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)

Lemnaphila scotlandae

Ephydridae

"Adult L. scotlandae are commonly found on or flying over the surface of floating duckweed thalli. The adults utilize the Lemna for food, leaving characteristic elongate gouges on the surface of the thallus. Adults have been collected in late Novembe

Leopoldius signatus

Conopidae

Whilst superficially resembling Conops species, Leopoldius species can be immediately recognised by their soft proboscis, nothing like the long sclerotised mouthparts found in Conops . There are only two predominantly yellow British species. Males of

Lepidophora lutea

Bombyliidae

Identification: the pale scales are mostly yellow, and there are abundant yellow scales on the sides of the fourth abdominal segment

Leptocera erythrocera

Sphaeroceridae

Identification: The most widespread and often the most common Leptocera in the Americas.

Leptometopa halteralis

Milichiidae

Identification: Shiny black. The other North American species of Leptometopa is comparatively dull.

Leptomorphus magnificus

Mycetophilidae

Identification: "The only extant species of Leptomorphus with R4 that has a completely yellow/orange thorax and abdomen (though abdomen rarely darker on posterior two segments) and foretarsomere I at least 1.5X the length of foretibia."

Leptomorphus subcaeruleus

Mycetophilidae

Identification: "Quite distinct among other species with vein R4 present, body black, legs mostly yellow with femora dark apically and hind tibia yellow basally, antennae completely dark, abdominal tergite 4 sometimes reddish in females." - Dmitry Ga

Leptopa vittata

Scathophagidae

Identification: Wings uninfuscated. Femora without strong ventral bristles. Katepisternum with 1 bristle. Pleura with a black line below the base of the wing. Leaf miner in several genera of orchids.

Leptopsilopa atrimana

Ephydridae

Identification: Small black ephydrids with black front legs that contrast with the yellowish middle and hind legs. Slight infuscation over crossvein dm-cu. Face striate.

Leptotarsus testaceus

Tipulidae

Identification: abdomen greatly elongated in both sexes Uncommon

Leschenaultia bicolor

Tachinidae

Identification: Males are distinguished from other Leschenaultia by lacking median marginal bristles on tergites 1+2 and 3. Females do have median marginals on tergite 3. Gudin and Carneiro (2020) (doi: 10.4039/tce.2020.46 ) write " Leschenaultia bi

Lesser Variegated Snipe Fly

Rhagio punctipennis

Rhagionidae

Identification: Representative Images Classification Kingdom Animalia (Animals) Phylum Arthropoda (Arthropods) Subphylum Hexapoda (Hexapods) Class Insecta (Insects) Order Diptera (Flies) No Taxon (Orthorrhapha) I

Leucophenga maculosa

Drosophilidae

Identification: Differs from the common varia in having a less distinct pattern on the abdomen and more extensive wing markings (crossveins darkened and dark band starting at tip of R1).

Leucophenga varia

Drosophilidae

One of the two common, widespread species of this genus in our area, the other being Leucophenga maculosa .

Leucophora apivora

Anthomyiidae

Identification: Distinguished from other common species of Leucophora by the combination of legs red (including femora), both female and male with widely separated eyes, and flight time in June.

Leucophora johnsoni

Anthomyiidae

Identification: In the eastern United States, the combination of legs partly yellow, a ventral bristle on mid tibia, and female eyes slightly closer together than normal but still separated by about 2/3 their width) will identify this species.

Leucophora marylandica

Anthomyiidae

Kleptoparasites of Colletes . Related to the Palaearctic species Leucophora grisella ( http://www.diptera.info/photogallery.php?photo_id=1957 )

Leucophora obtusa

Anthomyiidae

One of several almost identical species so great care is needed with identification. If detailed examination has not taken place it should be recorded as Leucophora sp. The genus has a characteristically wide parafacial and gena (the area in front of

Leucopis argentata

Chamaemyiidae

Identification: Larvae: Most Leucopis larvae have posterior spiracles on a diverging pair of stalks. That is the typical Leucopis condition. But Leucopis argentata is one of very few where they are not on such stalks (S.Gaimari, pers. comm.).

Leucopis bellula

Chamaemyiidae

Identification: "The spots on tergites 3-5 are distinctive for this species." -- Steve Gaimari

Leucostoma aterrimum

Tachinidae

Identification: Female has unusually long abdomen for genus (segments longer than wide).

Leucostoma perrarum

Tachinidae

Identification: Male with only narrow bands of pollen on last abdominal segments, last segment short and broadly truncate.

Leucozona glaucia

Syrphidae

Winglength 8 to 11.25 mm. The black stigma, yellow scutellum, large quadrate spots on tergite 2 and narrow bands on tergites 3 and 4 serve to readily distinguish this species. The markings on the abdomen are normally yellow, but specimens with grey d

Leucozona laternaria

Syrphidae

The scutellum of this species is black with just the tip yellow and the front and mid legs are extensively black on the tibiae and tarsi. Lowland habitats with lush vegetation, especially woodland edges where umbellifers are present. The larvae feed

Leucozona lucorum

Syrphidae

A striking hoverfly with a white band across the upper abdomen and black wing patches that align with the black abdominal band. In the male, the white band on tergite 2 can often be darker. Both sexes have an obvious yellow-orange scutellum that imme

Leucozona xylotoides

Syrphidae

Identification: Separated from Leucozona (Leucozona) by lack of dark markings on the wing and abdominal bands rather than solid segments and from L. (Ischyrosyrphus) velutina by the much larger pale spots on tergite 2 and geographic distribution.

Liancalus virens

Dolichopodidae

Length 7 or 8 mm. This colourful species is the largest of the dolichopodid or long legged flies in north western Europe. It lives amongst the mosses, liverworts and algae growing under bridges and beside waterfalls and fast running water. Scattered

Limnellia anna

Ephydridae

Identification: Grayish pollinose stripe on ventral margin of face, contrasting with rest of face; wing pattern different than the other eastern species.

Limnellia quadrata

Ephydridae

A very tiny (2 or 3 mm) fly with distinctively patterned wings. This is a member of the Ephydridae or 'shore flies' which are found around seashores and the shores of inland lakes and ponds. Widespread and probably fairly frequent in Britain, but lit

Limnia shannoni

Sciomyzidae

Identification: "One of the few Limnia that can be determined without dissection. The antennae have large brown swelling near the base." -- Bill Murphy

Limnophila munda

Limoniidae

Identification: Shiny black body, wings with dark markings along some veins, femora with black tips.

Limonia canadensis

Geranomyia canadensis

Limoniidae

Identification: Wings unmarked except for stigma, body yellowish brown, thorax with dark marks, legs brownish yellow, femora dark tipped (Alexander, 1943)

Limonia parietina

Limoniidae

Identification: The wingtip is nearly truncated instead of evenly rounded. Page creation based on Chen Young's identification of this image .

Linden Wart Gall Midge

Contarinia verrucicola

Cecidomyiidae

Larvae develop in warty galls on leaves, twigs, and fruit of American and European lindens ( Tilia spp.). Mature larvae exit galls (from the underside, if in leaves) and overwinter in the soil. Adults have not been reared.

Linnaemya comta

Tachinidae

Western specimens tend to be redder than eastern. This supposedly holarctic species may consist of more than one species in North America Tachinidae of Gila National Forest

Linnaemya picta

members so detailed examination is needed.

10-12mm. A large tachinid fly which is a relatively recent addition to the UK fauna. Black and grey patches on the abdomen become orange at the sides. Very similar in appearance to other family members so detailed examination is needed. https://tachi

Liohippelates pallipes

Chloropidae

Identification: Pale yellow legs. Paler specimens are distinctive with the front half of the frons contrasting yellow and the base of abdomen pale, but the frons can be mostly dark and the abdomen entirely dark.

Lipara lucens

Chloropidae

Introduced species from Europe, perhaps not established. Gall maker of the introduced Common Reed ( Phragmites australis ). Enters shoot at the tip and mines down. Causes shortening of the nodes.

Lipochaeta ranica

Ephydridae

Identification: antennae widely separated in deep pits; arista much shorter than the rest of the antenna; body bristles very weak

Lipochaeta slossonae

Ephydridae

Identification: Small antennae widely separated in deep pits, with arista much shorter than rest of antenna. Body with very weak bristles.

Liriomyza amoena

Agromyzidae

The larvae of the fly Liriomyza amoena mine the leaves of Elder, creating a large blotch mine with conspicuous frass. See the National Agromyzidae Recording Scheme webpage for this species for further details of puparium and adult insect. ref.: Warri

Liriomyza arctii

Agromyzidae

Larvae of Liriomyza arctii form narrow, white, linear mines in leaves of burdock ( Arctium minus ), exiting before pupating . Two polyphagous Liriomyza species, L. trifolii and L. huidobrensis , have also been reported from Arctium , but are unlikely

Liriomyza cicerina

Agromyzidae

The fly mines the leaves of Restharrow ( Ononis ), creating a winding mine with the frass in short threads. See the National Agromyzidae Recording Scheme webpage for this species for further details of puparium and adult insect. Liriomyza bryoniae re

Liriomyza galiivora

Agromyzidae

Larvae form linear mines in in Galium boreale and triflorum (and probably other species). The species name means "eater of Galium ." According to Spencer and Steyskal this species is externally indistinguishable from G. vockerothi . It is also found

Liriomyza pisivora

Agromyzidae

The larvae of the fly Liriomyza pisivora mine the leaves species in the pea family, including Garden Pea, Broad-leaved Everlasting-pea and Tufted Vetch. They create a long linear mine which starts on the lower surface of the leaf but then penetrates

Liriomyza puella

Agromyzidae

The larva of the Agromyzid fly Liriomyza puella mines the leaves of Nipplewort. The mine starts as a corridor which then expands into a blotch which is dark with white borders. The blotch mine is initially circular, or slightly elongated, but becomes

Liriomyza sonchi

Agromyzidae

The larvae of the fly Liriomyza sonchi form large upper surface blotch mines on the leaves of sow-thistle species. Secondary feeding corridors are often present. Scattered frass can be seen in the mine. Several larvae may feed together in the mine. S

Liriomyza taraxaci

Agromyzidae

The larvae of the fly Liriomyza taraxaci mine the leaves of Dandelion, Sow-thistle species and Autumn Hawkbit. They form small, irregular, elongated blotch mines with little frass inside. See the National Agromyzidae Recording Scheme webpage for this

Lispe sociabilis

Muscidae

Identification: Male distinguished from other members of the tentaculata group by lack of long spine at the end of the fore basitarsus. Female distinguished by dark legs, details of bristles on hind legs, and range.

Lispe tentaculata

Muscidae

Identification: Male long spine at end of fore basitarsus longer than basitarsus and about half as long as second segment. Female often with pale legs (usually black in related species).

Lispocephala alma

Muscidae

Identification: Distinguished from related species by combination of spots over crossveins, spots on edge of scutellum, and third segment of antennae without red on inside.

Lispocephala erythrocera

Muscidae

Identification: In Central Europe the keys diagnose it as (in Gregor et al., 2016): mid and hind femora predominantly black, postpedicel reddish yellow at base, crossveins not infuscated, mid tibiae without a submedian anterodorsal bristle, all tibia

Litolinga tergisa

Therevidae

Identification: Contrary to what many keys mention, this species can have 0-2 pairs of scutellar bristles.

Little Clusterfly

Pollenia griseotomentosa

Polleniidae

Pollenia griseotomentosa averages as our smallest clusterfly and has proportionately short legs, with the front tarsi only about the length of the front tibiae. The tergites are less conspicuously tessellated than most clusterflies, with a conspicuou

Little Hanging Thief

Diogmites misellus

Asilidae

Identification: Smallest Diogmites . Central stripe on top of thorax shades to red towards front

Little House Fly

Fannia canicularis

Fanniidae

May be a nuisance up to two miles from the breeding site. Males often seek shade indoors, where they may hover in rooms for long periods.

Little Snipe Fly

Chrysopilus asiliformis

Rhagionidae

A relatively small and delicate, grey-dusted snipe fly with rather striking green eyes. It can be found in a variety of habitats including scrub, woodland edge, wetlands and even gardens where it is usually encountered on foliage. The larvae are pres

Liverfluke Snail Predator Fly

Sepedomerus macropus

Sciomyzidae

Identification: porrect (forward-pointing) antennae are standard features in the genera Sepedon, Parasepedon, Sepedonea, Sepedomerus . The extremely long, orange hind femora and tibia with the prominent black band is diagnostic for this unique specie

Locust Blowfly

Stomorhina lunata

Calliphoridae

A distinctive mid-sized blowfly which is sometimes mistaken for a hoverfly or Muscid. It has a three dark stripes on the thorax and a strongly protruding lower face. Tergites 3 and 4 (apparent 2 and 3) have orange patches on the side in males, or gre

Loewia foeda

Tachinidae

Native to Europe, first found in North America on Long Island in 1958. Parasitoid of Lithobius centipedes; one of the very few Tachinidae not to parasitize insects.

Lonchaea tarsata

Lonchaeidae

A small, black, hairy fly with a rather plump body and milky coloured wings. There are other similar species and detailed examination is needed for a safe id. This family is usually associated with woodland, but little seems to be known about the lif

Lonchaea ultima

Lonchaeidae

Lonchaea species are generally of rather uniform appearance, being moderately small flies, with dumpy bodies that are black in colour. Identifiecation to species level requires detailed examination and is often very difficult. Detailed examination of

Lonchoptera bifurcata

Lonchopteridae

3-4mm. Body colour variable, from pale yellow to dark brown. Legs are pale. As with other species in the family, the wings are long and thin giving them their common name of 'Spear-winged Flies'. See ID guidance below for the specific features seen i

Long Hoverfly

Sphaerophoria scripta

Syrphidae

The male is readily identifiable as its body is longer than the wings, though the pattern of black and yellow is variable with a darker form fairly frequent. Females however cannot be readily identified. Found from April to November, peaking in July

Long-horned Black Legionnaire

Beris geniculata

Stratiomyidae

Like all flies in the Beris genus, this species has six spines at the base of the scutellum. B. geniculata has a black, or dark, abdomen and dark legs with yellow 'knees'. There are 6 British species in the Beris genus and these can usually be distin

Longhorn Cactus Fly

Odontoloxozus longicornis

Neriidae

Identification: Brown, face and lower part of head yellow. Eye has two black spots along front, brown stripe behind. Antennae have broad third segment. Legs yellow-brown, femora with spines. Stem of halteres yellow, knobs brown.

Lordotus planus

Bombyliidae

Identification: Seven small wing spots, mostly on the cross veins.

Lordotus pulchrissimus

Bombyliidae

Identification: Outwardly very similar to the closely related L. zona , i.e. in vestiture and antennal proportions. However, both sexes of pulchrissimus have black coxae (Hall, 1954; Hall & Evenhuis, 1982); coxae in zona are yellow. Genitalia also

Lordotus zona

Bombyliidae

Identification: Very similar to the closely related L. pulchrissimus , but coxae in both sexes are yellow, as opposed to black in pulchrissimus . Genitalia also differ (see details in Hall & Evenhuis, 1982) Sexually dimorphous, with males' vestiture

Loxocera collaris

Psilidae

Identification: Wing unmarked. Pedicel (2nd antennal segment) shorter than high. Arista short pubescent. Distinguished from the similar western species L. microps by its longer antennae (first flagellomere about twice as long as the face or more), th

Loxocera cylindrica

Psilidae

Identification: Wing darkened at apex and posterior crossvein. Pedicel (2nd antennal segment) longer than high. Arista with long pubescence:

Loxocera fumipennis

Psilidae

Identification: Wing evenly infuscated. Pedicel longer than high. Arista with short pubescence.

Loxocera ojibwayensis

Psilidae

Identification: Description in Buck & Marshall 2006

Lucilia bufonivora

Calliphoridae

Identification: Very similar to L. silvarum and L. elongata . Previously unreported in North America, this species was absent from calliphorid keys, leading to reports of Anuran myiasis from the previously mentioned species. This species is included

Lucilia caesar

Calliphoridae

This blow fly is bright iridescent green though like all the 'greenbottles' is becomes more bronze with age. It is very similar to other Lucilia species but has just two pairs of acrostichal bristles behind the suture line on the thorax and a dark ba

Lucilia eximia

Calliphoridae

Identification: Two postsutural acrostichals, male frons very narrow (broader in cluvia ), basicosta brown (paler in coeruleiviridis ). "This is one of only 2 species with yellow palps and a dark basicosta. This species has pale, weak setae below and

Lucilia illustris

Calliphoridae

Identification: has black setae on the subcostal sclerite on ventral surface of wing (requires ~50x magnification); all other NA Lucilia spp. have only fine pubescence in that area

Lupine Leaf Gall Midge

Dasineura lupinorum

Cecidomyiidae

Identification: Causes small galls on leaflets of Lupinus species, apparently preferring perennial species (e.g. L. albifrons and L. argenteus ). The gall become reddish over time and contain several larvae.

Lutomyia spurca

Heleomyzidae

Identification: reddish; no anterodorsal bristles on mesotibia, R2+3 touching costa over most of its length, and several ventral spines on male metafemur

Lygistorrhina sanctaecatharinae

Lygistorrhinidae

Identification: Long beak, R2+3 absent, base of vein M missing, body mostly black. Females of several other species in the genus will also match this description; the population from the United States belongs to a single species as far as is known.

Lypha dubia

Tachinidae

Relatively small (4-7mm), this fly has an overall brassy look with a chequered abdomen. The front of the thorax usually has short white stripes. Woodland - often seen on tree trunks and foliage. One generation per year. The larvae parasitise Winter M

Lypha setifacies

Tachinidae

Identification: Male genitalia needed to place to species; usually smaller than other Nearctic Lypha species (except L. parva ); male vertex width 0.20-0.28 of head width; eye height of 0.71-0.78 head height; flagellomere 1 length of 0.36-0.47 head h

Lytogaster excavata

Ephydridae

Identification: "Frontal triangle with lateral orbital margins distinctly and sharply raised" (Clausen, 1982)

Machimus griseus

Asilidae

Identification: Per Eric Fisher, the only Machimus in the U. S. with spotted wings.

Machimus maneei

Asilidae

Identification: Excerpts from Robber Flies of the Southeast: " Machimus maneei occurs in sandy pinewoods throughout the eastern U.S. and Canada though populations appear to be spotty...Compared to other Machimus , this species is relatively easy to i

Machimus sadyates

Asilidae

Identification: "Distinctive in the Northeast by having a combination of the all-black femur, tibia with black anterior but pale posterior, and shiny black last (non-ovipositor) tergite." (Comment by Tristan McKnight)

Macquartia tenebricosa

Tachinidae

6-9mm. Dark green/bronze abdomen and thorax, with a pale collar on the thorax behind the head. Larvae of Macquartia tenebricosa are endoparasities of Chrysolina beetles. Unless identified by a recognised expert, a photo is required and the specimen s

Macrocera formosa

Keroplatidae

Identification: Wings have two apical bands, connected along veins, as well as a median band and basal spot. Abdominal segments blackish apically. Type images at MCZ: https://mczbase.mcz.harvard.edu/MediaSearch.cfm?action=search&media_id=96505,96506,

Macrocera inconcinna

Keroplatidae

Identification: Abdomen without regular bands or spots (irregular dark patches may be present). Tip of R1 swollen. Scutum slightly darker than rest of body. Antennae with base yellow, remainder dark. Wing with central spot but no apical band. Th

Macrodiplosis castaneae

Cecidomyiidae

Causes galls on chestnut ( Castanea ), which develop in spring. In June-July, larvae exit through an elongate opening that develops along the vein on the upper surface of the leaf. Adults have never been reared.

Macrodiplosis majalis

Cecidomyiidae

Literature records list Quercus palustris as a host. BugGuide photos show other species of the red oak section.

Macrodiplosis niveipila

Cecidomyiidae

Forms galls on leaves of white oak ( Quercus alba ) and other oaks: "Amorphous, thin-walled, large fold with white down on inside surface, often deforming leaf." In addition to an illustration of a highly distorted white oak leaf, Gagne illustrates a

Macromya crocata

Tachinidae

The species ranges from extreme southern USA to Brazil, where it was recorded parasitizing Mazaeras conferta (Arctiidae) and Megalopyge lanata (Megalopygidae).

Macronychia dolini

Sarcophagidae

A relatively distinctive Sarcophagid, with a body length of 10 to 12 mm. The abdomen has three triangular marks on each tergite, and is constricted towards its base. The wings extend well beyond the abdomen and have some pale brown shading. The legs

Macrorrhyncha coxalis

Keroplatidae

Though a century old, the key in Johannsen 1910 covers all three species of Asindulum and Macrorrhyncha known to date from North America. His A. flavum is now called A. winnertzi .

Malloewia abdominalis

Chloropidae

Identification: all-white abdomen and shiny black thorax are characteristic for this species. ‒ Terry Wheeler

Mallota albipilis

Syrphidae

Identification: Eyes bare; thorax and scutellum pale yellow pilose; abdomen entirely pale pilose; wing obfuscation restricted to the area around the veins; cell c almost completely bare. Molecular data and morphological differences support splitting

Mallota bautias

Syrphidae

Identification: abdomen black pilose beyond first segment; eyes bare (not pilose as in M. posticata ); Western specimens (i.e. Texas, Kansas, Nebraska, Colorado) usually have T4 yellow pilose. Males show hilltopping behavior: they congregate in open

Mallota diversipennis

Syrphidae

Identification: Eyes bare; thorax and scutellum pale yellow/reddish pilose; abdomen mostly pale pilose, but black pilose medially; wing obfuscation restricted to the area around the veins. Cell c almost completely bare.

Mallota illinoensis

Syrphidae

Identification: Eyes bare; thorax and scutellum pale yellow/reddish pilose; abdomen completely pale pilose; wing obfuscation extensive, not just restricted to the area around the veins. Cell c almost completely bare. Barcode and genitalia differ from