Deer Flies Research Articles

A picture speaks a thousand words: A case of ocular Loa loa

The ‘African eye worm’, also known as Loa loa, is filarial nematode that is commonly, transmitted by deer flies. A history of recent travel to endemic countries near western, Africa is common in patients with Loiasis. While a majority of patients infected with Loa, loa are asymptomatic, common presentations of Loiasis include localized areas of, edema, Calbar swellings, and ocular symptoms secondary to the migration of worms, through the spaces within the eye. This case illustrated presents a healthy 31-year-old, man with no history of recent travel who presented after his friend reported that a worm, was seen in his right eye., The patient had described symptoms of pain, redness, and excessive lacrimation in his, right eye for the past five days. Although the patient originally lived in Cameroon, he, had not travelled there or to any other country since arriving to the United Arab, Emirates two years ago. On physical examination, a worm was not visualized in his, eye. However, a personal photograph of the patient taken two days prior was provided, showcasing a long thin worm migrating in the lateral subconjunctival space of his right, eye. Laboratory investigations revealed eosinophilia in this patient. The personal, photograph along with these findings allowed for the diagnosis of Loiasis, and the, patient recovered completely following an extended 42-day course of oral albendazole., This case highlights the importance of a patient’s history and the physical evidence, they bring with them, especially in patients with ambiguous physical findings and, laboratory results

Direct Observation of Feeding Behavior of Adult Tabanidae (Diptera) on Beef Cattle from Khon Kaen Province in Thailand.

Tabanidae (horse flies and deer flies) are hematophagous insects that cause direct and indirect damage to animal production. 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 infestation by tabanids. The population of tabanids was surveyed on certain body parts of the beef cattle (fore udder, tail, navel, leg, dewlap, body, and under) during the morning hours (9.00-10.30 a.m.), midday (12.00-13.30 a.m.), and afternoon (15.30-17.00 p.m.) every day for 10 days. The findings showed that two genera, Tabanus Linnaeus, 1758, and Chrysops Meigen, 1803, landed on the cows. The leg was statistically significantly the most frequent landing site for tabanids (15.067 ± 7.54) compared with other parts. The average feeding duration for each insect was 2.76 ± 1.77 min. The results showed that a significant number of tabanids were present during midday, as compared with the morning and afternoon. Temperature was found to be positively associated with fly abundance. A regression model was derived in this study (y = 4.23x - 116.09). This information is important for tabanid control and prevention in beef cattle.

Wounded but unstressed: Moose tolerate injurious flies in the boreal forest.

Moose (Alces alces) in boreal habitats feed and rest where they are exposed to Dipteran flies and the parasites they carry. We collected 31,905 flies during the summer from 12 habituated moose on the Kenai Peninsula, Alaska. Moose flies, Haematobosca alcis (Snow), Diptera: Muscidae-a species that completes its entire life cycle on or around moose-accounted for 91% of flies collected; the reminder of the flies collected included mosquitoes (Culicidae), black flies (Simuliidae), and deer flies (Tabanidae). Flies impose physiological costs for moose, e.g., vectors for parasites such as Legworm (Onchocerca spp.) which causes sores on the hind legs of moose. We found that the number of sores present on the hind legs of moose is positively correlated with body fat, which suggests a correlation between gains of energy and damage from flies. We also found that the number of sores is negatively correlated with serum albumin, which is indicative of an inflammatory response and body protein being used to repair injuries from flies and parasites. The number or type of flies present on a Moose were not correlated with the concentration of corticosteroids in saliva or feces. Flies do not elicit a stress response in moose even though the costs of repairing wounds and resisting infections of those wounds likely reduce gains of protein from summer foraging. Moose can tolerate the injuries from biting flies with regular gains from summer foraging but exposure to insect-borne parasites poses a risk to reproduction and survival.

Evaluation of knowledge, attitude and practices towards loiasis in the rural community of Sindara, in central African Gabon.

More than 20 million people are infected with L. loa, and around 40 million live in high or intermediate-risk areas in West- and Central Africa. Although loiasis is associated with significant morbidity and excess mortality, little is known about the perception of loiasis by affected communities. This study assessed the knowledge, attitudes, and practices in the rural population of Sindara, Gabon, a region characterized by high loiasis prevalence. A community-based cross-sectional survey was conducted in Gabon between January and June 2022. During systematic door-to-door visits, randomly selected inhabitants were invited to participate in this questionnaire based survey. Venous blood was collected at midday from all participants for microscopic detection of filarial infection and clinical signs of loiasis were assessed. A total of 150 participants were recruited, of which 66% were infected by L. loa. While almost everyone had some knowledge about L. loa, 72% of the participants understood that L. loa is a parasitic worm. The transmission of L. loa via the deer fly was known to only 21% of participants. The most frequently mentioned clinical symptoms attributed to loiasis were itching (84%), eye worm migration (59%), and conjunctivitis-like symptoms (53%). Participants who experienced migratory loiasis had better knowledge of loiasis and considered it as more serious. Traditional and herbal medicine was reported most often as an available treatment option (72%). While the formal healthcare sector was mentioned as the preferred treatment provider, 60% of the reported infections were treated by traditional medical practitioners. Loiasis is in general well known by this community residing in a region of high L. loa transmission. Important gaps in knowledge were discovered foremost regarding the mode of transmission. The available healthcare system does not seem to provide adequate management for loiasis.

An illustrated list for the Tabanidae (Diptera: Brachycera) from thirteen localities of the São Paulo state and redescription of Catachlorops (Amphichlorops) flavus (Wiedemann)

ABSTRACT The family Tabanidae (Diptera: Brachycera) is composed of flies commonly known as horse flies and deer flies. The family is cosmopolitan and possesses both economic and conservation interests. The females are hematophagous attacking a variety of animals, including cattle, but both females and males from several genera are flower visitors. Despite the fauna of São Paulo being largely explored due to historical factors, several species of Tabanidae in the state are still poorly known. Several are known only from the type series, and information from the literature is limited to old, sometimes inadequate descriptions and drawings. Herein we provide an illustrated list, based on the literature and specimens collected in thirteen localities from São Paulo state. For all the identified specimens we provide high-definition images from different views. Important diagnostic features for each species are supplied to facilitate the identification of the species in the region. We report five new records for São Paulo state: Catachlorops (Amphichlorops) flavus (Wiedemann), Dichelacera rubricosa (Wulp), Leucotabanus sebastianus Fairchild, Phaeotabanus aphanopterus (Wiedemann), Tabanus schadei Fairchild and one for Brazil: D. rubricosa. Also, C. flavus is redescribed along with the description of the male.

First record of Lipoptena cervi (Diptera: Hippoboscidae) among goats in Bulgaria

The investigation was conducted on 4,599 goats from eight breeds, naturally infected with ectoparasitic insects. The visit to the farms was paid after the owners alarmed for signs of considerable discomfort and itching among the animals. Two of examined flocks turned out to be infected with Lipoptena cervi (Linnaeus 1758) from the Hippoboscidae family, order Dipterа, also known as deer ked or deer fly. Complete morphological description of detected 34 flies was performed. The total body length of male specimens varied from 2.754 to 3.754 mm, and that of females: from 3.508 tо 4.500 mm. This is the first report about this insect species among goats in our country, which confirms the studies reporting expansion of its distribution area. The deer fly spread among this non-specific host incurs risk from emergence of new vector-borne diseases in men and animals

Horse fly and deer fly (Diptera: Tabanidae) species and abundance following logging in northwestern Ontario

Horse flies and deer flies are important components of habitat for many species, but how logging may alter the communities of biting flies in the boreal forest is largely unexplored. Such knowledge is important to conservation, because biting flies can shape the behaviour and sometimes even the demography of vertebrates in the boreal forest. We compared the abundance and distribution of Tabanidae species in managed boreal forest stands in northwestern Ontario with three harvest histories. Using sweep nets during 2 summers, we collected specimens from forest stands that were young (harvested 20–35 years ago), intermediate (harvested 36–69 years ago), and old (unharvested or harvested ≥ 70 years ago). We tested the hypothesis that greater harassment potential in young stands was due not only to more abundant tabanids, but more abundant obligate blood-feeding (anautogenous) tabanids, which are more persistent in host seeking. We caught 8,895 specimens from 44 species. The oldest stands had the highest species richness, but the lowest abundance of individuals, whereas young stands had the highest relative abundance and the most anautogenous specimens, potentially causing more stress to hosts in young stands. These results demonstrate that forest harvesting may reduce habitat suitability for many large mammals due to an altered tabanid community.

Human hosts recruit more host-seeking deer flies (Diptera: Tabanidae) while walking than sitting

Biting flies can strongly influence the behaviour of their hosts, for example, there is evidence that some species may avoid harassment by reducing their locomotory activity. We tested the hypothesis that potential hosts can reduce their attraction to deer flies by remaining stationary—that reducing locomotory movement reduces exposure to new deer flies compared to remaining still. During early summer in central Ontario, Canada, we conducted 20-min trials where a human host either walked or sat quietly; tabanids were captured and counted each minute using a hat outfitted with a sticky trap. During 10 trials in each treatment, we captured a total of 868 deer flies, all in the genus Chrysops; the total capture while walking was nearly five-fold greater than while sitting. During trials, the change in catch rate also differed with host activity. While the host was sitting, the mean rate of capture declined rapidly (−16% per min) to nearly zero by 20 min. In contrast, while the host was walking, this decline was much more gradual (−5% per min); after 20 min, the catch rate remained nearly constant, at roughly half the initial rate. These results are consistent with the hypothesis.

Distribution of Biting Flies Associated with Swine Production Facilities in the Southeastern United States

High populations of pest flies on swine facilities can be detrimental to the animals and producers. The purpose of this study was to identify the distribution pattern and the influence of habitats on distribution of adult biting flies surrounding commercial swine production barns in North Carolina. In this study, fly surveillance was conducted on four swine facilities in Bladen County, North Carolina, U.S.A., from January to October 2019. Biting flies typically associated with livestock were passively collected weekly on sticky traps, which were placed in three concentric circles surrounding swine barns, and then counted and identified. Stable flies [Stomoxys calcitrans (L.); Diptera: Muscidae] were most abundant on swine facilities that were mixed-use with pastured beef cattle. However, swine producers with no pastured cattle should be aware of the potential for stable flies to disperse from off-property larval development sites. Therefore, adult fly management may be necessary if populations reach nuisance levels. Horse and deer fly (Diptera: Tabanidae) captures were not related to trap proximity to water. Differences in horse and deer fly trap captures was likely less of a reflection of differences in potential fly development habitat quality (e.g., water) and more related to adult fly habitat selection.

Nanopore adaptive sampling for targeted mitochondrial genome sequencing and bloodmeal identification in hematophagous insects

BackgroundBlood-feeding insects are important vectors for an array of zoonotic pathogens. While previous efforts toward generating molecular resources have largely focused on major vectors of global medical and veterinary importance, molecular data across a large number of hematophagous insect taxa remain limited. Advancements in long-read sequencing technologies and associated bioinformatic pipelines provide new opportunities for targeted sequencing of insect mitochondrial (mt) genomes. For engorged hematophagous insects, such technologies can be leveraged for both insect mitogenome genome assembly and identification of vertebrate blood-meal sources.MethodsWe used nanopore adaptive sampling (NAS) to sequence genomic DNA from four species of field-collected, blood-engorged mosquitoes (Aedes and Culex spp.) and one deer fly (Chrysops sp.). NAS was used for bioinformatical enrichment of mtDNA reads of hematophagous insects and potential vertebrate blood-meal hosts using publically available mt genomes as references. We also performed an experimental control to compare results of traditional non-NAS nanopore sequencing to the mt genome enrichment by the NAS method.ResultsComplete mitogenomes were assembled and annotated for all five species sequenced with NAS: Aedes trivittatus, Aedes vexans, Culex restuans, Culex territans and the deer fly, Chrysops niger. In comparison to data generated during our non-NAS control experiment, NAS yielded a substantially higher proportion of reference-mapped mtDNA reads, greatly streamlining downstream mitogenome assembly and annotation. The NAS-assembled mitogenomes ranged in length from 15,582 to 16,045 bp, contained between 78.1% and 79.0% A + T content and shared the anticipated arrangement of 13 protein-coding genes, two ribosomal RNAs, and 22 transfer RNAs. Maximum likelihood phylogenies were generated to further characterize each insect species. Additionally, vertebrate blood-meal analysis was successful in three samples sequenced, with mtDNA-based phylogenetic analyses revealing that blood-meal sources for Chrysops niger, Culex restuans and Aedes trivittatus were human, house sparrow (Passer domesticus) and eastern cottontail rabbit (Sylvilagus floridanus), respectively.ConclusionsOur findings show that NAS has dual utility to simultaneously molecularly identify hematophagous insects and their blood-meal hosts. Moreover, our data indicate NAS can facilitate a wide array of mitogenomic systematic studies through novel ‘phylogenetic capture’ methods. We conclude that the NAS approach has great potential for broadly improving genomic resources used to identify blood-feeding insects, answer phylogenetic questions and elucidate complex pathways for the transmission of vector-borne pathogens.Graphical

Towards a practical trap for deer flies (Diptera: Tabanidae): initial tests of a bi-level Nzi trap

Abstract A modified Nzi trap was tested at a residence and at a farm in eastern Ontario, Canada to better capture high-flying tabanids (Diptera) such as Chrysops Meigen. A new upper trap entrance was created to provide a higher and larger opening by reducing the front blue top shelf to half its height. To minimise escape of low-flying tabanids, a vertical inner baffle was added to direct low-flying tabanids up into the cone. Half of the tests of 18 new designs caught 1.5–2.7 times more deer flies than the Nzi trap did, with the other trap designs being as effective as the Nzi trap. The optimal design that maintained equal catches of other biting flies relative to the Nzi trap was one with a phthalogen inner horizontal shelf and a netting inner vertical baffle. This design is defined in the present as the “bi-level Nzi trap.” Chrysops entered the trap mostly through the top (88%; 17 spp.), along with Hybomitra Enderlein (94%; 12 spp.). Tabanus Linnaeus (9 spp.) entered through both entrances. The most abundant Tabanus, T. quinquevittatus Wiedemann, entered mostly through the bottom (70%), whereas Stomoxys calcitrans Linnaeus entered mostly through the top (92%).

Complex host/symbiont integration of a multi-partner symbiotic system in the eusocial aphid Ceratovacuna japonica.

Some hemipteran insects rely on multiple endosymbionts for essential nutrients. However, the evolution of multi-partner symbiotic systems is not well-established. Here, we report a co-obligate symbiosis in the eusocial aphid, Ceratovacuna japonica. 16S rRNA amplicon sequencing unveiled co-infection with a novel Arsenophonus sp. symbiont and Buchnera aphidicola, a common obligate endosymbiont in aphids. Both symbionts were housed within distinct bacteriocytes and were maternally transmitted. The Buchnera and Arsenophonus symbionts had streamlined genomes of 432,286bp and 853,149bp, respectively, and exhibited metabolic complementarity in riboflavin and peptidoglycan synthesis pathways. These anatomical and genomic properties were similar to those of independently evolved multi-partner symbiotic systems, such as Buchnera-Serratia in Lachninae and Periphyllus aphids, representing remarkable parallelism. Furthermore, symbiont populations and bacteriome morphology differed between reproductive and soldier castes. Our study provides the first example of co-obligate symbiosis in Hormaphidinae and gives insight into the evolutionary genetics of this complex system.

2021 AMCA Presidential Address.

2021 AMCA Presidential Address.

Cretaceous Horse flies and their phylogenetic significance (Diptera: Tabanidae)

Popularly known as horse flies or deer flies, Tabanidae, has 4.400 described species distributed worldwide. Most of the females are hematophagous, but several species are also flower visitors. Cretaceous fossils of Tabanidae are scarce and the known fossil species have plesiomorphic features unknown in modern horse flies. Here, we revised the taxonomy of the Tabanidae from the Crato Formation of Brazil describing a new genus, Araripusgen. nov., and two new species – Araripus crassitibialissp. nov. and Cratotabanus cearensissp. nov. The holotype of Cratotabanus stonemyomorphus, the type species of Cratotabanus, is redescribed, and the male is described for the first time. In addition, we investigate the phylogenetic position of Cretaceous horse fly fossils using morphological characters in the context of a wider analysis also including representatives of extant lineages.

Tularemia: a re-emerging tick-borne infectious disease.

Tularemia is a bacterial disease of humans, wild, and domestic animals. Francisella tularensis, which is a Gram-negative coccobacillus-shaped bacterium, is the causative agent of tularemia. Recently, an increase in the number of human tularemia cases has been noticed in several countries around the world. It has been reported mostly from North America, several Scandinavian countries, and certain Asian countries. The disease spreads through vectors such as mosquitoes, horseflies, deer flies, and ticks. Humans can acquire the disease through direct contact of sick animals, consumption of infected animals, drinking or direct contact of contaminated water, and inhalation of bacteria-loaded aerosols. Low infectious dose, aerosol route of infection, and its ability to induce fatal disease make it a potential agent of biological warfare. Tularemia leads to several clinical forms, such as glandular, ulceroglandular, oculoglandular, oropharyngeal, respiratory, and typhoidal forms. The disease is diagnosed through the use of culture, serology, or molecular methods. Quinolones, tetracyclines, or aminoglycosides are frequently used in the treatment of tularemia. No licensed vaccine is available in the prophylaxis of tularemia and this is need of the time and high-priority research area. This review mostly focuses on general features, importance, current status, and preventive measures of this disease.

New records and DNA barcoding of deer flies, Chrysops (Diptera: Tabanidae) in Thailand

Chrysops spp. or deer flies (Diptera: Tabanidae) are hematophagous flies of medical and veterinary importance and some species are important vectors of Trypanosoma evansi, the causative agent of surra in Thailand. However, data regarding deer fly species and their molecular identification are limited. Accurate species identification will indicate the appropriate control measures. In this study, an entomological survey of deer flies from different sites in Thailand between May 2018 and June 2019 were conducted. In addition, mitochondrial cytochrome oxidase subunit I (COI) barcoding region was used for species identification. A total of 82 females were collected and 6 species were identified. Of these, three species are new records for Thailand: C. designatus, C. fuscomarginalis and C. vanderwulpi bringing the species total found in Thailand to nine. The COI sequences revealed an intraspecific divergence of 0.0%–2.65% and an interspecific divergence of 7.03%–13.47%. Phylogenetic analysis showed that all deer fly species were clearly separated into distinct clusters according to morphologically identified species. These results indicated that COI barcodes were capable in discriminating between deer fly species on the basis of the barcoding gap and phylogenetic analysis. Therefore, DNA barcoding is a valuable tool for species identification of deer flies in Thailand.

Seasonal surveillance of deer and horse flies (Diptera: Tabanidae), Gyeonggi province, Republic of Korea

• A total of 9985 tabanid flies comprising 2 subfamilies, 4 genera and 17 species. • The predominant species collected was Chrysops mlokosiewiczi . • The highest numbers of tabanids were collected from June-August. • A bimodal peak was observed for Chrysops mlokosiewiczi in June and late-July. Deer and horse flies, Family Tabanidae, are biological, mechanical, and potential vectors of approximately 27 viral, bacterial, and helminthic pathogens of veterinary and medical importance. Biting fly surveillance was conducted using New Jersey light traps and Mosquito Magnet® traps from May-October during 2015–2018 at eight sites (villages and US military installations and training areas) near/in the Demilitarized Zone and at a US military installation in southern Gyeonggi province, Republic of Korea. A total of 9985 deer and horse flies, comprising 4 genera and 17 species, were collected. The predominant species collected was Chrysops mlokosiewiczi (95.39%), followed by Chrysops suavis (1.48%) and Haematopota koryoensis (1.07%), while the remaining species accounted for only 2.06% of the specimens collected. A bimodal peak was observed for C. mlokosiewiczi in June and late-July, but not for the other two predominant species during the whole of the study period. This study provides and insight into ecological behavior and seasonal abundance of deer and horse flies in Gyeonggi province, Republic of Korea.

A Case-control Study on the Role of Deer Fly in the Transmission of Hepatitis B in Kerala, South India.

Background:The sudden increase in the number of Hepatitis B-positive cases between December 2018 and June 2019, in Pathanamthitta District of Kerala in South India, aroused fear both among the government and the people. Some earlier studies postulated that deer flies act as vectors for the transmission of Hepatitis B. Deer flies were found to be in plenty in the concerned area and their bite was also considered part and parcel of everyday life. Hence, it was considered necessary to prove whether deer flies played a role in the transmission of Hepatitis B.Aims and Objective:The aim of this study is to investigate the role of deer fly in the transmission of Hepatitis B.Materials and Methods:A case–control study design was adopted to test the hypothesis concerning the possible role of deerfly in disease transmission. Cases were those who were picked up by the routine surveillance system (Integrated Disease Surveillance Project) and found to be positive for Hepatitis B surface antigen (HBsAg). Controls were age- (±5 years) and gender-matched neighborhood individuals negative for HBsAg. Data was collected with the help of a pretested interview schedule.Results:There was no significant association between bite of deer flies and acquisition of Hepatitis B.Conclusion:This study concluded proving the deer fly hypothesis to be false.

Management of Plant and Arthropod Pests by Deer Farmers in Florida

Abstract Deer farming is a growing livestock industry. As with established livestock farming, biting arthropod pest control is a challenge, but knowledge about pest control practices being utilized by deer farmers is limited. To fill this knowledge gap and to assess if recommended integrated pest management (IPM) programs were being used, we surveyed Florida deer farmers about their pest management programs via an online questionnaire. Of surveyed deer farmers in Florida, 94% reported using chemicals for plant and arthropod pest control. Deer farmers reported controlling biting midges, mosquitoes, horse flies, and deer flies as their target arthropods. The primary herbicide and arthropod-targeted pesticide reported were glyphosate and permethrin, respectively. Two thirds of deer farmers reported that they were concerned about pesticide resistance developing on their properties, and 72% reported utilizing resistance mitigation techniques such as alternating pesticides or using less pesticide at the start of a management routine. A majority, 66%, of deer farmers reported using a combination of control techniques. Future work should focus on best management practice development based on the study findings, as well as educational materials regarding IPM use for deer farmers. Together these tools should improve animal health and well-being on deer farms by facilitating safe and sustainable arthropod management.

Identification of a species of deer fly attacking human and live stocks in Assam, India

During April 2018, a sudden appearance of some unknown flies was observed in some villages under Sibsagar district of Assam, Northeast India. The flies attacked in groups and had more attraction towards human than livestock. The present article describes the entomological and molecular identification of the fly at species level in Sibsagar district of Assam, northeast India. Preliminary examination revealed the fly to be an insect of order Diptera, Family Tabanidae and Genus Chrysops as they posses short proboscis, ocelli, third antennal joint with five divisions and wings demarcated with dark median cross-band. This was supported by molecular data where the partial nucleotide sequences of Mitochondrial COI gene revealed maximum identity (90.6%-92.3%) with genus Chrysops. The mitochondrial COI sequence data of Chrysops flavocinctus has been made available in NCBI Gen Bank. Gen Bank Accession No. MH998226.