Abdomen. The hindmost of the three main body divisions of an insect.

Acanthophorite. Lamelliform dorsal appendage at base of proctiger.

Acropod. Pretarsus.

Acrostichal spines. Two rows of spines along midline of suture.

Acute. Ending in a sharp point.

Aedaegus. Intromittant organ in most insects, formed from a subdivision of the primary phallic lobes.

Aedeagal tines. Lateral branches of 3-branched aedeagus in Tabanomorpha.

Alula. Restricted membranous basal portion of posterior wing margin, distal to upper calyptera and basal to anal lobe.

Anal angle. Hind angle of wing.

Anal lobe. Posterior lobe of wing.

Anal vein (A). Longitudinal unbranched vein posterior to cubitus.

Anepimeron. Upper division of mesepimeron.

Anepisternum. Upper division of mesepisternum.

Annulated. Ring-like.

Antenna (pl., Antennae). Pair of segmented appendages located on the head and usually sensory in function.

Anterior. Concerning or facing the front, towards the head.

Apex. The point where the costal vein and the outer margin of the forewing meet.

Aphidophagous. Pertaining to or descriptive of insects which feed upon aphids, typically as predators.

Apical. At or concerning the tip or furthest part of any organ: apical cells, for example are at the wing-tip.

Apodeme. Ridge-like in-growth of the exoskeleton of an arthropod that supports internal organs and provides attachment points for muscles.

Appendage. Any limb or other organ.

Appressed. Closely applied to.

Aquatic. Organisms living in fresh or salt water (salt-water forms are usually described as marine).

Archaic. Ancient.

Arista. A specialized bristle, or process on the antenna, usually dorsal, rarely apical.

Aristomere. Article of Arista.

Arolium. A median, more or less sac-like protrusion from the end of the pretarsus.

Atrophied. Reduced in size

Axillary membrane. Membrane at base of wing.


Basal. Concerning the base of a structure - that part nearest the body.

Biological control. The control of pests by employing predators, parasites, or disease; the natural enemies are encouraged and disseminated by man.

Bisinnate. With two distinct inward and outward bends.

Book lungs. Book-like gill for air-breathing, open to exterior by a small slit.

Bulbous. Bulb-like.


Calcar. Movable spur or spine-like process.

Calyptera. Basal lobes formed from the posterobasal portion of the axillary membrane.

Cell. Any closed area in an insect wing bounded by veins. (For nomenclature in Diptera see Glossary Fig. A).

Cephalothorax. United head and thorax.

Cercus (pl., Cerci). Paired appendage of abdominal segment X1.

Chitin. A white amorphous horny substance forming the harder part of the outer integument of insects, crustacea, and various other invertebrates.

Cibarial. Pertaining to the cibariu.

Cibarium. Preoval cavity between base of hypopharynx and under surface of clypeus.

Clavate. Club-like or becoming thicker towards the apex.

Claw. A hollow, sharp, multicellular organ; generally paired and at the apex of the insect leg.

Clypeus. Part of head below frons, to which labrum is attached.

Cocoon. The protective case of larval from before they pupate.

Comb. A group of spines on the leg of an insect specifically used for cleaning other parts of the insects body.

Compound eye. An eye consisting of many individual elements or ommatidia each of which is represented externally by a facet.

Concave. Hollowed or rounded inward.

Contiguous. Touching.

Convex. Bulging or rounded outwards.

Cosmopolitan. Common everywhere; widely spread; found in all parts of the world.

Costagial break. Costal break slightly proximal to humeral crossvein.

Costa (C.). First longitudinal vein of wing, running along anterior margin.

Costal lappet. A somewhat triangular, free region of the wing formed by a deep notch at the subcostal break.

Costal margin. The front edge of the wing.

Costal. Relating to the costa.

Coxa (pl., Coxae). The basal segment of the insect leg. The coxa articulates with the pleural wall of the thorax and is attached to the trochanter. Coxae are paired, ventrolateral in position and found on each of the thoracic body segments.

Coxopleural streak. A suture-like depression separating the katepimeorn.

Crossvein. Typically short veins between the length-wise veins and their branches (For nomenclature in Diptera see Glossary Fig. B).

Ctenidial spine. Relatively large brittle armory comprising the ctenidium on the fore femur.

Ctenidium. Comb-like structure at distal end of antero-ventral surface of fore femur.

Cubital. Pertaining to the cubitus.

Cubitus (Cu). The sixth longitudinal vein of the wing, and posterior to the median.

Cupuliform. Cup-shaped.

Cuticle. A secretion of the epidermis covering the whole insect as well as invaginations of the epidermis.


Dichoptic. In adult Diptera, having the eyes markedly separated medially.

Dimorphism. A genetically controlled, non-pathological condition in which individuals of a species are characterized by distinctive or discrete patterns of colouration, size or shape. Dimorphism can be a seasonal, sexual or geographic manifestation.

Distal. Near or toward the free end of any appendage, or the part of a structure farthest from the body.

Dorsal. On or concerning the back or top of an animal.


Ectoparasite. A parasite that lives on the outside of its host.

Emarginate. With a distinct notch or indentation in the margin.

Empodium (pl., Empodia). An unpaired process arising from the ventral part of the arolium.

Endemic. Restricted to a certain region.

Endoparasite. Organism that develops as a parasite within the body of another organism, at the expense and to the detriment of the "host".

Epimeron. Posterior division of a thoracic pleuron.

Episternum. Anterior division of a thoracic pleuron.

Excavate. Made hollow.

Extant. Still existing.

Eye bridge. Narrow row of facets above the antennae connecting the two compound eyes.


Face. In the Diptera, the area between the base of antennae, oral margin, eyes and cheeks.

Facet. Lens-like divisions of the compound eye.

Family. In zoological classification, refers to a level in the taxonomic hierarchy below the Order and above the Genus. All zoological Family names end in IDAE; all zoological Subfamily names end in INAE. The Family-level taxon must include a type-genus which holds a type-species.

Femur. The 3rd (counting out from the body) and often the largest segment of the insect leg.

Flagellum. The distal (furthest away from the body) part of the antennae, the third primary segment of the antenna.

Frass. Excrement of larva, or refuse left by boring insects.

Frons. Upper part of the insect face, dorsal to the insertion of the antennae, above the clypeus.

Frontal vitta. Relatively elastic median area of the frons.

Furcated. Forked.


Gena. Part of the head on each side below the compound eye.

Geniculate. Bent like a knee-joint.

Genus. An assemblage of species, agreeing in one character or a series of characters. It is usually considered arbitrary and opinionative grouping, though some consider it a natural assemblage.

Glabrous. Smooth, without setae.

Globose. Spherical, or nearly so.

Greater ampulla. A bulbous swelling in the basal portion of the pleural wing process.


Halter. Modified hindwing in Diptera, which are sense organs concerned with the maintenance eof stability in flight.

Head. The anterior body region of insects which bears the mouthparts, eyes, and antennae.

Hemispherical. Like half a sphere.

Herbivorous. Feeding on plants.

Holometabolous. Of an insect undergoing complete metamorphosis.

Holoptic. With the eyes touching or almost touching on the top of the head. In adult Diptera, having the eyes touch each other medially.

Humeral break. Break in costa located slightly distal to the humeral crossvein.

Humeral pit. Pits coincident with the prescutal suture.

Hyaline. Clear, transparent or partly so; glass-like, water-like in color.

Hypermetamorphosis. Metamorphosis involving two or more distinct types of larval instars.

Hypopharynx. A median lobe in mouthparts, immediately behind the mouth.


Infuscate. Darken with a brownish tinge, as of insect wings.

Integument. Outer layer of an insect.

Interfrontal setae. Setae on the frontal vitta.


Katepimeron. Lower portion of a divided epimeron.

Katepisternum. Lower portion of a divided espisternum.

Kleptoparasite. Food stealing.


Labellum (pl., Labella). Paired oval lobes or pads at distal end of proboscis.

Labium. The mouth part or appendage of the sixth head segment, forming the lower lip.

Lanceolae. Spear-shaped.

Larva (pl., Larvae). Immature stage of insect that has a complete metamorphosis.

Lateral. Concerning the sides.

Lateroclinate. Directed laterally.

Linear. Elongated or nearly parallel-sided.

Lunule. A small oval or crescent space above the bases of the antennae.


Macrotrichia. Setal conspicuously larger than adjacent setae.

Mandible. The jaw of an insect.

Maxilla (pl., Maxillae) One of the two components of the insect mouth-parts lying just behind the jaws.

Medial. Referring to, or at the middle of a structure.

Median (M). The fifth longitudinal vein of the wing.

Membranous. Thin, transparent, and not heavily sclerotized.

Meron. Posterior part of the proximal rim of coxa.

Mesepimeron. The epimeron of the mesothorax.

Mesonotum. Dorsal sclerite on the mesothoracic segment.

Mesoscutum. Scutum of the mesothorax.

Mesothorax. Second or middle thoracic segment.

Metanotum. Dorsal sclerite or notum of the mesothorax.

Metathorax. Third or posterior thoracic segment.

Metepisternum. Episternum of the metathorax.

Micropubescent. With dense microsetae.

Microtrichia. Small covering setae, found on the wings of some insects, distinguished by the absence of basal articulation.

Monocotyledonous. Having only one cotyledon, seed lobe, or seminal leaf.

Monophyletic. A monophyletic taxon is one which includes all the evolutionary descendants of the taxon's common evolutionary ancestor and only those descendants.

Multifaceted. With numerous facets.

Mycelia. Thread-like vegetation part of fungi.

Mycetophagous. Feeding on fungi.

Mystax. A patch of stiff setae on the lower part of the face.


Notopleural. Pertaining to the notopleuron.

Notopleuron. Clearly delimited sunken area in the anterior region of the scutum, between the post-pronotal lobe and the base of the wing.

Notum. Dorsal. Sclerite of a thoracic segment.

Nuptial. Mating gift.


Obligate. Not optional.

Oblique. Slanting.

Obtuse. Of blunt form, not sharp pointed.

Occiput. In the Diptera, the entire posterior surface of the head.

Ocellus (pl., Ocelli) One of the simple eyes of insects, usually occurring on the top of the head.

Ommatidium (pl., Ommatidia). One of the single eyes forming the compound eyes of crustaceans, insects, and other invertebrates; one of the eyes of an ommateum.

Order. Any comprehensive group of animals or plants including several subordinate related groups.

Osmeterium. Specialized scent producing area on the hind tibia.

Ovipositon. Egg-laying.

Ovipositor. Egg laying apparatus.

Ovoid. Egg-shaped.


Palp. A segmented leg-like structure arising on the maxilla or labium. Palps have a sensory function and play a major role in tasting food.

Parafacial. Area between ptilinal fissure and eye.

Paraphyletic: A paraphyletic taxon is one which includes descendants from only one ancestor, but not all of them; and a polyphyletic taxon is one descended from more than one ancestor.

Parasite. An organism which lives in, on, or at the expense of another organism during at least part of its lifetime.

Parasitoid. An organism that, during its development, lives in or on the body of a single host individual.

Parthenogenesis. Referring to reproduction without fertilization. Development of individuals from egg-cells without fertilization by the male gamete.

Pedicel. The 2nd antennal segment.

Pedicellate. Supported by a pedicel or stalk.

Petiolate. Stemmed or stalked projection.

Pharynx. Part of foregut between mouth cavity and oesophagus.

Phytophagous. Feeding upon plants.

Pilose. Covered with setae.

Pleural wing process. The produced dorsal margin of the pleuron, which serves as a fulcrum for the movement of the wing.

Pleural. Pertaining to the plura or lateral sclerites of the thoracic segments.

Pleuron (pl., Pleura). The lateral sclerotized area of a thoracic segment.

Plumose. Feather-like.

Pollinose. Covered with a loose, mealy, often yellow dust.

Pollinosity. A pollinose covering.

Porrect. Extruding horizontally forward.

Postabdomen. Modified, slender, posterior part of the abdomen including the genital segments.

Posterior. Term of position pertaining to a structure situated behind the axis. Referring toward the rear, caudal or anal end of the insect.

Postnotum. The dorsal sclerite below and behind the scutellum of the mesothorax.

Postocellar seta. Seta arising just behind the ocelli or the vertex.

Postpronotal. Pertaining to the postnotum, or posterior region of the pronotum.

Preabdomen. The broader, unmodified basal part of the abdomen.

Predator. An animal that attacks and feeds on other animals, usually smaller and weaker than itself.

Pregenital. Anterior to the genital segments.

Prehalter. A membranous scale in front of the true halter.

Prehensile. Adapted for grasping.

Prementum. Region of the labium distal to the mentum.

Prescutal suture. Suture separating prescutum from scutum.

Prescutum. Anterior area of the mesonotum or metanotum in front of the scutum.

Presutural. Pertaining to the prescutum.

Pretarsus. Last segment of insect leg.

Primary phallic lobe. Pair of ectodermal out grows that give rise to all or part of the intromittent organ in insects.

Proboscis. In Diptera, it refers to the extensile mouthparts.

Proclinate. Inclined forward or downward.

Proctiger. Reduced abdominal segment X, bearing the anus.

Proepimeral. Pertaining to the epimeron of the prothoracic.

Proepisternum. Anterior division of the lateral sclerite of the prothoracic segment.

Prognathous. Having a more or less horizontal head, with the mouth-parts at the front.

Proleg. An unjointed fleshy lobe on larvae that functions as a leg.

Prong. A slender sclerotized projection.

Pronotum. Dorsal sclerite of the prothorax.

Proscutellum. A small ridge proceeding the scutellum.

Prosternum. Sternum of the prothorax.

Prothorax. First or anterior thoracic segment.

Protrusible. Capable of being extended or protruded.

Pruinose. Covered with fine dust, as if frosted; with the brightness of a surface somewhat obscured by the appearance of a plum-like bloom, but which cannot be rubbed off.

Pseudopod. Same proleg.

Pterostigma. An enlarged, pigmented area on the costal margin of the wing near its middle or at the apex of the radius.

Ptilinal fissure. A transverse groove on the frons that crosses above the antennae.

Ptilinal suture. The same as the ptinal fissure.

Ptilinum. An eversible sac capable of being thrust out of a fissure in the head, thereby splitting of the cap of the puparium and permitting emergence of the adult.

Pubescent. Clothed with soft, short, fine, loosely set setae.

Pulvilliform. Shaped like a pulvillus.

Pulvillus (pl., Pulvilli). Membranous, pad-like structures located between the tarsal claws. Cushions of short, stiff setae on underside of tarsal joints.

Punctate. Covered with tiny pits or depressions.

Pupa. Any insect in that stage of its metamorphosis which usually immediately precedes the adult, or imago, stage.

Puparium. The sclerotized, caste skin of the third larval instar, within which the pupa is formed.


Radial. Pertaining to the radius.

Radius (R). The third longitudinal vein of the wing.

Raptorial. Adapted for seizing prey.

Reclinate. Inclined backward and upward.

Recumbent. Lying down, reclining.

Relict. Surviving relatively unchanged over time.

Riparian. Associated with streams or river banks.

Rostrum. A snout-like projection of the head.

Rugose. With many wrinkles or ridges.


Saprophagous. Pertaining to insects, which feed on dead or decaying animal or vegetable matter.

Scale. A flat unicellular outgrowth of the integument.

Scape. The 1st antennal segment, especially if it is longer than the other segment.

Scavenger. Feeding on dead organisms.

Sclerite. An area of sclerotization in the integument.

Sclerotized. Hardened especially by the formation of sclerotin: an insoluble tanned protein permeating and stiffening the chitin of the cuticle of arthropods.

Scutellum. Small and shield-like sclerite. In Diptera, a subhemispherical part cut off by an impressed line from the mesonotum.

Scutum. The second dorsal sclerite of the meso- or metathorax, being the middle division of the notum.

Seam. Line of junction between two edges.

Seep. Site of seepage or oozing out.

Segment. One of the rings or divisions of the body, or one of the sections of a jointed limb.

Semiaquatic. Partly living in or near water.

Sensoria. Sensory organs.

Serrate. Toothed like a saw.

Seta (pl., Setae). A sclerotized hair-like structure of the insect cuticle, arising from a single cell, and surrounded at base by the cuticular ring.

Setaceous. With setae.

Setifarous. Bearing setae.

Setiform. Seta-like.

Setose. With many setae.

Setulae (pl., Setulae). Small stiff seta.

Setulose. With setulae.

Silk glands. Glands that secrete liquids that harden into silk on exposure to the air.

Sinuate. With distinct inward and outward bends.

Sinuous. With many curves.

Speciose. With many species.

Spiracle. One of the breathing pores - openings of the tracheal system - through which diffusion of gases takes place. They usually occur on the third thoracic segment and all the abdominal segments.

Spur. A large and usually movable spine, normally found on the legs.

Spurious vein. In adult Syrphidae, a vein-like thickening of the wing membrane between the radius (R) and the media (M).

Sternum. Ventral sclerite of a segment.

Styliform. In the shape of a stylus.

Stylus (pl., Styli). A small pointed non-articulated process.

Subcosta (Sc). The second, usually unbranched, longitudinal wing vein, posterior of the costa.

Subcosta break. Break in costal vein just proximal to where the subcosta joins the costa or two the point where it would join the costa if the subcosta was complete.

Subcranial cavity. Ventral cavity of cranium from which mouthparts protrude.

Subfamily. One of the subdivisions, of more importance than genus, into which certain families are divided.

Subscutellum. A transverse ridge or lobe on median portion of the longitudinal divided postnotum.

Subvibrissae. Seta along the anteroventral margin of the gena.

Suture. Line of junction between two sclerites.

Synanthropic. Associated with man.

Synonym. Identical to.


Tarsomere. Subdivision of the primary tarsal segment.

Tarsus (pl., Tarsi). The insect's foot: primitively a single segment but consisting of several segments in most living insects.

Taxon. Animal or plant group having natural relations.

Tergite. Subdivision of the tergum.

Tergum. Dorsal sclerite of a segment.

Terminal. Pertaining to the apex or extreme tip of a structure or appendages.

Terminalia. The terminal abdominal segments modified.

Terrestrial. Living on or in the land.

Thorax. The middle of the three major divisions of the insect body. The legs and wings (if present) are always attached to the thorax.

Tibia (pl., Tibiae) The fourth leg segment between the femur and the tarsus.

Tomentum. A form of pubescence composed to form the genital segments of short, matted, wooly setae.

Trachea. (pl., Tracheae). One of the minute tubes which permeate the insect body and carry gases to and from the various organs etc. They open to the air at the spiracles.

Trochanter. The second segment of the leg, between coxa and femur: often very small and easily overlooked.

Tubercle. A small knob-like or rounded protuberance.


Ubiquitous. Being everywhere.

Urogenital. Of or relating to the urinary and reproductive systems.


Vector. A carrier, especially any agent transferring a parasite to a host.

Vectoring. The act of being a vector.

Vein. Any chitinous, rod-like or hollow tube-like structure supporting and stiffening the wings in insects, especially those extending longitudinally from the base of the wing to the outer margin.

Venation. Complete system of veins in an insect wing.

Ventral. Pertaining to the under surface of abdomen.

Vertex. The top of the head, between and behind the eyes.

Vestigial. Small, or degenerate. The remains of a previously functional part, or organ, like remnants or vestiges. Structure in the process of disappearing.

Vestiture. The general surface covering comprised of cuticular projections, such as setae or scales, etc.

Vibrissa. Stout setae arising on the angular prominence at the ventral edge of the facial ridge.

Vittae. A band, or stripe, of color.


Glossary Figures A and B

Figure A. Dorsal view of right wing to show structure and venation. Redrawn from Manual of Nearctic Diptera, Volume 1, Research Branch, Agriculture & Agri-food Canada, Monograph No. 27, 1981 (Fig. 67).


Figure B. Dorsal view of complete right wing of Paralucilia wheeleri (Hough). Redrawn from Manual of Nearctic Diptera, Volume 1, Research Branch, Agriculture & Agri-food Canada, Monograph No. 27, 1981 (Fig. 69).




A1, A2; branches of anal veins

a1, a2; anal

bm-cu, basal medial-cubital*

C, costa

bc, basal costal

dm-cu, discal medial-cubital

CU, cubitus

bm, basal medial

h, humeral

CuA, anterior branch of cubitus

br, basal radial

m-cu, medial-cubital*

CuA1, CuA2; anterior branches of cubitus

c, costal

m-m, medial

CuP, posterior branch of cubitus

cua1, anterior cubital (cubital fork)

r-m, radial-medial

M, media

cup, posterior cubital

sc-r, subcostal-radial

M1, M2, M3; posterior (sectoral) branches of media

d, discal (1m2)


MA, anterior branch of media

dm, discal medial


R, radius

m1, m2, m3, medial


R1, anterior branch of radius

r1, r2, r3, r4, r5; radial


R2, R3, R4, R5; posterior (sectoral) branches of radius

Sc, subcostal


Rs, radial sector


Sc, subcosta


*Crossvein bm-cu is the same as crossvein m-cu, but the designation bm-cu is used to distinguish crossveins bm-cu from m-cu when both occur.