs 23B, 25 A, 26 A, C, D

basitarsomere

Leg

First/proximal tarsomere of each tarsus (after Speight 1987).

Figs 38 A, B, 42 B

basitarsus (Sorkin & Herman 2018; Cumming & Wood 2017)

Leg

see basitarsomere

basoflagellomere (Thompson 1999)

Head

see postpedicel

basotarsomere (Thompson 1999)

Leg

see basitarsomere

beaded (Shannon 1926b).

General

see premarginal sulcus

body length

General

Length of the fly from base of antenna to apex of abdomen (Thompson 1999).

see arrowed lines in Fig. 1 A.

bristle (Sorkin & Herman 2018)

General

see seta

buccal arm of tentorial sulcus (Speight 1987)

Head

see subcranial sulcus

buccal cavity (HAO 2010)

Head

see subcranial cavity

bulla (pl. bullae)

General

A blister-like, round shiny swelling, found on abdominal terga in some Afrotropical Phytomia (De Meyer et al. 2020).

Fig. 3D

calcar (pl. calcars, adj. calcarate)

General

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).

Head

see facial tubercle

callus of 1st tergite of abdomen (van Steenis et al. 2016)

Abdomen

see lateral tubercle of tergum I

callus of sternite I (van Steenis et al. 2016)

Thorax

see metapostnotal “protuberance”

calypter (pl. calypteres)

Wing

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).

Figs 23C, D, 27 B, 29B, 30 B, 32 A, D

capitellum (Harbach & Knight 1980)

Thorax

see capitulum

capitulum (pl. capitella)

Wing

Apical and bulbous part of the halter; knob (Sorkin & Herman 2018).

Fig. 23C

carina (pl. carinae, adj. carinate)

General

Sharp low ridge, longer than high, found on the face, legs and genitalia (Harris 1979; Thompson 1999).

Figs 4 , 39 A, D, 41 B–D

cell

Wing

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).

Figs 34 B, 36 D

cell a₁

Wing

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).

Fig. 34 B

cell a₁; first anal cell (McAlpine 1981)

Wing

see cell cup

cell a₂; second anal cell (McAlpine 1981)

Wing

see cell a₁

cell bc

Wing

Area of the wing enclosed by vein C anteriorly, crossvein h apically, and vein Sc posteriorly; basal-costal cell (Cumming & Wood 2017).

Fig. 34 B

cell bm

Wing

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).

Figs 34 B, 36 D

cell br

Wing

Area of the wing enclosed by vein Rs anteriorly, crossvein r-m apically, and vein M posteriorly; basal radial cell (Cumming & Wood 2017).

Figs 34 B, 36 D

cell c

Wing

Area of the wing enclosed by crossvein h basally, vein C anteriorly, and by vein Sc apically and posteriorly; costal cell (Cumming & Wood 2017).

Figs 34 B, 36 D

cell cua

Wing

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).

Figs 34 B, 36 D

cell cua₁; first anterior cubital cell (McAlpine 1981)

Wing

see cell m₄

cell cup

Wing

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).

Figs 34 B, 36 A

cell cup; posterior cubital cell (McAlpine 1981)

Wing

see cell cua

cell dm

Wing

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).

Figs 34 B, 36 D

cell m₄

Wing

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).

Fig. 34 B

cell r₁

Wing

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 2017).

Figs 34 B, 36 D

cell r₂₊₃

Wing

Area of the wing delimited by vein R₂₊₃ anteriorly, and vein R₄₊₅ posteriorly; second + third radial cell (McAlpine 1981; Cumming & Wood 2017).

Fig. 34 B

cell r₄₊₅

Wing

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).

Figs 34 B, 36 D

cell sc

Wing

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).

Fig. 34 B

cercus (pl. cerci)

Male terminalia

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).

Figs 48 D, 51 B, 54 A, 55 A, D, 56 A, C, E, 57 A, C, D

cercus (pl. cerci)

Female terminalia

Pair of single segment structures lateral to the anus; membranous or slightly sclerotized, position in relation to epiproct varies among taxa (Miranda & Moran 2017).

Fig. 52

cervix

Thorax

The neck; primarily membranous area between thorax and head (Knight & Laffoon 1970; McAlpine 1981).

Figs 23A, 26 D, 30 B

chaetotaxy

General

The disposition of setae/pile on the body surface, especially on the costal vein of the wings (McAlpine 1981).

Fig. 33 A

chitinous box

Male terminalia

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).

Fig. 56 F

chitinous box sensu Metcalf (1921)

Male terminalia

see phallus

cicatrix (pl. cicatrices)

Leg

Sulcus or ridge-like scar on the femur and tibia of many genera within Microdontinae (Hull 1949, see also Harris 1979).

Fig. 40 A

cilium (pl. cilia)

General

Special thick pile found on the occiput in some species, e.g., Ceriogaster. Narrower defined than Thompson (1999).

Figs 4 , 15A

claw

Leg

Paired gripping structure, apico-lateral to fifth tarsomere (Thompson 1999).

Figs 42 A, E

clypeal knob

Head

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).

Figs 12B, 14A, D

clypeus

Head

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).

Figs 16B, D, 17A–C, 22

comb (Sorkin & Herman 2018)

General

see ctenidium

compound eye (Sorkin & Herman 2018)

Head

see eye

copulatory pocket (Hippa 1986)

Female terminalia

see genital chamber

cornea (Sorkin & Herman 2018)

Head

se facet

coronal sulcus (in part, Nayar 1964)

Head

see occipital sulcus

coronal suture (in part, Harbach & Knight 1980)

Head

see occipital sulcus

costagium (Doczkal & Pape 2009)

Wing

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.

coxa (pl. coxae, adj. coxal)

Leg

First, or most basal, segment of the leg, with prefix pro- meso- or meta- (Thompson 1999).

Figs 23A, C, 25 C, 26 C, 27 A, C, 28A, 29A, 30 A, 31 , 32 B, C, 38 A, C, D, 39 A, C, 40 A, C, 42 C, F

coxal spur (Thompson 1972)

Leg

see anterocoxal spina

cranium

Head

The sclerotized cuticle of the head, indicated in one figure only (Snodgrass 1947).

Fig. 10 A

crescent-shaped (Thompson 1999)

General

see lunulate

crossvein

Wing

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).

Figs 3B, 34 A, 35, 36 , 37 A, C, D

crossvein bm-cu; basal medial-cubital crossvein (McAlpine 1981)

Wing

see crossvein m-cu

crossvein bm-cu; basal medial-cubital crossvein both in part (McAlpine 1981)

Wing

see M₄ base

crossvein c-r₁

Wing

Additional crossveins between vein C and vein R₁, as seen in Lycastris (Saigusa 2006; Wootton & Ennos 1989).

Figs 3B, 35D

crossvein dm-cu; discal medial-cubital crossvein (McAlpine 1981)

Wing

see crossvein dm-m

crossvein dm-m

Wing

Apical crossvein between M₄ and M. In the old system crossvein dm-cu (McAlpine 1987; Saigusa 2006; Wootton & Ennos 1989).

Figs 34 A, 35, 36 , 37 C, D

crossvein h

Wing

Short crossvein between veins C and Sc; humeral crossvein (McAlpine 1981; Cumming & Wood 2017).

Figs 34 A, 35, 36 A–C

crossvein m-cu

Wing

Crossvein between veins CuA and M₄; medial-cubital crossvein, bm-cu (McAlpine 1981; Saigusa 2006; Wootton & Ennos 1989).

Figs 34 A, 36 A, 37 C

crossvein r-m

Wing

Crossvein between veins R₄₊₅ and anterior branch of M; radial-medial crossvein (McAlpine 1981; Saigusa 2006; Wootton & Ennos 1989).

Figs 34 A, 35A, D

crossvein r_1-r₂₊₃

Wing

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).

Fig. 35B

crossvein r₄₊₅-m₁

Wing

vein dividing cell r₄₊₅ in two parts, running from vein R₄₊₅ to vein M₁, found in the genus Lyneborgimyia (Doczkal & Pape 2009).

Fig. 37 A

crossvein sc-r

Wing

Crossvein between veins Sc and R₁; subcostal-radial crossvein (McAlpine 1981; Cumming & Wood 2017); stigmal crossvein (Reemer & Ståhls 2013a).

Figs 35A, C, 36 C

ctenidial lobe (Hippa & Ståhls 2005)

Male terminalia

see postgonite

ctenidion, especially on the postgonite (Hippa & Ståhls 2005)

General

see ctenidium

ctenidium (pl. ctenidia)

General

Closely set row of short spinae, comb-shaped; might be applied to a specific structure in some male genitalia (Thompson 1999; Hippa & Ståhls 2005).

Figs 54 B, D, 56 C, 58 A

dens (pl. dentis, adj. dentate)

General

A pointed, short, non-articulating extension of the exoskeleton, as long as, or shorter than, broad (Thompson 1999).

Figs 4 , 24 A, 44 B

dentate carina (Hippa 1978a)

Leg

see setulate carina

dichoptic

Head

Eyes do not meet each other dorsally between antennal base and vertex; condition seen in all females and some males (Cumming & Wood 2017).

Figs 6 D, 10 A

discal cell; cell d (Speight 2020)

Wing

see cell dm

discal sclerite

Proboscis.

Sclerotized strengthening on the labellum, together with the epifurca, furca and paraphysis (Schiemenz 1957).

Fig. 22

disticoxa

Leg

Apical/ventral part of the eucoxa of the mesoleg (McAlpine 1981).

Fig. 42 F

distiphallus

Male terminalia

Apical part of two-segmented phallus (Cumming & Wood 2017).

Figs 55 C, D

dorsal (adv. dorsally)

General

On the upper side of a structure; opposite to ventral (Thompson 1999).

Figs 1 C, D, 2 , 54 A, B

dorsal occiput

Head

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.

Figs 6 A, B, 7B, 9 D, 15C, 16A

dorsomedial anepimeron

Thorax

Dorso-medial part of the plate ventral to the wing base, pilose in Eristalinus (Thompson 1999).

Fig. 29B

dorsoventral bulge (Doczkal & Pape 2009)

Head

see postcranial tubercle

dull

General

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).

Fig. 3D

ejaculatory apodeme

Male terminalia

Unpaired sclerotized structure of the sperm pump; not articulated to other sclerites of the genitalia; its shape varies among groups (Cumming & Wood 2017).

Figs 54 C, 55 C, D, 56 D–F

ejaculatory duct

Male terminalia

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).

n/a

ejaculatory hood (Metcalf 1921)

Male terminalia

see phallus

ejaculatory process

Male terminalia

Apically placed processes of the phallus “ejaculatory sac” in Microdontinae (Reemer & Ståhls 2013a) and possibly also homologous in Cerioidini (van Steenis et al. 2016).

Figs 56 B, F

elongated anterior tentorial pit (authors)

Head

see facial sulcus

emarginate (Vockeroth 1969).

General

see premarginal sulcus

emargination on posterior eye margin

Head

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).

Fig. 14D

empodium

Leg

Long, seta-like, median process of the arolium (McAlpine 1981).

Figs 42 A, E

endophallus

Male terminalia

Internal seminal duct of the phallus that extends basally into the sperm sac; only visible in some Microdontinae (Cumming & Wood 2017).

n/a

epandrial arm

Male terminalia

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.

Fig. 58 B

epandrial rim

Male terminalia

A border on the apical part of the epandrium in Pipizella and Ceriana (van Steenis & Lucas 2011; van Steenis et al. 2016).

Fig. 58 C

epandrium (adj. epandrial)

Male terminalia

Tergum IX, bearing the cerci+anus medially and the surstyli apically; usually clefted apically, but might completely encircle the cercus+anus (e.g. Victoriana parvicornis); articulates to the basolateral corners of the hypandrium (Cumming & Wood 2017).

Figs 43C, 45 B, 46 D, 47 B, 48 , 49 , 50 , 51 , 54 A, 55 A, C, 56 C, E, 57 A, C, D, 58 B, E

epaulet (Hippa 1990)

Wing

see basicosta

epifurca

Proboscis.

A small oval sclerite in the middle of the outer wall of the labellum (Schiemenz 1957).

Fig. 22

epimeral spine of metapleura (Reemer & Hippa 2005)

Thorax

see metapostnotal protuberance

epimeral spine of metathoracic pleura (Speight 1987)

Thorax

see metapostnotal protuberance

epimeron (Crampton 1942)

Thorax

see proepimeron

epimeron (pl. epimera)

Thorax

Plates of mesothoracic pleuron behind posterior anepisternum; anepimeron + katepimeron (Cumming & Wood 2017).

Figs 23C, 28, 29A, 30

epimeron of methothoracic pleura and the metathoracic notum sensu Speight (1987)

Thorax

see metapostnotum

epipharynx

Proboscis.

Dorsal and lateral sides of the food canal, connected with the labrum, as part of the haustellum (Gilbert & Jervis 1998).

n/a

epiproct

Female terminalia

Dorsal sclerite of proctiger; single plate in Microdontinae, paired structure in other groups; it can be separate, connected by an apical extension, or fused to cerci (Miranda & Moran 2017).

Figs 52A–C, E

episternum (Crampton 1942)

Thorax

see proepisternum

epistoma (Crampton 1942)

Head

see postclypeus

equilateral

General

All sides of the triangle of equal length and thus all angles too, often used to indicate the relative distance of the ocelli to each other (Merriam et al. 2022).

Fig. 5

erect

General

Standing straight up out of the body (Merriam et al. 2022). In Syrphidae used for pile and armature, see Fig. 4 in which e.g. the pile and the spina are erect.

Fig. 4

eucoxa

Leg

Anterior part of mesocoxa, often divided into a basicoxa and a disticoxa (McAlpine 1981).

Fig. 42 F

external process of sternite 10 (Thompson & Rotheray 1998)

Male terminalia

see subepandrial sclerite

eye

Head

Visual organs on the postero-lateral part of the head, formed by individual ommatidia, the compound eye (McAlpine 1981) here shortened to eye.

Figs 8 A, 12B, 15C

eye contiguity

Head

Line along which compound eyes meet in holoptic males; males of some species eyes very narrowly separated medially leaving a bare, shiny area free between eyes; eye-bridge sensu Doczkal & Pape (2009), not to be confused with eye bridge of McAlpine (1981) and others, restricted to a connection of eyes with narrow row of ommatidia forming a bridge between the large compound eyes, not found in Syrphidae see Merz & Haenni (2000); (Thompson 1999).

Figs 6 B, 7A

eye-bridge (Doczkal & Pape 2009).

Head

see eye contiguity

face

Head

Antero-ventromedial area of head, bordered dorsally by  acetabula /antennal fossa, ventrally by mala, and laterally by eyes, or by parafacial sulcus in several species; very variable among taxa, e.g. flat, concave, convex, with tubercle(s), etc (Crampton 1942).

Figs 6 C, 8 C, D, 9 C, 10 A, 12A, B, D, 13A, C, 14A

facet

Head

The outer, transparent, cuticular covering of the individual ommatidia which make up the compound eye.

n/a

facial carina

Head

Longitudinal ridge on face; not facial carina of McAlpine (1981), Cumming & Wood (2017) and Sorkin & Herman (2018) which is a structure separating the acetabula. The carina can either be placed medially, in Syritta and Tropidia scita or laterally in Ceriogaster (after Thompson 1972; Hippa & Ståhls 2005).

Figs 11 B, 12A

facial depression (Sorkin & Herman 2018)

Head

see antennal fossa

facial groove (Hippa & Ståhls 2005)

Head

see facial sulcus

facial pit (Curran 1925)

Head

see anterior tentorial pit

facial prominence (Speight 1987)

Head

see facial tubercle

facial ridge (Doczkal & Pape 2009)

Head

see parafacia

facial stripe (Hippa & Ståhls 2005)

Head

see parafacia

facial sulcus

Head

Groove parallel to eye margin along face ending in (anterior) tentorial pit, often a sharp border between face and paraface (Speight 1987).

Figs 10 C, D, 12B, 17A, C

facial tubercle

Head

Medial to medio-ventrally positioned tubercle on the face, in Ornidia obesa there are more "protuberances" which are called lateral facial tubercles (Speight 1987).

Figs 7C, 10 C, 11 C, D, 12B, C, 13C, D, 14, 15A, B, 17C

falcate

General

Sickle-shaped, hook-shaped (Sorkin & Herman 2018), an adjective used in male terminalia (Hippa et al. 2015) and antennae (Reemer & Ståhls 2013a).

Fig. 5

false vein (Sorkin & Herman 2018)

Wing

see vena spuria

fascia (pl. fasciae, adj. fasciate)

General

A transverse band (Thompson 1999).

Figs 9 D, 44 A, C, D, 46 A, D, 53 E, F

Female terminalia

Female terminalia

The female postabdomen with genital organs and adjoining structures. Focusing on mostly sclerotized external structures and not internal soft tissue organs (Cumming & Wood 2017).

Fig. 52

femoral discus

Leg

Flange on the apico-posterior outline of the mesofemur in some Eumerus species (van Steenis et al. 2017)

Fig. 39 A

femoral lamina

Leg

Triangular-shaped anteroventral plate on the apex of the metafemur, like in the genera Merodon, Tropidia and others (Ssymank et al. 2021).

Figs 38 C, 40 B, 41 A

femoral patch of setulae

Leg

Anterobasal area on the femur with short black setulae, present only in Eristalinae (Thompson 1999).

Fig. 39 B

femoral spina

Leg

Spur on apico-lateral part of metafemur, as in genera Milesia and Spilomyia (Hippa 1990).

Fig. 40 C

femoral tubercle

Leg

Any rounded to elongate extension of femur, most often on mesofemur as in Brachypalpus and Eumerus stackelbergi, dentate as in Syritta and Xylota, or with setae as in Parhelophilus frutetorum (Hippa 1978a); not triangular-shaped femoral spina or femoral lamina, see under those terms for explanation.

Figs 39 B, 41 A, B

femur (pl. femora, adj. femoral)

Leg

Third basal segment of the leg, between trochanter and tibia (Thompson 1999).

Figs 2 A, 38 A, D, 39 A, C, 40 C, D, 41 A, 42 G.

femoral expansion (Ssymank et al. 2021)

Leg

see femoral lamina

fenestra, adj fenestrate

Male terminalia

Membranous areas on genitalia; on hypandrium in several Eristalinae but also found in other tribes (Hippa 1978a; Harris 1979).

Fig. 55 C

first basal cell (Speight 2020)

Wing

see cell br

first costal cell (Speight 2020)

Wing

see cell bc

first flagellomere (Cumming & Wood 2017),

Head

see postpedicel

first segment of flagellum (Speight 1987)

Head

see postpedicel

flange (Sorkin & Herman 2018)

General

see lamina

foramen magnum (Sorkin & Herman 2018)

Head

see occipital foramen

fore leg (Cumming & Wood 2017)

Leg

see proleg; both terms are interchangeable

fossette

Head

Elongate cavity on the anterodorsal surface of the postpedicel (Séguy 1961; Doczkal & Pape 2009).

Figs 18C, D

fringed plates (Hurkmans 1993)

Male terminalia

see postgonite

fringed posteroventral extension of subalar sclerite (Ssymank et al. 2021)

Thorax

see plumule

frons

Head

In dorsal view, the anterodorsal part of the head, bounded anteriorly by the lunule, laterally by the eye margin and posteriorly by the vertex, or the eye contiguity in holoptic males (Thompson 1999).

Figs 6 A, D, 7C, D, 8 A, C, D, 9 A–C, 13A, C

frontal

General

Used to indicate features of the frons (Sorkin & Herman 2018). This term is thus restricted to the head and used in e.g. frontal triangle (Thompson 1999). Not indicating any direction.

Figs 6 B, C, 7A, B, D

frontal lunule (Speight 1987)

Head

see lunule

frontal prominence

Head

In lateral view the anterodorsal produced part around the antennal fossa (parts of the face and frons), more or less triangular-shaped, posterolaterally bounded by the eyes, and anteriorly by the lunule or the antennifer (in part Thompson 1999).

Figs 12A, C, 13, 14A, B, D, 15A

frontal rugae

Head

Area of rugae on ventral part of frons; Phytomia (De Meyer et al. 2020)

Fig. 11 D

frontal striae (Speight 2020)

General

see regulae

frontal triangle

Head

In holoptic males, the frons is bordered posteriorly by the eye contiguity, giving it a triangular shape (Thompson 1999).

Figs 6 B, C, 7A, B

frontal tubercle

Head

Tubercle on frons, dorsal to frontal prominence, found in some species of Nausigaster. Not frontal tubercle of Speight (1987) which is frontal prominence and not frontal tubercle of McAlpine (1981) which is a structure of the vertex, hypothesised to be modified ocelli.

Fig. 15B

frontal tubercle (McAlpine 1981)

Head

a structure of the vertex, possibly modified ocelli

frontal tubercle (Speight 1987)

Head

see antennifer

fumose, fumeus (Sorkin & Herman 2018)

General

see infuscate

fulcrum

Proboscis.

Extension sclerite of the rostrum (Gilbert & Jervis 1998)

Fig. 22

furca

Proboscis.

Sclerotized strengthening on the labellum, together with the epifurca, apical sclerite and paraphysis (Schiemenz 1957).

Fig. 22

furcasternum

Thorax

Furcasternum, a distinct part of the sternum, serving as a site for muscle attachment (McAlpine 1981).

Figs 25 A, 26 C

furcate

General

Latin for forked (Sorkin & Herman 2018), used in the postpedicel which can be bi- or multifurcate in Cacoceria and several Microdontinae, also used for pile or features of the terminalia.

Figs 21 B, D

gena (pl. genae)

Head

Area on head ventral to eye, anterior to occiput and posterior to tentorial pit and buccal sulcus; more restricted definition (as Snodgrass 1960), not broader definition used by McAlpine (1981) and Thompson (1999), which includes part of mala, after Crampton (1942).

Figs 11 C, D, 12, 13B–D, 14, 15A, 16B, D, 17B–D

gena of authors (McAlpine 1981; Thompson 1999)

Head

see parafacia

genal sulcus

Head

Groove on the ventral part of the head, extending from the anterior tentorial pit to the eye margin (after Speight 1987).

Figs 12A, 13A, 16B, 17A

genal suture (Doczkal & Pape 2009)

Head

see genal sulcus

genital chamber

Female terminalia

Membranous pocket, invaginated into segment VIII, with external opening between apex of sternum VIII and hypoproct; may have a distinct sternum IX on its dorsal wall; a more restricted view of the term genital chamber of Kotrba (2000), which is here limited to the external invaginated area located between the secondary gonopore and the genital opening (Miranda & Moran 2017).

Figs 52D, E

genital opening

Female terminalia

Opening of genital chamber to exterior; ventrally located, between sternum VIII and hypoproct (Kotrba 2000; Miranda & Moran 2017).

Figs 52D, E

genital opening (Cumming & Wood 2017)

Female terminalia

see secondary gonopore

genital orifice/genital cleft (Kotrba 2000)

Female terminalia

see genital opening

gonite (Claussen 1991)

Male terminalia

see postgonite

Gonotreme (Nayar 1965), gonotrema (Kotrba 2000)

Female terminalia

see genital opening

granulum (pl. granula, adj. granulate)

General

Upheaved ornamentation of cuticle, grain-like, triangular to rounded and often black found in Cerioidini and some Paragus species. In Syrphidae, granula always surrounding single pilus or alveoli (Sorkin & Herman 2018).

Fig. 53 C

hair (Speight 1987)

General

see pile

haltere (pl. halteres)

Wing

Drumstick-shaped reduced second wing, for balance during flight; consists of scabellum, pedicellum and capitulum (Thompson 1999).

Figs 23C, D, 27 C, 29A

hamus (pl. hami)

Male terminalia

Hook-like paired structure attached dorso-basally to the phallus and to the interior dorso-lateral wall of the hypandrium, and seamlessly connected ventrally to the apex of the phallapodeme. Seen in Eumerus; possibly homologous to the 'lateral sclerite of the aedeagus' in Merodon (Doczkal 1996).

Fig. 54 D

hang-vein (Speight 2020)

Wing

see appendix R₄₊₅

Head

Head

Anterior division of the insect body (Thompson 1999).

Figs 1 A–C, 3A, 5 –17, 53 C

hind leg (Cumming & Wood 2017)

Leg

see metaleg; both terms are interchangeable

haustellum

Proboscis.

Apical of the two main parts of the proboscis (Gilbert & Jervis 1998).

Fig. 22

holoptic

Head

Eyes meet each other dorsally between antennal base and vertex; condition seen only in males (Cumming & Wood 2017).

Figs 6 B, C, 10 B

horn-shaped production (Curran 1941)

Abdomen

see lateral tubercle of tergum II

humeral plate (Speight 1987; Cumming & Wood 2017)

Wing

see basicosta

humerus, humeral callus (McAlpine 1982)

Thorax

see postpronotum

hyaline

General

Transparent or clear; mostly used for the wing (Thompson 1999).

Fig. 35D

hypandrial arms

Male terminalia

Apico-dorsal portion of hypandrium that articulates with base of subepandrial sclerite, usually connecting dorsally over phallus (Cumming & Wood 2017). Usually fused in Syrphidae, forming dorsal wall on hypandrium, and can be narrow/short to wide/long; subepandrial sclerite always articulating with basal portion of this area.

Fig. 55 D

hypandrial labium

Male terminalia

Weakly chitinous flange on the baso-dorsal margin of the hypandrium, found in several species of Pipizella; inner median flange of hypandrium; "auffaltung der dorsalen Hypandriumwand" (Claussen 1991; van Steenis & Lucas 2011).

Fig. 58 B

hypandrial process

Male terminalia

Additional extension of the hypandrium, most often tooth-like and apically placed; upper process of hypandrium; appendage upper process of hypandrium (van Steenis & Lucas 2011).

Figs 58 D, E.

hypandrium (adj. hypandrial)

Male terminalia

Sternum IX + fused gonocoxites (indistinguishable from one another), ventral segment of male genitalia, articulating to baso-lateral corners of epandrium; bears postgonites apically; seem to have two distinct components in Microdontinae: a basal, convex in lateral view, sclerotized part and an apical, microtrichose, less sclerotized part, possibly fused gonocoxal component (Reemer & Ståhls 2013a).

Figs 43C, 46 D, 47 B, 48 A–C, 49 A, 50 A, 51 A, C, D, 54 B, D, 55 B, D, 56 A, C, E, 57 A, C, D, 58 D, E.

hypopharynx

Proboscis.

Tongue-like process between the labrum and the rest of the haustellum; with salivary canals (Gilbert & Jervis 1998).

Fig. 22

hypopleuron (McAlpine 1981)

Thorax

see meron

hypoproct

Male terminalia

Sclerite ventral to cerci, ventral to anus; indistinguishable in male Syrphidae; not to be confused with the subepandrial sclerite (Cumming & Wood 2017).

n/a

hypoproct

Female terminalia

Membranous unpigmented to lightly pigmented; as a distinct plate only in the Microdontinae; might bear a posterior apodeme (Miranda & Moran 2017).

Figs 52D, E

hypopygium

Male terminalia

Epandrium, hypandrium and associated structures (Cumming & Wood 2017).

Figs 55 C, 57 A, C, D

hypostomal bridge

Head

Region ventral to occipital foramen, bounded by the postgena, and sometimes separated by a suture, including transverse crest of hypostomal bridge (Doczkal & Pape 2009); not hypostomal bridge of Doczkal & Dziock (2004), which is the postgena (McAlpine 1981).

Figs 15C, D, 16A, C

incrassate

General

Thickened, swollen; often used in combination with the shape of the metafemur or the arista (Sorkin & Herman 2018).

Figs 19 C, 20 D, 41 A

inferior lobe of gonite (Claussen & Hayat 1997)

Male terminalia

see ventral postgonite

infuscate (adj. infuscated)

General

Darkened; an adjective used for a partly to entirely darkened wing (Sorkin & Herman 2018).

Figs 35B, 36 A

inner median flange of hypandrium; auffaltung der dorsalen Hypandriumwand (Claussen 1991; van Steenis & Lucas 2011)

Male terminalia

see hypandrial labium

inner prong of the ejaculatory hood (Thompson 1974

Male terminalia

see inner surstylar lobe

inner surstylar lobe

Male terminalia

Basal lobe on medial surface of surstylus in Trichopsomyia and several Sphegina; "zahn des syrstylus" (Claussen et al. 1994; Hippa et al. 2015).

Fig. 58 F

isosceles

General

A triangle with two sides of equal length, often used to indicate the relative distance of the ocelli to each other (Merriam et al. 2022)

Fig. 5

katatergite (McAlpine 1981)

Thorax

see katatergum

katatergum

Thorax

Dorsoposterior plate of mesothoracic pleuron, dorsal to posterior spiracle (Thompson 1999).

Figs 28A, 30 A

katepimeron

Thorax

Posteroventral plate of the mesothoracic pleuron; demarcation between katepimeron and meron often weak (Thompson 1999).

Figs 23C, 28, 30 A

katepisternum

Thorax

Anteroventral plate of mesothoracic pleuron; sternopleuron of older authors (Thompson 1999).

Figs 28, 29B, 30 A, 31

knob (Cumming & Wood 2017)

Wing

see capitulum

labellum

Proboscis.

Apical cushion-like prolongation of the labium, with pseudotracheae; they are highly modified labial palps (Gilbert & Jervis 1998).

Fig. 22

labium

Proboscis.

Forms the ventral wall of the proboscis, the prementum + labellum; connected to apical part of fulcrum (Gilbert & Jervis 1998)

n/a

labrum

Proboscis.

Dorsal and lateral sides of the food canal, connected with the epipharynx, as part of the haustellum (Gilbert & Jervis 1998).

Fig. 22

lacinia

Proboscis.

Blade-like sclerite, connected with the maxillary palp and stipes (Gilbert & Jervis 1998))

Fig. 22

lamina (pl. laminae, adj. laminate)

General

Thin extension of the exoskeleton, not much longer than high, plate (Thompson 1999).

Figs 4 , 38 B, C, 40 B, 41 A

lateral (adv. laterally)

General

At the side, away from the centre; opposite of medial (Thompson 1999).

Fig. 1 B

lateral arm of lunule

Head

The lunule consists of two lateral arms and in many cases a medial arm (Speight & Sarthou 2017).

Figs 10 C, D

lateral cervical sclerite

Thorax

Laterally positioned sclerite of the cervix (Martin 1916).

Figs 23B, 25 A, C, D, 26 C

lateral facial strips (Shannon 1922a)

Head

see parafacia

lateral facial tubercles

Head

Tubercles on the dorso- and ventrolateral side of face as in Ornidia obesa (Thompson 1972).

Fig. 14C

lateral keel (Thompson 1972)

Head

see facial carina

lateral lobes to epiproct

Female terminalia

Small pigmented area located baso-laterally to the epiproct in 'Eristalinae'; might bear pile; assumed as tergum IX by authors (Miranda & Moran 2017).

Fig. 52C

Lateral parapsidial suture (Cumming & Wood 2017)

Thorax

see parapsidal suture

lateral plate (Thompson 1972)

Leg

see femoral lamina

lateral sclerite of phallus

Male terminalia

Sclerotized structure that sheathes the phallus in Merodon; seemingly continuous with the phallapodeme (Marcos-García et al. 2007).

Fig. 54 C

lateral strips

Male terminalia

In some Microdontinae, basal dark lines on both sides of the ejaculatory hood that seem to extend into the hypandrium (Reemer & Ståhls 2013a, b).

Fig. 56 E

lateral tubercle of tergum I

Abdomen

Rounded and slightly upheaved section on anterolateral corner of tergum I in several Microdontinae and Cerioidini; erroneously mentioned as callus on 2nd tergite in Speight (1987).

Figs 3A, 29B, 43A, 46 A, 53 F

lateral tubercle of tergum II

Abdomen

Dens-like protuberance on anterolateral margin of tergum II, in Nausigaster (Shannon 1922a) and Ubristes (Reemer & Ståhls 2013a).

Fig. 47 E

laterotergite (McAlpine 1981)

Thorax

see anatergum and katatergum

laterotergite (Speight 1987)

Thorax

see anatergum

laterotergum

Thorax

Lateral part of postnotum ventrally from the scutellum, the anatergum + katatergum (McAlpine 1981).

Fig. 27 C

Leg

Leg

The thoracic locomotory organ; paired organs in descriptions used in singular form, e.g. proleg, mesoleg and metaleg; proleg (singular) in contrast to prolegs, which is the term used for the locomotory organs of dipteran larvae (Thompson 1999).

Figs 1 A, B, D, 2 , 32 B, C, 38 –42 , 53 A, B

lingula

Male terminalia

An apical projection from the ventral surface of the hypandrium, e.g. Merodon tarsatus (Metcalf 1921; Speight 1987).

Figs 56 A, C, 58 A

lingular appendages; apico-lateral; medio-dorsal projection; medio-ventral flange; dorso-basal tooth (see van Steenis et al. 2016).

Male terminalia

see lingular process

lingular process

Male terminalia

Apically placed processes of lingula, e.g., Cerioidini (van Steenis et al. 2016).

Figs 56 C, 58 A

longitudinal depression (Sedman 1964)

Head

see medial frontal sulcus

longitudinal furrow (Sedman 1964)

Head

see medial frontal sulcus

lower pair (Shatalkin 1981)

Female terminalia

see apodemes of the epiproct

lunulate

General

Adjective for more deeply curved macula or vitta (Thompson 1999).

Figs 5 , 44 C

lunule

Head

Anterior boundary of frons, above acetabula; different texture and usually shiny, bare and differently coloured than rest of frons, consisting of two lateral arms and in many cases a medial arm; not lunule of Cumming & Wood (2017) (Thompson 1999).

Figs 6 A, B, D, 7C, D, 8 D, 9 B, 10 A, B, 11 A, C

M₄ base

Wing

Base of vein M₄, a crossvein between veins M₄, M and crossvein m-cu; crossvein bm-m in Cumming & Wood (2017). In the old system crossvein m-cu and bm-cu, in part (McAlpine 1981).

Figs 34 A, 37 C

macrotrichium (pl. macrotrichia, adj. macrotrichose)

General

Vestiture connected to nerves and arising from an alveolus. Found on the body surface and sometimes also on the wing veins, comprising pile, cilium, seta, setula and scale (Thompson 1999).

Figs 4 , 39 A, B

macula (pl. maculae, adj. maculate)

General

A marking on the insect body, requiring an adjective to describe its shape, e.g. arcuate, lunulate, rectangular (= bar), punctate, triangular, round (= spot) (Thompson 1999).

Figs 3D, 9 D, 43D, 44 A–C, 45 A, C, 46 C, D

mala (pl. malae)

Head

Anteroventral part of face (Taxo-Fly); not a true structure but area often non-pilose and black with shiny areas, contrasting to rest of face; part of prefrons (Crampton 1942), part of the rostrum or nasus in Tipulidae (Cumming & Wood 2017) and part of the "snout" in Syrphidae (Ssymank et al. 2021).

Figs 12A, C, D, 13, 14A, C, D, 15B, 16D, 17C, D

malar tubercle

Head

Lateral protuberance at the antero-ventral corners of the anteroventral part of the face, i.e. mala.

Figs 11 B, 12B, 13B, 14B

Male terminalia

Male terminalia

The male postabdomen with its genitalia and adjoining structures (Cumming & Wood 2017)

Figs 43C, 46 A, D, 47 B, C, 48 –51 , 54 –57

marginal cell; cell M (Speight 2020)

Wing

see cell r₁

markings

General

Different patterns of the integument of the body, might be from different colouration/reflection of the exoskeleton or different coloured/type of microtrichia/macrotrichia; further classified into macula, fascia or vitta (Thompson 1999).

Figs 3D, 9 D, 43D, 44 A–C, 45 C, 46 C, D

matt(e) (Merriam et al. 2022)

General

see dull

maxillary palp

Proboscis.

Sensory appendage on the maxilla (Speight 1987).

Fig. 22

medial (adv. medially)

General

On, or towards, the middle/centre of a structure (Thompson 1999).

Fig. 1 B

medial arm of lunule

Head

The lunule consists of two lateral arms and in many cases a medial arm (adopted from Speight & Sarthou 2017).

Fig. 10 D

medial callus, in Graptomyza (Ssymank et al. 2021)

Head

see facial tubercle

medial frontal sulcus

Head

Medial longitudinal impression on the frons; in some species visible as a non-pruinose shiny depression (after Sedman 1964, 1965).

Figs 6 B, D, 11 C

medial surstylar lobe

Male terminalia

Medial lobe of the surstylus on the ventral margin (Hippa 1978a).

Fig. 54 A

median keel (Thompson 1972)

Head

see facial carina

median mesocoxite (Speight 1987)

Leg

see basicoxa

median postnotal sclerite of mesonotum (Speight 1987)

Thorax

see mediotergum

median spinose ridge (Hippa 1978a)

Leg

see tibial carina

median vein (Speight 2020)

Wing

see vein M

median-cubital crossvein; crossvein m-cu (Speight 2020)

Wing

see crossvein dm-m

mediocoxal spina

Leg

Medio-lateral extension on the mesocoxa (McAlpine 1981).

Fig. 42 F

mediotergal suture

Thorax

Dorsoventral suture on the posterior part of the thorax, lateroventrally to the scutellum, located between the medio- and laterotergum

Fig. 27 B

mediotergum

Thorax

Part of the postnotum ventral to the scutellum; part of subscutellum sensu Doczkal & Dziock (2004) (Cumming & Wood 2017). In some Cyclorrhapha, named the dorsal transverse convex bulge bordering the mediotergum as subscutellum (McAlpine 1981).

Figs 27 B, C

membranous socket (McAlpine 1981)

General

see alveolus

meron

Thorax

Posteroventral plate of the mesothoracic pleuron ventrally to katepimeron, The demarcation between the meron and the katepimeron is not always clear, earlier authors used meropleuron for this fused plates; meropleuron, hypopleuron (McAlpine 1981).

Figs 23C, 28A, 29B, 32 B, 42 F, G.

meropleuron (McAlpine 1981)

Thorax

see meron

meso

General

Related to the mesothorax; middle, mid; used for the leg or thoracic pleura (Thompson 1999).

Fig. 2 A

mesoanepimeron (Thompson 1999)

Thorax

see anepimeron

mesoanepisternum (Thompson 1999)

Thorax

see anepisternum

mesocoxite of middle leg (Speight 1987)

Leg

see eucoxa

mesoleg

Leg

The leg, related to the mesothorax (Thompson 1999).

Fig. 2 A

mesonotum

Thorax

Dorsal part of thorax including scutum and scutellum (Thompson 1999).

Fig. 23A

mesopleuron (Thompson 1999)

Thorax

see anepisternum

mesoscutum (Thompson 1999)

Thorax

see mesonotum

mesothoracic leg (Sorkin & Herman 2018)

Leg

see mesoleg

meta

General

Related to the metathorax; last, hind; used for the leg or thoracic pleurae (Thompson 1999).

Fig. 2 A

metabasisterno-precoxite (Speight 1987)

Thorax

see metasternum

metaepimeron, in part (Thompson 1999)

Thorax

see metepimeron

metakatepimeron

Thorax

Sclerite of the metepimeron, anterodorsally to metacoxa. The different sclerites of the metepisternum are not always clearly defined, visible in some Microdontinae (Tachi 2014).

Figs 32 B, C

metakatepisternum

Thorax

Sclerite of the metepisternum, antero-dorsally to metacoxa. The different sclerites of the metepisternum are not always clearly defined (Tachi 2014).

Figs 23C, 28B, 29, 32 B, C

metaleg

Leg

The leg, related to the metathorax (Thompson 1999).

Fig. 2 A

metanepimeron

Thorax

Sclerite of the metepmeron, antero-dorsally to metacoxa. The different sclerites of the metepisternum are not always clearly defined (Tachi 2014).

Figs 32 B, C

metanepisternum

Thorax

Sclerite on which the posterior thoracic spiracle is embedded in. Part of the metepisternum, not always clearly defined (Tachi 2014).

Figs 28B, 32 B, C

metanotum

Thorax

Sclerite of the metathorax, ventrally to the postnotum and hidden under the connection of tergum I and the thorax, so only visible when detaching the abdomen from the thorax (Crampton 1942).

Figs 27 A, B

metanotum sensu Hippa & Ståhls (2005).

Thorax

see subscutellum

metapleuron