common name: eye gnats, grass flies, eye flies, frit fliesscientific name: Liohippelates spp. (Insecta: Diptera: Chloropidae)

advent - Synonymy - distribution - description - Life cycle - Medical and also Veterinary prominence - management - Selected References

Introduction (Back come Top)

Members that the genus Liohippelates, previously Hippelates, room very tiny true flies and a typical occurrence in lot of North and South America (Sabrosky 1980, Kumm 1935). This non-biting pests are attracted come fluids secreted by the eyes, nose and also ears top top both humans and animals. Some species are attracted to discharge from open wounds and excrement (Goddard 2007). Because of your propensity because that hovering roughly the eyes, this genus has been referred to typically as eye gnats, but are also known together grass flies, eye flies, and frit flies.


Figure 1.

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Lateral see of one adult Liohippelates sp., native a equine farm in north central Florida. Picture by Lyle J. Buss, university of Florida.

Extremely big aggregations the eye gnats are common in locations that have loose sandy soils, specifically in the southerly United States. This high concentrations of flies room a an excellent nuisance come humans and animals in rural towns and also agricultural, recreational and also tourist areas. When they perform not bite, Liohippelates spp. Have actually been implicated in the transmission of several diseases to humans and livestock including person acute conjunctivitis (pink eye). As result of the rise of infection of pink eye and also the palliation in labor efficiency caused by excessive numbers of eye gnats in the Coachella Valley, California, a manage project was initiated through the office of Entomology in the 1920s to focus on the life history and feasible control actions for this pest. Hall (1932) consequently implicated Liohippelates pusio (Loew) as one of the limiting factors in the advance of the Coachella Valley.

The bulk of the paris encountered in the southeastern region of the United says are Liohippelates pusio and also Liohippelates bishoppi (Sabrosky), and also as a an outcome the organic information listed below will focus extensively on these two species.

Synonymy (Back to Top)

Lioppelates pusio was an initial named Hippelates pusio through Loew in 1872, and also Liohippelates bishoppi was explained by Sabrosky together Hippelates bishoppi in 1941. In 1929, Duda defined the genus Liohippelates, which now has the most necessary common species of eye gnats in the southeastern unified States including what was Hippelates pusio and Hippelates bishoppi.

Liohippelates pusio (Loew)

Hippelates pusio Loew, 1872 Hippelates splendens Adams, 1904 Hippelates lituratus Becker, 1912 Liohippelates pusio; Duda

Liohippelates bishoppi (Sabrosky)

Hippelates bishoppi Sabrosky, 1941 Liohippelates bishoppi; Duda

Distribution (Back to Top)

Both Liohippelates spp. And closely associated Hippelates spp. Take place throughout much of north America (Sabrosky 1941) and 270 species have been described (Sabrosky 1987). Bingham (1941) identified during his investigations of Liohippelates in the southeastern U.S. The Liohippelates pusio was the most common pest that this genus. Later on that year, Sabrosky (1941) found and also described a brand-new species, Liohippelates bishoppi, misidentified through Bingham as Liohippelates pusio, which consisted of a moderate portion of the southeastern Liohippelates. Liohippelates bishoppi is discovered from February v September and Liohippelates pusio year round. Liohippelates pusio can be uncovered from Washington to phibìc Dakota, southern to Pennsylvania, and also California south to Mexico and east to the southeastern joined States and also Bermuda (GNI 2010). Liohippelates bishoppi is uncovered from Saskatchewan come Quebec, south to Colorado, Texas and Florida. Various other Liohippelates species found in the southeastern and eastern U.S. Room Liohippelates bicolor (Coquillett) and also Liohippelates pallipes (Loew), whereas Hippelates species found in the same area encompass Hippelates nobilis Loew, Hippelates plebejus Loew, and also Hippelates dorsalis Loew (Sabrosky 1941).

Description (Back come Top)

Adults: Adult Liohippelates are true paris (bearing just two wings) and are an extremely small, roughly 1.5 come 2 mm long, and shiny black color or grayish in shade with clean wings. Some varieties have red or yellowish heads. Legs tend to it is in reddish-yellow come brown through brown bands (Hall 1932).


Figure 2. Lateral watch of an adult Liohippelates, unknown species. Photo by Erika T. Machtinger, university of Florida.

Eggs: The eggs of Liohippelates flies space a pearlescent white and also approximately 0.5 mm long. Lock are half as wide (0.25 mm) as long , the same, similar thing a banana through one side curved and also one nearly straight (Hall 1932). Eggs room deposited below the surface of loosened soils.

Larvae: The larvae flower in seven to 11 days and feed ~ above organic issue (Kahn 2008). The larvae typical 3 mm in length and also are a whitish shade (Hermes and also Burgess 1930). Larvae space pointed in the direction of the anterior end and also rounded towards the posterior. The mouth hook is darker 보다 the remainder of the body and curved tenderness downward.

Pupae: The pupae are approximately 2.25 mm in length, relying on the media in i beg your pardon larvae developed and also grew (Hall 1932), and also a reddish-brown color, transforming darker together they age. Liohippelates pupate in or around sand mixed with organic matter, such as manure, hay and remaining harvested chop debris.


Figure 3. Primary Liohippelates breeding sites in Florida include loose soils with organic matter and also moisture, as is uncovered on numerous livestock infrastructure throughout the state. Picture by Erika T. Machtinger, college of Florida.

Life bike (Back to Top)

Liohippelates spp. Are holometabolous, definition they have actually four unique life stages; egg, larvae, pupa and adult. The life bicycle of Liohippelates can selection from 11 job to 3 months escape on advance conditions such together temperature and also moisture (Hall 1932). Advance from egg emergence to the adult is perfect in about three weeks during the summer in Florida (Bigham 1941) and also multiple generations can occur each year. Reproduction sites are primarily those with freshly disturbed soil combined with organic matter, such as cut grass and hay, and also moisture. Disturbances have the right to be led to by digging, plowing, harrowing, or also by livestock activities (Bigham 1941, Mulla 1962).


Figure 4. Life cycle of Liohippelates species.

Medical and also Veterinary importance (Back to Top)

Liohippelates are not host certain and will certainly feed ~ above the liquid from wounds, eyes, nose, and other locations on humans and livestock and also domestic pets in a variety of situations. When they perform not bite, because of their persistent feeding actions this group of insects is responsible for excessive annoyance come people and animals once they happen in huge numbers. In livestock, it has actually been argued that high number of Liohippelates can cause losses in condition, such together weight, early out to continuous and unrelieved attack (Hinkle et al. 2001).


Figure 5. Congregation of adult Liohippelates spp. Approximately the eye that a horse. Photo by Erika T. Machtinger, university of Florida.

Many types of Liohippelates have been implicated in the mechanical transmission of several diseases and also conditions in humans and also livestock. Mechanical transmission of pathogens causing an illness from Liohippelates to people or livestock occurs once a fly come in call with a pathogen, such as a bacter or virus, and subsequently feeds or rests ~ above a human or animal, transmitting the microorganism from one location to another by contact. As feeding occurs on the blood, mucus, and other fluids approximately natural orifices of mammals, pathogens have the right to be carried easily right into the body.

person acute conjunctivitis, likewise known as "pink eye" or "sore eyes," is led to by one or more bacteria that can be mechanicallytransfer by Liohippelates. Pink eye reasons pain, swelling, changes in vision and also extreme sensitivity to light (MIDEHA 2010). Cases of conjunctivitis have been presented to increase throughout Liohippelates outbreaks (Dow and Hines 1957, Greenberg 1973). In California, hall (1926) correlated pink eye to high populations of Lioppelates flavipes (Loew) .

Liohippelates flavipes and also Liohippelates pallipes have been displayed to mechanically transmit the spirochete Treponema pertenue, the causative agent of yaws, in Jamaica and also parts of south America (Kumm 1935, Kumm and also Turner 1936, Saunders et al. 1936). Yaws is a skin infection that reasons ulceration and, in severe cases, can influence bone and cartilage. Yaws occurs largely in warm and humid areas of the world, including much of southern America, and also primarily affects kids under the age of 15. Yaws is especially usual in bad communities and those in crowded conditions (DNZ 2010).


Figure 6.

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This person has yaws with 8 month-old juxta-articular nodules ~ above the left elbow. Picture by Peter Perine, CDC.

Another type of acute conjunctivitis brought about by the bacter Haemophilus influenzae biotype aegyptius has been connected to a few species the Liohippelates (Tendella et al. 1994). This bacterium has actually been connected to the reason of Brazilian purpuric fever, which causes sepsis in children (Harrison et al. 1989, The Brazilian Purpuric fever Study team 1992). Sepsis is a serious problem caused by incredibly high number of international microbes in the bloodstream that outcomes in hyperactivity that the body"s organic immune response, negatively affecting other body functions. Additionally, Liohippelates is capable of mechanically transmitting streptococcal epidemic to human skin (Francy et al. 1988). While they perform not bite or bloodfeed, Liohippelates possess sponging mouthparts through "spines" which have the potential to reason ocular lesions in pets (Hinkle et al. 2001). Two species of Hippelates found in Florida, Hippelates plebejus and Hippelates nobilis, room larger species with rasping mouthparts qualified of developing a biting sensation once feeding on sensitive skin (Bigham 1941).

Liohippelates has actually been implicated in mechanical infection of pathogens between animals as well. In cattle, Liohippelates deserve to transmit the causative agents the acute bovine mastitis (Sanders 1940) and also vesicular stomatitis (Taplin et al. 1967). Acute bovine mastitis is inflammation the the mammary glands, primarily caused by bacterial infection, which deserve to be exceptionally painful and also compromise milk quality. Mastitis may also cause fatality in extreme situations (Bradley 2002). Treatment for mastitis contains the use of antibiotics, i m sorry has feasible implications in public health and wellness as resistant bacter strains might not answers to therapy (Bradley 2002) and milk from treated cattle cannot be marketed for human consumption until the compelled withholding time has elapsed.

Vesicular stomatitis is a reemerging viral an illness that presents together lesions on the tongue, coronary bands and other body regions of cattle and horses, sheep, goats and pigs (USDA 2007). This disease is remarkably similar in presentation come the deadly foot-and-mouth disease, which was eradicated native the United claims in 1929 (USDA 2007) and infection have the right to transfer to world who take care of infected animals.


Figure 7. Congregation that adult Liohippelates roughly the puncture wound of a horse. Picture by Erika T. Machtinger, university of Florida.

Management (Back to Top)

Currently, over there is no effective area-wide control. Miscellaneous insecticides, fogs, and soil treatments have been tested, however due come the tremendous numbers of flies created in the soil, area-wide treatment is practically impossible. Insecticides used on a community level because that mosquito manage may minimize attack, but breakthrough sites easily repopulate together the insecticide dissipates (Kahn 2008).

physics barriers, such as screened porches and also windows top top houses and fly masks or fly sheets (which resemble a fine cloth mesh, mostly impenetrable by even the the smallest pests) on breed cub , can carry out some relief native annoyance and also protection from possible microorganism transmission. Sanitation techniques to get rid of potential reproduction sites, such as reducing manure and organic issue in soil and reducing loose soil matter, might reduce breeding at the location. However, regularly reducing Liohippelates and Hippelates reproduction sites is nearly impossible in livestock framework as manure, moisture and soil disturbance space inseparable native animals.

Repellents containing diethyl toluamide (DEET) carry out temporary security from eye gnats (Hall and also Gerhardt 2009), and many commercial livestock insecticides the contain pyrethrins, piperonyl butoxide or other typical ingredients may provide some relief to animals.

Florida Insect Management overview for outside parasites around pet facilities Florida Insect Management guide for filth-breeding flies

Selected recommendations (Back to Top)

Bigham JT. 1941. Hippelates (eye gnats) investigate in the southeastern states. Journal of financial Entomology 34: 439-444. (BPFSG) The Brazilian Purpuric Fever examine Group. 1992. Brazilian purpuric fever established in a brand-new region of Brazil. Newspaper of Infectious condition 163: 516-519. Bradley A. 2002. Bovine mastitis: one evolving disease. The Veterinary journal 164: 116-128. (DNZ) DermNet NZ. (January 2010). Yaws. DermNet NZ: the dermatology resource. Http:// (28 February 2011). Dow RP, Hines JD. 1957. Conjunctivitis in southwest Georgia. Public Heath Reports 72: 441-448. Dow RP, Bigham JT, Sabrosky CW. 1951. Sequel come "Hippelates (eye gnat) investigate in the southeastern states" by man T. Bigham. Proceedings the the Entomological culture of Washington 53: 263-271. Francy DB, Moore LG, smith GC, Jakob WL, Taylor SA, Calisher CH. 1988. Epizootic vesicular stomatitis in Colorado, 1982: Isolation of virus from insects gathered along the northern Colorado Rocky hill Front Range. Journal of clinical Entomology 25: 343-347. (GNI) worldwide Names Index. (2010). An international Names index - index of scientific Names. Http:// (28 February 2011). Goddard J. 2007. Non-biting Flies. Pp. 191-200. In Physicians guide to Arthropods of clinical Importance, 5th edition. CRC Press, Boca Raton, FL. 480 pp. Greenberg B. 1973. Flies and also Disease. Vol. 2. Biological and condition Transmission. Princeton college Press, Princeton, NJ. 856 pp. hall RD, Gerhardt RR. 2009. Paris (Diptera). In Mullen Gr, Durden LA (editors), Medical and also Veterinary Entomology, second Edition. Elsevier, Burlington, MA. 637 pp. hall Jr. DG. 1932. Some researches on the breeding media, development, and also stages the the eye he knows Hippelates pusio Loew (Diptera: Chloropidae). American newspaper of public health 16: 854-864. Harrison IH, Da Silva GA, Pitman M, Fleming DW, Vranjac A, Broome CV. 1989. Epidemiology and clinical spectrum of Brazilian purpuric fever. Newspaper of Clinical Microbiology 27: 599-604. Herms WB, Burgess, RW. 1930. A description of the immature stages of Hippelates pusio Loew and also a brief account of its life history. Journal of economic Entomology 23: 600-603. Hinkle NC, Scholl PJ, Mock DE and Warner WB. 2001. Research and extension needs for incorporated pest monitoring for arthropods of vet importance. Pp. 261-262. In Geden CJ, Hogsette JA (editors), Proceedings of a workshop in Lincoln, Nebraska. 2nd Edition. 328 pp. (ITIS) (2010). Liohippelates. Integrated Taxanomic details System. Http:// (28 February 2011). Kahn C (ed.). (2008). Eye gnats. The Merck veterinary Manual. Http:// (28 February 2011). Kumm HW. 1935. The herbal infection of Hippelates pallipes Loew v the spirochete of yaws. Royal culture of tropical Medicine and Hygiene 29: 265-272. Kumm HW, Turner TB. 1936. The infection of yaws from guy to rabbit by pest vector, Hippelates pallipes Loew. American journal of Tropical medication 16: 1-16 Looper M, Stokes SR, Waldner DN, and also Jordan ER. (2001). Feeding rubbish milk to dairy calves. New Mexico State college College the Agricultural, Consumer and Environmental Sciences. Http:// (28 February 2011). (MIDEHA) Infectious disease and ecological Health Administration. (2010). Conjunctivitis ("Pink Eye"). Maryland department of health and wellness & mental Hygiene. Http:// (05 might 2011). Mulla MS. 1962. The breeding niches that Hippelates gnats. Annals the the Entomological society of America 55: 389-393. Sabrosky CW. 1941. The Hippelates flies or eye gnats: preliminary notes. Canadian Entomologist 73: 23-27. Sabrosky CW. 1987. Chloropidae. Pp. 1049-1067. In McAlpine JF, et al. (editors), hand-operated of Nearctic. Diptera. Volume 2. Research study Branch Agriculture. Canada Monograph 28: 675-1332. Sanders DA. 1940. Hippelates flies as vectors the bovine mastitis (preliminary report). Journal of the American Veterinary clinical Association 97: 306-308. Saunders GM, Kumm HW, Rerrie JI. 1936. The partnership of certain environmental components to the circulation of yaws in Jamaica. American newspaper of toilet 23: 558-579. Taplin D, Zaias N, Rebell G. 1967. Infection by Hippelates flies. Lancet 2: 472. Tondella MLC, Paganelli CH, Bortoloho IM, Tankano OA, Trino K and also Brandileone MCC. 1994. Isolamento de Harmophilus aegyptius associado a febre purpurica Brasileira de cloropideos (Diptera) dos generosity Hippelates e Liohippelates. Revista execute Instituto de Medicina dry de São Paulo 36: 105-109. (USDA) United claims Department that Agriculture. (March 2007). Information around vesicular stomatitis because that the beef producer. Http:// (06 may 2011).