Flies

Order Diptera

The Flies (Order Diptera) includes 6,350 species across 141 families and 1,800 genera in our directory.

About Flies

Diptera includes over 150,000 described species of flies, mosquitoes, and midges. Mosquitoes are the deadliest animal on Earth (CDC). Malaria alone causes ~249 million cases and over 608,000 deaths annually, mostly children under 5 (WHO). Vector-borne diseases account for over 17% of all infectious diseases, causing 700,000+ deaths per year.

Economic Impact

In the U.S., vector-borne disease cases tripled between 2004-2016, with over 640,000 cases reported in that period (CDC). Tickborne diseases doubled from 22,000 to 48,000 annual reports. Globally, mosquito-borne diseases cost billions in healthcare and lost productivity.

Ecological Role

Despite their disease impact, flies are critical decomposers and pollinators. Hoverflies alone pollinate hundreds of crop and wildflower species. Flies are also the primary food source for many birds, bats, and fish. Forensic entomology relies heavily on fly species for crime scene analysis.

Families in Diptera (141)

Species in Diptera (6,350)

Ptecticus sackenii

Stratiomyidae

Identification: See comments on images here, and original description (Williston, 1885): (female) Length 11 mm. Front narrow, shining black, the lower part and the face yellowish white. Thorax yellow, the dorsum with three broad, more brownish, strip

Pterodontia johnsoni

Acroceridae

This is a western species that is virtually entirely black (with some reddish-brown undertones/tints).

Pterodontia notomaculata

Acroceridae

This is the only known Pterodontia species with substantial yellow-orange coloration on the thorax (at anterior corners of the mesonotum, and on the anterior half of the mesopleura). All other species have almost the entire thorax black.

Pterodontia westwoodi

Acroceridae

Identification: The distinguishing characters of this species in the genus are: discal cell open; 3rd and 4th vein both present, forming a fork in the apical portion of the wing; 3rd antennal segment slender, clavate (= "club-shaped"), 3 or more time

Ptilodexia maculata

Tachinidae

Identification: Most importantly, strongly contrasting dark patches under the tips of the femora. Body with a lot of red or orange.

Ptychoptera quadrifasciata

Ptychopteridae

Western populations of "Ptychoptera quadrifasciata" are probably an undescribed species.

Puliciphora borinquenensis

Phoridae

Identification: Key to Nearctic females Key to Neotropical females Photograph and wing description of male

Purple Bromeliad Fly

Copestylum violaceum

Syrphidae

Identification: Alula at least without microtrichae on the apical 1/3. Original description .

Pygmy Phantom Crane Fly

Bittacomorphella jonesi

Ptychopteridae

Identification: The only Bittacomorphella in Eastern North America. Has a white band on the tibia, which the Western species lack.

Pyrgotella chagnoni

Pyrgotidae

Identification: "Posterior apical corner of anal cell 90°, vein closing cell straight; alula rudimentary; face with single cuplike depression, without median keel; body without strong bristles, even on scutellum."

Rachicerus obscuripennis

Xylophagidae

Identification: our only species with pectinate flagellomeres

Rachispoda spuleri

Sphaeroceridae

Identification: Three dorsocentral bristles in addition to the incurved one (most other species with at least a weak fourth), no stong acrostichals but about 8 rows of weak hairs, third segment of antenna reddish, scutum with at least faint stripes w

Radiant Laphria

Laphria aktis

Asilidae

Identification: Nearly identical to Laphria sericea . Clear view of male terminal appendages necessary for identification from photographs. Females not separable from photos. Difficult to impossible to distinguish from L. sericea from photographs. Ph

Rafaelia rufiventris

Sarcophagidae

Aldrich (1916) published a description of this species misidentified as Sarcophaga rufiventris Wiedemann.

Range Crane Fly

Tipula simplex

Tipulidae

See also the Handbook of Forage and Rangeland Insects, which presumably has much more current information: https://www.entsoc.org/Pubs/Books/Handbooks/forage .

Ravinia acerba

Sarcophagidae

Identification: Arista plumose, frontal rows not distinctly diverging, parafacial with scattered hairs, tegulae pale, 3 PS DC, 1st segment hypopygium red (sometimes dark basally)

Red-backed Tiger Fly

Ceraturgus elizabethae

Asilidae

Identification: Very dark, with elongate antennae, perhaps a mimic of Tachytes

Renocera cressoni

Sciomyzidae

Identification: One fronto-orbital, densely plumose arista

Renocera pallida

Sciomyzidae

Size 4.2 to 6.2 mm. Generally orange-brown in colour. Can only be identified by detailed examination. Water margins, wet woodland and areas with waterlogged soil. Appears to be bivoltine with a flight period between May and September. The larvae are

Resseliella clavula

Cecidomyiidae

Causes galls in flowering dogwood ( Cornus florida ): a smooth, clublike enlargement just below the bud in apical branches. Most of the dogwood stem galls on BugGuide probably do not represent this species. When shown the images that were placed here

Rhagio albicornis

Rhagionidae

Identification: Female front mostly glossy black. Wings with dark markings mostly along veins. Abdomen yellow with black spots.

Rhagio gracilis

Rhagionidae

Identification: Note, the males have an eye-gap that is similar to the females. (see below) ♂ ♀

Rhagio lineola

Rhagionidae

Like other Rhagio species R. lineola are yellowy-orange flies with long, slender legs. Length 6 to 8 mm. The thorax is uniformly grey, and the wing has a solid dark blackish stigma. Hedgerows woods and other well wooded areas with rich vegetation. Th

Rhagio maculifer

Rhagionidae

Identification: The first flagellomere is usually concave above the insertion of the arista. The palpi are slender and usually white-haired. The abdomen has yellow markings or is largely yellow except in subspecies styx from Montana.

Rhagio scolopaceus

Rhagionidae

Length 8 to 16 mm. Like other Rhagio species R. scolopaceus are yellowy-orange (sometimes darkened) flies with long, slender legs. The sides of the thorax are grey as are the tops of the legs. The wing has several darkened marks. They tend to sit on

Rhagio tringarius

Rhagionidae

Length 8 to 14 mm. Like other Rhagio species, R. tringarius is a yellowy-orange fly with long, slender legs. This species lacks the dark wing stigma of most other Rhagio species. The black patterning on the orange abdomen is variable, sometimes showi

Rhagoletis alternata

Tephritidae

Rhagoletis alternata is a species of fruit fly with well marked banding on the wings. This genus contains a number of similar species and care must be taken over identification. Unless identified by a recognised expert, a photo is required. If the ph

Rhagoletis juglandis

Tephritidae

Identification: The other two yellow-bodied Rhagoletis have more wing bands.

Rhagoletis meigenii

Tephritidae

The wing is distinctively patterned, but there are similar species and detailed examination is needed for a positive identification to species level. Where no detailed examination has taken place, the image is shown in a red box to indicate that the

Rhagoletis striatella

Tephritidae

Identification: wing has three transverse bands, the third one resembling the letter "F" - with the top segment of the "F" touching the outer edge of the wing (see drawing of wing ). body mostly black; thorax with two pale dorsal stripes; base of scu

Rhagoletis tabellaria

Tephritidae

Identification: body mostly black; 4 white longitudinal stripes on back; scutellum white; abdomen with thin white bands; cross-banded wing pattern is distinctive

Rhamphomyia crassirostris

Empididae

Length 5.5 to 6.5mm. This species has a fairly typical Empid form but the legs are not very strongly bristled. The female discal cell is a useful id aid, being enormously enlarged but still closed with the lower crossvein closing the cell near to and

Rhamphomyia gracilis

Empididae

Identification: "A very characteristic species, skinny, yellow legs, females with a little spot near the wing apex." -- Isaac Winkler

Rhamphomyia leucoptera

Empididae

Identification: Male black with white wings and halteres and swollen hind basitarsi.

Rhamphomyia luteiventris

Empididae

Identification: Loew's description (translated from Latin using Google translate): "Head dark gray, eyes contiguous. Antennae slender, black, with the first two short black-hairy joints, the second except the brown base, with a slightly short termina

Rhamphomyia nigripennis

Empididae

This small, dark coloured Dagger Fly (also known as Dance Flies) is very similar to other members of the genus and detailed examination is needed to identify to species level. Detailed examination is needed to identify to species level. Often seen vi

Rhamphomyia subcinerascens

Empididae

An early Spring species. Identification is difficult but the identifying features are a dark cloud on the anal lobe of the female wings, whilst the males have long tarsal hairs. It differs from R. sulcatella in that the front and hind tibia are disti

Rhamphomyia sulcata

Empididae

This is quite a large dance fly with a grey and pinkish appearance. Males provide females with a nutritious prey item as a nuptial gift No additional images available for this species.

Rhamphomyia testacea

Empididae

Identification: The female is red with legs almost entirely fringed with black hairs.

Rhaphiomidas parkeri

Mydidae

Identification: Description on pg. 206 of Cazier . Author is Mont A. Cazier (1911-1995), see: Scarab Workers Directory , Gordh and Headrick .

Rhaphium appendiculatum

Dolichopodidae

One of many Rhaphium species with enlarged 3rd antennal segment. In R. appendiculatum , the arista is very short - no longer than one eighth the length of the third segment. The genital lamella is long and ribbon-like. Rhaphium caliginosum has a long

Rhaphium browni

Dolichopodidae

Identification: Fore and mid tibiae pale, hind black. Femora black except female hind femora pale basally. Antennae long in both sexes. Female arista less than half as long as first flagellomere. Male arista and fore tarsi apically expanded.

Rhaphium fascipes

Dolichopodidae

Identification: Mid and hind femora black, face black, tibiae yellow except tip of hind tibia thickened and black.

Rhaphium melampus

Dolichopodidae

Identification: The only Eastern Rhaphium with all black legs

Rhingia campestris

Syrphidae

The genus is easily recognised by its long snout. With R. campestris the abdomen usually has a black line or stripe along the axis, but always along the lateral margins of the tergites. It has a largely orange abdomen and dark thorax. There are just

Rhingia nasica

Syrphidae

Identification: has a conspicuous snout which aids it in extracting nectar from flowers Larvae associated with animal dung

Rhingia rostrata

Syrphidae

Wing length 7.5 to 9.5 mm. Similar to the much more common R. campestris, but in Rhingia rostrata the thorax is more bluish in colour, there are no dark edges to the abdomen, the legs have more orange and less black and it is generally brighter in co

Rhinoleucophenga obesa

Drosophilidae

Identification: Distinguished from most other Drosophilidae by its very large, hairy frons.

Rhipidia domestica

Limoniidae

Identification: "Note the slightly expanded antennal segements and the pale color of the few antennal segments prior to the apical segment." -- Chen Young " Rhipidia domestica have antennomeres 12 & 13 light, not R. duplicata ." -- Matt Bertone Sever

Rhipidia maculata

Limoniidae

Identification: Male flagellomeres branched, wing with many small spots in cells, scutum with broad darker median stripe.

Rhipidia maculata

Rhipidia maculata-b

Limoniidae

Identification: The bipectinate antennae of the male and the heavily spotted wing pattern are distinctive.

Rhipidia schawrzi

Limoniidae

Identification: Wing spotted. Antenna with two pale flagellomeres, as in domestica . Scutum with broad pale margin.

Rhopalomyia anthophila

Cecidomyiidae

Larvae develop in goldenrod ( Solidago ) florets modified into fuzzy, roughly cylindrical galls that are widest at the base. Encyclopedia of Life Revision of the Goldenrod Galling Rhopalomyia species. Page 6

Rhopalomyia chrysothamni

Cecidomyiidae

Gall is a conical swelling on stems of Chrysothamnus nauseosus with cottony fibers filling the exit. C. nauseosus is also known as Ericameria nauseosa . The species was originally described from C. graveolens , which is now considered a variety of na

Rhopalomyia fusiformae

Cecidomyiidae

The biology is probably similar to that of R. pedicellata , which forms a similar gall but with a pedicel.

Rhopalomyia gutierreziae

Cecidomyiidae

Identification: This midge induces capsule-shaped, yellow or green galls on the flowers of several species of western Gutierrezia (Snakeweed).

Rhopalomyia hirtipes

Cecidomyiidae

Identification: The largest of the Rhopalomyia on goldenrods. Bright orange-red abdomen and dark antennae and legs. Antennae 21 flagellomeres in males, 20-22 in females. Pupa bright orange, sclerotized parts black. Large and robust.

Rhopalomyia inquisitor, maybe

Rhopalomyia inquisitor-maybe

Cecidomyiidae

When Felt (1908) described this species, he believed it to be an inquiline in rosette galls of R. capitata on Solidago gigantea . However, R. inquisitor is closely related to R. clarkei , and Dorchin et al. (2009) hypothesize that R. inquisitor is a

Rhopalomyia pedicellata

Cecidomyiidae

Identification: Adult yellowish-white with dark scales and hairs. Legs covered with fine scales. Pupa orange. Galls found on stems, leaves or inflorescences of the goldenrod Euthamia graminifolia . They are delicate, slender (14-21 mm long) and posse

Rhopalomyia undescribed-species-on-amorpha

Cecidomyiidae

Forms galls on Amorpha canescens . "Galls are reddish and about 4 mm long. They have been attributed to either Rhopalomyia or Diarthronomyia (the second now a subgenus of the first), but the gall makers were apparently not preserved."

Rhopalomyia utahensis

Cecidomyiidae

Identification: Induces ovoid stem galls on Ericameria nauseosa. The galls are usually green and covered with white hairs. These hairs do not obscure the gall surface. They are covered with small leafy bracts that protrude from the surface. A similar

Rhopalopterum atriceps

Chloropidae

Identification: Distinguished from other Rhopalopterum and Stenoscinis by the shining mesonotum (without pollinose stripe) and yellow legs.

Rhopalopterum carbonarium

Chloropidae

Identification: Among Oscinella -like Chloropidae, distinguished by black palpi, legs, head, and antennae; third antenna segment rounded apically, frontal triangle smaller than Oscinella frit , fronto-orbital bristles small and uniform. (Sabrosky, 1

Rhopalopterum painteri

Chloropidae

Identification: "Near O. nudiuscula (Loew), but with median black bands on both mid and hind femora, and the ocellar tubercle not pollinose." (Sabrosky, 1940)

Rhopalosyrphus ramulorum

Syrphidae

Identification: Similar to R. guentherii , but is smaller, narrower, not as robust, and has much more extensive black pile on face, scutum and anepisternum. For complete description, see cited reference.

Ringed Micropanther

Atomosia glabrata

Asilidae

Identification: Face/mystax with white hairs; ocellar tubercle with two long white setae and several shorter ones; antennae about 0.6 times head width; antennae mostly dark; scutellum with two long thin white lateral setae; front & mid femora black d

Riponnensia splendens

Syrphidae

This is the only species of its genus in the UK. The thorax is a greenish copper with two grey stripes. There is a broad belt of whitish dusting across the face. It prefers marshes, fens and wet woodland, and particularly favours Meadowsweet and umbe

Rivellia coquilletti

Platystomatidae

Identification: The wing pattern is unique, though at least one species is similar. Thorax dark green to black, abdomen yellow at base. Femora yellow.

Rivellia metallica

Platystomatidae

Identification: One of a few species with weak wing bands

Rivellia syngenesiae

Platystomatidae

A distinctive little picture-winged fly that is most likely to be confused with the ulidiid Herina frondescentiae or some tephritids of the genus Urophora, though the wing markings are very different when compared with these. The adults wave their wi

Rivellia vaga

Platystomatidae

Identification: fourth band usually narrowly joined to third band at costal margin Both sexes with thorax and abdominal tergites sometimes brown; tarsi of front legs sometimes wholly yellow; fourth band sometimes separated from third band at costal m

Roederiodes distinctus

Empididae

Identification: Unique feature: Base of M2 forming distinct crossvein at apex of cell dm, longer than r-m crossvein

Rush skeletonweed gall midge

Cystiphora schmidti

Cecidomyiidae

Introduced in 1975 from Greece as biocontrol of the invasive skeleton weed Chondrilla juncea (Cichoriaceae). It forms galls in the leaves and stems.

Sackenomyia commota

Cecidomyiidae

Causes blister galls on Viburnum leaves. It is not known whether similar galls on different viburnums are all caused by the same species.

Sage Leaf Gall Midge

Rhopalomyia audibertiae

Cecidomyiidae

Identification: This midge induces galls on the leaves of black sage ( Salvia mellifera ) and white sage ( Salvia apiana ). Galls have a tubular protrusion on either side of the leaf, with the opposite side being a shallow lump. Galls can be gray gre

Sagebrush Hammertail

Efferia benedicti

Asilidae

Identification: "The very short bristles on the front half of the top of the thorax, the gray body and the male's silver-white abdomen with white-parted hairs is diagnostic in the northern part of its range (BC and Washington), where no other Efferia

Saltbush Blister Gall Midge

Asphondylia atriplicicola

Cecidomyiidae

Identification: Induces leaf blister galls on Atriplex canescens, leucophylla, and spinifera.

Saltella sphondylii

Sepsidae

Size 2 to 3 mm. This fly has orange thighs and an orange scutellum although the degree of colouration is variable. It has a rather matt appearance compared to other Sepsidae and the scutellum is large and flat. Unless identified by a recognised exper

San Rafael Bandit

Cyrtopogon longimanus

Asilidae

Identification: Per Eric Fisher: "This sp. is actually a close relative of C. marginalis , of the eastern U.S. & Can. They both share a puffed-up, shiny black scutellum, which lines-up with a series of shiny-black spots along the sides of the thorax;

Sand Hammertail

Efferia albibarbis

Asilidae

Identification: mystax (moustache) white; female has relatively short and conical ovipositor, compared to E. aestuans The north shore of Lake Erie is the only region where it occurs in eastern Canada. -- Rob Cannings

Sapphire-tailed Twigsitter

Holopogon sapphirus

Asilidae

"It perches on twig tips of leguminous plants, just like many other Holopogon ." (comment by Eric Fisher)

Sapromyza rotundicornis

Lauxaniidae

Identification: A yellow species with round flagellomere (presumably the source of the species name) and two or three round, black spots on a shining yellow abdomen.

Sapromyza sexpunctata

Lauxaniidae

This small fly is all-orange with a shiny thorax. It usually has six black spots on the abdomen (note other Sapromyza species also have black spots). See ID guidance below . Sapromyza opaca has a dull, not shiny, thorax Photographs must be submitted

Sarcophaga carnaria

Sarcophagidae

A large species but similar in appearance to other members of the family. Unless confirmed by an expert detailed examination is necessary to confirm the species. Please supply a photograph with your records. It is necessary to key out this species un

Sarcophaga crassipalpis

Sarcophagidae

This species is frequently cultured in laboratories and used for research on insect development and behavior.

Sarcophaga melanura

Sarcophagidae

"Perhaps the best known and biologically most-diverse species in the subgenus Helicophagella is Sarcophaga (Helicophagella) melanura Meigen. It occurs widely in the Holarctic, extending northward to the Arctic Circle and south to the northern parts

Sarcophaga nearctica

Sarcophagidae

Identification: DNA barcoding of Sarcophaga nearctica or Sarcophaga caerulescens specimens often matches sequences for both species, but once narrowed down to those two species they can easily be told apart morphologically - S. nearctica has red geni

Sarcophaga sarraceniae

Sarcophagidae

Identification: See comments on images (linking to iNaturalist ) and print reference. Definitive identification likely requires microscopic examination of genitalia.

Sarcophaga sarracenioides

Sarcophagidae

Identification: Hypopygium red, genitalia diagnostic.

Sarcophaga sinuata

Sarcophagidae

Identification: Black tip to the abdomen as in S. melanura , setae of the midfemora are orange. The subgenus Sarcotachinella is treated as a genus in Manual of Nearctic Diptera , but placed as a subgenus by Pape (Catalogue of the Sarcophagidae of the

Sargus fasciatus

Stratiomyidae

Identification: the only Sargus with a constricted waist in male (Martin Hauser, pers.comm. to =v= 26.v.2026)

Scaeva affinis

Syrphidae

Identification: Eyes with dense hair; upper 2/3 of male eye "with extensive area of almost uniformly enlarged facets" ; abdomen dark, with six white, curved stripes. Larvae are light green with a white dorsal longitudinal stripe. Usually with abdomin

Scaeva selenitica

Syrphidae

Wing length 10.5 to 12 mm. This is a large distinctive fly with three pairs of yellow comma markings (lunules) on the abdomen; these are white on Scaeva pyrastri. The commas on selenitica extend equally far forward at both the inner and outer ends. M

Scaly Bee Fly

Lepidophora lepidocera

Bombyliidae

Identification: Hunch-backed shape is shared with L. lutea . In L. lepidocera , the pale scales are white or pale yellow, and usually no pale scales are evident on the fourth abdominal segment. Also note fringe at end of abdomen. May be a mimic of Ro

Scaptomyza adusta

Drosophilidae

"This is a very common and widely distributed species over the eastern half of the continent, extending west into the foothills of the Rocky Mountains. The larvae are undoubtedly leaf miners for the most part but apparently other situations will serv

Scaptomyza flava

Drosophilidae

The adult is a browish fly with a body length of about 2.5 mm. Scaptomyza flava larvae cause white 'corridor-blotch' mines when feeding between the upper and lower epidermes of the leaves of cruciferous plants of the Brassicaceae family. Around the l

Scaptomyza pallida

Drosophilidae

Identification: This species has a grey and a yellow color form. If using the key in Wheeler , this species keys to S. graminum (Fall.)

Scarce Orange Legionnaire

Beris clavipes

Stratiomyidae

The scarcer of the two Beris species with a black thorax and orange abdomen. Easily separable from the other (B. vallata) by the entirely (or almost entirely) orange hind tibiae. The female also has much darker wings than vallata, and these can obscu

Scatella marinensis

Ephydridae

Identification: A member of the Scatella triseta group with upper face brown and lower face white (all brown in melanderi ) and scutellum weakly convex (flat in triseta ).

Scathophaga aldrichi

Scathophagidae

Identification: The female is rather similar to S. spurca (brownish and gray coloration, pale legs, plumose arista) but with the antennae blackish, a very strong cloud on crossvein dm-cu, and a small grey streak on the fore femur. The male is general