Stable Fly Stomoxys Calcitrans Research Articles

Defensins of the stable fly (Stomoxys Calcitrans) have developmental-specific regulation and evolve at different rates.

Organisms produce antimicrobial peptides (AMPs) either in response to infection (induced) or continuously (constitutively) to combat microbes encountered during normal trophic activities and/or through pathogenic infections. The expression of AMPs is tightly regulated often with specificity to particular tissues or developmental stages. As a result, AMPs face varying selective pressures based on the microbes the organism's tissue or developmental stage encounters. Here, we analyzed the evolution and developmental-specific expression of Defensins, which are ancient AMPs in insects, in the stable fly (Stomoxys calcitrans). Stable fly larvae inhibit microbe-rich environments, whereas adult flies, as blood-feeders, experience comparatively fewer encounters with diverse microbial communities. Using existing RNA-seq datasets, we identified six Defensins that were only expressed in larvae (larval Defensins) and five that were not expressed in larvae (non-larval Defensins). Each of the non-larval Defensins was expressed in at least one adult tissue sample. Half of the larval Defensins were induced by mating or feeding in adults, and all three of the induced Defensins were located downstream of canonical binding sites for an Imd transcription factor involved in the highly conserved NF-κB signaling that regulates induction of AMPs. The larval and non-larval Defensins were located in distinct genomic regions, and the amino acid sequences of the larval Defensins formed a monophyletic clade. There were more amino acid substitutions across non-larval Defensins, with multiple genes losing a highly conserved furin cleavage site thought to be required for the removal of the amino terminus from the mature Defensin domain. However, larval Defensins had a higher proportion of radical amino acid substitutions, altering amino acid size and polarity. Our results reveal insights into the developmental stage-specific regulation of AMPs, and they suggest different regulatory regimes impose unique selection pressures on AMPs, possibly as a result of variation in exposure to microbial communities across development.

Surveillance and screening of Stomoxyinae flies from Mallorca Island (Spain) reveal the absence of selected pathogens but confirm the presence of the endosymbiotic bacterium Wolbachia pipientis

Adult brachycera biting flies can significantly impact livestock through both direct effects (reduction of food intake, disturbance, painful bites, and blood loss) and indirect effects (pathogen transmission), leading to substantial economic losses and production damage. This study aimed to assess the presence of blood-sucking flies in six mixed-animal farm environments on the island of Mallorca (Balearic Islands, Spain) by employing multiple trapping methods. Additionally, distribution maps of brachycera biting fly species recorded in Spain were created, based on data extracted thorough review of scientific literature and citizen digital databases. Investigation of several pathogens, including equine infectious anemia virus (EIAV), Anaplasmataceae bacteria, and piroplasm protozoa, was carried out using different PCR targets (18S rRNA, 16S rRNA, groESL, and tat genes). Citizen science databases and literature review corroborated the consistent distribution trend for two Stomoxyinae species, underscoring the importance of citizen collaboration as a complement to traditional entomological surveillance. Our study confirmed the presence of two biting Stomoxyinae species: the prevalent stable fly Stomoxys calcitrans across all sampled farms, and the horn fly Haematobia irritans, which turned out to be less abundant. DNA barcoding techniques validated the identification of the two species. Neither EIAV nor bacterial/protozoan pathogens were detected using the selected PCR targets in either fly species. However, Wolbachia pipientis (clustered in the supergroup A together with the only sequence of W. pipientis from the USA) was identified through PCR targeting 16S rRNA, groESL and wsp genes in all pools of H. irritans (n = 13) collected from two of the examined farms. This study represents the first attempt to investigate pathogens in Stomoxyinae biting flies in Spain. The discovery of the endosymbiotic Wolbachia organism in H. irritans represents the first record in Spain and the second from Europe. This finding holds significant implications for future research on the applications of this bacterium in biocontrol programs.

First Report of Mermithidae (Enoplea: Mermithida) Parasitizing Adult Stable Flies in Japan

Abstract Mermithidae is a family of nematodes that parasitize a wide range of invertebrates worldwide. Herein, we report nematodes that were unexpectedly found in three of 486 adult stable flies (Stomoxys calcitrans) captured from three farms (F1, F2, and F3) in different regions of Gifu Prefecture, Japan. We aimed to characterize these nematodes both at the morphological and molecular level. Morphological studies revealed that the nematodes were juveniles of Mermithidae. Phylogenetic analysis based on 18S and 28S rDNA indicated that the mermithids from farms F1 and F2 could be categorized into the same cluster as Ovomermis sinensis and Hexamermis sp., whereas the mermithid from farm F3 clustered with Amphimermis sp. Additionally, these mermithids could be categorized within the same clusters as related mermithids detected in Japan that parasitize various arthropod orders. Our findings suggest that these stable flies may have been parasitized by mermithids already present in the region and that genetically distinct species of mermithids occur across Japan. To the best of our knowledge, this is the first report of mermithids parasitizing adult stable flies in Japan.

The Defensive Behaviors and Milk Production of Pastured Dairy Cattle in Response to Stable Flies, Horn Flies, and Face Flies.

Thirty-four crossbred dairy cows were observed on pasture six times per week from June to August 2014 at the University of Minnesota West Central Research and Outreach Center grazing dairy in Morris, MN, for defensive behaviors in response to three species of muscid flies. Counts of stable flies (Stomoxys calcitrans (L.)), horn flies (Haematobia irritans (L.)), and face flies (Musca autumnalis DeGeer) were recorded before and after pasture observation. Individual cows were monitored for 5 min intervals to observe the frequencies of five different defensive behaviors: front and back leg stomps, head tosses, skin twitches, and tail swishes. Fly numbers averaged 5 stable flies per leg, 37 horn flies per side, and 1 face fly per face during the study. The fly counts and behavior frequencies increased with ambient temperature. The results showed a very strong relationship between the numbers of flies and numbers of defensive behaviors, though correlations between specific flies and behaviors were low. Younger cows had fewer stable flies and horn flies than older cows. The thresholds of flies to lower production for pastured organic dairy cows may be greater than 5 for stable flies, 37 for horn flies, and 1 for face flies.

Insecticidal efficacy of the drug «Phytocreolin», which affects the number of zoophilic flies

This article examines the insectoacaricidal effectiveness of the drug «Phytocreolin» on the number of zoophilic flies in open and closed livestock premises. For the first time, the authors conducted studies of the insectoacaricidal efficacy of the drug «Phytocreolin» based on pine tar, how it differs from creolin, and having a repellent effect against insects and, thereby, contributing to a decrease in the number of zoophilic flies in livestock premises. Studies conducted to establish the background number of imago flies in open and closed types, followed by an entomological assessment of zoophilic flies, showed that the dominant biological species was the gray meat fly (Sarcophaga bullata), which accounted for about 80% of the total number of flies. Such a large number of this species is due to the active summer season, as well as the time of research. The housefly (Musca domestica) was also found in the insects, the number of which amounted to 10% of the total number of zoophilic flies. In addition, the autumn stable fly (Stomoxys calcitrans), which accounted for about 7%, and the common green carrion (Lucilia caeza), 3% of the total number of zoophilic flies, were also found in livestock facilities. It was found that the effectiveness of the insecticide drug in the disinfection of livestock premises of a closed type for the entire period of experience, when disinfecting with a 25% solution of the drug in reducing the number of insects was 15,3%, when treated with a 50% solution, the effectiveness was the best and amounted to 29,8% and when disinfecting with a 100% solution, the decrease in the number of zoophilic flies was about 21,7%. Similar results of the effectiveness of the use of an insecticidal drug were obtained in open-type livestock facilities. So, over the entire period of the experiment, when disinfecting with a 25% solution of the drug, the decrease in the number of insects was 9,6%, when treated with a 50% solution – 23% and when disinfecting with a 100% solution, the insecticidal efficiency was the best and amounted to 26%.

An update on the occurrence of flies (Diptera: Muscidae, Calliphoridae) and sucking lice (Phthiraptera: Anoplura) of veterinary importance in Malta: First record of Lucilia cuprina and Linognathus africanus.

To obtain new data on the species diversity, host associations and spatiotemporal occurrence of flies and blood-sucking lice of veterinary importance in Malta, ectoparasites were collected at cattle, sheep and goat, pig farms, as well as dog shelters, and in two places in the absence of domestic animals. The species were identified morphologically, but voucher specimens were also analyzed with molecular-phylogenetic methods following DNA extraction. Altogether 3,095 flies (Diptera: Muscidae, Calliphoridae) were collected at farms and kennels near domestic animals, as well as 37 blowflies (Calliphoridae) in rural and urban areas without animals nearby. Regarding Muscidae, the great majority of flies (n = 3,084) were identified as the common housefly (Musca domestica). Eight flies represented the stable fly (Stomoxys calcitrans). Three blowflies associated with dogs and small ruminants belonged to Lucilia cuprina. By contrast, all 37 blowflies collected without domestic animals nearby, were identified as Lucilia sericata. In addition, 22 sucking lice were collected from goats, and all belonged to Linognathus africanus. Molecular identification of 28 flies and four lice confirmed the above species. Considering the sex ratio of M. domestica among samples collected randomly at cattle farms, females predominated in the whole study period, but the abundance of males increased significantly toward the autumn. Stomoxys calcitrans was associated with cattle and dogs, whereas L. cuprina was found near small ruminants and dogs. To our knowledge, this is the first study including the molecular analysis of flies and lice of veterinary-medical importance from Malta. The most important finding of this study is the first evidence for the autochthonous occurrence of L. cuprina in Malta. The exclusive presence of L. cuprina at animal-keeping facilities in rural areas and association of L. sericata with urban areas void of livestock might reflect similar habitat preference of these species in Malta to what was reported in South Africa. Based on the sucking-louse burden in the examined goat herds, the situation in Malta was similar to northern Africa where the exclusive presence of L. africanus was reported, unlike toward the north in the Mediterranean Basin where populations of this species are mixed with Linognathus stenopsis.

African Swine Fever Virus Load in Hematophagous Dipterans Collected in Outbreaks from Romania: Risk Factors and Implications

African swine fever (ASF) is a contagious viral disease of swine that causes significant economic damage. The summer peaks and river courses have triggered the hypothesis that vectors may be involved in the transmission of the virus. In temperate climates, insect numbers increase in the late summer. Low temperatures and frosts decrease the number of active insects. Their presence is strongly associated with the nearby wetlands or swamps around the farms. The aim of our study was to evaluate the risk factors associated with the presence of ASFV DNA in hematophagous dipterans and to analyze the relevance of Ct values obtained following RT-PCR analysis of the positive samples in ASF outbreaks in Romania, as an indication for the viral load. The current study included 99 pools of stable flies (Stomoxys calcitrans) and 296 pools of biting midges (Culicoides spp.), collected in June-September 2020, from 30 outbreaks of ASF in domestic swine from backyard farms (BF), type A farms (TAF), and commercial farms (CF). All extracted DNA was tested for the presence of the ASFV genome using a real-time PCR protocol. Ct values of 39.53 and below were considered as positive (min: 18.19; median: 31.41; max: 39.53). The blood meal source was identified in the hematophagous insects by using a PCR protocol targeting the mitochondrial gene cytochrome c oxidase subunit 1. Data were analyzed using R software v. 4.0.5. In total, 3,158 insects (S. calcitrans n = 198 and Culicoides n = 2960) were collected in 23 farms of the 30 outbreak farms. Ten species of biting midges were identified. The total number of insect pools showed significant differences according to the month of sampling, with a higher number of pools collected in August and September. Overall, 137 pools out of the 395 examined were positive for the presence of ASFV DNA. There was a higher viral DNA load in farms where pigs were present at the moment of sampling compared to farms where pigs were already culled, in S. calcitrans compared to Culicoides spp. and in CF and TAF compared to BF.

Stable fly outbreaks in Brazil: a 50-year (1971-2020) retrospective.

Over the last decades, stable fly (Stomoxys calcitrans) outbreaks associated with agricultural and/or livestock production systems have become a serious problem in some Brazilian locations. This article presents a survey on the history, evolution and mapping of such outbreaks in Brazil over five decades (1971-2020). Outbreaks (n= 579) were recorded in 285 municipalities from 14 states, mainly associated with by-products from the ethanol industry (82.7%), in natura organic fertilizers (12.6%) and integrated crop-livestock systems (3.1%). Few cases were reported until the mid-2000s, progressively increasing since then. Outbreaks associated with ethanol mills occurred in 224 municipalities, mainly in Southeast and Midwest states, while those associated with organic fertilizers (mainly poultry litter and coffee mulch) affected 39 municipalities, mostly in the Northeast and Southeast states. More recently, outbreaks in integrated crop-livestock systems during the rainy season have occurred in Midwest states. This survey highlights the magnitude of the problem of stable fly outbreaks in Brazil and its relationship with environmental public policies, agricultural production chains and regional trends. Specific public actions and policies are urgently needed to prevent their occurrence and impact in the affected regions.

Evidence of Lumpy Skin Virus DNA in Blood-Feeding Flies During Outbreaks in Russia in 2018-2019

Abstract In this study we report the testing of blood-feeding and synanthropic flies captured near animals affected by lumpy skin disease virus (LSDV) in Russia during the outbreaks in the Kurgan region in 2018 and Saratov region in 2019. The insects of interest were the stable fly Stomoxys calcitrans, Tabanidae horse flies, Culicoides midges and the house fly Musca domestica examined as individuals or pools. The obtained findings demonstrate that viral DNA was found in pools of S.calcitrans and M. domestica and in the head and abdomen of stable flies. This is the first report of LSDV DNA detection in Tabanidae flies from the field. The presented data are envisaged to help further guide the search for putative vectors of LSDV in different climatic regions and interpret laboratory-controlled experiments on vector-borne transmission of LSDV.

Putative roles of mosquitoes (Culicidae) and biting midges (Culicoides spp.) as mechanical or biological vectors of lumpy skin disease virus.

The stable fly Stomoxys calcitrans (Diptera: Muscidae) is considered as the main mechanical vector of the lumpy skin disease virus (LSDV). In addition, the mosquito species Aedes aegypti (Diptera: Culicidae) was shown to transmit the virus from donor to receptor animals. Retention of the virus for several days was shown for two additional tropical mosquito species and the biting midge Culicoides nubeculosus (Diptera: Ceratopogonidae). In the present study, viral retention for 10‐ or 7‐days post feeding on virus‐spiked blood through a membrane was shown for field‐collected Aedes japonicus and laboratory‐reared Culex pipiens, two widely distributed mosquito species in temperate regions. Viral DNA could be detected from honey‐coated Flinders Technology Associates (FTA) cards and shedded faeces for 1 or 4 days after an infectious blood meal was given to Ae. aegypti. Virus increase over time and virus dissemination was observed in laboratory‐reared C. nubeculosus, but the virus could be isolated from field‐collected biting midges only from the day of exposure to the blood meal. Thus, mosquitoes might serve as mechanical vectors of LSDV in case of interrupted feeding. A putative biological virus transmission by Culicoides biting midges, as suspected from field observations, deserves further investigations.

Contact and Fumigant Activities of Citrus aurantium Essential Oil against the Stable Fly Stomoxys calcitrans (Diptera: Muscidae).

The stable fly, Stomoxys calcitrans (L.), is a cosmopolitan hematophagous fly of medical and veterinary importance. It is widely considered a major livestock pest that can cause significant economic losses. This study aimed to evaluate the insecticidal activity of Citrus aurantium (L.) essential oil against S. calcitrans based on contact and fumigant toxicity tests. Chemical analysis by gas chromatography-mass spectrometry of the essential oil showed the dominance (93.79%) of limonene in the total essential oil composition. Furthermore, the insecticidal test results showed that the mortality of flies increased with concentration and time within 24 h of exposure. In the contact toxicity test, the median lethal dose was 105.88 µg/fly, while the 90% lethal dose was 499.25 µg/fly. As for the fumigant toxicity test, the median lethal concentration was 13.06 mg/L air, and the 90% lethal concentration was 43.13 mg/L air. These results indicate that C. aurantium essential oil exhibits insecticidal activity against S. calcitrans. Therefore, it can be used as an alternative to synthetic insecticides for achieving stable fly control.

Odorant-binding protein from the stable fly (Stomoxys calcitrans) has a high-histidine N-terminal extension that binds transition metals

The role of odorant- and pheromone-binding proteins (OBPs) in olfactory function is not fully understood. We found an OBP sequence from the stable fly, Stomoxys calcitrans, ScalOBP60, that has a 25 amino acid N-terminal extension with a high content of histidine and acidic amino acids, suggesting a possible metal binding activity. A search of public databases revealed a large number of other fly OBPs with histidine-rich N-terminal extensions, as well as beetle, wasp and ant OBPs with histidine-rich C-terminal extensions. We recombinantly expressed ScalOBP60, as well as a truncated sequence which lacks the histidine-rich N-terminal region, tScalOBP60. Using fluorescence quenching and electrospray quadrupole time-of-flight mass spectrometry (ESI-QTOF), we detected two different types of metal-binding sites. Divalent copper, nickel and zinc bind to the N-terminal histidine-rich region, and divalent copper binds to an internal sequence position. Comparison of the ESI-QTOF spectra of ScalOBP60 and tScalOBP60 showed that the histidine-rich sequence is structurally disordered, but it becomes more ordered in the presence of divalent metal. When copper is bound to the internal site, binding of a hydrophobic ligand to ScalOBP60 is inhibited. The internal and N-terminal metal sites interact allosterically, possibly through a conformational equilibrium, suggesting a mechanism for metal regulation of ligand binding to ScalOBP60. Based on our studies of ScalOBP60, we propose several possible olfactory and non-olfactory functions for this OBP.

Stable fly activity is associated with dairy management practices and seasonal weather conditions.

Stable flies (Stomoxys calcitrans) are blood-sucking insects commonly associated with cattle production systems worldwide and are known to cause severe irritation to cattle due to painful bites. Cattle react to biting stable flies with an aggregating behavior known as bunching. Bunching behavior reduces grazing or feed consumption and thus reduces cattle productivity and welfare. Cattle’s fly-repelling behaviors include foot stomping, head tossing, tail switching and skin twitching. A longitudinal study was conducted in 2017 on 20 California dairies (average lactating herd size = 2,466 (SE±28.392)) during the stable fly season from April to July. The study objectives were to estimate the association between environmental factors and dairy characteristics including facility design, feed and manure management, total mixed ration (TMR) components fed to cattle, and operational pest management procedures and the outcome stable fly activity on California dairies. Stable fly activity was measured by counting stable flies on cow forelimbs (leg count) and on Alsynite traps (trap count) over the 13-week study period. Weekly leg counts were performed for cattle in lactating cow pens (31 pens from 10 study dairies) with counts made during the morning (AM) and again during the afternoon (PM). Trap counts were performed on all 20 study dairies. Data were analyzed using linear mixed models which revealed temporal variation in the average leg and trap counts with stable fly activity increasing from May to June and then decreasing to the lowest activity in July. Leg counts were higher during the afternoon compared to morning. Ambient temperatures ≤30⁰C and relative humidity (RH) measurements <50% were associated with higher leg and trap counts. Traps located at the periphery of study dairies had higher stable fly counts compared to traps located in the interior of the dairy. Cow pens with trees on the periphery had higher leg counts in comparison to pens away from trees. Specific TMR components were associated with both leg and trap counts. Dairies feeding by-products including almond hulls, wet distillers’ grain, fruits, and vegetables had higher trap counts compared to dairies that did not feed these ingredients. At the pen level, pens with rations that contained straw had lower average leg counts compared to pens fed with rations that did not contain straw. A similar association was observed for pens with rations that contained wheat silage when ambient temperatures were ≤30⁰C. In contrast, pens with water added to the TMR while the RH was ≥50% had higher average leg counts compared to pens without water added to the TMR. Dairies that applied insecticides for fly control to their entire facility had lower trap counts compared to dairies that did not apply insecticides. Stable fly activity measured on California dairies using leg and trap counts varied according to the month, environmental factors, pen surroundings, trap location, TMR components, and insecticide use.

Livestock-associated MRSA survival on house flies (Musca domestica) and stable flies (Stomoxys calcitrans) after removal from a Danish pig farm

We caught stable- and house flies on a Danish LA-MRSA positive pig farm. Stable- and house flies were housed together and culled over time to test for the presence of live LA-MRSA bacteria at 24 h intervals to establish the length of time for which LA-MRSA can persist on flies. On average, 7% of stable flies and 27% of house flies tested positive for LA-MRSA immediately upon removal from the farm. LA-MRSA prevalence decreased over time and estimates based on a Kaplan–Meier time-to-event analysis indicated that the probability of a stable- or house fly testing positive for LA-MRSA was 5.4% and 7.8% after 24 h, 3.5% and 4.3% after 48 h, 3.1% and 2.2% after 72 h and 0.4% and 0% after 96 h of removal from the pig farm, respectively. Simultaneously, we found that caged cultivated house flies became carriers of LA-MRSA, without direct contact with pigs, in the same proportions as wild flies inside the farm. We provide distance distributions of Danish pig farms and residential addresses as well as the calculated maximum dispersal potentials of stable- and house flies, which suggest that there is a potential for stable- and house flies dispersing live LA-MRSA bacteria into the surrounding environment of a pig farm. This potential should therefore be considered when modelling the spread between farms or the risk posed to humans living in close proximity to LA-MRSA pig farm sources.

Filth Fly Impacts to Animal Production in the United States and Associated Research and Extension Needs

AbstractMany flies are considered serious pests of livestock, poultry, and equids. These pests can negatively impact animal welfare and contribute to considerable production losses. Management of filth fly pests in particular, including the house fly (Musca domestica L.), stable fly (Stomoxys calcitrans (L.)), horn fly (Haematobia irritans (L.)), face fly (Musca autumnalis De Geer) (Diptera: Muscidae), and little or lesser house fly (Fannia canicularis (L.) (Diptera: Fanniidae)), has been a research and Extension priority of veterinary entomologists for many decades. However, ongoing changes to animal husbandry and production practices, coupled with an increasing development of behavioral and physiological resistance to insecticides require renewed focus on new and more effective management strategies. This article is the first in a series of updates to these historical reports and the purpose is to serve as a resource for veterinary practitioners, consultants, funding agencies, veterinary entomologists, industry, commodity groups, and the scientific community working towards control of these pests. Companion articles will review individual filth fly species of importance to animal agriculture in the United States

Attractivity of vinasse spraying to stable flies, Stomoxys calcitrans in a sugarcane area

ABSTRACT: Stable fly (Stomoxys calcitrans) outbreaks have been associated with sugarcane mills in Brazil. This study aimed to evaluate the attractivity of vinasse, a liquid byproduct of ethanol production applied to postharvest sugarcane fields, to adult S. calcitrans. Stable fly abundance was monitored for 21 days in August-September 2014, at a sugarcane mill in the municipality of Nova Alvorada do Sul, state of Mato Grosso do Sul, Brazil. Following mechanized harvesting of sugarcane and the consequent deposition of large amounts of plant residue (straw) in the field, the study area (13.5ha) was surrounded by 22 sticky cylinder (“alsynite”) traps. The area was fertigated with vinasse immediately after the traps were placed. Insects caught in the traps were collected daily at 7:00 a.m., 11:00 a.m. and 15:00 p.m. A total of 83,593 specimens of S. calcitrans were caught, of which 5,516 (6.6%) were attracted within the first five hours after vinasse application. The highest number of S. calcitrans was caught in the first week following vinasse application, with a peak on the 4th day (12,818 flies), which was influenced by adverse weather conditions on the previous days. This study confirms that fertigation of sugarcane fields by spraying vinasse after the harvest attracts S. calcitrans, thus quickly increasing their abundance over the days following application.

Potential mechanical transmission of Lumpy skin disease virus (LSDV) by the stable fly (Stomoxys calcitrans) through regurgitation and defecation.

Lumpy skin disease (LSD) is a viral disorder of cattle caused by the lumpy skin disease virus (LSDV) which can induce severe infections leading to high economic losses. Being of African origin, the first LSD outbreaks in Europe occurred in Greece and later in the Balkan region. Little is known about the mode of transmission, especially in relation to the potential role of arthropods vectors. The purpose of our study was to investigate the role of Stomoxys calcitrans in the transmission of LSDV and their presence at different farms in Switzerland. Laboratory-reared flies were exposed to LSDV spiked-blood and incubated under a realistic fluctuating temperature regime. Body parts, regurgitated blood, and faecal samples were analysed by qPCR for the presence of viral DNA and infectious virus at different time points post-feeding (p.f.). LSDV DNA was detected in heads, bodies, and regurgitated blood up to three days p.f. and up to two days p.f. in the faeces. Infectious virus was isolated from bodies and faeces up to two days and in the regurgitated blood up to 12 h p.f. There was no increase in viral load, consolidating the role of S. calcitrans as mechanical vectors for LSDV. Stomoxys flies were present at all eight farms investigated, including a farm located at 2128 m asl. The persistence of LSDV in S. calcitrans in combination with the long flight ranges of this abundant and widespread fly might have implications on LSD epidemiology and on implementing control measures during disease outbreaks.

First report of the presence of Anaplasma marginale in different tissues of the stable-fly Stomoxys calcitrans (Linnaeus, 1758) in Rio de Janeiro state, Brazil.

Stomoxys calcitrans is a cosmopolitan hematophagous insect with significant veterinary importance. Besides causing great stress with its bites, the fly is a mechanical vector of several pathogens of the most diverse phylogenetic groups to their hosts. The objective of this study was to test for the presence of Anaplasma marginale in stable flies collected at three points inside the campus of the Federal Rural University of Rio de Janeiro (UFRRJ), Seropédica, Rio de Janeiro, Brazil. The collected flies were dissected and separated into three parts - heads, carcass and guts - which were individually submitted to A. marginale specific semi nested PCR gene amplification. A total 150 samples of 50 flies were assayed and 11.33% were positive with predominant presence in guts. In parallel, 6 F1 colony S. calcitrans flies fed with bovine blood were also investigated, being all positive for the presence of the bacteria. This is the first report of the presence of A. marginale in S. calcitrans at Rio de Janeiro state, actually in Brazil, indicating that the epidemiological importance of this vector in the transmission of diseases with great economic impact must not be ignored.

Stomoxys calcitrans (Diptera: Muscidae): Value for Veterinary Medicine. Review

The purpose of the research is analysis and compilation of literature data on involvement of the stable fly Stomoxys calcitrans in the spread of livestock animal pathogens. Materials and methods. We have analyzed literature data from foreign sources over the past 30 years, which are indexed in the PubMed, Crossref, Web of Science and Scopus databases, about S. calcitrans as a potential vector of livestock animal pathogens. Results and discussion. A literature review is presented on assessment of economic impact by the stable fly S. calcitrans on animal husbandry, as well as possible involvement of the S. calcitrans imago in the transmission of viruses, bacteria, protozoa and helminths which are animal pathogens.

The Stable Fly (Stomoxys calcitrans) as a Possible Vector Transmitting Pathogens in Austrian Pig Farms.

This pilot study aimed to investigate stable flies from Austrian pig farms for the presence of defined swine pathogens, such as porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus 2 (PCV2), hemotrophic mycoplasmas in ingested blood and/or body parts and bacteria on the surface of the flies. Furthermore, the use of stable flies as a diagnostic matrix for the detection of pathogens in the ingested pig blood should be investigated. In total, 69 different microorganisms could be found on the surface of tested S. calcitrans from 20 different pig farms. Escherichia coli was the most common bacterium and could be found on flies from seven farms. In seven farms, hemotrophic mycoplasmas were detected in stable flies. PRRSV could not be found in any of the samples of these 20 farms but PCV2 was detected in six farms. Whether the stable fly can be used as a matrix to monitor the health status cannot be accurately determined through this study, especially in regard to PRRSV. Nevertheless, it might be possible to use the stable fly as diagnostic material for defined pathogens like Mycoplasma suis and PCV2.