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)

Helina annosa

Muscidae

Identification: Among Nearctic Helina, identified by fine hairs on the underside of the scutellum that are restricted to the basal half and by fine hairs on the hypopleuron that are restricted to the anteroventral border of the spiracle.

Helina evecta

Muscidae

This is a common muscid fly with a pale brown or blue abdomen with dark spots. It has infuscated cross-veins on its wings. It requires microscopic examination to be certain of identification. One identifying feature is the presence of long, dark hair

Helina impuncta

Muscidae

6.7-8.2mm. Grey/brown with fine stripes on the thorax and no patterning on the abdomen. It has red femora and tibia, with yellow-tinted wings and darkened cross-veins. It breeds on cow dung so most commonly encountered around cow pasture. Males most

Helina lasiophthalma

Muscidae

5.25 to 7.5 mm. Grey head, thorax and abdomen with paired brown spots on the abdominal tergites. Red legs with black tarsi, though the front femur may be darkened. The cross-veins are darkened and it has 2+1 sternopleural bristles. Several other Heli

Helina pertusa

Muscidae

Size 6 to 8.5 mm. A rather long grey looking fly with black patches on its abdomen and with black tarsi. It is a characteristic species of dead wood habitats and most often seen on the trunks of trees. The larvae are found in rot holes and under bark

Helina reversio

Muscidae

Length 5 to 7 mm. Usually beige or greyish in appearance, but very variable. It has dark femora but with reddish apices, reddish tibia and paired spots on the abdomen. Various habitats including hedgerows, flower meadows and woodland. Adults feed on

Helina rufitibia

Muscidae

Identification: Body black and pruinose, with dark markings on thorax and abdomen. Legs black except for tips of femora and most of tibiae. Hind femora with strong, nearly complete anteroventral row of bristles. Hind tibia with 2 anterodorsal and

Helina sexmaculata

Muscidae

Most Helina species are very difficult to identify from a photograph alone, though this species is perhaps the exception to the rule. It is a brown/grey colour with brown spots on both the thorax and on the abdomen. It has a distinctive pair of brown

Helina troene

Muscidae

Identification: Females of troene and procedens may be difficult to separate. Snyder's (1949) key separates them by the number of AD bristles on the hind tibia (one in procedens, two in troene). I have seen specimens with a single AD on one leg and

Helius flavipes

Limoniidae

Identification: Head: Head brownish-gray. Palpi and proboscis black. Proboscis a little longer than head. Antenna: Brown at base, rest of segments lighter brown. Thorax: Either yellowish or brownish, usually stripes are indistinct. Wings: Clear with

Helophilus hybridus

Syrphidae

Wing length 8.5 to 11.25 mm. In size and general appearance this species is similar to H. pendulus . The male is usually distinctive in having continuously broad yellow sides to tergites 2 and 3, whereas there is a dividing black bar near the posteri

Helophilus intentus

Syrphidae

Identification: Black facial stripe. Hind femora are reddish on the apical fifth and hind tibia are yellow on the basal half and reddish on the apical half. Spots on the third abdominal tergite are pointed, helping to distinguish from H. obscurus .

Helophilus neoaffinis

Syrphidae

Identification: Black facial stripe. Spots on T2 large; spots on T3 intermediate, occupying anterior 2/3 of tergite, with whitish inner ends. Differs from the very similar H. groenlandicus by the broad inner ends of the spots on T2. Oddly, despite no

Helophilus trivittatus

Syrphidae

This species is slightly larger and longer in build than other members of the genus, and the yellow side patches on the abdomen are more pronounced often giving a more lemony appearance. A particularly good identification feature is the fact that the

Hemerodromia superstitiosa

Empididae

Identification: One of two species of Hemerodromia with legs yellow except for last two tarsomeres on mid and hind legs. Female has broad dark stripe on thorax. Male may have thin stripes. A similar species from southern Texas and Mexico is distin

Hemipenthes inops

Bombyliidae

Identification: Distinct from congeners by: 1) largely hyaline wing with faint pigmentation; and 2) shape of the CuA1, which forms a cross with a continuous m-cu/m-m such that dm and CuA1 never actually touch (Fig. 12) H. inops & H. lepidota are the

Hemipenthes morioides

Bombyliidae

Identification: Head: Round; dark brown to black. Male and female identical, eyes of female only slightly wider, barely discernable. Antenna: Black, very short. Thorax: Dark brown to black with rust hairs across shoulders; sometimes thorax is bald. T

Hemipenthes scylla

Bombyliidae

Identification: Distinguished from H. sinuosa by apical half of discal cell clear (apical quarter in sinuosa ) and apical spot in cell r1 separated from remaining dark area. See comment by Joel Kits:

Hemipenthes webberi

Bombyliidae

Identification: Head: Round, black with a few yellowish flecks. Females and males identical, except for space between the eyes at top of head. Antenna: Black, very short. Thorax: Black hair with some yellowish flecks; a few white hairs at side edges

Hemyda vittata

Tachinidae

This fly has a black thorax and a pale orange abdomen which has a black central band that is usually broken. The larvae in common with all tachinids are parasitoids of other invertebrates, in this case true bugs of the family pentatomidae. A rather u

Herina frondescentiae

Ulidiidae

This is a very distinctive picture-winged fly. Its wings are patterned with wide dark bands. One of the smallest picture-winged flies, 3-3.5mm. Typically found in wet, rush-dominated habitats and brownfield sites. The larvae are belived to develop in

Herina nigrina

Ulidiidae

A relatively large picture-winged fly (to 6 mm) with a unique wing pattern comprised of a dark tip, and darkened outer crossvein and an L-shaped mark that occupies the costal cells but then extends at a right angle to encompass the inner crossvein. T

Hermetia sexmaculata

Stratiomyidae

Identification: The eyes are bare, the integument of the abdomen is wholly black dorsally in the male with at most a pair of small yellow spots in the female, femora and tibiae are mostly black, and the area including the calypters (squamae) is white

Hesperinus brevifrons

Bibionidae

Identification: Differs from all other Bibionidae in having long antennae.

Hessian Fly

Mayetiola destructor

Cecidomyiidae

An economically important crop pest. Larvae in stems of wheat ( Triticum spp.) and occasionally in other grasses.

Heteromyia fasciata

Ceratopogonidae

Identification: Distinguished from the other North American species, H. prattii , by the white pruinosity on top of the abdomen.

Heteromyza oculata

Heleomyzidae

Identification: Distinction from some European species of Heteromyza is discussed on diptera.info: http://www.diptera.info/forum/viewthread.php?forum_id=5&thread_id=64196 .

Heteromyza rotundicornis

Heleomyzidae

5mm. Grey thorax and scutellum with an orange abdomen. Costal spines on the wings. The face is slightly narrower than the frons. Heteromyza commixta is very similar but has a face as wide as the frons. Unless identified by a recognised expert, photog

Hexatoma spinosa

Limoniidae

Identification: Adult: body brownish-gray; wings yellowish-brown with conspicuous dark veins; legs dark yellow to brown, slightly darker at joints; thorax with two longitudinal dark dorsal stripes and two subdorsal stripes that are broken or shorter

Hickory Aggregate Gall Midge

Caryomyia aggregata

Cecidomyiidae

Causes brown, hairy galls on the veins on the undersides of hickory leaflets, "usually clustered in a row along major vein and often in such close aggregation as to partially coalesce."

Hickory Awl-shaped Gall Midge

Caryomyia subulata

Cecidomyiidae

Larvae develop in awl-shaped galls on the undersides of hickory ( Carya ) leaves. Adult and pupal stages are unknown.

Hickory Starburst Gall Midge

Caryomyia asteris

Cecidomyiidae

Larvae develop in star-shaped galls on the undersides of hickory ( Carya ) leaves. Adult and pupal stages are unknown.

Hickory Sticky Ginger Jar Gall Midge

Caryomyia viscidolium

Cecidomyiidae

One of only two Caryomyia galls that occur exclusively on the upper leaf surface of hickories ( Carya ). Pupae break out of the weak cap at the gall's apex. Adults emerge in April.

Hilara lutea

Empididae

Identification: A yellow species with a bright yellow third antennal segment.

Hilara seriata

Empididae

Males come in two forms, one with greatly enlarged front basitarsi and dense hairs on mid legs, the other with normal front basitarsi and weak hairs on mid legs.

Hilara umbrosa

Empididae

Identification: Over 5 mm, thorax gray, legs yellow, all femora with spines underneath distally.

Holly Leaf Miner

Phytomyza ilicis

Agromyzidae

The larvae of the Agromyzid fly Phytomyza ilicis mine the leaves of Holly. See the National Agromyzidae Recording Scheme webpage for this species for further details of puparium and adult insect. ref.: Warrington, B.P. (2023). Phytomyza ilicis . Acce

Homoneura littoralis

Lauxaniidae

Identification: Swollen yellow head, small eyes, anterior fronto-orbital much shorter than posterior, wings clear, two apical spurs on mid tibia.

Homoneura philadelphica

Lauxaniidae

Identification: The only eastern species with the combination of * Wing with three spots along R4+5 (one at r-m, one intermediate, and one at wing margin) * Two rows of strong acrostichals (possibly with weak setulae outside the main row) * Strong pa

Homoneura sheldoni

Lauxaniidae

Identification: Wing darkened along costa from slightly beyond humeral crossvein to apex of wing.

Homoneura shewelli

Lauxaniidae

Identification: Wing with dark bands along cross veins, weak spots at end of longitudinal veins, and no spots on R4+5 between r-m and apical spot. A strong pair of presutural dorsocentrals.

Homoneura unguiculata

Lauxaniidae

Identification: Six rows of small acrostichals (native species with 2-4 often larger pairs), wing unmarked, antenna yellow with brown tip (tip not dark in native species), face with conspicuous silvery spots when viewed from above, arista with longer

Hoplolabis armata

Limoniidae

Identification: In the East, the strong spur of M3 into the discal cell distinguishes this species from other Erioptera s. lat.

Horse Stomach Bot Fly

Gasterophilus intestinalis

Oestridae

can cause medical problems in humans, such as ocular myasis

House-fly

Musca domestica

Muscidae

Length 6 to 7 mm. With varying amounts of orange on the basal segments of the abdomen and four black stripes on the thorax. The legs are all black and the eyes are bare. As with other Musca species, the arista has feather-like long hairs. Similar to

Huron Shore Bee Fly

Dipalta banksi

Bombyliidae

Identification: brown body, black spots on dorsal midline of abdomen, wings with black patches and spots

Hyadina albovenosa

Ephydridae

Named after the white crossveins. Some Nostima also have white crossveins, but have additional wing or thorax markings that H. albovenosa lacks.

Hyadina furva

Ephydridae

Identification: Two subspecies recognized: Hyadina furva furva - eastern USA (west to KS-TX), Canada (Ontario), Bermuda Hyadina furva flavipes - southwest USA (AZ, CA), Mexico

Hybomitra cincta

Tabanidae

Identification: For both sexes: Subcallus denuded and shiny. Palpus black. Frontoclypeus and thoracic pleuron with black hairs. Wing distinctly pigmented. Females have first three segments of abdomen orange, rest of abdomen black (sharply delimited),

Hybomitra difficilis

Tabanidae

Identification: Eyes apparently bare; subcallus denuded & shining Drees et al. regard it as common, and a serious pest; Pechuman et al. consider it generally uncommon, but sometimes locally abundant.

Hybomitra lasiophthalma

Tabanidae

Identification: Female: subcallus denuded, shining; face below eyes not denuded or shining; wing crossveins spotted with brown; abdomen broadly orange brown laterally with median black area constricted on third segment.

Hybomitra sodalis

Tabanidae

Identification: Black abdomen with white triangles in middle only, "distinctive and unmistakable"

Hybomitra trispila

Tabanidae

With known pathogenic transmission of Vesicular stomatitis virus, a pathogen of animals that can also infect humans.

Hybos culiciformis

Hybotidae

There are three British species of Hybos , all are similar though H. femoratus has red legs (except the rear pair which are black). No additional images available for this species.

Hydatostega plumbea

Dolichopodidae

Identification: The white and black wing markings are distinctive according to Justin Runyon, who is an expert on the family.

Hydrellia albilabris

Ephydridae

Larvae mine and pupate in thalli of duckweed ( Lemna minor ; also recorded from Spirodela in the Palaearctic region).

Hydrellia formosa

Ephydridae

Identification: The only species that can be easily identified from photos.

Hydromya dorsalis

Sciomyzidae

Length 6-7mm. A reddish-brown species with a grey thorax and five spots on each wing, four along vein M1+2 and one at the base of the s-shaped cross-vein. Unless identified by an expert, good quality photos or examination of a specimen are required.

Hydromyza confluens

Scathophagidae

"The eggs are deposited singly at irregular intervals on the surface of the floating leaf petioles of the yellow water lily Nymphaea americana ." (Welch, 1917) Larvae form brown swellings, which Welch did not consider true galls because they were no

Hydrophoria lancifer

Anthomyiidae

It is a member of the Anthomyiidae family, which are closely related to the Muscidae but the 6th long vein reaches to the wing margin. It is a hairy beige-brown fly, varying in length from 4 to 11 mm. This species has a red ID rating and unless ident

Hydrophoria linogrisea

Anthomyiidae

Similar to the more common Hydrophoria lancifer , but its legs are reddish yellow. This species has a red ID rating and unless identified by a known expert you must provide a satisfactory explanation of how it was identified for the record to be acce

Hydrotaea armipes

Muscidae

There are other very similar species and detailed examination is necessary. There are other very similar species and detailed examination is necessary. Mostly recorded between April and September. Widespread and fairly frequent in Britain. No additio

Hydrotaea cyrtoneurina

Muscidae

Like other Hydrotaea species, this is predominently black or dark brown. Males have an indented front femor which is typical of the genus. Uncommon but widespread in England and Wales, few records in Scotland.

Hydrotaea dentipes

Muscidae

6·5 to 7·75 mm. Like most flies in the Hydrotaea genus it is dark and shiny. Males have the front femur notched and toothed. The thorax, seen from behind, has conspicuous whitish dusting, at least in front of the suture, in line with the acrostichal

Hydrotaea similis

Muscidae

One of the larger Hydrotaea species at up to 10mm in length. Generally black with some pale grey dusting on the abdomen and pale stripes at the top of the thorax. Males have ornamentation on the underside of the front femora including a short, sharp

Hylemya alcathoe

Anthomyiidae

Identification: " H. alcathoe is notable in the genus due to its long pectinate aristal hairs, yellow palpi, normally yellow legs and partly reddish abdomen. The female abdomen may occasionally be wholly gray." In addition, the female may have humeri

Hylemya vagans

Anthomyiidae

9mm - large for an anthomyiid. H. vagans has a yellow hind tibia (other leg parts may also be yellow but this is variable) and a very plumose arista, though with the hairs not very numerous. The lower squamae is small and narrow - largely hidden behi

Hylemya variata

Anthomyiidae

As with other flies in the Anthomyiidae family, this genus are thin bodied. Most are grey/brown and lack obvious identification features. Hylemya species have long plumose arista, with the rays not very numerous (similar to Hydrophoria), but with sma

Hylemyza partita

Anthomyiidae

Hylemyza partita has a brown thorax with dark lateral stripes. It has plumose arista with hairs longer than the width of the antennae diameter. This species has a red ID rating and unless identified by a known expert you must carry out detailed exami

Hypocharassus pruinosus

Dolichopodidae

Identification: The shape of the antenna is distinctive:

Hypocritanus fascipennis

Syrphidae

Identification: dark medial band on wing; basal and distal portions of wing clear

Hypovoria discalis

Tachinidae

Identification: Voriini with discals, large pteroplerual, vein R1 haired, and last two sections of Cu similar in length.

Ilione albiseta

Sciomyzidae

An orangey brown species with striped eyes and thorax. Unless identified by a recognised expert, a photo is required and the specimen should be examined with a microscope. In the comments box, state the key or ID method used and describe the size and

Ilythea caniceps

Ephydridae

Identification: Similar to spilota with legs largely yellow.

Inland Floodwater Mosquito

Aedes vexans

Culicidae

Identification: Larvae: - Antennae are shorter than head - Short siphon with a tuft half as long as the diameter of the base, between pecten teeth - Saddle on anal segment incomplete Adult Female: - Unbanded proboscis - Scutum with short brown scales

Iridescent centurion

Sargus iridatus

Stratiomyidae

Length 6 to 12 mm. The sexes of this soldier fly are similar in appearance, but the female is slightly broader at the hind end. The body is an iridescent deep blue and the wings are uniformly smoky. Unless identified by a recognised expert, a photo i

Iris Bud Fly

Neorthacheta dissimilis

Scathophagidae

Identification: 3 katepisternal bristles, only 1 pair of strong scutellar bristles, and R1 with setulae dorsally. Frons black.

Jenkinshelea albaria

Ceratopogonidae

"This species is commonly found around lakes and streams and ranges west to Texas and Illinois, northwards to Ontario."

Johannsenomyia annulicornis

Ceratopogonidae

Identification: Distinguished from J. argentata by the entirely dark female abomen and the lack of a preapical yellow ring on the hind femur.

Juriniopsis aurifrons

Tachinidae

Identification: Distinguished from adusta by the broader frons of the male and narrow (normal) fore tarsi of the female. Distinguished from floridensis by the mostly dull whitish frons.

Juriniopsis floridensis

Tachinidae

Identification: Distinguished from other North American species by the dark, slightly shining frons (parafrontals dull white or yellow in other species), dark bases of palpi (entirely reddish yellow in other species), and almost entirely dark antenna

Keroplatus militaris

Keroplatidae

Identification: Distinguished from other North American Keroplatus by the combination of antennae without white tips and claspers of male long and pointed.

Kiefferulus dux

Chironomidae

There is at least one similar, uncommon, undescribed species in Florida.

Kite-tailed Robberfly

Machimus atricapillus

Asilidae

Generally larger and greyer than M. cingulatus with a more strongly marked abdomen. There are also differences in details of the antennae and genitalia. The front tibia are largely red and lack the black bands seen in other Machimus species. Males of

Knapweed Gall Fly

Urophora affinis

Tephritidae

Introduced from Europe in 1971 to control knapweed ( Centaurea spp.)

Lamprolonchaea smaragdi

Lonchaeidae

Identification: The only shining green Lonchaeidae known from North America. Often called "Metallic Green Tomato Fly", partly due to confusion with the tomato pest L. brouniana .

Lantana-Leafminer

Ophiomyia lantanae

Agromyzidae

Larvae in Lantana spp. "Larva feeding in seed heads, either in pulp of immature berries or lower in peduncle, where pupation takes place."

Large Marsh Horsefly

Tabanus autumnalis

Tabanidae

Wing length is 13 to 16 mm and 16 to 22 mm in body length. A fairly large horse-fly. The dark abdomen has a central row of pale triangles and a dark and broad central stripe on the underside. The eyes lack stripes. Tabanus bromius is similar but smal

Lasioptera ephedrae

Cecidomyiidae

Identification: Gall -- fusiform twig gall, about 1/2" long. Develops in stem galls on Ephedra .

Lasioptera lorrainae

Cecidomyiidae

Galls are spheroid, 5–8 mm in diameter, and occur in early summer on lateral twiglets and later near branch tips. Galls collected in Iowa were found subtending flower heads, but this has not been observed elsewhere. Each gall contains 1–11 yellow lar

Lasiosina canadensis

Chloropidae

Identification: Eyes elongate oval. Not with an unusual proliferation of strong dorsocentral bristles. In winged forms, crossveins more widely separated than in L. approximatonervis , by about twice the length of the hind crossvein. "Legs dark yel

Lauxania albiseta

Lauxaniidae

Identification: 1+3 pairs dorsocentrals, legs pale except for mid and hind femora, arista white, wing base not darkened.

Lauxania glabrifrons

Lauxaniidae

Identification: "This species can be distinguished from other Nearctic species of Lauxania externally by the shining frons, white arista, 0 + 3 dorsocentral setae, four rows of acrostichal setulae, beige halter, and pale wing base." (Pérusse and Whee

Lauxania shewelli

Lauxaniidae

"There are five species of Lauxania in North America, but L. shewelli is the only one known east of the Rockies, and is the only one with a dark wing base (the western species have the entire wing yellowish). A lot of older publications list Lauxania

Leia bivittata

Mycetophilidae

Identification: From Johannsen 1911: "Length 3.75 mm. Honey yellow; trunk bilineate, and tergum with 2 series of black punctures. Body rather pale honey-yellow; antennae black at tip; stemmatae very distinct, in a curved line; thorax a little hairy,

Leia opima

Mycetophilidae

Identification: From Johannsen 1911: "Head yellow, vertex and upper half of occiput fuscous; antennae fuscous, scape, first flagellar joint and palpi yellow. Thorax including scutellum yellow; dorsum shining, on each side with large, black, oval spot

Leia sublunata

Mycetophilidae

Identification: Similar to L. bivittata , but with smaller black spots on dorsum of thorax.

Leia varia

Mycetophilidae

Identification: From Johannsen 1911: "Body yellow; head black between the eyes, which, and the feelers are also black; the latter are yellow at the base; chest except the fore part, black; segments of the abdomen bordered with black, which color exte

Leia ventralis

Mycetophilidae

Identification: From Johannsen 1911: "Head black; antennae brown, 3 basal joints and the palpi yellow. Thorax and abdomen shining black, venter with segments 3 and 4 largely yellow; hairs pale. Coxae, femora, tibiae, and metatarsi yellow remainder of

Lejogaster metallina

Syrphidae

A small metallic green hoverfly with comparatively large antennae. Found in all types of open wetland habitats including wet meadows, marshes, fens and flushes (including mildly acidic conditions), especially where Juncus is abundant. Adults are freq