Deer Flies Research Articles

Ocular Lyme disease

Lyme disease is reported from all over the United States. Transmitted by deer ticks, mosquitoes, and deer flies, it affects numerous organ systems. All age groups are vulnerable to this disease and must be educated about early signs and symptoms to speed diagnosis and appropriate treatment.

Evaluation of Tsetse Attractants as Baits for Horse Flies and Deer Flies (Diptera: Tabanidae) in Louisiana

Two experiments were conducted near Washington, Louisiana, to evaluate attraction of Tabanidae to known tsetse attractants. In the first experiment octenol was dispensed from reaction vials and polyethylene sachets, acetone was dispensed from a jar capped with a perforated lid, and a mixture of octenol, 3-n-propylphenol, and 4-methylphenol (4:1:8) was dispensed from sachets. Fourteen species or species groups of tabanid flies were attracted equally to octenol, whether dispensed from reaction vials or sachets. There were no differences in numbers of tabanids attracted to 4:1:8 bait and to octenol, whether dispensed from sachets or reaction vials. Acetone was no more attractive than were control traps. In the second experiment, 4:1:8, acetone, 4:1:8 + acetone (1:50), and commercially available pepper sauce (TabascoR) were compared. Nine species or species groups of tabanid flies were collected. The 4:1:8 and 4:1:8 + acetone baits were equally attractive to tabanids, whereas there were no differences among the pepper sauce, acetone, and unbaited controls.

Serologic and Genomic Relatedness of Group VIII and Group XVII Spiroplasmas and Subdivision of Spiroplasma Group VIII into Subgroups

Spiroplasmas are currently classified in a group system. Criteria for separation of the twenty-four currently designated groups include serologic relatedness, polyacrylamide gel electrophoretic patterns of proteins, guanine-plus-cytosine base ratios, and, in some cases, DNA-DNA homology. The analysis of DNA-DNA homology and serologic data from a large array of strains recently discovered in dipteran insects reveals that group VIII strain EA-1 from a syrphid fly, strain TAAS-1 from a horse fly, and group XVII strain DF-1 from a deer fly belong to a large complex (supergroup) of strains with various degrees of interrelatedness. Strains DF-1 and EA-1 share DNA-DNA homology of 33 to 48% (high-stringency conditions), while strain TAAS-1 shares 42 to 67% homology with DF-1 and EA-1. The strains had temperature optima of 30 to 37°C, but the temperature minima and maxima reflected the geographic region of strain origin. These three strains also share G+C values of about 30 mol%, utilize arginine, and tend to grow in culture to very high titers (1011 cells per ml). The helical cells of these strains are smaller than those of other spiroplasmas and readily pass through filter pores of 220 nm. These data support the taxonomic placement of the biotypes represented by strains EA-1, DF-1, and TAAS-1 into one supergroup, group VIII, with subgroups designated as VIII-1, VIII-2, and VIII-3, respectively. It is proposed that group XVII remain vacant.

The Horse Flies and Deer Flies of Canada and Alaska. Part 16: the Insects and Arachnids of Canada

The Horse Flies and Deer Flies of Canada and Alaska. Part 16: the Insects and Arachnids of Canada

The etiologic agent of Lyme disease in deer flies, horse flies, and mosquitoes.

The etiologic agent of Lyme disease in deer flies, horse flies, and mosquitoes.

Blood feeding and oviposition by tabanids (Diptera) in the laboratory.

Deer flies and horse flies (Diptera: Tabanidae) were collected during 1983–1984 from pastures and salt marshes in Connecticut, USA. Females were given warmed (31–37 °C), citrated beef blood in the laboratory by Kimwipe tissues soaked with blood or by membrane feeding devices. Of the 673 tabanids observed, 152 (22.6%) ingested blood. Members of the following species fed from one or both blood sources: Hybomitra aurilimba, H. hinei, H. sodalis, Tabanus lineola, T. marginalis, T. nigrovittatus, T. quinquevittatus, and T. superjumentarius. Based on a minimum of 15 individuals, the proportion that fed from membrane feeders varied from 20% for T. lineola to 43.4% for T. nigrovittatus. Fully engorged T. nigrovittatus and T. quinquevittatus deposited fertile eggs that hatched in ≤ 10 days after oviposition. Comparisons of these 2 species revealed minor differences in rates of follicular development, numbers of days to oviposition, or durations to eclosion.

Caloric Reserves in Salt Marsh Deer Flies, Chrysops fuliginosus (Diptera: Tabanidae)

The behavior of Chrysops fuliginosus adults was observed near a salt marsh in Milford, Conn., during 1978, 1979, and 1981–1983. Males and females were analyzed by a chemical test, consisting of a sulfuric acid solution of sodium bichromate, to quantify available caloric reserves in mating, resting, and blood-seeking individuals. Mean available energy reserves were highest in males (mean = 2.7 cal/mg) and females (mean = 2.5 cal/ mg) captured in copula. There were no appreciable differences between these groups and males resting on vegetation (mean = 2.6 cal/mg), but lower amounts of mean available caloric reserves were noted for females resting on vegetation (mean = 1.2 cal/mg) or seeking vertebrate hosts (mean = 1.4 cal/mg). The relatively higher caloric values recorded for copulating deer flies and resting males were attributed to nectar-feeding and quantities of stored reserves remaining after eclosion.

The Diptera, or True Flies, of Illinois

The tabanids, or horse flies and deer flies, are well known to dairy farmers and livestock producers as well as to campers, fishermen, and outdoor enthusiasts as annoying and pain-inflicting inhabitants of most wooded areas of Illinois. These large and persistent flies impart a painful bite and can occur in large enough numbers to make canoeing and hiking virtually impossible. The tabanid fauna of Illinois has never been studied, although several of the surrounding states have published various reports: Indiana (Burton 1975; Meyer & Sanders 1975), Wisconsin (Roberts & Dicke 1958), Iowa (Richards &: Knight 1967), Missouri (Andrews & Wingo 1975), Tennessee (Goodwin 1966), Michigan (Hays 1956), Ohio (Hine 1903), Minnesota (Philip 1931), and Arkansas (Schwardt 1936; Schwardt & Hall 1930). This study is intended to make available in brief form our present knowledge of the tabanids in the central United States, with keys for their determination, and the distribution of those species occurring in Illinois. No attempt is made to give detailed taxonomic descriptions of species. If needed, these can be found for most species in the papers of Brennan (1935) and Stone (1938). Philip (1954, 1955) has keys to all the North American Pangoniinae and Chrysopsinae known at that time. The most recent list of the North American species of Tabanidae is given by Philip (1965).

External Parasites of Dairy Cattle

Insects such as stable flies, house flies, horn flies, face flies, mosquitoes, horse flies, deer flies, cattle grubs, and lice as well as ticks and mites are the major external parasites of dairy animals in the United States. These pests cause obvious discomfort to livestock and economic effects of heavy populations usually are discerned easily. However, research efforts to date have failed to establish reproducible losses caused by specific ectoparasites. Research efforts involving a multidisciplinary systems approach are necessary to provide the data needed to develop total dairy management programs.

Oviposition Behavior and Fecundity in Chrysops Cincticornis (Diptera: Tabanidae)1

Chrysops cincticornis females deposited eggs in clusters of 2 or 3 tiers on the leaves of Juncus effusus (rush), Carex crinita (sedge), and on grasses at the edge of a pond in southwestern Virginia, USA. Although variable in size and shape, 44 egg masses contained an average of 215.5 eggs (range = 33–612). Thirty-one gravid females captured while resting on vegetation had an average of 403 stage V oocytes (range = 161–603). Fecundity was significantly correlated with wing lengths, but in each of 31 females there were an additional 15–50 ovarioles that had neither evidence of prior egg release nor development of primary follicles beyond stage II. The multi-tiered egg masses of C. cincticornis differ from those of some other deer flies

Reduction of Horse and Deer Flies on the Cottonwood Range and Livestock Experiment Station as a Result of Grazing12

Horse fly and deer fly populations were sampled on an experiment station in southwestern South Dakota during the summer of 1977, 1978, and 1980. Tabanus similis Macquart and Chrysops aestuans van der Wulp were the most common species collected by blackball and sticky-drum traps. T. similis adults were commonly observed as a pest of beef cattle from June to early August, whereas C. aestuans was attracted more commonly to humans during this period. Fly populations were lower in 1980 when compared with numbers found in previous years. It is suggested that weather conditions and grazing by beef cattle in 1979 reduced the amount of vegetation on which flies could oviposit, resulting in fewer adults caught dunng the 1980 season. C. sequax Williston and C. carbonarius Walker also were attracted to humans, whereas collections of T. marginalis F., T. orbicallus Philip, and Silvius pollinosus Williston represent new records for South Dakota.

The reproductive life history and blood meal sources of Chrysops hirsuticallus (Diptera: Tabanidae).

The reproductive life history and blood meal sources of the deer fly Chrysops hirsuticallus from Mendocino Co., California, were determined during 1971–1974. Nulliparous specimens predominated in late April and most of May, whereas uniparous and biparous flies constituted the majority of the late May–June collections. Two triparous flies observed in 1973 are the first recorded for wild-caught deer flies in North America. Egg retention increased with advancing gonotrophic age. Sweeping of vegetation yielded comparable proportions of females with their terminal follicles in developmental stages N to II (55%) and III to V (45%), with 85% of flies in stages II or V. More than 80% of flies hand-captured while attacking man were in stage II, whereas only 2% were in stages III to V. C. hirsuticallus is anautogenous at this site, since females reared from pupae and held alive for up to 8 days entered ovarian diapause in stage II by day 4. Mating preceded blood feeding, as spermathecae of all 17 host-seeking nullipars examined contained spermatozoa. Serologic analyses (capillary precipitin and passive hemagglutination inhibition tests) of 19 engorged specimens revealed that cattle and Columbian Black-tailed Deer were frequent hosts. Limited feeding also occurred on Blacktailed Jack Rabbit, Virginia Opossum, and Raccoon.

Deer Fly, Chrysops atlanticus Pechuman 1 , Activity in Cultivated Fields and Nearby Salt Marsh Breeding Places 2

The deer flies, Chrysops atlanticus , are important pests of humans which move from the salt marsh and concentrate in wooded areas, especially along field edges. Studies at four sites showed that <2% of the deer flies attracted to a human host occur 50 and 100 m into the field whereas 64% were encountered at the field margin and the rest in the ecotone and on the salt marsh. No concentration of flies occurred where no vegetative barrier was present between the marsh and fields. More flies were taken in the morning than at noon and in the late afternoon during June and July near Cedarville, N.J.

Resmethrin and Permethrin Sprays to Reduce Annoyance from a Deer Fly, Chrysops atlanticus12

Resmethrin and permethrin were applied to reduce annoyance from Chrysops atlanticus Pechuman in agricultural areas of southern New Jersey. Resmethrin was applied at rates of 0.015 to 0.112 kg/ha by mist blower. Spray was directed from the edge of the fields into the vegetative wooded barrier between cultivated fields and the salt marsh. At the aforementioned rates, deer fly annoyance (except in 1 application) was reduced by more than 95% 1 h posttreatment, by 27–97% after 8 h, and by 0–96.% after 24 h. Resmethrin in 2 applications by ULV and 2 applications with low volume mist blower at 0.0078 and 0.041 kg/ha, respectively, also was effective. Permethrin in limited tests similarly reduced annoyance.

Diurnal Nectar-Feeding of Salt Marsh Tabanidae (Diptera) 1

Chrysops fuliginosus Wiedemann adults visited Rosa palustris Marsh. and Achillea millefolium L. flowers primarily during the morning (0700–1100 h), but following a mid-day lull in their attraction to these plants, a small number of males and females resumed feeding on flowers between 1800 and 2000 h. Chrysops atlanticus Pechuman adults were sighted on these nectar sources sporadically throughout the diurnal period. Anthrone tests showed that C. fuliginosus , C. atlanticus and Tabanus nigrovittatus Macquart females contained fructose throughout daylight h. Thin-layer chromatography detected glucose alone or a combination of glucose and fructose in more than 90% of the deer flies tested, whereas a mixture of glucose, fructose, and sucrose was found in 51.6% of the T. nigrovittatus females analyzed. Compositae, Rosaceae, Gramineae, Acer, Quercus , and/or Salix pollen grains were recovered from digestive tracts in 28% of the 150 flies examined. The presence of common nectar sugars and pollen grains in tabanids suggests an important association between these salt marsh insects and host plants. In addition to carbohydrates, proteins and amino acids (derived from pollen and nectar) may be important dietary components for adults.

Diurnal Activity of Chrysops atlanticus: Some Questions Concerning Sampling Techniques 12

Blood-seeking Chrysops atlanticus Pech. females begin to respond to a host shortly after sunrise and will remain at a high level of responsiveness until shortly before sunset. Based upon hourly counts, the largest numbers visit the human host shortly after sunrise and shortly before sunset. When counts begin in the afternoon, however, a peak also occurs at 1300 h. The data suggest that destructive sampling methods may bias the results of studies of saltmarsh deer fly biting cycles and lead to misinterpretations of apparent cyclic patterns. One hour past sunrise appears to be the most favorable time for applying insecticidal sprays.

Records of horse flies and deer flies (Diptera: Tabanidae) in New Brunswick

Forty-three species of tabanids in five genera are recorded from New Brunswick. Locality data, notes on seasonal distribution, and relative abundance are given. Modifications to keys of tabanids of the Maritime Provinces are given.

Biting flies of the eastern maritime provinces of Canada. I. Tabanidae.

Fifty-seven species of Tabanidae are recorded from maritime Canada. Thirty-one species have been collected during the period 1973–1976 in the Maritime Provinces, particularly in the Nova Scotia–New Brunswick border region. Larval and pupal habitats were not determined. Feeding habits of 20 species of tabanids were determined; 15 species were collected feeding on man, and 9 species feeding on cattle. Chrysops mitis was the most abundant deer fly and accounted for 14.5% of the tabanid population, 37.1% of the deer flies collected, and 52.6% of the deer flies feeding on man. Hybomitra epistates was the most abundant tabanid; it comprised 19.7% of the tabanids collected and 32.6% of the Hybomitra population. Hybomitra frontalis was the most abundant horse fly feeding on man, and comprised 74.2% of this group. Chrysops frigidus accounted for 42.9% of the deer flies feeding on cattle, while H. typhus Form A accounted for 50% of the horse flies feeding on cattle. Hybomitra illota was the most abundant tabanid collected in tabanid traps. Generally, species of Chrysops were more annoying to man while species of Hybomitra were more of a pest of cattle. Specimens of Tabanus were uncommon.

Digestive processes of hematophagous insects. X. Effects of mammalian sera upon two trypsins from female horse flies and deer flies (Diptera: tabanidae).

Trypsins from tabanids were partially purified by Sephadex gel filtration and DEAE-cellulose chromatography at pH 7.0. The effects of sera from cow, dog, horse, man, pig, rabbit and sheep upon these trypsins were determined. Trypsins [from Chrysops excitans Walker, Chrysops frigidus Osten Sacken, Chrysops furcatus Walker, Haematopota americana Osten Sacken, Hybomitra affinis (Kirby), Hybomitra frontalis (Walker), Hybomitra lasiophthalma (Macquart), Hybomitra nuda (McDunnough), and Hybomitra pediontis (McAlpine)] eluted from DEAE-cellulose by 0.1 M or 0.2 M KC1 were inhibited by mammalian sera. Trypsins (from C. excitans, C. frigidus, H. frontalis, H. lasiophthalma, H. nuda and H. pediontis ) eluted from DEAE-cellulose by 0.3 M or 0.4 M KC1 were activated by mammalian sera. The effects of cow serum upon trypsin (from C. frigidus, H. lasiophthalma , and H. nuda ) depend upon the stage of purification of the trypsin. A trypsin activator was found in the midgut of C. frigidus and H. nuda .

Animal disease agents transmitted by horse flies and deer flies (Diptera: Tabanidae).

Published reports of tabanid transmission of pathogenic agents of animals (including man) are reviewed. Experimental evidence for tabanid transmission of the following disease agents is discussed: viruses (equine infectious anemia, vesicular stomatitis, hog cholera, rinderpest, equine encephalitides, tick-borne encephalitis); bacteria ( Anaplasma marginale, Coxiella bumetii, Bacillus anthracis, Clostridium chauvoei, Pasteurella multocida, Francisella tularensis, Brucella spp., Listeria monocytogenes, Erysipelothrix rhusiopathiae, Leptospira spp.); protozoa [ Besnoitia besnoiti, Haemoproteus metchnikovi, Theileria tarandi rangiferis, Trypanosoma theileri, T. evansi, T. equiperdum, T. vivax, T. congolense, T. simiae, T. brucei brucei, T. b. gambiense (rhodesiense) ] ; and helminths ( Loa loa, Dirofilaria repens, D. roemeri, Elaeophora schneideri, Onchocerca gibsoni ). Results of laboratory and field studies indicate that tabanids are essential for the biological transmission of H. metchnikovi, T. theileri, L. loa, D. roemeri , and E. schneideri and that tabanids are mechanical vectors of the viruses of equine infectious anemia, vesicular stomatitis, hog cholera, and rinderpest; the bacteria A. marginale, B. anthracis, C. chauvoei, P. multocida, F. tularensis, Brucella spp., L. monocytogenes, E. rhusiopathiae ; and the protozoa B. besnoiti, T. evansi, T. equiperdum, T. congolense, T. brucei brucei, T. b. gambiense (rhodesiense) . The extent to which tabanids are important in the natural mechanical transmission of most of these agents is not known. Indirect modes of transmission involving secondary bloodfeeding insects (at tabanid bite sites) and contaminative transmission of agents adherent to external tabanid structures are briefly discussed.