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Chrysops

Chrysops is a genus of flies belonging to the family Tabanidae in the order Diptera, commonly known as deer flies, with approximately 300 species worldwide.^[1] These insects are characterized by their small size, typically measuring 7–10 mm in length, with bodies ranging from yellow to black, striped abdomens, and wings featuring distinctive dark bands or patches on a clear background.^[2]^[3] Adult Chrysops flies exhibit sexual dimorphism, with males having holoptic (contiguous) eyes and females dichoptic (widely separated) eyes; females are the primary blood-feeders, using blade-like mouthparts to slash skin and lap up blood from hosts such as mammals, birds, and occasionally reptiles, while males subsist on nectar and pollen.^[2]^[4] The life cycle involves complete metamorphosis, with eggs laid in compact masses of 100–800 on vegetation overhanging aquatic or semi-aquatic habitats; larvae are predaceous or scavenging, developing in moist environments like marshes and streams, overwintering, and pupating in spring or summer to emerge as adults that live 30–60 days.^[2]^[4]^[3] Distributed globally except in extreme regions like Hawaii, Greenland, and Iceland, Chrysops species thrive in areas with high moisture, such as woodlands, wetlands, and near livestock, where they peak in activity during daylight hours, particularly at sunrise and late afternoon.^[2] Their bites cause painful welts and irritation in humans and significant blood loss in livestock, leading to reduced weight gain and economic impacts estimated at millions annually in affected regions.^[3]^[2] Medically, certain species, notably C. silacea and C. dimidiata, serve as vectors for the filarial nematode Loa loa, causing loiasis in humans in West and Central Africa, while others transmit tularemia (deer fly fever) in parts of North America.^[5]^[4]

Taxonomy and classification

Etymology and history

The genus name Chrysops derives from the Ancient Greek words chrysos (χρυσός), meaning "gold," and ops (ὤψ), meaning "eye" or "face," alluding to the iridescent golden appearance of the compound eyes in adult flies.^[6] This etymology reflects a prominent morphological feature that distinguishes many species within the genus, particularly the metallic sheen observed in freshly emerged specimens.^[7] The genus Chrysops was formally established by the German entomologist Johann Wilhelm Meigen in 1803, marking the initial separation of deer flies from the broader Tabanus complex within the family Tabanidae.^[8] Prior to this, species now assigned to Chrysops had been classified under Tabanus Linnaeus, 1758, leading to early taxonomic confusion due to overlapping traits such as wing venation and body size; Meigen differentiated Chrysops primarily based on the presence of spurs on the hind tibiae and distinct eye patterns.^[9] Meigen's description, published in Illiger's Magazin für Insektenkunde, included Tabanus caecutiens Linnaeus, 1758 (now Chrysops caecutiens) as the type species by monotypy, solidifying the genus's validity amid ongoing debates in Dipteran systematics.^[10] Throughout the early 19th century, European entomologists expanded descriptions of Chrysops species, building on Meigen's foundation with regional faunal studies; for instance, Macquart's 1823–1838 works in Suite à Buffon and Schiner's 1862–1864 contributions in the Fauna Austriaca detailed additional Palearctic taxa, resolving some misidentifications from Linnaean times.^[11] By the mid-19th century, the genus's boundaries were further clarified through comparisons with related Tabanidae, emphasizing banded wings and slender antennae as key delimiters from bulkier Tabanus species. In the 20th century, North American taxonomy advanced significantly through the revisions of Cornelius B. Philip, whose 1955 paper provided comprehensive keys and synonymies for over 80 Nearctic Chrysops species, addressing historical lumping with Tabanus and incorporating distributional data from across the continent.^[12] Philip's later works refined genus delineation by integrating larval morphology and ecological notes, reducing earlier confusions in transatlantic comparisons.

Phylogenetic position

The genus Chrysops is classified within the kingdom Animalia, phylum Arthropoda, class Insecta, order Diptera, family Tabanidae, subfamily Chrysopsinae, tribe Chrysopsini.^[13] This placement reflects its position among the brachyceran flies, where Tabanidae encompasses blood-feeding species commonly known as horse flies and deer flies.^[14] Phylogenetically, Chrysops belongs to the tribe Chrysopsini, which includes sister genera such as Silvius and Neochrysops, with Silvius often positioned as paraphyletic and closely related to Chrysops in molecular analyses.^[15] Within Chrysopsini, Chrysops occupies a basal position supported by both morphological characters, such as antennal structure and wing venation, and molecular data from mitochondrial and nuclear genes, which resolve the tribe as monophyletic but the broader subfamily Chrysopsinae as potentially paraphyletic.^[16] Key synapomorphies defining the genus include distinctly banded wings and intricately patterned compound eyes, which distinguish it from other tabanid genera.^[17] Recent molecular studies since 2000, employing datasets like COI mitochondrial barcodes and multi-gene nuclear sequences (e.g., CAD, 28S), have robustly confirmed the monophyly of Chrysops with high posterior probabilities (PP > 0.95).^[18] These analyses, including Bayesian relaxed-clock methods calibrated with fossils, estimate the divergence of Chrysops lineages from other horse fly groups around 60-70 million years ago during the late Paleocene, aligning with the radiation of Tabanidae following the Cretaceous-Paleogene boundary.^[16] Recent genomic resources, such as the chromosome-level genome assembly of C. caecutiens published in 2025, further support these phylogenetic inferences.^[19]

Physical description

Adult morphology

Adult Chrysops flies, commonly known as deer flies, are medium-sized insects with body lengths ranging from 7 to 10 mm, making them larger than common houseflies but smaller than many horse flies in the Tabanidae family.^[2]^[20] Their bodies are generally slender and robust, covered in fine hairs, with a patterned abdomen that often features longitudinal stripes in black, yellow, or brown tones for species identification.^[21]^[11] The antennae are short and three-segmented, with the third segment tapering to a point, distinguishing them from the longer antennae of related tabanids.^[21]^[2] The compound eyes are a prominent diagnostic feature, appearing large and brightly colored with iridescent patterns, typically in shades of golden, green, or blue that fade upon death.^[20]^[22] In males, the eyes are holoptic, meeting along the dorsal midline of the head, while in females they are dichoptic with a separation by the frons; this arrangement aids in distinguishing sexes.^[11]^[23] The wings are clear and membranous, marked by distinct dark bands or spots, particularly on the anterior margin, with venation patterns featuring a characteristic fork in the fourth longitudinal vein (R4+5) that is key to genus identification.^[24]^[11] Sexual dimorphism is evident in both eye configuration and mouthparts. Females possess more robust, scissor-like mandibles and maxillae adapted for slicing skin during blood-feeding, forming a cross-shaped incision, whereas males have reduced mouthparts suited for nectar consumption.^[25]^[26] This contrasts with larval forms, which lack such specialized adult structures and instead exhibit elongated, aquatic-adapted bodies.^[11]

Larval characteristics

The larvae of Chrysops species are elongated and cylindrical in shape, typically measuring 10 to 25 mm in length at maturity, with a creamy white or whitish coloration that may include dark bands or pubescent markings around the body segments.^[2]^[21]^[27] They possess a small, pointed, sclerotized head capsule and a legless body tapered at both ends, adapted for life in moist, sediment-rich environments.^[2]^[21] These larvae exhibit key adaptations for an aquatic or semi-aquatic lifestyle, including creeping welts—low ridges encircling the abdominal segments—that facilitate inching movement through mud or waterlogged substrates.^[21]^[28] A prominent posterior breathing siphon allows for respiration at the water's surface while the body remains submerged in organic-rich mud or shallow water, classifying them as hydrobionts.^[2] Their mouthparts feature chewing mandibles adapted for tearing and ingesting organic detritus, decaying vegetation, or occasionally small invertebrates.^[20] Development proceeds through 6 to 8 instars, spanning a few months to one year or more depending on environmental conditions such as temperature and moisture, with later instars showing increased size and tolerance to drier margins of habitats.^[2]^[24]^[29] Upon maturation, larvae migrate to drier soil to form an exarate pupa, characterized by free appendages and dorsal respiratory horns on the prothorax for gas exchange; this stage lasts 1 to 2 weeks before adult emergence.^[30]^[21]^[31]

Life cycle and biology

Reproduction and mating

Males of Chrysops species typically emerge before females and form swarms near water edges or landmarks, where females enter to initiate mating.^[32]^[33] Mating begins in flight as the male pursues and captures the female, then completes on the ground.^[2]^[33] Females generally mate multiple times during their adult lifespan, promoting genetic diversity within populations through sexual reproduction.^[34]^[35] Adult emergence and mating activity are triggered by environmental cues such as increasing photoperiod and temperatures in late spring and summer, aligning with peak seasonal conditions for reproduction.^[2]^[21] Following mating, females require a blood meal to develop eggs, though some species can produce an initial batch autogenously without one.^[36]^[34] Oviposition occurs shortly after egg maturation, with females laying a single mass of 100 to 800 eggs, depending on species and nutritional status.^[36]^[2] These eggs are deposited in compact rafts or vertical stacks on vegetation, rocks, or other substrates overhanging water or moist soil, ensuring larvae can access aquatic habitats upon hatching.^[2]^[21] The eggs are elongated and cylindrical, measuring 1 to 2.5 mm in length, initially creamy white but darkening to black or gray, and coated in a shiny, chalky secretion that provides protection against desiccation.^[2] Hatching typically occurs synchronously in 3 to 7 days, influenced by ambient temperature and humidity.^[2]^[36]

Development stages

The life cycle of Chrysops species follows complete metamorphosis, encompassing egg, larval, pupal, and adult stages, with the entire process typically spanning 1 to 3 years depending on species and environmental conditions.^[2] Most species complete one generation per year, overwintering as larvae, while larger or northern populations may require up to 3 years due to prolonged larval development.^[2]^[37] Development is influenced by moisture and temperature, with larvae requiring aquatic or semi-aquatic habitats to avoid desiccation and support growth.^[2]^[38] Eggs are laid in compact masses of 100 to 1,000 on vertical surfaces such as aquatic vegetation overhanging water or wet ground, appearing cylindrical, 1 to 2.5 mm long, and initially creamy white before darkening to gray or black.^[2]^[3] Hatching occurs in 5 to 7 days under suitable weather conditions, after which first-instar larvae drop into the moist substrate below; eggs are highly vulnerable to desiccation if the surrounding environment dries out.^[2]^[39] The larval stage, the longest in the life cycle, lasts from a few months to 1 to 3 years and occurs in aquatic sediments, mud, wet soil, or seepage areas where larvae—whitish, brownish, or greenish with black bands—undergo 6 to 13 instars.^[2]^[40]^[38] Larvae feed on detritus and organic matter or prey on small invertebrates, overwintering in diapause within the sediment to survive cold periods.^[2]^[3] In late spring, mature larvae migrate to drier upper soil layers (2.5 to 5 cm deep) to prepare for pupation, facing elevated predation risks during this transitional movement.^[2]^[34] The pupal stage takes place in the soil and lasts 2 to 3 weeks (approximately 14 to 21 days), during which the non-feeding pupa—brown, rounded anteriorly, and tapered posteriorly with abdominal spines and a characteristic "aster" of six projections—undergoes transformation triggered by warming spring temperatures.^[2]^[21]^[41] Adults emerge synchronously in seasonal cohorts from late spring through summer, with males typically eclosing before females via a thoracic slit in the pupal case; this emergence often precedes mating swarms.^[2] The total life cycle duration varies from 1 to 3 years with increasing latitude, as cooler climates extend the larval phase.^[38]^[37] Key factors affecting development include optimal temperatures above 20°C for accelerated larval growth and high moisture levels to prevent desiccation across stages, alongside predation vulnerabilities during egg hatching and larval-pupal transitions.^[39]^[42]

Behavior and ecology

Feeding habits

Adult Chrysops exhibit distinct sexual dimorphism in their feeding strategies, with males primarily consuming nectar and pollen from flowers as their energy source, while females are hematophagous, requiring blood meals to support egg development (vitellogenesis).^[40]^[34] Both sexes supplement their diet with plant-derived sugars, such as nectar or honeydew from Hemiptera, but only fertilized females seek vertebrate hosts for blood.^[34] This blood-feeding behavior is essential for females, as a single gonotrophic cycle often necessitates multiple meals to complete oogenesis.^[34] Female Chrysops employ a pool-feeding (telmophagous) mechanism, using their scissor-like mandibles to slice the host's skin and create a pool of blood, which they then lap up with their proboscis.^[26]^[43] This laceration causes immediate pain and irritation, often resulting in host defensive reactions that interrupt feeding, prompting females to switch hosts mid-meal.^[34] Bites typically produce welts due to injected anticoagulants and vasodilators, though the initial incision may not always elicit instant discomfort.^[2] Host selection by female Chrysops relies on a combination of visual cues, such as dark silhouettes, movement, and color contrasts, along with olfactory signals like carbon dioxide (CO₂) plumes from vertebrate respiration.^[26]^[44] They preferentially target large mammals, including deer, cattle, and humans, approaching from behind or below to land on shaded areas like the head, neck, or legs.^[45]^[24] Feeding activity occurs throughout daylight hours, peaking in the morning (2–3 hours after sunrise) and late afternoon (2 hours before sunset), under direct sunlight and temperatures exceeding 22°C (72°F), with biting rates influenced by environmental factors like humidity and light intensity.^[40]^[46] Females may take several blood meals daily within a gonotrophic cycle, each lasting seconds to minutes depending on host evasion.^[47] In contrast, Chrysops larvae are non-hematophagous, inhabiting moist sediments where they rasp and consume organic detritus, microorganisms, or small arthropods such as insect larvae and nematodes.^[48]^[34] This detritivorous or predatory feeding supports their aquatic or semi-aquatic development in streams, ponds, or wet soils.^[2]

Habitat preferences and predators

Chrysops larvae primarily inhabit shallow, vegetated wetlands, including marshes, pond margins, and stream edges, where they develop in moist soils rich in organic matter and decaying vegetation.^[49]^[2] These hydrobiontic larvae favor substrata with moderate to high mineral soil content, often in semi-aquatic or terrestrial microhabitats such as mud or wet organic debris near slow-flowing waters, distinguishing them from other tabanids that prefer deeper swamps.^[50] Adults, while emerging near these aquatic breeding sites, exhibit broader habitat use, frequenting sunny, open areas adjacent to water bodies and extending into forested meadows and shaded woodlands for host-seeking and resting.^[51]^[50] Natural predators of adult Chrysops include various birds such as killdeer and other avian species that capture them in flight, along with dragonflies, wasps, hornets, spiders, frogs, and toads.^[52]^[35] Larval stages face predation from aquatic invertebrates and may experience interspecific competition with other Tabanidae larvae over limited moist microhabitats in wetlands.^[50] Male Chrysops contribute to symbiotic relationships by feeding exclusively on nectar and pollen, occasionally aiding in the pollination of flowering plants during these visits.^[34]^[17] Chrysops populations show sensitivity to climatic and habitat alterations, declining in drier or heavily shaded environments that reduce available moist larval substrates, while potentially expanding in areas with restored wetlands that enhance breeding sites.^[2]^[49]

Distribution and diversity

Global distribution

The genus Chrysops, comprising deer flies in the family Tabanidae, exhibits a cosmopolitan distribution across all major continents, excluding polar regions such as Iceland, Greenland, and isolated oceanic islands like Hawaii. This near-global range reflects their adaptation to diverse temperate, subtropical, and tropical environments, particularly those supporting large mammals for blood-feeding.^[2]^[40] Diversity is highest in the Holarctic and Neotropical realms, where ecological niches in forests, wetlands, and grasslands sustain numerous species. In North America, over 100 species occur, making it a hotspot of abundance alongside Europe and Asia, where dozens of species are recorded in similar habitats. In contrast, coverage is sparser in Africa and Australia; Australia has only one species, while Africa has approximately 30 species, including the two primary vectors of loiasis in West and Central Africa.^[40]^[24]^[53]^[54] Tropical populations, such as the loiasis vectors in West and Central Africa, predominate in lowlands at mean elevations around 400 m, associated with rainforest understories and riverine areas.^[55] Dispersal is primarily local but aided by wind, allowing adults to travel up to 5 km from breeding sites, with longer-range movement facilitated by human activities such as livestock transport. Historical patterns include post-glacial recolonization of northern latitudes in the Holarctic realm following the Pleistocene, enabling expansion into previously glaciated boreal forests.^[34]^[56]

Species overview

The genus Chrysops encompasses approximately 300 species worldwide, with over 100 species recorded in North America across two primary subgenera.^[54] The subgenera include Chrysops (sensu stricto), which dominates in temperate regions, and Rhinophoromyia, along with two others (Liochrysops and Graphomya) that contribute to the genus's overall taxonomic diversity.^[54] Diversity is highest in temperate forest ecosystems and associated wetland margins, where environmental conditions support a proliferation of these hematophagous flies.^[48] Notable species exemplify the genus's ecological roles and geographic variation. Chrysops discalis, the prairie deer fly, is widespread in the United States, particularly across the northern Great Plains, and is distinguished by its clear discal cell in the wing venation.^[57] In Africa, C. silacea serves as a key vector for loiasis, transmitting the filarial nematode Loa loa in tropical rainforests of Central and West Africa.^[5] C. caecutiens represents European populations, occurring in temperate woodlands and contributing to local biodiversity in Palearctic habitats.^[17] Regional endemism is evident in isolated hotspots, such as Madagascar, where six Chrysops species occur, several of which are endemic to the island's unique ecosystems.^[58] Conservation status varies, with some rare species, like certain North American taxa, monitored due to potential declines from habitat loss, though most remain secure globally.^[59] Identification of Chrysops species primarily relies on morphological traits, including distinct wing patterns with dark bands, the arrangement of eye facets (often forming colorful bands in living specimens), and structures of the male genitalia, which provide definitive diagnostic characters in taxonomic keys.^[60]

Human interactions

Medical significance

Chrysops species, commonly known as deer flies, serve as vectors for several zoonotic diseases affecting humans and animals, primarily through mechanical transmission via their contaminated mouthparts or, in specific cases, biological transmission.^[40] They are particularly significant in rural and forested areas where human-wildlife interactions are frequent._^[61] One of the primary diseases transmitted by Chrysops is tularemia, caused by the bacterium Francisella tularensis, with deer flies acting as mechanical vectors in the western United States by transferring bacteria from infected hosts to humans during bites.^[61] In Africa, certain Chrysops species, such as C. silacea and C. dimidiata, are biological vectors for loiasis, a filarial infection caused by Loa loa, where the parasite undergoes larval development within the fly before transmission to humans.^[5]^[62] Additionally, Chrysops can mechanically transmit anthrax (Bacillus anthracis) and equine infectious anemia virus, posing risks to both livestock and humans in endemic regions.^[25] While Chrysops rarely act as true biological vectors for other filarial parasites, they may mechanically spread filariasis pathogens on occasion.^[40] Bites from Chrysops often cause immediate painful welts and itching due to the fly's saliva, which can trigger allergic reactions ranging from local swelling to severe systemic responses like hives or anaphylaxis in sensitized individuals.^[63]^[64] These bites may also lead to secondary bacterial infections if the wound is not properly managed.^[25] In the context of disease transmission, tularemia acquired via deer fly bites is sometimes referred to as deer fly fever, presenting with symptoms including high fever, chills, headache, and ulceroglandular lesions at the bite site._^[65]^[66] Epidemiologically, tularemia outbreaks linked to Chrysops bites have been documented in rural areas of the United States, where in specific incidents, 72% of cases were attributed to deer fly exposure.^[67]^[68] Similar vector-borne transmission occurs sporadically in Europe, contributing to re-emerging cases in countries like Sweden and Germany.^[69]^[70] For loiasis, the disease impacts millions in rural West and Central Africa, with prevalence rates exceeding 20% in some hyperendemic communities, complicating efforts to control co-endemic filarial diseases like onchocerciasis._^[62]^[71] The zoonotic nature of these infections underscores Chrysops' role in bridging wildlife reservoirs—such as rabbits, rodents, and deer for tularemia, or forest primates for Loa loa—to human populations, amplifying public health risks in endemic zones._^[61]^[5]

Control and management

Control of Chrysops populations primarily targets larval habitats and adult flies, as these deer flies breed in moist environments and exhibit behaviors that make suppression challenging. Larval control focuses on habitat modification, such as draining wetlands to eliminate breeding sites in mud and swampy areas, though this approach is limited by environmental regulations protecting sensitive aquatic ecosystems.^[72]^[73] Approved insecticides, including pyrethrins, organophosphates, and synthetic pyrethroids, can be applied to larval habitats for partial suppression, but their use is restricted due to potential impacts on non-target aquatic organisms.^[72]^[36] Adult Chrysops are managed through trapping methods that exploit their attraction to dark colors and movement. Blue-black sticky traps, such as the Nzi or epsilon designs, effectively capture deer flies by mimicking host silhouettes, providing localized population reduction in areas like farms or recreational sites.^[74] The Manitoba trap, featuring a glossy black sphere elevated above ground, collects flies in an escape-proof chamber and can be enhanced with CO₂ for greater efficacy.^[75] Trolling traps, consisting of blue sticky surfaces attached to vehicles or headgear and moved at low speeds, offer personal relief by intercepting flies during outdoor activities.^[75]^[2] Insecticide applications to adult resting sites, such as shrubbery, provide temporary knockdown but are not sustainable for large areas due to the flies' wide dispersal.^[75] Personal protection strategies emphasize reducing bite exposure through behavioral and chemical measures. Wearing light-colored, long-sleeved clothing minimizes attraction, as Chrysops are drawn to dark shades resembling hosts.^[49] Treating clothing with permethrin offers repellent effects against landing adults, extending protection during outdoor work or recreation.^[76] DEET-based repellents provide partial deterrence but are only marginally effective, often requiring frequent reapplication and offering limited duration against persistent deer flies.^[76]^[36] Integrated pest management (IPM) for Chrysops combines habitat alteration, monitoring, and targeted interventions to achieve sustainable suppression. Modifying landscapes by removing vegetation around water bodies reduces egg-laying opportunities, while providing shaded shelters or screens for livestock limits adult access during peak activity.^[2]^[72] Monitoring with traps, including light or sticky designs, helps assess population levels and evaluate control efficacy in agricultural settings.^[75] For livestock, insecticide-impregnated ear tags and pour-ons serve as short-term repellents, integrated with rotational grazing to disrupt fly-host interactions.^[2] Key challenges in Chrysops management include insecticide resistance and regulatory constraints. Repeated use of pyrethroids and other chemicals has led to reduced susceptibility in tabanid populations, diminishing long-term effectiveness and necessitating rotation of active ingredients.^[77] Wetland protection laws, such as Executive Order 11990, restrict draining or chemical applications in breeding habitats to prevent ecological damage, complicating large-scale interventions.^[78]^[73] Overall, comprehensive control requires multifaceted IPM to balance efficacy with environmental preservation.^[36]

References

[1]
Report: Chrysops callidus - Integrated Taxonomic Information System
Family, Tabanidae – clegs, deer flies, horse flies, mouches à cheval, mouches à chevreuil, taons ; Subfamily, Chrysopsinae ; Tribe, Chrysopsini ; Genus, Chrysops.
[2]
Deer Flies, Yellow Flies and Horse Flies, Chrysops, Diachlorus, and ...
The family Tabanidae, commonly known as horse flies and deer flies, contains pests of cattle, horses, and humans.Missing: taxonomy | Show results with:taxonomy<|control11|><|separator|>
[3]
[PDF] Deer Flies, Yellow Flies, Horse Flies
Biology: Life Cycle: Deer flies (genus Chrysops), yellow flies (genus Diachlorus), and horse flies (genus Tabanus) develop in aquatic and semi-aquatic habitat. ...
[4]
Public Health and Medical Entomology | Purdue | Biology | Entomology | Insects | Ticks | Diseases | Monitoring | Control | Hot Topics | Agriculture | Extension
### Summary of Deer Flies (Genus Chrysops)
[5]
DPDx - Loiasis - CDC
... species of the genus Chrysops, C. silacea and C. dimidiata. During a blood meal, an infected fly (genus Chrysops, day-biting flies) introduces third-stage ...
[6]
Chrysops - Wiktionary, the free dictionary
Proper noun. Chrysops f. A taxonomic genus within the family Tabanidae – deer flies. Hypernyms. (genus): Eukaryota – superkingdom; Animalia – kingdom ...
[7]
Deer Flies (Genus Chrysops) - iNaturalist
Deer flies (also known as yellow flies, June flies, three corner flies or stouts in Atlantic Canada) are flies in the genus Chrysops of the family Tabanidae
[8]
https://www.irmng.org/aphia.php?p=taxdetails&id=1349872
[9]
https://deepblue.lib.umich.edu/bitstream/handle/2027.42/56342/MP098.pdf?sequence=1
[10]
Chrysops - Plazi TreatmentBank
Meigen (1803: 274) included the single species Tabanus caecutiens Linnaeus, 1758 [as “ Tabanus caecutiens Fabr. ”], which is the type species by monotypy.
[11]
[PDF] Adult and Immature Tabanidae - Essig Museum of Entomology
Genus Chrysops Meigen, 24. Genus Stenotabanus Lutz, 39. Genus Haematopota ... The biology and control of the deer fly, Chrysops discalk Williston, and ...
[12]
[PDF] new north american tabanidae. - to records of chrysops in florida
On the eye-coloration of the genus Chrysops. Ent. News, 17: 39-42. Hays, K. L. 1961. Tabanus aranti sp. nov. (Diptera, Tabanidae) from. Alabama. Ent. News ...
[13]
[PDF] horse flies and deer flies - Virginia Museum of Natural History
Genus Chrysops Meigen. Key to Species of Virginia Chrysops (Females). Key to ... A firm base for larval and pupal taxonomy was established by. Teskey ...
[14]
https://www.fws.gov/taxonomic-tree/25162
[15]
Chrysops - Explore the Taxonomic Tree | FWS.gov
Location in Taxonomic Tree ; Family, Tabanidae ; Subfamily, Chrysopsinae ; Tribe, Chrysopsini ; Genus, Chrysops ; Species, Chrysops bistellatus ...
[16]
ITIS - Report: Chrysopsini - Integrated Taxonomic Information System
Chrysopsinae. Tribe, Chrysopsini. Direct Children: Genus, Chrysops. Genus, Neochrysops. Genus, Silvius. References. Expert(s):. Expert: Notes: Reference for:.
[17]
[PDF] ABSTRACT TURCATEL, MAUREN. A Molecular Phylogeny of Deer ...
The cosmopolitan genus Chrysops is well supported as monophyletic in all analyses, however the relationships among species remain mostly unresolved. The genus ...
[18]
Horse flies, Clegs and Deer flies (Tabanidae) - InfluentialPoints
Nov 28, 2014 · Subfamily Chrysopinae · Genus Chrysops (Deer flies) · Subfamily Tabaninae · Genus Hybomitra · Genus Atylotus · Genus Tabanus · Genus Haematopota.Missing: split | Show results with:split
[19]
Phylogenetic Analysis of Mitochondrial Genome of Tabanidae (Diptera
Aug 3, 2022 · This study sequenced and analyzed six complete mitochondrial (mt) genome sequences of four genera of Tabanidae for the first time.Missing: delineation | Show results with:delineation<|control11|><|separator|>
[20]
Horse Fly, Deer Fly - Field Guide to Common Texas Insects
Deer flies (Chrysops spp., 33 species) range from 1/4 to ½ inch long, black to brown in coloration, often with yellowish markings.
[21]
Chrysops flavidus, Deer Flies (Diptera: Tabanidae) - LSU AgCenter
Oct 25, 2022 · It is one of approximately 30 species in the genus Chrysops recorded from Louisiana, and among the most serious pests of livestock within the ...Missing: taxonomy | Show results with:taxonomy
[22]
https://www.idph.state.il.us/envhealth/pcflies.htm
[23]
Chrysops excitans | INFORMATION - Animal Diversity Web
Oct 6, 2014 · Males are holoptic (eyes touch) and females have eyes separated on the head. The clypeus is black with a yellow, pruinose stripe.
[24]
The African Chrysops - IntechOpen
Apr 5, 2017 · The genus Chrysops is one of the three genera of veterinary and medical importance of the Tabanid family. There is no controversy on the ...Missing: evolution delineation
[25]
Horse Flies and Deer Flies - Integumentary System
Adult females of both species feed in the vicinity of open water and have reciprocating, scissor-like mouthparts, which they use to lacerate tissues and lap up ...
[26]
Tabanidae - an overview | ScienceDirect Topics
The oldest blood-feeding Tabanomorpha, which include the Tabanidae and a few related families, probably evolved about 160 million years ago.Missing: milestones | Show results with:milestones
[27]
[PDF] Larvae and pupae of New Guinea Tabanidae (Diptera). I. Species of ...
Jun 2, 2001 · Two of the four A~~stralasian species of Chrysops are found on the island of New Guinea, and both, C. albiciizct~~s. Wulp and C. azcstralis ...<|control11|><|separator|>
[28]
Key to the larval stages of aquatic true flies (Diptera), based on the ...
2 Creeping welts on the dorsal and ventral side of ab- dominal segments 2-7 ... (a) Taba- nidae, (b) Chrysops Meigen, 1803, Tabanidae. Fig. 24 ...
[29]
Prepupae - an overview | ScienceDirect Topics
... creeping welts on various segments to aid in locomotion. Pupae of Nematocera ... Tabanidae; Chrysops (lateral view). View chapterExplore book · Read full ...<|control11|><|separator|>
[30]
https://www.animaldiversity.org/accounts/Chrysops_excitans/
[31]
[PDF] Tabanidae: Horseflies & Deerflies
Size (length) most 0.5 to 1.25 inches nearly all species 0.25 to. 0.33 inches. Antennae shorter than head, with a thick base longer than head, nearly.
[32]
Horse and Deer Flies (Tabanids) | Missouri Department of ...
Deer flies: usually smaller than horse flies; often have spotted eyes and a dark-spotted pattern on the wings; Horse flies: usually larger than deer flies; ...Missing: synapomorphies | Show results with:synapomorphies
[33]
Tabanids: Tabanus species - Clegs - Learn About Parasites
Jun 17, 2021 · Tabanids: Tabanus species - Horse Flies; Chrysops species – Deer Flies; Haematopota species - Clegs · Summary · Taxonomy · Morphology · Host range ...
[34]
Chrysops frigidus | INFORMATION - Animal Diversity Web
Chrysops frigidus is found in a variety of wetland habitats. It is most commonly collected in swampy woodlands.Missing: eyes | Show results with:eyes
[35]
Kids' Inquiry of Diverse Species, Chrysops frigidus - BioKIDS
Chrysops frigidus has a small body compared to other deer flies. The front part of the head is yellow, the mouthparts are brown, and the antennae are brown or ...
[36]
HORSE AND DEER FLIES: BIOLOGY AND PUBLIC HEALTH RISK
Females of some species are capable of developing an initial batch of eggs without taking a blood meal, otherwise blood is required for the development of eggs.
[37]
Tabanids - eScholarship
... larval stage may last a several months or as long as two to three years. ... Chrysops.[7] A case of coexistent tabanid and hymenopteran (wasps and bees) ...
[38]
Checklist of Medico-Veterinary Important Biting Flies ... - MDPI
This pupal stage lasts approximately seven days, after which the adult fly emerges. The complete development from egg to adult generally takes around 20 days ...<|control11|><|separator|>
[39]
[PDF] Chrysops flavidus, Deer flies, (Diptera: Tabanidae) - LSU AgCenter
Chrysops flavidus larvae have small, pointed heads and 11 to 12 additional segments that are circled with low ridges. (“creeping welts”). Larvae are ...
[40]
Chrysops - an overview | ScienceDirect Topics
Tabanids in the subfamily Chrysopsinae are called deer flies; nearly all are members of the genus Chrysops, which includes more than 80 Nearctic species. The ...
[41]
Chrysops atlanticus | INFORMATION - Animal Diversity Web
Scientific Classification ; Kingdom, Animalia animals ; Class, Insecta insects ; Order, Diptera ; Family, Tabanidae.Missing: taxonomy | Show results with:taxonomy
[42]
Loa loa vectors Chrysops spp.: perspectives on research ...
Apr 5, 2017 · The main method of collecting adult Chrysops spp. was the use of local men (historically known as “fly-boys”), with hand nets to capture the ...
[43]
The Population Biology and Transmission Dynamics of Loa loa
This might be a product of the mechanism by which Chrysops feeds, which involves feeding from a pool of blood produced by laceration [51], rather than from ...Review · Parasite Biology And Life... · Resources
[44]
Behavioural and electrophysiological responses of females of two ...
Jun 11, 2012 · Like other haematophagous Diptera, female tabanids can find a host by heat, odour or visual cues (Allan et al., 1987). Tabanids are mainly ...
[45]
Loa loa vectors Chrysops spp.: perspectives on research ...
Apr 5, 2017 · Temporal environmental factors were related to climate and seasonality. For example, in Kumba, Crewe [57] found that C. silacea biting rates ...
[46]
[PDF] The African Chrysops - IntechOpen
Temperature, humidity and light intensity are some interdependent factors influencing the biting activity of Chrysops. Brilliant sunshine and very dull days ...
[47]
Direct Observation of Feeding Behavior of Adult Tabanidae (Diptera ...
Aug 10, 2024 · The aims of this study were to determine the preferred site, time of day, and duration of tabanid feeding on beef cattle and identify factors related to ...
[48]
Chrysops vittatus | INFORMATION - Animal Diversity Web
Chrysop vittatus is known as the striped deer fly due to the three longitudinal stripes on its thorax, and four stripes on its broad, blunt abdomen.
[49]
Deer Flies and Horse Flies - Wisconsin Horticulture
Apr 27, 2004 · The adult females are daytime blood feeders that are most abundant near swamps and marshes, along pond and stream banks, and at the edge of ...Missing: mating behavior
[50]
[PDF] The Deer Flies of Indiana (Diptera: Tabanidae: Chrysops)
Indiana Chrysops can be distinguished from other genera of Tabanidae in the state by a combination of: two apical spurs on hind tibiae, and an antenna1 ...
[51]
Protecting Horses From Horse and Deer Fly Bites
May 10, 2022 · Females will lay eggs on vegetation adjacent to wet habitats like marshes, streams, or ponds. Larvae develop in the mud in these areas.<|control11|><|separator|>
[52]
Deer Flies - Home and Garden IPM from Cooperative Extension
Natural predators of deer flies include frogs, toads, spiders, wasps and hornets, dragonflies, and birds such as the killdeer.
[53]
The tabanidae (Diptera) of Australia. 4. Subfamily chrysopinae
The subfamily Chrysopinae is represented in Australia by 1 species of Chrysops (Chrysopini) and 36 species of Bouvieromyiini, distributed in the monotypic.
[54]
Environmental factors associated with the distribution of Loa loa ...
Feb 6, 2019 · The predicted distribution of both Chrysops vectors from MaxEnt model is shown in Fig. 5a, b. Overall, the distributions were similar; however, ...
[55]
Genus Chrysops - BugGuide.Net
... (Tabanidae) » Deer Flies (Chrysopsinae) » Chrysopsini » Chrysops. Genus Chrysops. Classification · Synonyms and other taxonomic changes · Explanation of Names ...Missing: biology | Show results with:biology
[56]
Species Chrysops discalis - BugGuide.Net
Jun 14, 2009 · Chrysops discalis Williston 1880 The discal cell is clear (dark in most Chrysops) Range Northern Great Plains west to CaliforniaMissing: Notable silacea vittata
[57]
Chrysops vittatus - Wikipedia
Chrysops vittatus is a species of deer fly in the family Tabanidae. Chrysops vittatus. Scientific classification · Edit this classification.Missing: Europe | Show results with:Europe
[58]
[PDF] Part 1: Introduction, subfamily Pangoniinae and tribe Chrysopsini ...
In the tribe Chrysopsini, 6 species of Chrysops MEIGEN, 1803 and 10 species of Picromyza QUENTIN, 1979 are recognized in. Madagascar, of which one Chrysops ...
[59]
Chrysops discalis | NatureServe Explorer
Classification ; Order: Diptera ; Family: Tabanidae ; Genus: Chrysops ; Scientific Name Reference: Teskey, H. 1990. The horse flies and deer flies of Canada and ...Missing: worldwide | Show results with:worldwide
[60]
[PDF] Key to subfamilies and genera of Pangoniinae & Chrysopsinae east ...
Aug 4, 2023 · species (Chrysops discalis Williston and Chrysops fulvaster Osten Sacken) this account will cover all 40 species known from east of the ...
[61]
[PDF] PB1478-Horse Pest Management
Control of horse flies and deer flies is very difficult. Some control can be achieved by draining wetlands or by using approved insecticides for larval control.
[62]
Horse Flies and Deer Flies | Entomology - University of Kentucky
They breed in environmentally sensitive wetlands so effects of drainage or insecticide application on non-target organisms or water supplies is a concern.Missing: draining | Show results with:draining
[63]
Towards a practical trap for deer flies (Diptera: Tabanidae)
Jan 3, 2024 · ... to similar blue–black traps, such as the epsilon trap (Mihok Reference Mihok2002). In contrast to the high-flying behaviour of Chrysops, T.
[64]
Biting flies - Agricultural Biology - CSU College of Ag Sciences
Note that the antennae are longer than the length of the head. Image credit ... Chrysops spp. and Silvius spp. The relatively large flies (family ...Biting Flies · Description, Life History... · Culicoides Spp<|control11|><|separator|>
[65]
Biting Flies | Colorado State University Extension Website
Jun 1, 2013 · To control adults, direct insecticides at shrubbery and other resting sites. Deer flies and horse flies may also be trapped. The “Manitoba trap” ...Missing: strategies | Show results with:strategies
[66]
Deer flies, yellow flies, and horse flies | Integrated Pest Management
Sep 19, 2025 · As larvae, they feed on other small insects. After emerging as adults, they seek sources for blood, typically large ungulates such as horses, ...Missing: preferences | Show results with:preferences
[67]
Tabanidae - File: <identifymed
Chrysops larvae are mostly scavengers. Before the onset of pupation the larvae will move to drier habitats adjacent to their larval sites.
[68]
Protection of Wetlands (Executive Order 11990) | US EPA
May 24, 2025 · Each agency shall provide leadership and shall take action to minimize the destruction, loss or degradation of wetlands, and to preserve and enhance the ...Missing: deer fly