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)

Botanophila latifrontalis

Anthomyiidae

Identification: Proepisternum bare, palpi not expanded, face not narrowed, anepimeron bare, male frons width similar to female, 3 pairs of presutural acrostichal setae developed, tergites 3-5 with discal rows of setae, tibiae yellowish, hypopygium sl

Boxelder Gall Midge

Contarinia negundinis

Cecidomyiidae

Causes folded or swollen leaflets or swollen leaf buds in boxelder ( Acer negundo ), in early spring when the leaves are still expanding. Larvae are white and gregarious (many in each gall). They develop very quickly, then drop to the ground and spin

Boxwood Leafminer

Monarthropalpus flavus

Cecidomyiidae

Larve form 5 mm blisters on the upper sides of boxwood leaves. This is the only gall midge on boxwood in North America. The genus Buxus is not native and has no native gall makers.

Brachicoma devia

Sarcophagidae

Sarcophagidae are very difficult to determine to species level without microscopic examination, so will need to be checked in detail unless confirmed by a recognised expert. Unless identified by a recognised expert, a photo is required and the specim

Brachydeutera longipes

Ephydridae

Identification: Lacks a sharp demarcation between the brownish dorsal area and the grayish ventral area comes to light

Brachydeutera sturtevanti

Ephydridae

Identification: "The long, rounded facial carina, the very long third costal section, and stout, distally pointed male genital processes will readily distinguish this species from argentata and neotropica , which border its range on the east and sout

Brachyopa scutellaris

Syrphidae

All four British Brachyopa species have an orange/brown abdomen and grey thorax (note that the thorax has no bristly hairs as some flies do). Brachyopa scutellaris and Brachyopa pilosa can be separated from the other two Brachyopa species as the scut

Brachypalpoides lentus

Syrphidae

A very attractive hoverfly with a deep crimson band occupying most of the abdomen Xylota segnis is superficially similar but is somewhat smaller with a less striking orange band on the abdomen and partially pale legs. Favouring old woodland and is qu

Brachypalpus femorata

Syrphidae

Identification: Note yellowish pile on the thorax combined with black pile on the pleurae; yellowish pile rather than reddish as in B. alopex . Males always shortly holoptic. Likely a complex of several species.

Bradysia giraudii

Sciaridae

From Kai Heller (11/8/2018): "Apparently this is a complex of at least three different species, which [can] be distinguished by DNA barcoding. One of them is distributed in North America and Europe, the others are currently known only from either Ger

Brillia retifinis

Chironomidae

Identification: A western species with subapical lobe of gonostylus slightly shorter than or equal in length to apical lobe. The eastern Brillia parva is nearly identical. The other western species have shorter subapical lobe.

Broad Centurion

Chloromyia formosa

Stratiomyidae

9 mm. This is attractive soldier fly has sexes that are very different in appearance. Both have a shiny green thorax but the female has a blue-green abdomen, sometimes with a violet sheen, and the male has a bronze abdomen. The eyes are covered in de

Brontaea humilis

Muscidae

Identification: Males wholly dark, while females have a pattern of grey dusting.

Brown Heath Robberfly

Machimus cingulatus

Asilidae

Size 10 to 15mm. A smallish robberfly with black and red legs. The femora are black on the anterior surface and orange of the posterior surface, with an orange ring near the tip. The top of the thorax has a thick black central line. Machimus atricapi

Brown Saltmarsh Mosquito

Ochlerotatus cantator

Culicidae

Identification: Adult Female: - Dark scaled proboscis - Scutum is pretty plain with golden brown scales - Usually the last two tergites of the abdomen are pale scaled - Hind tarsomeres have narrow pale basal bands Adults don't travel far from salt wa

Brown-banded Hanging Thief

Diogmites salutans

Asilidae

Identification: medium-sized, brownish red; mesonotum with three dark brown stripes (the median one divided for its entire length)

Bucephalina megacephala

Scathophagidae

Identification: Dark body+femora and orange tibiae+tarsi are unique

Bucephalina setipes

Scathophagidae

Identification: Differs from B. megacephala by the mostly orange head, completely yellow legs, and orange markings (sometimes extensive) on the thorax.

Bumblerobber

Dasylechia atrox

Asilidae

Identification: From couplet 2 of Key to the Genera of the Laphriini in , p. 118: Antennae with a distinct terminal style; palpi enlarged, head thickly set with long hairs, genitalia very small, large robust hairy species, bumble bee - like in appear

Callicera erratica

Syrphidae

Identification: pile color variable; extreme color forms used to be treated as distinct taxa ( auripila , johnsoni )

Calliopum aeneum

Lauxaniidae

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 identifying characters. Some sources suggest that the

Calliphora alaskensis

Calliphoridae

Identification: Closely related to C. aldrichia, C. montana, C. loewi . Rare in collections, but locally abundant in some areas (Vancouver, southwestern Alberta, ~3,000m in northcentral Colorado) .

Calliphora latifrons

Calliphoridae

Identification: The male has a broad frons, about 1/4 head width, with two strong pairs of ocellar setae (one pair in males of other species of Calliphora ).

Calliphora vicina

Calliphoridae

In Britain this is the most common bluebottle and it is often associated with humans. It is 10-14 mm. The head and thorax are dull grey and the abdomen is bright metallic blue with black markings. Its body and legs are covered with black bristle-like

Calliphora vomitoria

Calliphoridae

This large 'bluebottle' fly has a characteristic shiny blue abdomen and a dark thorax. The orange hairs on the gena and post gena, looking like a ginger beard, help to distinguish this species. Although common and widespread, this species is not usua

Callomyia speciosa

Platypezidae

The long thin abdomen is somewhat variable but consists of amber and black with silvery white bands. The thorax is also usually black with silvery markings. Various habitats, especially woodland and around decaying wood. The flat bodied larvae are fu

Calycomyza artemisiae

Agromyzidae

The larvae of the fly Calycomyza artemisiae mine the leaves of Mugwort and some related plant species. The mine is an opaque, pale upper-surface blotch. See the National Agromyzidae Recording Scheme webpage for this species for further details of pup

Calycomyza flavinotum

Agromyzidae

In leaves of Ageratina, Arctium, and Eupatorium , larvae form whitish blotch mines, with several larvae in the same leaf. The mines frequently merge and give the appearance of a single very large mine.

Calycomyza malvae

Agromyzidae

Larvae mine leaves of Malveae (mallows) and some legumes, starting on the bottom side and moving to the top.

Camarota curvipennis

Chloropidae

A small dark-coloured fly that wraps its wings close to its abdomen giving it the appearance of a small red-headed beetle. Unless identified by a recognised expert, a photo is required showing the identifying characters. Various habitats including po

Camilla atrimana

Camillidae

Identification: Wings slender and slightly pointed at tip, legs dark, mesonotum not shining (see key by Beuk and de Jong, 1994)

Campiglossa albiceps

Tephritidae

Identification: Many rounded black and translucent spots on wings. Yellowish head and legs, gray with black spots thorax and abdomen.

Campiglossa malaris

Tephritidae

Campiglossa malaris is a small fruit fly with brown and white mottled wings. Unless identified by a recognised expert, a photo is required and examination of the specimen may be necessary. It is associated with Ragworts, mainly Senecio erucifolius, b

Campsicnemus oregonensis

Dolichopodidae

Identification: Apparently keys to C. thersites in Harmston & Knowlton (1942), but most notably, it has a dark spot on the vein M1+2 that the other species lacks. Original description: https://www.biodiversitylibrary.org/page/26388950#page/396/mode/1

Camptoprosopella dolorosa

Lauxaniidae

Identification: A large species with long antennae, dark wings and abdomen, and thorax brown with a darker stripe.

Camptoprosopella maculipennis

Lauxaniidae

Identification: The only Camptoprosopella with patterned wings. Most species have clear wings. Dolorosa has dark wings.

Camptoprosopella verticalis

Lauxaniidae

Identification: 3 pairs dorsocentrals, front pair nearly as long as others; palpi black and very wide at tip; ocellar spot large

Campylocheta semiothisae

Tachinidae

Identification: Antennae blackish in ground color. Tibiae yellowish, contrasting with black femora. Tegula orangish, basically concolorous with basicosta. Frons gray to silvery gray.

Campylocheta teliosis

Tachinidae

Identification: Antennae red, contrasting sharply with dark body and dark base of arista.

Carnus floridensis

Carnidae

Identification: Female with much longer setae on tergites than other species.

Carnus hemapterus

Carnidae

Adults are on birds, likely feeding on blood, often hiding in the axilla. The overwintering stage is the pupa.

Cartodiplosis nyssaecola

Cecidomyiidae

This species was thought by Beutenmuller 1907 and Felt 1917 to be the species that causes the galls it is an inquiline in, but according to Gagne 1989 it was determined to be only an inquiline.

Catotricha americana

Cecidomyiidae

The BugGuide photo shows the only known female of the species, which was described based on a male from New Hampshire and is also known as a larva.

Celery fly

Euleia heraclei

Tephritidae

This is a small picture wing fruit fly which has very heavily marked with brown patterning. It has green eyes. Unless identified by a recognised expert, a photo is required. If the photo doesn't show the key ID features then in the comments box descr

Cephenemyia phobifer

Oestridae

Identification: "Probably C. phobifera , based on the eastern distribution, yellow-haired mesonotum lacking a black crossband and entirely black-haired abdomen." -- Ray Fisher's comment

Ceratinostoma ostiorum

Scathophagidae

Identification: Body dark grey, with very long palpi and long anteroventral bristles on the fore tibia.

Ceriana tridens

Syrphidae

Identification: Some resources for aid in ID of C. tridens :

Cerocatus hardyi

Therevidae

Identification: Male : Head: Black with silvery-white pile. Antenna: Yellowish; last segment slightly more brownish. Thorax: Segment 1 (scutum) dull grayish-black thinly covered with yellowish-white hair and with 2 gray pile longitudinal stripes, one

Cerocatus pictipennis

Therevidae

Identification: Head: Black with silvery-white pile. Antenna: Yellowish-brown. Thorax: Segment 1 (scutum) black with 2 gray pile longitudinal stripes, one each side of center. Segment 2 (scutellum) black with wide white line across base. Thorax side

Cerocatus rufiventris

Therevidae

Identification: Head: Black with silvery-white pile. Antenna: Yellowish-brown, last segment brown. 1st segment quite short, unusual for Cerocatus. Thorax: Segment 1 (scutum) black with 2 gray pile longitudinal stripes, one each side of center. Segmen

Cerodontha (Dizygomyza) iraeos

Cerodontha iraeos

Agromyzidae

The larvae mine the leaves of Yellow Iris ( I ris pseudacorus ) and other related plants. The mine takes the form of a short, white, irregular corridor, parallel to the leaf blade. See the National Agromyzidae Recording Scheme webpage for this specie

Cerodontha (Dizygomyza) iridis

Cerodontha iridis

Agromyzidae

The larva form a blotch mine on the leaves on Stinking Iris ( I ris foetidissima ). The affected area may be large as several mines may coalesce. The mine has a mottled greenish appearance. See the National Agromyzidae Recording Scheme webpage for th

Cerodontha (Poemyza) phragmitidis

Cerodontha phragmitidis

Agromyzidae

The larvae mine the leaves of Common Reed ( Phragmites australis ). The mine takes the form of a large linear blotch in the leaf and the larva usually pupates in the leaf. The puparium is a metallic black, with an elongated posterior section. See the

Cerodontha bicolorata

Agromyzidae

Identification: Tergites 1-3, but not 4, contrasting yellow, first flagellomere of male not enlarged, last two sections of vein Cu approximately equal.

Ceromya flava

Tachinidae

Identification: R1 setulose over its length, CuA1 setulose, body completely yellow, male with large flagellomere, female unknown. Rare, known from 4 male specimens

Ceromya palloris

Tachinidae

Identification: R1 setulose only distally, CuA1 bare. Body entirely yellow. (Ceromya flava has similar coloration, but has CuA1 setulose and R1 setulose along its length).

Chaetochlorops inquilinus

Chloropidae

Identification: Very strongly bristled for Chloropidae Inquiline in midge galls, especially on asters.

Chaetogaedia analis

Tachinidae

Identification: Parafrontals shining black; abdomen with discals on tergites 3 and 4.

Chaetogaedia monticola

Tachinidae

Identification: Cell r5 open; parafrontals densely white pollinose; no parafacial bristles especially strong, the strongest closer to facial ridge than eye; abdomen with some yellow.

Chaetopsis aenea

Ulidiidae

Identification: This species has red legs, three complete wing bands, and about five pairs of fronto-orbital bristles plus two small frontal bristles. It is one of two species found in salt marshes.

Chaetopsis apicalis

Ulidiidae

Identification: In most of its range the only member of the genus with only a single dark band, at the apex of the wing (hence the species name). In the northern part of its range, Massachusetts to Maine, the preapical band found in most other speci

Chaetopsis debilis

Ulidiidae

Identification: Wing with 3 bands, legs pale, base of abdomen orange. This species may end up being a synonym of C. massyla (based on unpublished work by Steyskal).

Chaetopsis massyla

Ulidiidae

Identification: Two apical wing bands broadly joined along wing margin, first band nearly complete, legs dark, inhabitant of fresh water wetlands.

Chaetorellia jaceae

Tephritidae

Length about 4 mm. Strongly patterned wings with three brownish strips. Please provide supporting images with your records for this species. Meadows, verges and other grassy places, especially where Knapweed is present. Larvae live within the seed he

Chaetostomella cylindrica

Tephritidae

A well-marked member of the Tephritidae family. However there are similar species and good images are needed. Please provide supporting images with your records for this species. Meadows and verges where Knapweed and thistles are present. Larvae feed

Chalcosyrphus chalybeus

Syrphidae

Identification: Small syrphid, steely blue, probably a mimic of various steely-blue wasps.

Chalcosyrphus eunotus

Syrphidae

A medium-sized, brownish hoverfly superficially resembling Brachypalpus laphriformis , but the thorax is dull with faint stripes and the abdomen is broader with pairs of narrowly separated squarish grey patches on tergite 2 (male) and tergites 2 and

Chalcosyrphus inarmatus

Syrphidae

Identification: Black fly with yellow hair and shiny face. Can be mistaken for Brachypalpus oarus , but note hind tibiae broadly orange at the base and at least two basal tarsomeres orange on hind legs. In front view, Brachypalpus has a triangular he

Chalcosyrphus piger

Syrphidae

Identification: Medium-sized; metafemora enlarged. Dark thorax, wings. Abdomen bright red. Tarsi usually (or always?) dark. Note short appressed (not erect) hairs on thorax . This, and related members of the genus with a similar pattern are likely mi

Chalcosyrphus plesia

Syrphidae

Identification: Head: Shiny black. Face projecting outward at antenna base. Antenna: Base black, last segment large, rounded, brownish. Thorax: Dull brownish-black, flattened at end as in all Chalcosyrphus. Wings: Slightly tinted brownish. Wings exte

Chamaemyia aridella

Chamaemyiidae

2-3mm. Chamaemyiidae are nearly all small and grey flies. Chamaemyia aridella is all grey but with yellow tibia. The abdomen usually lacks spots or stripes. See the ID checklist below for a list of the key identifying features. There are 12 species i

Champlain Laphria

Laphria champlainii

Asilidae

Identification: According to Walton's original 1910 description (at BHL, here , figures of plate IX here ), champlainii has dense yellow pile on the first through the fourth abdominal tergites (fifth on male), with 'anvil-shaped' black patches on the

Chaoborus albatus

Chaoboridae

Identification: A small species with spotted wings and legs unmarked except for faint brownish bands at joints. Original description (Johnson 1921): Male - Head white; around the base of the antennae, the tips of the palpi and proboscis brown; the pl

Chaoborus astictopus

Chaoboridae

Sæther (1970) wrote " Chaoborus punctipennis is very similar to C. astictopus in all stages and it may well be that C. astictopus is merely a subspecies or even a form."

Chaoborus cooki

Chaoboridae

Identification: Wings spotted. Wing fringe narrow. Large, relatively dark species. Normally found in small, fishless ponds or temporary water bodies.

Chaoborus flavicans

Chaoboridae

Not easily distinguished from Chaoborus albipes (Johannsen, 1903). Flavicans is usually found in lakes and albipes in shallow, fishless ponds.

Chaoborus maculipes

Chaoboridae

"This species resembles C. punctipennis (Say) in wing pattern and spotting of legs although the spots are few and smaller; it resembles C. albatus Johnson in lacking dark spots between the scutal stripes, but albatus also lacks the leg spots and usua

Chaoborus punctipennis

Chaoboridae

This is the common eastern species. It is distinguished from similar eastern species by having spots on wings, legs, and between stripes on top of thorax. Other Sayomyia lack leg spots, thorax spots, or have a band instead of spots on the wings.

Chaoborus trivittatus

Chaoboridae

"Individuals overwinter as fourth instar larvae and are mostly restricted to permanent lentic habitats ranging from small shaded ponds to large deep lakes in woodland. Although some larvae live in temporary waters, they can not successfully overwint

Chasmatonotus bicolor

Chironomidae

Identification: Basal 2/5 of wing and base of abdomen pale.

Chasmatonotus maculipennis

Chironomidae

Identification: Wing with white spot (in addition to white base) extending from R1 nearly to, but not reaching Cu2; narrow unpigmented strip at wing tip.

Chasmatonotus unimaculatus

Chironomidae

Identification: In the eastern United States, nearly all Chasmatonotus midges with a single white spot near the middle of the wing are C. unimaculatus . There is an uncommon, undescribed species from the southern Appalachian Mountains with a nearly

Cheese Skipper

Piophila casei

Piophilidae

Identification: Black fly with yellow on front of head. No bristles on postpronotum and one pair of dorsocentrals. This is the only species in our area with the fine thoracic setulae confined to three narrow rows.

Cheilosia albitarsis sensu stricto

Syrphidae

Cheilosia albitarsis and Cheilosia ranunculi are very similar and can often only be safely determined by detailed examination. Any specimen that has not been subjected to detailed examination should be submitted as Cheilosia albitarsis/ranunculi agg.

Cheilosia caerulescens

Syrphidae

It is a bare-eyed, bluish-grey Cheilosia with pale knees and distinct smudges over the two cross veins of the wings. The lower face is rather strongly protruding, the third antennal segment is brownish-red and the antennal pits are fused. Unless iden

Cheilosia capillata

Syrphidae

Identification: Per Bill Dean, "Eyes bare; face bare; no scutellar bristles; pile on frons pale; tibiae mostly orange; hairs on thoracic dorsum pale yellow and more white on pleurae; wing veins very orange at base."

Cheilosia grossa

Syrphidae

A dark bodied hoverfly with red brown hairs. C. grossa is very similar to C. albipila but on close examination C. grossa will be found to have black antennae. Areas where thistles are common, damp meadows woodland rides etc. March to May – peaking la

Cheilosia illustrata

Syrphidae

A furry bumblebee mimic with a dark wing cloud. Body is usually pale haired with a black band across the centre of the thorax, and another across tergite 3. It is typically seen settled with its wings closed tightly over its back. Hedgerows and woodl

Cheilosia pagana

Syrphidae

One of the smallest Cheilosia . The female has an exceptionally large, orange coloured, third antennal segment. The males often have strong reflective grey triangles on the sides of the abdomen. They have bare arista and the female has an entirely bl

Cheilosia ranunculi

Syrphidae

A robust all black, shiny hoverfly and only separated from C. albitarsus recently. Males have yellow front tarsi. Females cannot be separated but males can distinguished by the shape of the apical segments of the front tarsi which in C. ranunculi tap

Cheilosia soror

Syrphidae

One of our three fungus-feeding Cheilosia (characterised by bare eyes, long wings, partially pale legs and fused antennal pits), and readily separable from the other two by the orange-red 3rd antennal segment. Confusion is more likely with the smalle

Cheilosia variabilis

Syrphidae

This species has an elongate, rather parallel sided grey abdomen and black thorax. It is relatively large, and has dark wings. It lives in wooded areas, and lush woodland edges. April to September, peaking in May and early June Breeds on Figwort, whe

Chersodromia inusitata

Hybotidae

Identification: The only eastern Chersodromia with dark legs, femora black and remainder dark brown. Thorax dark gray, but with yellow "shoulders" at least in some males.

Chersodromia megacetes

Hybotidae

Identification: Wings longer than abdomen; thorax shiny-black above; wings whitish (no infuscation); halteres white; in males, pygidium about as large as the rest of abdomen ( Melander 1945:80 )

Chersodromia parallela

Hybotidae

Identification: Distinguished from other American Chersodromia by the reduced wings with apical third dark and wing veins running more or less parallel to margin.

Chetostoma curvinerve

Tephritidae

7mm long with a bright-tawny orange body and a dark wing pattern which includes a dark wing-tip and a diagonal line reaching almost entirely across the forewing. In addition, the males have very distinctive dark curved spines guarding the mouthparts.

Chionea albertensis

Limoniidae

Named after Alberta, where it was discovered, this species is found in "forested, generally mountainous areas" from Banff south to central Oregon and Idaho.

Chionea obtusa

Limoniidae

Identification: "Brown to grayish brown in color, with antennae having five to seven flagellomeres"

Chionea valga

Limoniidae

Identification: A wingless Crane Fly with external genitalia.

Chironomus dilutus

Chironomidae

Identification: Male genitalia of the subgenus Chironomus (Camptochironomus) are distinctive. Dark abdomen, strongly contrastly dark stripes on light brown or greenish thorax. "Usually the coloration and rather strongly produced middle portion of th