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)

Exoprosopa pueblensis

Bombyliidae

In AZ, it has a faint banding to the wing, whereas in central Mexico (thus the name 'pueblensis'), the bands are dark chocolate brown. It is common in Madera Canyon (Andy Calderwood).

Exoprosopa rostrifera

Bombyliidae

Identification: It has by far the longest bill of any US Exoprosopa . The white belt on a uniformly brown-patterned abdomen is characteristic, too. (Comment by Andy Calderwood) Author of the species Jaennicke, 1867

Exorista larvarum

Tachinidae

A European species introduced into New England and now widespread in Canada as well. The key to central European Tachinidae lists habitat, habits, and hosts: "Open countryside, thin deciduous woodland, orchards, Pine forest. Mid May to End September,

Exorista rustica

Tachinidae

This tachinid fly has the characteristic hairy abdomen, and a wide, black, central dorsal line. They are often seen sunning themselves or scurrying around on foliage, hunting for their hosts. The adult flies from late June to late September. It is pa

Face Fly

Musca autumnalis

Muscidae

Averaging about 7 - 8 mm long with 4 dark stripes on the thorax. The male has an orange and black patterned abdomen whereas in the female this is a grey pattern. This species gets its common name from its habit of landing on the faces of cattle where

False Peacock Fly

Chaetorellia succinea

Tephritidae

Introduced from Europe in 1996 or earlier, accidentally. Its introduction to combat yellow star thistle was considered and rejected because it posed a threat to safflower. ( Balciunas et al. 2001 )

Fannia brevipalpis

Fanniidae

Identification: One of several species with reduced palps.

Fannia difficilis

Fanniidae

Identification: Hairs on the propleuron, relatively long and fine posteroventral hairs on the hind femur, abdomen basally orange and apically dark brown/black, legs usually completely black, no stripes on the thorax.

Fannia fuscula

Fanniidae

Identification: Dark species, with reddish/yellowish tibia and slightly orange wings. Female with 8th abdominal sternite bulging and shiny (usually requires dissection to see,) male with strong ventral spines on the sternopleura and mid coxae, frons

Fannia pellucida

Fanniidae

Identification: The female has a narrow frons and yellow abdomen.

Fannia scalaris

Fanniidae

This species has been implicated in several kinds of myiasis.

Fannia sociella

Fanniidae

Identification: "This species is easily recognized from all related forms by the three strong, median, anteroventral mid-femoral bristles, and the dark, blue-grey-pollinose abdomen." "The adults have been found associated with aphid-infested plants."

Ferdinandea buccata

Syrphidae

Identification: black terminal bands on the first few abdominal terga ( F. croesus has no black terminal borders and is supposed to have arista all black)

Fiery Chiselmouth

Andrenosoma igneum

Asilidae

Identification: Similar to A. fulvicaudum except the postpedicel (first flagellomere) is red and the male genitalia are different.

Forcipomyia bipunctata

Ceratopogonidae

Identification: A brown species with rows of scales on mid and hind tibiae of female (in addition to long hairs) but not on fore tibiae. Wing with contrasting pale spots.

Forcipomyia bystraki

Ceratopogonidae

"Large species with pale yellow legs, distal 1/2 of hind femur and narrow band on distal portion of hind tibia brown."

Forcipomyia fuliginosa

Ceratopogonidae

Identification: The only known North American Ceratopogonidae parasitic on caterpillars.

Forcipomyia macswaini

Ceratopogonidae

Identification: The only species in western North America with six pale marginal wing spots (two of them large).

Forcipomyia pictoni

Ceratopogonidae

Identification: Thorax black on top and white on the sides. Legs mostly pale, with narrow black bands near tips of mid and hind femora and black spots on tibiae. Not a predatory species. In the tropics this species pollinates cocoa (as do many smal

Forcipomyia pluvialis

Ceratopogonidae

Identification: A small, pale species with two dark spots on the wing, occasionally with additional small spots at the ends of veins, sides of scutellum spotted, legs brown or yellow with brown apices of segments.

Four-barred Major

Oxycera rara

Stratiomyidae

Body length 7mm. This is a beautiful little yellow and black soldier fly, and although small it is one of the largest of the eleven species in the genus. This species differs in being entirely black on the second tergite. Unless identified by a recog

Four-lined Hornet Fly

Spilomyia sayi

Syrphidae

Four-lined Hornet Fly (Spilomyia sayi) is a species in the family Syrphidae, commonly known as hover flies, belonging to the order Diptera (Flies). It is classified within the subfamily Eristalinae, tribe Milesiini, superfamily Platypezoidea. This sp

Fox Maggot

Wohlfahrtia vigil

Sarcophagidae

Identification: The western form is distinctive with its tan abdomen with three rows of dark spots. In the eastern form the dark spots are much larger and blend together, leaving four rows of pale spots. Larvae cause myiasis in young mammals, develo

Freraea montana

Tachinidae

Identification: Once identified as Tachinidae, it is very distinctive with the gradually convergent R4+5 and M veins, nearly bare body, and dark, shining color with dark wings. It was previously placed in subfamily Phasiinae with other bare species,

Friendly Fly

Sarcophaga aldrichi

Sarcophagidae

Identification: Similar to house flies but larger. Appear in large numbers when tent caterpillars ( Malacosoma spp. and spongy moths Lymantria dispar ) are abundant. They help control tent caterpillar populations. They are called friendly flies becau

Fucellia tergina

Anthomyiidae

Identification: Separated from F. maritima by the narrower genae (allegedly 0.5-0.65 times eye height compared to 0.6-0.7 times) and the absence of setulae between the presutural two rows and pairs of acrostichal setae. In males, the ventral femoral

Fucellia thinobia

Anthomyiidae

Identification: Presutural acrostichals with setulae in between, prealar absent. Scutellum dorsally largely setulose. Wings subinfuscated.

Gallinipper

Psorophora ciliata

Culicidae

Identification: Florida Medical Entomology Lab - FMEL Adult: Very large mosquito, integument yellowish-brown, apices of tibiae and femora and some tarsomeres with broad, erect, black scales. Scutum with median stripe of golden-yellow scales, submedia

Gastrolepta anthracina

Tachinidae

Body length 6 to 8.5 mm. Overall appearance is of a very smart, slim, black and white fly. The thorax is black with two white 'shoulder' stripes and the abdomen is black with white, or greyish-white bands at the start of each tergite. In this species

Gastrops nebulosus

Ephydridae

Identification: The only Gastrops in the USA with dark wing spots.

Gaurax dorsalis

Chloropidae

Identification: Halteres yellow, scutellum black, thorax with large black mark with three teeth on posterior margin.

Geminaria canalis

Bombyliidae

Identification: Wing with 9―14 more or less isolated brown spots

Geminaria pellucida

Bombyliidae

Identification: Wing hyaline or with faint coloring around r-m and posterior crossveins. (Key to Nearctic Species of Geminaria , by Hall & Evenhuis, see reference below).

Genea texensis

Tachinidae

Identification: Palps long, proboscis not long, arista nearly bare, abdomen with small black spots. Male with broad frons, proclinate orbital bristles, and short claws on fore legs. DNA barcoding suggests Genea texensis is a species complex.

Geomyza apicalis

Opomyzidae

Identification: Propleuron without strong bristles, apical wing cloud covering apex of M1+2, thorax brownish (at least partly), posterior crossvein longer than anterior crossvein, wings very narrow and pointed at the tip.

Geomyza balachowskyi

Opomyzidae

This fly is a member of a confusing species group, but the species with which it has been confused are not found in North America.

Geomyza combinata agg.

Opomyzidae

Only two species in the combinata group are currently found in Britain – they are Geomyza balachowskyi and G. hackmani . Separation of these two species on male genitalia is extremely difficult, and females cannot be separated. For this reason we hav

Geomyza tripunctata

Opomyzidae

A small fly with very distinctive patterning on the wings, though this is similar to other Geomyza species. The abdomen colour is varied, from red-brown to black. Peaking in summer, but may be seen in most months of the year. Larvae tunnel in the ste

Geranomyia rostrata

Limoniidae

Identification: The wing pattern, with 4-5 conspicuous costal marks, tibiae with darkened tips, and fore tibiae with tips expanded or swollen, will separate this species from all Nearctic congeners and closely allied Neotropical species. These close

Giant Crane Fly

Tipula abdominalis

Tipulidae

Identification: Large size coupled with black velvety patches on thorax is diagnostic feature for subgenus Nippotipula . Tipula abdominalis has a spot at the end of vein R1+2 and pale rings near tips of femora. Wing venation:

Glade Sandpirate

Lasiopogon currani

Asilidae

Identification: Many have reddish tarsi, tibiae and genitalia and the third antennal segment is often reddish, too. The giveaway here (if you can see it) is that the top surface of the halter is completely black. This is the only Lasiopogon in the re

Glyptotendipes barbipes

Chironomidae

Identification: Second segment of fore tarsus shorter than third (male) or equal (female). Fore tarsus of male with long, dense beard.

Glyptotendipes testaceus

Chironomidae

Identification: Fore legs much darker than other legs; scar on tergite 6 about 0.7 as long as tergite.

Gnadochaeta nigrifrons

Tachinidae

Identification: See notes on images, such as this one: Eyes usually thickly pubescent in the male, median marginal setae present on the first visible abdominal segment in males, also present in the second visible abdominal segment in both sexes. Prof

Gnophomyia tristissima

Limoniidae

Identification: body black with bright yellow halteres Page creation based on Chen Young's identification of this image .

Goeldichironomus amazonicus

Chironomidae

Identification: Males have their genitalia twisted about 180° to the right or left and have very short middle and hind tarsomeres.

Goeldichironomus carus

Chironomidae

Identification: The three black marks on the side of the thorax are distinctive. Has been described as a nuisance species in Florida due to mass emergence.

Golden Club-legged Hammertail

Efferia armata

Asilidae

Identification: Modified hind tibia of male is distinctive.

Golden Tiger Fly

Ceraturgus aurulentus

Asilidae

Identification: distinctive species, readily recognized by its small size, rich golden pollen, bicolored femora and tibiae, and short, thin, parallel-sided proboscis Rare species: fewer than two dozen specimens collected in the past 200 years. BugGui

Goldenrod Bunch Gall

Rhopalomyia solidaginis

Cecidomyiidae

Identification: Eastman states some other flies do make similar galls. Gall is relatively distinctive--see photo. The female deposits an egg at the tip of the growing plant. Its larva secretes a chemical that prevents the goldenrod stem from growing

Goldenrod Gall Fly

Eurosta solidaginis

Tephritidae

Identification: Galls distinctive Some parasitoids listed at ( 3 )

Gonia brevipulvilli

Tachinidae

Identification: First flagellomere dark beneath the dull colored bloom

Gonia picea

Tachinidae

A large (10mm), dumpy tachinid fly and typically hairy. The dark abdomen has pale stripes across each segment. Larva parasitise lepidoptera caterpillars particularly those of the Antler Moth.

Gonia sagax

Tachinidae

Identification: The antennae are noticeably yellowish in color. Species with dark antennae such as G. frontosa can be confused as having pale antennae due to the white brownish dusting. Sharing with G. frontosa a short proboscis and more hair-like an

Gonia senilis

Tachinidae

Gonia senilis and sagax are very similar, both having bright yellow antennae. Senilis is a summer species and has some orange on the arista. Sagax is a spring species with a dark arista.

Goniglossum wiedemanni

Tephritidae

A distinctively marked member of the genus. Identification is made easier if the insect is recorded in the vicinity of its host plant White Bryony. This species is host specific on White Bryony and is most likely to be encountered where that plant is

Goniocera io

Tachinidae

Identification: Distinguished from other North American Siphononi by the row of anterodorsal bristles on mid tibia (one or sometimes none in other genera). Also the scutellum is nearly bare dorsally (with many setulae in most Siphonini), femora are

Gonomyia alexanderi

Limoniidae

Identification: Only two branches of Rs reaching wing margin (R3 and R4 fused), tibiae contrasting white, costal margin of wing white (not yellow).

Gonomyia helophila

Limoniidae

Identification: Distinguished from most other Gonomyia by color pattern, especially dark fore femora and white fore tibiae. There are a few other similarly colored species in or near North America:

Gonomyia hoogstraali

Limoniidae

Identification: The basistyle continues as a thin, curved projection far beyond the attachment of the dististyles.

Gonomyia pleuralis

Limoniidae

Identification: Veins R3 and R4 fused to wing margin. Legs without contrasting markings except for dark ring near tip of each femur. Stigma conspicuous.

Gonomyia puer

Limoniidae

Identification: Veins R3 and R4 fused to wing margin. Dististyles with asymmetric long black curved hooks. Thorax with contrasting yellow stripe on side. Stigma lacking, legs without contrasting markings.

Gooseberry gall midge

Rhopalomyia grossulariae

Cecidomyiidae

Identification: Length of head + body of adult, 1.8-2.0mm. Head and thorax brown, abdomen with marked reddish tinge (apparently a common color pattern within this genus). Structural characters as for the genus (Rübsaamen 1892) ( 3 ) . Felt (1911)

Graphomya maculata

Muscidae

The males have an orangey-brown patterned abdomen but females have a grey/black pattern. Both have distinctive stripes on the thorax. Meadows, hedgerows and roadside verges nectaring on various flowers, especially umbellifers. The larvae are predator

Great Lakes Sandpirate

Lasiopogon tetragrammus

Asilidae

Identification: four apparent scutal stripes, half light/half dark tergite tomentum, and bluntish ovipositor shape ( comment by Tristan McKnight)

Green Gem

Microchrysa flavicornis

Stratiomyidae

Length 3 to 5 mm. This is a small soldier fly usually has a brilliant green abdomen and thorax with mainly yellow antennae. M. polita - abdomen darker (blackish green) and all-black antennae. Unless identified by a recognised expert, a photo is requi

Green Jewel Fly

Ornidia obesa

Syrphidae

Identification: Body shiny, metallic, green or purplish-blue. Wings mostly hyaline, but with two spots along anterior margin: one near middle, the other smaller and before the apex. Scutellum with a shallow transverse depression before posterior edge

Greenhead

Tabanus nigrovittatus

Tabanidae

Identification: "Brilliant green eyes with a single purple stripe and a restriction to Atlantic salt-marshes makes this species readily identifiable." common on East Coast salt marshes, "The bane of bathers" With known pathogenic transmission of Anap

Grey Flesh fly

Sarcophaga bullata

Sarcophagidae

Pupae are available to buy from biological supply houses such as Ward's Science as hosts for the parasitoid wasp Nasonia .

Grey S-veined Snail-killer.

Elgiva cucularia

Sciomyzidae

One of two British Elgiva species, which are medium-sized, slimly-built sciomyzids with a strongly curved posterior cross vein and wings bearing several spots and smudges (notably a spot on each cross vein plus the end of vein R2+3). Elgiva cucularia

Gymnocheta viridis

Tachinidae

Length 6 to 12 mm. Gymnocheta viridis is a metallic green tachinid fly, its brassy abdomen and thorax are covered by stiff bristly hairs. Gymnocheta viridis is very similar to Chrysosomopsis aurata but this species flies in the summer so can be large

Gymnochiromyia concolor

Chyromyidae

Identification: 2‒3 pairs of dorsocentrals; mesotarsi all yellow

Gymnochiromyia flavella

Chyromyidae

Identification: Distinguished from congeners by small size and four pairs of dorsocentrals.

Gymnochiromyia nigrimana

Chyromyidae

Identification: 2-3 pairs of dorsocentrals and mid tarsi with apical segment black (males) or brown (females).

Gymnoclytia dubia

Tachinidae

Identification: The combination of cell r5 long petiolate and antennae long and completely black will distinguish this from the other species north of Mexico.

Gymnoclytia immaculata

Tachinidae

The female is occasionally entirely black, especially in the north, more often with some red on the abdomen. The male abdomen is orange or orange with a dark median line.

Gymnoclytia occidentalis

Tachinidae

Identification: Like Gymnoclytia occidua , but yellower. Keep in mind that males are generally yellower than females in this genus, so compare like sexes.

Gymnoclytia occidua

Tachinidae

In the last revision of this group Brooks (1946) recognized two eastern species with dark females and red males and M ending near tip of R4+5, minuta and occidua . There may be additional species based on photos on boldsystems.org.

Gymnomus caesius

Heleomyzidae

Detailed examination is necessary to identify to species level. No additional images available for this species.

Gymnopternus exilis

Dolichopodidae

Identification: Antennae long, femora yellow except usually with a prominent dark spot at the tip of the hind femur. If the spot is absent, distinguishable from subulatus by the shorter antenna with more basal arista and from opacus by male genitali

Gymnopternus nigribarbus

Dolichopodidae

Identification: The male has a long arista with a large, swollen tip of the kind often found in Tachytrechus .

Gymnopternus opacus

Dolichopodidae

Identification: Legs entirely pale, except some dark on coxae; antennae large, dark with some reddish marks. See Robinson and Loew for additional details.

Gymnopternus scotias

Dolichopodidae

Identification: Dark femora; dark, shining green thorax; antennae black, male with third segment longer than wide, slightly pointed, with long hairs.

Gymnopternus subulatus

Dolichopodidae

Identification: Long, pointed third segment of antenna ("subulate") with arista nearly apical. Femora yellow.

Gymnosoma par

Tachinidae

This is a variable species. Pale individuals can be similar to fuliginosum and dark individuals to canadense .

Haematobosca stimulans

Muscidae

Around cattle on which they feed, and in farm buildings such as milking parlours etc. April to October peaking in May and August. This fly is associated with cattle where it can be a nuisance by biting the animals to feed on their blood.

Haematopota rara

Tabanidae

Identification: The dark halter knob, darker wing pattern, and range (northeastern USA and extreme southeastern Canada) distinguish this species from americana . The rare champlaini is also paler, but might overlap in range.

Haigia nevadana

Ulidiidae

Identification: An unusual, but not unique, character is the approximation of the r-m and m-cu crossveins.

Hairy Maggot Blow Fly

Chrysomya rufifacies

Calliphoridae

Identification: The fleshy tubercles on these larvae are unique among maggots found on carrion in the US. The only species they might be confused with is Chrysomya albiceps which has not yet been recorded as far north as the US. For adults, the prese

Hairy-Legged Horsefly

Hybomitra bimaculata

Tabanidae

A medium-large, highly variable horsefly with a body length of 13 to 16.5 mm. Both males and females possess long hair fringes on the anterior and posterior surfaces of the mid tibiae with males also having a posteroventral fringe along the length of

Hairy-horned Bromeliad Fly

Copestylum caudatum

Syrphidae

Identification: the dense silvery hairs on tergite 4 are distinctive --comment by Joel Kits and/or Jeff Skevington

Halloween Goldenrobber

Callinicus pictitarsis

Asilidae

one of several spp. of this genus in Calif. Sort of a generalized vespid wasp mimic. --Eric Fisher, 16.vi.2007

Hamatabanus carolinensis

Tabanidae

Identification: Basal portion of third antennal segment with a prominent, forward projecting tooth reaching nearly to base of annulate portion. Eyes pilose. Brownish species. Stump vein on R4 absent. Eyes in life green with a narrow, diagonal purple

Hamatabanus exilipalpis

Tabanidae

Identification: Dr. John Burger commented on this species (20 April 2007): Moved from Tabanus with some hesitation based on 1 - dorsal tooth of basal flagellomere (of antenna) is pronounced and has a slightly forward projection, although quite short.

Haplusia rubra

Cecidomyiidae

Identification: adult body pale; legs banded black and white

Harvey's Pond Fly

Sericomyia harveyi

Syrphidae

Identification: Dense yellow setae on first three quarters of scutum, scutellum is black setose.

Hebecnema nigra

Muscidae

Identification: Per Pont (1984), when using Huckett's 1965 key, his H. vespertina should be H. nigra and his H. affinis should be H. vespertina

Helcomyza mirabilis

Helcomyzidae

Identification: Distinguished from other nearctic Dryomyzidae (s. lat.) by combination of spotted wing and antennae separated by more than the diameter of one antenna. Also grayish compared to orange color of most species.

Heleomyza serrata

Heleomyzidae

Identification: The combination of the katepisternum with only 1 or 2 strong bristles, the mesopleuron bare except for a patch of hairs near the propleuron, and unmarked wings is diagnostic for this species.

Helicobia rapax

Sarcophagidae

Larvae are usually parasitoids of land snails, but can develop in other invertebrates, living or dead.