Musca Autumnalis Research Articles

External Parasites on Horses

Arthropod parasites of horses include internal bots that infest the digestive tract, mites that burrow in the skin and feed on the skin surface, ticks that infest the ears as well as the skin, lice that either suck blood or feed on skin, blood sucking flies and mosquitoes that range in size from biting gnats just observable with the naked eye to the large black horse flies which are almost one inch long. Non-biting flies such as house flies and face flies are also important in producing fly worry, irritation and disease transmission. This document is ENY-283 (IG139), one of a series of the Entomology and Nematology Department, UF/IFAS Extension. Original publication date May 1980. Revised March 2006. ENY-283/IG139: External Parasites on Horses (ufl.edu)

Genetic and environmental factors associated with incidence of infectious bovine keratoconjunctivitis in preweaned beef calves1

Infectious bovine keratoconjunctivitis (IBK) is one of the most economically important diseases in preweaned calves. This study examined the health records of 45,497 calves over a 20-yr period to determine environmental and genetic factors influencing the incidence of IBK. Three data sets were analyzed with an animal model. The first data set (n = 41,986) evaluated environmental factors and genetic differences among nine purebred (Angus, Braunvieh, Charolais, Gelbvieh, Hereford, Limousin, Pinzgauer, Red Poll, and Simmental) and three composite breeds (MARC I, MARC II, and MARC III). Weaning weights of calves diagnosed with IBK were 8.9 kg lighter (P < 0.05) than weights of healthy calves. Incidence of IBK was related to age of the calf and the seasonal life cycle of the face fly (Musca autumnalis). Incidence of IBK increased in the spring (June), peaked during the summer months (July to September), and then decreased in the fall. Herefords were the most susceptible breed (P < 0.05) compared with all other purebreds and composites. Estimates of direct heritability for the incidence of IBK were generally low and ranged from 0.00 to 0.28 by breed. The maternal permanent environmental and genetic effects of the dam on the incidence of IBK were not significant for most breeds. The second data set (n = 9,606) was used to estimate heterosis for the incidence of IBK from a Hereford and Angus diallel design. The heterosis effect for the incidence of IBK in reciprocal Hereford/Angus crossbred calves was slightly negative (P = 0.12) but not large. The higher incidence of IBK in Angus x Hereford calves compared with Hereford x Angus calves (13.3 vs. 8.9%) suggests a maternal effect related to the incidence of IBK. Incidence of IBK in crossbred calves sired by tropically adapted breeds (Brahma, Boran, Tuli) compared with purebred and crossbred Bos taurus types was investigated in the third data set (n = 2,622). Crossbred calves sired by tropically adapted breeds had a lower incidence of IBK than most Bos taurus types (P < 0.05), but they were not different than either reciprocal crosses of Hereford and Angus or purebred Angus calves. Response to selection for decreasing the incidence of IBK is likely to be slow because of low heritability and low incidence in most breeds. Significant breed differences for incidence of IBK may be important to some producers and management systems.

North American face flies Old World origins: mitochondrial evidence

Analysis of a 513 base sequence of mitochondrial cytochrome oxidase I gene in Musca autumnalis De Geer (Diptera: Muscidae) from the U.S.A., England, Russia and Kazakhstan confirms that North American flies originated in Western Europe. Flies from the U.S.A., England and southern Russia shared most of their mitochondrial diversities, but face flies from Kazakhstan were substantially dissimilar, suggesting highly restricted gene flow and a species complex within the Palearctic.

The role of volatile semiochemicals in mediating host location and selection by nuisance and disease‐transmitting cattle flies

The role of volatile semiochemicals in mediating the location and selection within herds of Holstein-Friesian heifers by nuisance and disease-transmitting cattle flies was investigated using coupled gas chromatography-electrophysiology (GC-EAG), coupled gas chromatography-mass spectrometry (GC-MS), electrophysiology (EAG), laboratory behaviour and field studies. Using volatile extracts collected by air entrainment from heifers in the Netherlands, a number of active peaks were located by coupled GC-EAG for Musca autumnalis (de Geer) (Diptera: Muscidae) and Haematobia irritans (L.) (Diptera: Muscidae). Volatile samples were also collected from two heifers in Denmark shown in previous counting experiments to differ significantly in their fly loads. Coupled GC-EAG using Ha. irritans antennae revealed differences in the EAG response to the samples, with additional EAG activity in the sample collected from the heifer with the lower fly load. To identify more EAG active compounds, volatiles were also collected from 48-h-old urine by air entrainment. In total, 23 compounds were located and identified by coupled GC-EAG and GC-MS. Further electrophysiological testing of these compounds with five fly species [M. autumnalis, Ha. irritans, Hydrotaea irritans (L.) (Diptera: Muscidae), Stomoxys calcitrans (L.) (Diptera: Musicidae) and Wohlfahrtia magnifica (Schiner) (Diptera: Sarcophagidae)] showed that only some of the compounds were physiologically active across the range of flies tested. These included 1-octen-3-ol, 6-methyl-5-hepten-2-one, (Z)-3-hexen-1-ol, naphthalene, and all EAG active compounds identified from urine. Compounds showing significant EAG activity were tested for behavioural activity using a wind-tunnel designed for measuring upwind flight behaviour. At certain concentrations, 1-octen-3-ol, 6-methyl-5-hepten-2-one and 3-octanol increased upwind flight, whereas naphthalene, propyl butanoate and linalool reduced upwind flight. In field studies using small herds of heifers ranked according to their fly load, individual slow-release formulations of 1-octen-3-ol and 6-methyl-5-hepten-2-one, when applied to low and high fly loading heifers, reduced fly loads on these individuals. This study provides evidence for the hypothesis that the natural differential attractiveness within herds of Holstein-Freisian heifers, i.e. a single host species, for cattle flies is partly due to differences in volatile semiochemicals emitted from the host. It is suggested that this phenomenon applies to other vertebrate host species and their associated insect pests.

Adults of the native face fly (Hippelates insignificans) (Diptera: Chloropidae) accumulate in areas of elevated carbon dioxide

The native face fly, Hippelates insignificans was observed in greater numbers in the elevated CO2 rings of a Free Atmospheric Carbon Dioxide Experiment near Bulls, New Zealand. In samples taken over 18 months, adults peaked in abundance in February and counts on exposed skin were eight times higher in the elevated CO2 areas than in ambient areas. Soil, litter and herbage samples were extracted in Tullgren funnels in a search for larvae but none was found.

Molecular epidemiological survey on the vectors of Thelazia gulosa, Thelazia rhodesi and Thelazia skrjabini (Spirurida: Thelaziidae).

A Polymerase Chain Reaction (PCR)- based assay developed for the specific identification of Thelazia gulosa, Thelazia rhodesi and Thelazia skrjabini (Nematoda, Spirurida), which cause bovine ocular thelaziosis, was evaluated for its usefulness in detecting the intermediate hosts and in estimating the infection prevalence of vectors in field conditions throughout 5 years (from 1997 to 2001). A total of 5190 flies were captured and identified as Musca larvipara, Musca osiris, Musca autumnalis, Musca tempestiva or Musca domestica. Genomic DNA was extracted from pools constituted by heads, thoraces, abdomens and wings of 10 flies of each species, and 2076 samples were subjected to a PCR assay to specifically detect the ribosomal ITS-1 sequence of bovine Thelazia. Amplicons were sequenced and subjected to digestion with CpoI restriction enzyme. M. autumnalis, M. larvipara, M. osiris and M. domestica species were shown to be PCR positive. T. gulosa was specifically detected by PCR in M. autumnalis, M. larvipara, M. osiris and M. domestica, whereas T. rhodesi is in M. autumnalis and M. larvipara. Of 27 positive samples, 23 were positive for T. gulosa and 4 for T. rhodesi, with a mean prevalence of 2.86% in the whole fly population collected. The highest mean prevalence values of infection were detected in M. autumnalis (4.46%) and M. larvipara (3.21%), and the former species was confirmed to be the vector of T. gulosa and T. rhodesi. This study is the first report of M. osiris as a vector of T. gulosa and M. larvipara as a vector of T. gulosa and T. rhodesi under natural conditions. The occurrence of Thelazia in fly populations in the Apulia region of Italy (in the 5 grazing seasons considered) indicates that cattle thelaziosis is enzootic in southern Italy. This molecular assay should be a useful epidemiological tool for assessing the role of different species of flies as intermediate hosts of thelaziae.

Chronological age-grading of house flies by using near-infrared spectroscopy.

The sensitivity and accuracy of near-infrared spectroscopy (NIRS) was compared with that of the pteridine fluorescence technique for estimating the chronological age of house flies, Musca domestica (L.). Although results with both techniques were significantly correlated with fly age, confidence limits on predicted ages generally were smaller with NIRS. Young flies could be readily differentiated from old flies by using NIRS. Age predictions using the pteridine method are dependent upon size, sex, and temperature at which adult flies are exposed. In contrast, those factors do not need to be determined for age-grading using NIRS. Classification accuracy using the NIRS method was similar for whole flies, fresh heads, dried heads, and ethanol-preserved heads. The NIRS method was also suitable for predicting age of stable flies, Stomoxys calcitrans (L.), and face flies, Musca autumnalis De Geer. NIRS has several advantages over the measurement of pteridine levels for age-grading field-collected flies, including speed and portability of instrumentation, and not needing to determine sex, size, and temperatures to which adult flies were exposed.

Microsatellite loci in the house fly, Musca domestica L. (Diptera: Muscidae)

AbstractGenomic libraries from house flies enriched for (CA)15 and (CAG)10 repeats were constructed by using biotinylated probes. Twenty‐five loci were isolated and evaluated for polymorphisms in wild flies representing two geographically diverse populations. Fourteen of 19 dinucleotide loci, and one of six trinucleotide loci were polymorphic. One hundred and twenty‐seven alleles were detected, 39 of which were private. Average number of alleles per polymorphic locus was 8.4 ± 2.5 and average heterozygosity was 72 ± 4%. FST by the private allele method was 0.73. Three of 15 loci showed significant heterozygote deficiencies, attributed to null alleles. Five of 15 loci were amplified in the face fly, Musca autumnalis.

Rationale for mass antibiotic distribution for trachoma elimination.

Rationale for mass antibiotic distribution for trachoma elimination.

A35 ノサシバエの寄生が牛の血液成分に及ぼす影響

A35 ノサシバエの寄生が牛の血液成分に及ぼす影響

Entomopathogenic Fungi in Flies Associated with Pastured Cattle in Denmark

Cattle flies, including Musca autumnalis, Haematobia irritans, and Hydrotaea irritans, are pests of pastured cattle. A 2-year study of the natural occurrence of entomopathogenic fungi in adult cattle flies and other flies associated with pastures showed that the four species included in the Entomophthora muscae species complex (E. muscae sensu lato) caused high infection levels in several species of flies. However, only a few specimens of cattle flies were infected by E. muscae sensu stricto despite the fact that cattle flies were observed to perch on spear thistles, which acted as transmission site for all four Entomophthora species. Transmission experiments with E. muscae s.l. supported the field data. Of the two species considered host specific, E. syrphi caused substantial infection in a muscid, and E. scatophagae likewise could be transmitted to a muscid. This emphasizes the need for a revision of the two species. Low prevalences were recorded of another entomophthoralean, Furia americana, and of the hyphomycetes Beauveria bassiana and Verticillium lecanii.

Species ofTrichomalopsis(Hymenoptera: Pteromalidae) associated with filth flies (Diptera: Muscidae) in North America

AbstractFive species ofTrichomalopsisCrawford associated withHaematobia irritans(L.) (horn fly),Musca domesticaL. (house fly),Musca autumnalisDeGeer (face fly), andStomoxys calcitrans(L.) (stable fly) in North America are reviewed. The speciesTrichomalopsis americana(Gahan),Trichomalopsis dubia(Ashmead),Trichomalopsis sarcophagae(Gahan),Trichomalopsis tachinae(Gahan), andTrichomalopsis viridescens(Walsh) are described, keyed, and differentiated from other recognized North American species. Lectotypes are designated forT.dubia,T.sarcophagae, andT.tachinae. Distribution and host associations are recorded for the species.Trichomalopsis americanaandT.viridescensare newly recorded as parasitoids ofM.domestica;T.dubiaandT.sarcophagaeare also newly recorded as parasitoids ofHypoderma lineatum(Villers) (common cattle grub) andHypoderma bovis(L.) (northern cattle grub), respectively. Some previously published host associations and parasitoid identifications are corrected based on examination of voucher specimens. The known biology of each species is reviewed. The presence ofTrichomalopsis albipilosa(Gahan) in North America is considered to be erroneous based on a misidentification ofT.americana.

Dynamics of diapause recruitment in populations of the face fly, Musca autumnalis.

Field populations of face flies, Musca autumnalis DeGeer (Diptera: Muscidae) were sampled serially in the late summers and autumns of 1985-96, in order to measure the dynamics of diapause development in Iowa, U.S.A. Fat body hypertrophy and ovarian development were assessed through dissection, and pteridine quantities in the fly heads were measured spectrofluorometrically to estimate their physiological and chronological ages. Published laboratory studies of diapause induction established the expectation that diapause incidence would vary over successive years with prevailing temperatures. The expectation was not met by field data. Patterns in the frequencies of hypertrophied fat body and of vitellogenic nullipars indicated that about 50% of recruited adults began developing into diapause in the second week of September in each year. Degree-day summations for each year from 1985 to 1996 suggested that the hypothetical mean optimal time for switching into diapause would be in the second week of September, because a rapidly diminishing proportion of eggs laid later would result in viable, overwintering flies. It was concluded that face flies do not use daily temperatures in late summer, but instead cue on photoperiod for diapause.

Age structure of overwintered face fly populations estimated by pteridine concentrations and ovarian dynamics

Pteridines in the head capsules of face flies, Musca autumnalis DeGeer, were measured spectrofluorometrically to provide estimates of age. The flies also were dissected to determine ovarian development and fat body hypertrophy. Physiological ages in terms of degree-day accumulations were estimated among late autumn, winter, and early spring face flies. The reproductive history of eight overwintered face fly populations near Ames, Iowa, U.S.A., suggested that each had behaved as a single cohort, maturing their eggs and ovipositing according to a simple heat unit model. 83.8 +/- 16.4 degree-days above a 12 degrees threshold (DD > 12 degrees) were estimated to elapse between 1 January and the date at which 50% of overwintered cohorts had oviposited. Pteridine deposits indicated that diapausing females in late autumn had acquired a mean 96 +/- 36 DD > 9.8 degrees and the males 135 +/- 39 DD > 9.8 degrees. Soon after emergence from hibernaculae, females were average physiological ages of 135 +/- 25 DD > 9.8 degrees and the males were 152 +/- 28 DD > 9.8 degrees. Mean physiological age of overwintered females was 155 +/- 37 DD > 9.8 degrees compared with 110 +/- 38 DD > 9.8 degrees among parous flies in summer. Overwintered males in spring were an average 175 +/- 41 DD > 9.8 degrees compared with 144 +/- 65 DD > 9.8 degrees among summer flies.

Serum and skin surface antibodies and their associations with sheep biting lice, Bovicola ovis, on experimentally infested sheep.

The sheep biting louse (Bovicola ovis) feeds superficially on the skin of sheep but appears to stimulate an immune response. In this study we examined the association between louse infestation and serum and skin surface antibodies. Louse numbers were monitored on experimentally infested Polypay and Columbia ewes for two years and on their lambs in the second year. Serum and skin wash samples were tested for antibodies to soluble extracts of B. ovis, Stomoxys calcitrans and Musca autumnalis by enzyme linked immunosorbent assay (ELISA). In addition, the effects of skin wash extracts on B. ovis were examined in vitro. The titre of anti-B. ovis antibodies in the serum did not differ significantly between infested and naive ewes. However, there was an increase in serum antibody titre which coincided with periods of high louse density in ewes with high louse counts. Infested lambs had higher serum antibody levels than naive lambs. Substantial cross reactivity was evident among extracts of the different insects. Densities of lice on the ewes during population decline were negatively related to the titre of skin surface antibodies. Skin washings collected from sheep during B. ovis population decline reduced the number of louse progeny when incorporated into louse diet. These results indicate that B. ovis stimulates an immune response in sheep and suggest that compounds on the skin surface may play a role in the regulation of louse populations.

Pruritis and dermal response to insect antigens in sheep infested with Bovicola ovis

This study examined the relationships among louse density, pruritis and dermal response to insect antigens in sheep infested with Bovicola ovis. Polypay and Columbia ewes were allocated to two groups, infested and naive, and louse densities and pruritis were monitored for 15 months. Ten months after the initial infestation, all sheep were tested for hypersensitivity on the midside and ears by intradermal injection of soluble extracts of B. ovis, Stomoxys calcitrans and Musca autumnalis. The areas of skin reactions were measured at 20 min, 1, 3 and 24 h after injection and skin thickness was measured at 24 h. Louse densities on Polypays were approximately 10 times greater than on Columbias, and pruritis was correlated with louse numbers at most inspections. Most pruritic behaviour was directed to the sides of infested sheep. Wheal and flare reactions developed rapidly to all extracts in both infested and naive ewes. Reactions to louse extract were larger in infested than naive sheep at all four times after injection. In the infested Polypays, reactions to louse extract were greater than to the fly extracts, but in naive sheep there was little difference among extracts. Reactions in naive Columbias were larger than in naive Polypays at 20 min, 1 and 3 h, but had almost completely abated in both groups at 24 h. Reactions in infested Columbias were greater than in infested Polypays at 20 min, but at 24 h reactions in the Polypays were larger. Louse numbers and pruritis were correlated with wheal areas and skin thickness at 24 h, but there was little relationship with the size of reactions at earlier times. These findings are consistent with the development of a hypersensitive response to B. ovis and suggest that dermal reactions to lice may influence sheep susceptibility.

Hydrocarbon profiles of diapausing and reproductive adult face flies (Musca autumnalis)

Hydrocarbons present on the cuticle surface of adult face flies, Musca autumnalis, were identified by GC-MS and quantified by GC. Hydrocarbons consisted of n-, monomethyl, and dimethyl alkanes ranging in chain length from 23–29 carbons. Also present were monounsaturated alkenes with chain lengths of 23, 25, 27, and 29 carbons. Wild-caught flies were extracted and hydrocarbon profiles determined for both diapausing and reproductive adult males and females. Few qualitative differences were found between males and females in the hydrocarbon profile. Differences in percent composition were found between diapausing and reproductive flies in monounsaturated alkenes, 4 and 45%, n-alkanes, 24 and 37%, monomethylalkanes, 57 and 15%, and dimethylalkanes, 15 and 2%, respectively, for females. A small difference was found in the total amount of hydrocarbon present, 7.3 ± 0.6 and 9.7 ± 1.1 μg/fly, between diapausing and reproductive female flies, respectively. Adult males also exhibited a similar change in hydrocarbon profile and amount between diapausing and reproductive flies. A laboratory strain of face flies originating in Minnesota was also analyzed, and again similar differences were observed in both male and female flies that were kept under a reproductive or diapause condition. Arch. Insect Biochem. Physiol. 37:206–214, 1998. © 1998 Wiley-Liss, Inc.

Predator–prey relationship between insect larvae: growth ofSphaeridiumlarvae (Coleoptera: Hydrophilidae) under time constraints through predation onMusca autumnalismaggots (Diptera: Muscidae)

Beetles in the genus Sphaeridium (Coleoptera: Hydrophilidae) and face flies, Musca autumnalis (Diptera: Muscidae), oviposit in freshly deposited cow dung. The carnivorous Sphaeridium larvae prey on M. autumnalis maggots. Most larvae reach their third instar within 4 days, before M. autumnalis maggots emigrate and food becomes scarce. The results of field studies indicate that Sphaeridium larvae prey heavily on M. autumnalis maggots: predator and prey densities are negatively correlated. In feeding experiments carried out in small plastic boxes, growth rate, measured as the relative increase in mass of a Sphaeridium larva at 24-h intervals, was correlated with the biomass of the fly maggot ingested. The results of predation experiments with one Sphaeridium larva in a 100-g portion of dung containing maggots at various densities showed that a predator searching for prey in a dung pat requires energy, so in most cases the growth rates measured in the predation experiments were lower than those predicted from the feeding experiments.

Crystallization Temperature and Chilling Injury During Overwintering in a Feral Face Fly (Diptera: Muscidae) Population

Adult face flies, Musca autumnalis DeGeer, overwinter in reproductive diapause. In this study, we monitored temperature in a hibernaculum, and periodically assessed cold hardiness of flies from this site. Of flies collected in Keats, KS (39° 13′ N, 96° 42′ W) in late December and January, a40% exposed to −15°C for 5 h froze internally, whereas, the remainder successfully supercooled. Of flies collected in February, a70% froze internally. All flies that froze internally died. In December and January, all flies that did not freeze recovered fully and immediately, whereas in February nearly 80% of the flies that avoided freezing were killed or impaired. Unfed flies held at room temperature (23°C) for 8 h and then subjected to −15°C for 5 h had low crystallization temperatures, but were killed by chilling injury. Flies that were warmed, allowed food, and then held at 4°C overnight before being exposed to −15°C had higher crystallization temperatures than unfed flies. These data indicate that fully acclimatized face flies in midwinter are susceptible to freezing but not direct chilling injury, and that susceptibility to freezing and chilling injury in overwintering flies increases progressively with time. The laboratory studies show that, when warmed, diapause-induced and cold-acclimatized flies will take available food. Results from the laboratory studies suggest that flies warmed by exceptionally mild temperatures in midwinter are more susceptible to chilling injury from subsequent sudden cold weather, and that feeding when warmed increases crystallization temperatures. Higher crystallization temperatures could cause mortality under more mild conditions conditions that those in our test.

Predation among Sphaeridium larvae: the role of starvation and size differences (Coleoptera Hydrophilidae)

Hydrophilid beetles from genus Sphaeridium colonize fresh cow pats. Their carnivorous larvae feed mostly on maggots of Musca autumnalis. Cannibalism and intrageneric predation among larvae of S. scarabaeoides and S. lunatumwere studied in the laboratory to ascertain under which conditions such predation may occur in the field. The probability of predation among Sphaeridiumlarvae increased with increased size difference between the larvae or when larvae were starved before and during the trials. It is concluded that predation among Sphaeridium larvae is an adaptation to uncertain availability of fly maggots in cow pats. Sphaeridium females oviposit in fresh pats and their young develop quickly.