Diel activity and preferred landing sites in Culicoides biting midges attacking Fjord horses

NARCIS (Netherlands)

Elbers, A.R.W.; Heuvel, van den S.J.; Meiswinkel, R.

2016-01-01

In the summer of 2014, in the central part of The Netherlands, Culicoides spp. (Diptera: Ceratopogonidae) attack rates, biting rates, and preferred landing sites were determined for a pair of Fjord horses maintained permanently at pasture in an area devoid of cattle. Eleven body regions of the

Field evaluation of the efficacy and safety of a deltamethrin pour on formulation (Butox® 7.5 mg/ml pour on) for the control of Culicoides midges in sheep

OpenAIRE

Weiher, Wiebke

2014-01-01

Culicoides spp. (Diptera: Ceratopogonidae) are the main vectors of Bluetongue and Schmallenberg virus disease, which are infectious diseases of ruminants. Recently, both viral diseases occurred for the first time in Germany and caused substantial suffering and large economic losses, primarily in sheep flocks. None of the currently available insecticides is registered to control infestations with Culicoides midges in ruminants. This study aimed to assess the safety and efficacy of a pour on fo...

Culicoides variipennis (Diptera: Ceratopogonidae) complex in California.

Science.gov (United States)

Holbrook, F R; Tabachnick, W J

1995-07-01

Genetic relationships were examined among 24 collections, representing 23 populations of Culicoides variipennis (Coquillett) using isozyme electrophoresis of 11 protein encoding loci. The populations were collected from alkaline or fresh water larval habitats in California. Distance analysis demonstrated that C. v. occidentalis Wirth and Jones and C. v. sonorensis Wirth and Jones are genetically distinct. All C. v. occidentalis were geographically isolated from each other in highly alkaline or saline larval habitats, whereas C. v. sonorensis populations were collected from artificial freshwater habitats that were polluted with organic wastes. Higher levels of gene flow were found between C. v. sonorensis populations than from C. v. sonorensis populations to nearby C. v. occidentalis populations, indicative of genetic isolation between subspecies. Northern California C. v. sonorensis were genetically distinguishable from southern California C. v. sonorensis. The relationship between this variation and bluetongue disease epidemiology in California is discussed.

Culicoides variipennis (Diptera: Ceratopogonidae) complex in Virginia.

Science.gov (United States)

Schmidtmann, E T; Holbrook, F R; Day, E; Taylor, T; Tabachnick, W J

1998-09-01

Immature Culicoides variipennis (Coquillett) were sampled from aquatic habitats throughout Virginia, reared to adults, and examined by isozyme electrophoresis to assess their taxonomic status. Data from 22 counties showed that C. v. variipennis is widespread and common, the predominant taxon throughout Virginia, and genetically similar to C. v. variipennis in Maryland. Because C. v. variipennis is considered an inefficient vector of the bluetongue viruses, this observation is consistent with the low seroprevalence of bluetongue in indigenous livestock of the mid-Atlantic region. Culicoides v. sonorensis Wirth & Jones, considered to be the primary North American vector of the bluetongue viruses, was recovered in large numbers only from a wastewater lagoon at a dairy in southeastern Virginia, but also was detected at low levels in 6 other counties. Comparison of genetic distances and patterns of discriminating alleles among Virginia populations of C. v. variipennis and C. v. sonorensis showed that respective subspecies are genetically distinct and show no evidence of introgression, irrespective of geographic- and habitat-level sympatry. The persistence of a pure C. v. sonorensis population in a dairy wastewater lagoon may reflect physico-chemical factors that influence the distribution of immature C. variipennis complex populations. A better understanding of the distribution of the C. variipennis complex will benefit regionalization of U.S. exports of livestock and livestock germplasm to bluetongue-free countries.

The Culicoides of Southeast Asia (Diptera: Ceratopogonidae)

Science.gov (United States)

1989-01-01

Type.-Holotype male, Chiang Mai Prov., Thailand, 1933, O.R. Causey (on slide, Type in USNM). Southeast Asia Records.-- INDONESIA: Sulawesi (North...Kapit Dist., Nanga Pelagus (Traub). SINGAPORE: Kg. Chantek Bahru (Colless); Nee Soon (Colless). THAILAND: Chiang Mai (Causey); Chiang Rai (Causey...THAILAND: Chiang Mai (Notonanda, Scanlon). Cholburi, Bangphra,(Scanlon). Khon Kaen Prov., Ban Phai and Chum Phae (Manop R.). Loei Prov., Dan Sal, Ban

Insectos acuáticos de la Meseta del Somuncura, Patagonia, Argentina. Inventario preliminar Aquatic insects from Somuncura plateau, Patagonia, Argentina. Preliminary inventory

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Javier Muzón

2005-12-01

Full Text Available RESUMEN. Se brinda un inventario preliminar de los insectos acuáticos de la Meseta del Somuncura y su área de influencia (Patagonia, Argentina realizado sobre la base de colecciones y registros previos de especies pertenecientes a los órdenes Ephemeroptera, Odonata, Hemiptera (Heteroptera, Trichoptera, Diptera (familias Ceratopogonidae, Culicidae y Psychodidae y Coleoptera. Se han relevado diversos tipos de ambientes en 14 localidades. El número de especies registrado asciende a 78, agrupadas en 51 géneros y 26 familias, de las cuales 33 se citan por primera vez del área. De los taxa registrados 83% de los géneros corresponden a grupos de amplia distribución (neotropicales, americanos o cosmopolitas, mientras que 41% de las especies presentan una distribución patagónica o andina.ABSTRACT. A preliminary inventory of the aquatic insects from the Somuncura plateau and its area of influence (Patagonia, Argentina is presented. It was done on the basis of the study of collections and previous records of species belonging to the orders Ephemeroptera, Odonata, Hemiptera (Heteroptera, Trichoptera, Diptera (families Ceratopogonidae, Culicidae, and Psychodidae and Coleoptera. Different kinds of environments were surveyed in 14 localities. Seventy eigth species grouped in 51 genera and 26 families were registered, and 33 species are new records for the area. Eighty three % of the registered genera are widely distributed (neotropical, american or cosmopolitan, while 41 % of the species exhibit patagonic or andean distribution.

[Parahaemoproteus desseri n. sp.; gametogony and schizogony in the natural host: Psittacula roseata from Thailand, experimental sporogony in Culicoides nubeculosus (author's transl)].

Science.gov (United States)

Miltgen, F; Landau, I; Ratanaworabhan, N; Yenbutra, S

1981-01-01

The gametogony and the tissue schizogony of Parahaemoproteus desseri are described in the natural host: Psittacula roseata; the schizonts develop in muscle fibres; they are large (up to 900 micrometer) and often sausage shaped with pseudo-septa. Experimental sporogony was studied in laboratory bred Culicoides nubeculosus (Ceratopogonidae). Oocysts are small and give rise to a small number of sporozoites. The morphological characteristics of the schizonts of our Parahaemoproteus are very similar to those of schizonts of Arthrocystis galli and therefore it is possible that the two genera are synonymous.

Kuş Gölü (Bandırma Makrobentik Omurgasız Faunası Hakkında Bir Ön Araştırma.

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Süleyman Balık

2015-12-01

Full Text Available Kuş Gölü’nün makrobentik omurgasız faunasını belirlemek amacıyla 1987 ve 1988 yılları arasında aylık periyotlar halinde, bir yıl süre ile 5 istasyonda arazi çalışması yapılmıştır. Ekman grab ile alınan çamur örnekleri 500 μm göz açıklığındaki elekten geçirilmiş ve örnekler %4’lük formaldehit solüsyonunda tespit edilmiştir. Araştırma sonucunda, Oligochaeta sınıfından 10, Chironomidae familyasından 5 ve Ceratopogonidae familyasından 1 olmak üzere toplam 16 takson tespit edilmiştir. Kuş gölü’nde metrekarede ortalama 6759 birey tespit edilmiş, grupların oransal dağılımında %81,94 ile Oligochaeta bireylerinin en baskın grubu oluşturduğu, bu grubu Chironomidae (%17,90 ve Ceratopogonidae (%0,16 larvalarının takip ettiği saptanmıştır. Tespit edilen grupların istasyonlara göre oransal dağılımlarında ise, 1. istasyonun en zengin (%28,71, 4. istasyonun en fakir (%12,77 istasyon olduğu gözlenmiştir

The bloodsucking biting midges of Argentina (Diptera: Ceratopogonidae

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Gustavo R Spinelli

2005-04-01

Full Text Available A key is presented for the identification of the adults of 54 species of bloodsucking ceratopogonids, 51 of which are known inhabitants of Argentina, and Culicoides uruguayensis Ronderos, C. pifanoi Ortiz, and C. trilineatus Fox, which are known to occur in bordering Uruguay and Paraguay. Wing photographs are provided of females of the 45 species of Culicoides. Three new species of Culicoides Latreille from Northeastern Argentina are described and illustrated: C. austroparaensis Spinelli, C. bachmanni Spinelli, and C. williamsi Spinelli. The following six species are recorded for the first time from Argentina and/or bordering localities in Paraguay: Leptoconops brasiliensis (Lutz, C. gabaldoni Ortiz, C. ginesi Ortiz, C. pifanoi Ortiz, C. pseudocrescentis Tavares and Luna Dias, and C. trilineatus; and C. estevezae Ronderos and Spinelli is newly recorded from Misiones province of Argentina. C. lopesi Barretto is excluded from the Argentinean ceratopogonid fauna.

Operation & Maintenance Environmental Impact Statement for the Federal Facilities at Sault Ste. Marie, Michigan, Addressing Limited Season Extension of Operation. Supplement.

Science.gov (United States)

1979-10-01

azteca Aca r ina I sopoda Ar renur us Asellus Lirceus Castropoda Anic ola Diptera Campe loma Tipulidae (S) Gyraulus Ceratopogonidae Helisoma...turbidity could affect the primary productivity in the area for a brief period. Solar energy entering a body of water is converted by microscopic...8217. 4 U 0 Cd co m4 Z i C4 i dio C. ’. U ’U d 0 . C dd W 𔃾 Cd 4 d d > d - U 0 - C ’. i d . - d 44tl n C> - _4 In 0 0 -d W - C C. U : A i ’U 0 di -0 A

Effects of cutting disturbance in Schoenoplectus californicus (C.A. Mey. Soják on the benthic macroinvertebrates - doi: 10.4025/actascibiolsci.v33i1.6383 Effects of cutting disturbance in Schoenoplectus californicus (C.A. Mey. Soják on the benthic macroinvertebrates - doi: 10.4025/actascibiolsci.v33i1.6383

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Norma Luiza Würdig

2011-02-01

Full Text Available Lagoons are considered protected areas because these systems play a key ecological role. However, the extraction of macrophyte Schoenoplectus californicus is held for manufacture of handcrafts, being an alternative income for riverbank communities. This study evaluated the impact of S. californicus experimental cutting on benthic macroinvertebrates trough a field experiment. Macroinvertebrates were sampled at 1, 12, 26 and 60 days after the macrophyte cutting in demarked plots (1 m², as well at control plots. The families number was not statistically different (ANOVA, p > 0.05, but the total density of invertebrates, and the density of Ceratopogonidae were significant (ANOVA, p S. californicus, in this area, as the intensity of the cut held, did not affect considerably the aquatic macroinvertebrates. The results suggest that the small-scale extractivism in these regions carries little effect because the fauna of adjacent areas probably can quickly colonize the disturbed areas.Lagoons are considered protected areas because these systems play a key ecological role. However, the extraction of macrophyte Schoenoplectus californicus is held for manufacture of handcrafts, being an alternative income for riverbank communities. This study evaluated the impact of S. californicus experimental cutting on benthic macroinvertebrates trough a field experiment. Macroinvertebrates were sampled at 1, 12, 26 and 60 days after the macrophyte cutting in demarked plots (1 m², as well at control plots. The families number was not statistically different (ANOVA, p > 0.05, but the total density of invertebrates, and the density of Ceratopogonidae were significant (ANOVA, p S. californicus, in this area, as the intensity of the cut held, did not affect considerably the aquatic macroinvertebrates. The results suggest that the small-scale extractivism in these regions carries little effect because the fauna of adjacent areas probably can quickly colonize the disturbed

Biting Midges (Ceratopogonidae: Culicoides Latreille) Recorded from Farms in Sweden

DEFF Research Database (Denmark)

Nielsen, S. A.; Nielsen, B.O.; Chirico, J.

2009-01-01

In light of the emergence of bluetongue in Northern Europe, populations of Culicoides species were monitored in and around several Swedish livestock farms (surveillance in 2007 and 2008). The position of the sampling sites ranged from about latitude 55° N to about 68° N. Thirty-three Culicoides s...

Culicoides midges (Diptera: Ceratopogonidae as vectors of orbiviruses in Slovakia

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Adela Sarvašová

2014-09-01

Full Text Available In recent years, rapid spread of Culicoides-borne pathogens such as bluetongue (BT and Schmallenberg viruses have been reported in Europe. In this study we examined the Culicoides populations in farms with wild and domestic ruminants in Eastern Slovakia with the aim to confirm the presence of biting midges serving as potential vectors of important pathogens. The main vector complexes were the Obsoletus complex (54%; n=4,209 and the Pulicaris complex (23%; n=1,796. To estimate the relative abundance of the cryptic species of the Obsoletus complex (Culicoides obsoletus, Culicoides scoticus and Culicoides montanus, we performed the multiplex polymerase chain reaction (PCR based on ITS-2 and ITS-1 segments, on 125 midges randomly sampled. The relative abundance of C. obsoletus ranged from 5.26% in the farm with wild ruminants to 85.71% in another farm with cattle and sheep. A total of 112 pools of parous and gravid females belonging to the Obsoletus and Pulicaris complexes were tested for virus detection by the real-time reverse transcription polymerase chain reaction (RT-PCR for BT virus, as well as for the Epizootic Hemorrhagic Disease Virus (EHDV, with negative results.

MACROZOOBENTHIC COMMUNITIES STRUCTURE CHARACTERISTIC OF CERTAIN TRIBUTARIES OF THE SIRET RIVER FROM HARGHITA, MARAMUREŞ AND VRANCEA MOUNTAINS AND MOLDOVEI PLATEAU

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Elena-Andreea GHIBUŞI

2012-01-01

Full Text Available 35 qualitative macrozoobentonic samples were collected in 2011 from many Siret river tributaries coming from the Harghita Mountains (5 stations, Maramureş Mountains (14 stations, Moldavian Plateau (4 stations and Vrancea Mountains (12 stations. Laboratory analysis of samples revealed the existence of the following 15 groups of benthic invertebrates: Ephemeroptera, Plecoptera, Trichoptera, Oligochaeta, Diptera (Chironomidae, Simuliidae, Ceratopogonidae, Limoniidae, Gastropoda, Bivalva, Coleoptera, Acarina, Odonata, Hirudinea, Isopoda, Heteroptera, Turbellariata and Collembola. Groups that have the highest frequencies were mayflies and dipterans (each with a frequency of 97.1%, followed by caddisflies (80%, amphipods (68.6%, oligochaetes (57.1% and stoneflies (54.3%. Presence of sensitive groups to water quality degradation (Ephemeroptera, Trichoptera and Plecoptera with high frequency shows good quality water at most stations investigated.

Insectos acuáticos de la Meseta del Somuncura, Patagonia, Argentina. Inventario preliminar

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Javier MUZÓN

2005-01-01

Full Text Available Se brinda un inventario preliminar de los insectos acuáticos de la Meseta del Somuncura y su área de influencia (Patagonia, Argentina realizado sobre la base de colecciones y registros previos de especies pertenecientes a los órdenes Ephemeroptera, Odonata, Hemiptera (Heteroptera, Trichoptera, Diptera (familias Ceratopogonidae, Culicidae y Psychodidae y Coleoptera. Se han relevado diversos tipos de ambientes en 14 localidades. El número de especies registrado asciende a 78, agrupadas en 51 géneros y 26 familias, de las cuales 33 se citan por primera vez del área. De los taxa registrados 83% de los géneros corresponden a grupos de amplia distribución (neotropicales, americanos o cosmopolitas, mientras que 41% de las especies presentan una distribución patagónica o andina.

Sympatry in the Culicoides variipennis complex (Diptera: Ceratopogonidae): a taxonomic reassessment.

Science.gov (United States)

Holbrook, F R; Tabachnick, W J; Schmidtmann, E T; McKinnon, C N; Bobian, R J; Grogan, W L

2000-01-01

We report sympatry among larval populations of the Culicoides variipennis complex in widespread and diverse aquatic habitats throughout the United States. Six sites in California, Nevada, New Mexico, and Texas were co-inhabited by C. v. occidentalis and C. v. sonorensis, whereas 8 sites in Florida, Georgia, Louisiana, Maryland, and Texas were co-occupied by C. v. sonorensis and C. v. variipennis. No intermediate forms were identified either electrophoretically or morphologically in adults reared from field-collected larvae and pupae. The absence of intergrades in zones of sympatry represents sufficient evidence to confirm species status for Culicoides variipennis (Coquillett) and Culicoides occidentalis Wirth & Jones, and to elevate Culicoides sonorensis to species rank (NEW STATUS). Culicoides v. albertensis Wirth & Jones is a synonym of C. sonorensis (NEW SYNONYMY); C. v. australis Wirth & Jones also is confirmed as a synonym of C. sonorensis. We also demonstrated a correlation between population taxonomic status as determined by electrophoresis and adult morphology.

First-generation physical map of the Culicoides variipennis (Diptera: Ceratopogonidae) genome.

Science.gov (United States)

Nunamaker, R A; Brown, S E; McHolland, L E; Tabachnick, W J; Knudson, D L

1999-11-01

Recombinant cosmids labeled with biotin-11-dUTP or digoxigenin by nick translation were used as in situ hybridization probes to metaphase chromosomes of Culicoides variipennis (Coquillett). Paired fluorescent signals were detected on each arm of sister chromatids and were ordered along the 3 chromosomes. Thirty-three unique probes were mapped to the 3 chromosomes of C. variipennis (2n = 6): 7 to chromosome 1, 20 to chromosome 2, and 6 to chromosome 3. This work represents the first stage in generating a physical map of the genome of C. variipennis.

[Socio-entomologic survey in human trypanosomiasis focus of Yamba (Peoples Republic of Congo)].

Science.gov (United States)

Gouteux, J P; Malonga, J R

1985-01-01

A study carried out at villagers level in a focus infected by human trypanosomiasis (Yamba, Bouenza region, Congo, Mikengue ethnic group) revealed that modern medicin is recognized by them as the sole possibility to treat the sleeping sickness. The witch doctor, if he cannot transmit the sickness, is perfectly able to aggravate it. He is considered as the responsible for any fatal issue. Tsetse flies are charged of transmitting the sickness as well as other biting insects (black flies, ceratopogonidae). The elders give an historical role to pigs in spreading the sickness. Villagers seem very determined to assume themselves fighting against the tsetse fly by trapping, but impregnation of traps by an insecticide got some problems (technical know-how, equipment) which have been solved by a new model of trap designed by the ORSTOM Center in Brazzaville.

Effects of cutting disturbance in Schoenoplectus californicus (C.A. Mey. Soják on the benthic macroinvertebrates = Efeito do distúrbio de corte em Schoenoplectus californicus (C.A. Mey. Soják sobre a fauna de macroinvertebrados bentônicos

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Thiago Cesar Lima Silveira

2011-01-01

Full Text Available Lagoons are considered protected areas because these systems play a key ecological role. However, the extraction of macrophyte Schoenoplectus californicus is held for manufacture of handcrafts, being an alternative income for riverbank communities. This studyevaluated the impact of S. californicus experimental cutting on benthic macroinvertebrates trough a field experiment. Macroinvertebrates were sampled at 1, 12, 26 and 60 days after themacrophyte cutting in demarked plots (1 m², as well at control plots. The families number was not statistically different (ANOVA, p > 0.05, but the total density of invertebrates, and the density of Ceratopogonidae were significant (ANOVA, p No Brasil, as margens de lagoas são consideradas áreas protegidas por desempenharem importante papel ecológico. No entanto, a extração da macrófita Schoenoplectus californicus é realizada para a fabricação de artesanato, sendo alternativa de renda para as comunidades ribeirrinhas. Este estudo teve como objetivo avaliar o impacto do corte de S. californicus sobre os macroinvertebrados bentônicos por meio de um experimento de campo. Os macroinvertebrados foram amostrados um dia, 12, 26 e 60 dias após o corte em macrófitas em parcelas demarcadas (1 m², bem como nas parcelas-controle. As famílias de macroinvertebrados mais abundantes não apresentaram diferenças significativas (ANOVA, p < 0,05, mas a densidade total de invertebrados e a densidade de Ceratopogonidae foram significativas (ANOVA, p < 0,05 para a interação entre a data de amostragem e tratamento. A Análise de Componentes Principais identificou que a profundidade no local do experimento foi a variável que influenciou a variabilidade entre as amostras coletadas no experimento. Concluiu-seque o corte de S. californicus, nessa área, como a intensidade do corte realizado, não afeta drasticamente a composição de macroinvertebrados aquáticos. Os resultados sugerem que o extrativismo em pequenas

Spatial abundance and clustering of Culicoides (Diptera: Ceratopogonidae) on a local scale

DEFF Research Database (Denmark)

Kirkeby, Carsten; Bødker, Rene; Stockmarr, Anders

2013-01-01

, and cluster locations shifted between catch nights. No significant temporal autocorrelation was detected. CAR models for both species groups identified a significant positive impact of humidity and significant negative impacts of precipitation and wind turbulence. Temperature was also found to be significant...... abundance pattern of these two species groups in the field by intensive sampling with a grid of light traps on 16 catch nights. Neighboring trap catches can be spatially dependent on each other, hence we developed a conditional autoregressive (CAR) model framework to test a number of spatial and non...... of Culicoides moved around in a dynamic pattern varying between catch nights. This conforms with the modeling but was not explained by any of the tested covariates. The mean abundance within these clusters was up to 11 times higher for the Obsoletus group and 4 times higher for the Pulicaris group compared...

Dermatozoonosis by Culicoides bite (Diptera, Ceratopogonidae in Salvador, State of Bahia, Brazil

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Italo A. Sherlock

1964-01-01

Full Text Available Os autores iniciam com êste, uma série de trabalhos sôbre a Dermatozoonose provocada pela picada de Culicoides, em Salvador, Bahia, Brasil. No presente, tratam das espécies de Culicoides encontradas em Salvador, baseados na coleta de 2.947 exemplares, durante os anos de 1959 a 1963. Encontraram as 4 espécies seguintes; C. (O. paraensis (Goeldi, 1905 C. (O. limonensis Ortiz & Leon, 1955 C. (C. insignis Lutz, 1913 C. (C. flavivenula Costa Lima, 1937. Não reencontraram o C. (C. maruim, Lutz, 1913 assinalado por fox (1948 e WIRTH & BLANTON (1956 para Salvador. Dessas espécies o C. (C. paraensis se mostrou a predominante, abrangendo 98% de exemplares coletados. Apresentam a distribuição das espécies por bairros e respectivas quantidades coletadas. Finalizando, dão as principais características morfológicas das espécies, ilustrando essas com desenhos do material por êles estudado.

On morphology and distribution of Neurohelea luteitarsis (Waltl) (Diptera: Ceratopogonidae) in Europe

Czech Academy of Sciences Publication Activity Database

Tóthová, A.; Knoz, J.; Gelbič, Ivan

2009-01-01

Roč. 45, č. 3 (2009), s. 297-301 ISSN 0037-9271 R&D Projects: GA AV ČR(CZ) IBS6022201 Institutional research plan: CEZ:AV0Z50070508 Keywords : phylogeny * eversible sacs * spermatheca Subject RIV: EG - Zoology Impact factor: 0.600, year: 2009

The salivary secretome of the biting midge, Culicoides sonorensis

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Christopher J. Lehiy

2014-06-01

Full Text Available Culicoides biting midges (Diptera: Ceratopogonidae are hematophagous insects with over 1400 species distributed throughout the world. Many of these species are of particular agricultural importance as primary vectors of bluetongue and Schmallenberg viruses, yet little is known about Culicoides genomics and proteomics. Detailed studies of members from other blood-feeding Dipteran families, including those of mosquito (Culicidae and black fly (Simuliidae, have shown that protein components within the insect’s saliva facilitate the blood feeding process. To determine the protein components in Culicoides sonorensis midges, secreted saliva was collected for peptide sequencing by tandem mass spectrometry. Forty-five secreted proteins were identified, including members of the D7 odorant binding protein family, Kunitz-like serine protease inhibitors, maltase, trypsin, and six novel proteins unique to C. sonorensis. Identifying the complex myriad of proteins in saliva from blood-feeding Dipteran species is critical for understanding their role in blood feeding, arbovirus transmission, and possibly the resulting disease pathogenesis.

The range of attraction for light traps catching Culicoides biting midges (Diptera: Ceratopogonidae).

Science.gov (United States)

Kirkeby, Carsten; Græsbøll, Kaare; Stockmarr, Anders; Christiansen, Lasse E; Bødker, René

2013-03-15

Culicoides are vectors of e.g. bluetongue virus and Schmallenberg virus in northern Europe. Light trapping is an important tool for detecting the presence and quantifying the abundance of vectors in the field. Until now, few studies have investigated the range of attraction of light traps. Here we test a previously described mathematical model (Model I) and two novel models for the attraction of vectors to light traps (Model II and III). In Model I, Culicoides fly to the nearest trap from within a fixed range of attraction. In Model II Culicoides fly towards areas with greater light intensity, and in Model III Culicoides evaluate light sources in the field of view and fly towards the strongest. Model II and III incorporated the directionally dependent light field created around light traps with fluorescent light tubes. All three models were fitted to light trap collections obtained from two novel experimental setups in the field where traps were placed in different configurations. Results showed that overlapping ranges of attraction of neighboring traps extended the shared range of attraction. Model I did not fit data from any of the experimental setups. Model II could only fit data from one of the setups, while Model III fitted data from both experimental setups. The model with the best fit, Model III, indicates that Culicoides continuously evaluate the light source direction and intensity. The maximum range of attraction of a single 4W CDC light trap was estimated to be approximately 15.25 meters. The attraction towards light traps is different from the attraction to host animals and thus light trap catches may not represent the vector species and numbers attracted to hosts.

The range of attraction for light traps catching Culicoides biting midges (Diptera: Ceratopogonidae)

DEFF Research Database (Denmark)

Kirkeby, Carsten; Græsbøll, Kaare; Stockmarr, Anders

2013-01-01

Background Culicoides are vectors of e.g. bluetongue virus and Schmallenberg virus in northern Europe. Light trapping is an important tool for detecting the presence and quantifying the abundance of vectors in the field. Until now, few studies have investigated the range of attraction of light tr...... light trap was estimated to be approximately 15.25 meters. The attraction towards light traps is different from the attraction to host animals and thus light trap catches may not represent the vector species and numbers attracted to hosts.......Background Culicoides are vectors of e.g. bluetongue virus and Schmallenberg virus in northern Europe. Light trapping is an important tool for detecting the presence and quantifying the abundance of vectors in the field. Until now, few studies have investigated the range of attraction of light...... traps. Methods Here we test a previously described mathematical model (Model I) and two novel models for the attraction of vectors to light traps (Model II and III). In Model I, Culicoides fly to the nearest trap from within a fixed range of attraction. In Model II Culicoides fly towards areas...

Macroinvertebrates associated with bryophyta in a first-order Atlantic Forest stream

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Beatriz F. J. V. Rosa

2011-06-01

Full Text Available This study describes the composition and structure of the benthic community associated with bryophytes in a first-order stream, located in a biological reserve of the Atlantic Forest, during two seasons. During three months of the dry season of 2007 and three months of the rainy season of 2008, samples of bryophytes attached to stones were collected randomly, along a 100 m stream reach. The structure of the community was analyzed through the mean density of individuals, Shannon's diversity index, Pielou's evenness, family richness, dominance index, and the percentage of Ephemeroptera, Plecoptera and Trichoptera (% EPT. Chironomidae larvae were dominant in the two periods of study, followed by Ceratopogonidae in the rainy season, and Naididae in the dry season. The orders EPT contributed 14 families. The results showed that bryophytes constitute suitable habitat which is able to shelter an abundant and diversified benthic fauna in a small extension of the stream. This habitat provides refuge during spates, and thus minimizes downstream transport of the macroinvertebrate fauna.

In situ effects of titanium dioxide nanoparticles on community structure of freshwater benthic macroinvertebrates.

Science.gov (United States)

Jovanović, Boris; Milošević, Djuradj; Piperac, Milica Stojković; Savić, Ana

2016-06-01

For the first time in the current literature, the effect of titanium dioxide (TiO2) nanoparticles on the community structure of macroinvertebrates has been investigated in situ. Macroinvertebrates were exposed for 100 days to an environmentally relevant concentration of TiO2 nanoparticles, 25 mg kg(-1) in sediment. Czekanowski's index was 0.61, meaning 39% of the macroinvertebrate community structure was affected by the TiO2 treatment. Non-metric multidimensional scaling (NMDS) visualized the qualitative and quantitative variability of macroinvertebrates at the community level among all samples. A distance-based permutational multivariate analysis of variance (PERMANOVA) revealed the significant effect of TiO2 on the macroinvertebrate community structure. The indicator value analysis showed that the relative frequency and abundance of Planorbarius corneus and Radix labiata were significantly lower in the TiO2 treatment than in the control. Meanwhile, Ceratopogonidae, showed a significantly higher relative frequency and abundance in the TiO2 treatment than in the control. Copyright © 2016 Elsevier Ltd. All rights reserved.

Papular dermatitis induced in guinea pigs by the biting midge Culicoides sonorensis (Diptera: Ceratopogonidae).

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O'Toole, D; Pérez de León, A A; Hearne, C; McHolland, L; Yun, L; Tabachnick, W

2003-01-01

Histological, ultrastructural, and virological examinations were performed on abdominal skin from guinea pigs after a blood meal by colony-bred biting midges, Culicoides sonorensis. Small, superficial, cutaneous, crateriform ulcers with necrosis of superficial dermis developed at feeding sites and healed within 24-48 hours. Animals developed nonpruritic erythematous papules 5 days after feeding that persisted until the study ended at 12 days after feeding. Papules corresponded histologically to foci of epidermal hyperplasia and superficial interstitial dermatitis with intraepidermal micropustules and scattered intraepidermal polykaryons. The principal ultrastructural changes were spongiosis in germinal epithelium and neutrophilic-histiocytic exocytosis. No viral agents or broken mouthparts were identified in lesions. The dermatitis may represent a host reaction to persisting insect salivary secretion and should be considered as an additional consequence of blood feeding in future studies involving biting midges.

Cold storage effects on egg hatch in laboratory-reared Culicoides variipennis sonorensis (Diptera: Ceratopogonidae).

Science.gov (United States)

Hunt, G J; Tabachnick, W J

1995-09-01

The effects of cold storage (5 degrees C) on the hatching rates of laboratory-reared Culicoides variipennis sonorensis eggs were examined. Mortality increased with storage time. Average maximum embryo survivorship for 4 trials was 55.0 +/- 4.2 (+/- SEM) days. Alternating daily cycles of high and then low mean hatching rates occurred and possibly were due to location differences in temperature within the temperature-controlled rearing system. During cold storage at 5 degrees C, C. v. sonorensis eggs may be kept for ca. 28 days with an anticipated hatching rate of about 50%.

Biting Midges (Diptera: Ceratopogonidae: Culicoides Latr.) associated with livestock farms in the Faroe Islands

DEFF Research Database (Denmark)

Nielsen, Søren Achim; Holm, Høgni; Overgaard Nielsen, Boy

2017-01-01

) pseudoheliophilus Callot & Kremer, 1961, new to the Faroese fauna. C. impunctatus was common at most of the farms, females contributing >95% of the catch. Apparently C. pseudoheliophilus has a more limited distribution in the Faroe Islands and was only recorded from nine byres. The relative distribution of female C...

Fungal biological control agents for integrated management of Culicoides spp. (Diptera: Ceratopogonidae of livestock

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B. W. Narladkar

2015-02-01

Full Text Available Aim: Entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana had wide host range against insects and hence these are being exploited as fungal bio-pesticide on a large scale. Both fungi are proved pesticides against many crop pests and farmers are well acquainted with their use on the field. Thus, research was aimed to explore the potency of these fungal spores against larval and adult Culicoides midges, a pest of livestock. Materials and Methods: In-vitro testing of both fungal biological control agents was undertaken in Petri dishes against field collected Culicoides larvae, while in plastic beakers against field collected blood-engorged female Culicoides midges. In-vivo testing was undertaken by spraying requisite concentration of fungal spores on the drainage channel against larvae and resting sites of adult Culicoides midges in the cattle shed. Lethal concentration 50 (LC50 values and regression equations were drawn by following probit analysis using SPSS statistical computerized program. Results: The results of this study revealed LC50 values of 2692 mg and 3837 mg (108 cfu/g for B. bassiana and M. anisopliae, respectively, against Culicoides spp. larvae. Death of Culicoides larvae due to B. bassiana showed greenish coloration in the middle of the body with head and tail showed intense blackish changes, while infection of M. anisopliae resulted in death of Culicoides larvae with greenish and blackish coloration of body along with total destruction, followed by desquamation of intestinal channel. The death of adult Culicoides midges were caused by both the fungi and after death growth of fungus were very well observed on the dead cadavers proving the efficacy of the fungus. Conclusion: Preliminary trials with both funguses (M. anisopliae, B. bassiana showed encouraging results against larvae and adults of Culicoides spp. Hence, it was ascertained that, these two fungal molecules can form a part of biological control and alternative to chemical control and, therefore, can be inducted in integrated management programs.

Dynamics of epizootic hemorrhagic disease virus infection within the vector, Culicoides sonorensis (Diptera: Ceratopogonidae.

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Mary K Mills

Full Text Available Culicoides sonorensis biting midges are confirmed vectors of epizootic hemorrhagic disease virus (EHDV, which causes mortality in white-tailed deer and ruminant populations. Currently, of the seven EHDV serotypes, only 1, 2, and 6 are detected in the USA, and very few studies have focused on the infection time course of these serotypes within the midge. The objective of this current research was to characterize EHDV-2 infection within the midge by measuring infection prevalence, virus dissemination, and viral load over the course of infection. Midges were fed a blood meal containing 106.9 PFU/ml EHDV-2, collected every 12 h from 0-2 days post feeding (dpf and daily from 3-10 dpf, and cohorts of 20 C. sonorensis were processed using techniques that assessed EHDV infection and dissemination. Cytopathic effect assays and quantitative (qPCR were used to determine infection prevalence, revealing a 50% infection rate by 10 dpf using both methods. Using immunohistochemistry, EHDV-2 infection was detectable at 5 dpf, and shown to disseminate from the midgut to other tissues, including fat body, eyes, and salivary glands by 5 dpf. Stain intensity increased from 5-8 dpf, indicating replication of EHDV-2 in secondary infection sites after dissemination. This finding is also supported by trends in viral load over time as determined by plaque assays and qPCR. An increase in titer between 4-5 dpf correlated with viral replication in the midgut as seen with staining at day 5, while the subsequent gradual increase in viral load from 8-10 dpf suggested viral replication in midges with disseminated infection. Overall, the data presented herein suggest that EHDV-2 disseminates via the hemolymph to secondary infection sites throughout the midge and demonstrate a high potential for transmission at five days at 25°C after an infective blood-meal.

Dermatozoonosis by Culicoides' bite (Diptera, Ceratopogonidae in Salvador, State of Bahia, Brazil: III - Epidemiological aspects

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Italo A. Sherlock

1965-01-01

Full Text Available Nesta terceira contribuiçãos os Autores apresentam os aspectos Epídemiológicos da Dermatozoonose pela picada de Culicoides em Salvador. Salientam que embora a densidade de insetos outros de hábitos antropófilos seja elevada na cidade, as seguintes evidências os conduziram a responsabilizar os Culicoides: conincidência do aparecimento de casos de Dermatozoonose após um período de maior densidade de Culicoides; maior número de casos, desde que a densidade de Culicoides aumentou nos últimos anos; proveni~encia de maior número de casos dos bairros onde há maior infestação de Culicoides. A Dermatozoonose é acentuadamente mais freqüente no sexo feminino. Houve maior número de casos entre os negros, talvez devido a maior freqüencia de negros que procuram tratamento no Hospital das Clínicas. Não há predominância acentuada para determinado grupo etário. Num levantamento que fizeram sôbre a incomodidade do Culicoides observaram que 81% de 593 residências visitadas em diferentes bairros, são incomodadas, sendo o inverno a época de maior incômodo. As horas de maior incômodo, coincidem com a ocorrência horária máxima do Culicoides. Observaram que as medidas usadas pela população para combate ao inseto são inadequadas pois, em 56% das residências não se obtém qualquer resultado. Considerando que nesses último cinco anos a densidade de Culicoides aumentou inexplicàvelmente em Salvador, julgam que os seguintes fatôres participara para que êsse fenômeno ocorresse: a extinção do Serviço de Profilaxia da Febre Amarela em 1956, o qual, indiretamente, por meio de sua "polícia de fócos" combatendo o Aedes aegypti, controlava os Culicoides; o crescimento da cidade, aumentando o número de fossas, já que não existe um sistema de esgotos adequado; e a deficiência do Serviço de Limpeza Pública da Cidade, ocasionando o acúmulo de lixo nos quintais, terrenos baldios e mesmo em logradouros públicos. Essas condições permitiram a existência de uma extensa rêde de "focos potenciais" para a proliferação dos Culicoides que agora infestam a cidade.

Sexual dimorphism and developmental change of the salivary glands in adult Culicoides variipennis (Diptera: Ceratopogonidae).

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Perez de Leon, A A; Lloyd, J E; Tabachnick, W J

1994-11-01

Salivary glands of adult male and female Culicoides variipennis (Coquillett) were sexually dimorphic when examined by phase contrast light microscopy. Female salivary glands were larger and more complex than those in males. Each female gland consisted of a main gland, which was subdivided into a proximal neck and a distal body with reference to the salivary duct, and four accessory glands. Each male salivary gland consisted of a pear-shaped body with a constriction, or neck, that divided it into a proximal and a distal portion, with reference to the salivary duct. Salivary glands of both sexes increased in length from emergence to day 3, followed by a sex-specific pattern of decrease. Based on these morphological observations, we suggest that the salivary glands of female C. variipennis are specialized in the production of secretory materials for blood-feeding.

A new species of predaceous midge of the genus Monohelea Kieffer from Mexico (Diptera: Ceratopogonidae).

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Felippe-Bauer, M L; Huerta, H; Bernal, S I

2000-01-01

A description and illustrations of Monohelea maya, new species, based on male and female characteristics are provided. The specimens were collected in the special biosphere Reserves of Ria Lagartos and Ria Celestun, Yucatan State, Mexico.

Association between land cover and Culicoides (Diptera: Ceratopogonidae) breeding sites on four Danish cattle farms

DEFF Research Database (Denmark)

Kirkeby, Carsten; Bødker, Rene; Stockmarr, Anders

2009-01-01

from 30 sampling points. Soil samples were set up in emergence chambers for hatching adult Culicoides. Two species of Culicoides (C punctatus and C pulicaris) emerged from nine of 12 soil samples from a wet, grazed field with manure. Seventy-two other samples from similar land cover on the three other......Biting midges of the genus Culicoides are vectors of bluetongue virus. Their larval habitats are poorly known in Northern Europe. Three classes of the CORINE land cover index, found within 300 in of four farms in Denmark, were used to stratify sampling sites for a total of 360 soil core samples...... farms were negative. Seven sampling points from pastures were incorrectly classified by CORINE. The remaining 23 sampling points were classified correctly. The visually observed land use was not sufficiently detailed to adequately predict Culicoides breeding sites in this study. The CORINE index failed...

Molecular identification of bloodmeals from biting midges (Diptera: Ceratopogonidae; Culicoides Latreille) in Denmark

DEFF Research Database (Denmark)

Lassen, Sandra Boline; Nielsen, Søren A; Skovgård, Henrik

2011-01-01

engorged biting midges, and hosts were identified in 115 of 125 analysed specimens (90%). Cow, roe deer, horse, mallard and wood pigeon were identified as hosts. The most abundant host species was cow, which constituted 73.9% of the total identified bloodmeals, but the common wood pigeon was found...

A new species of predaceous midge of the genus Monohelea Kieffer from Mexico (Diptera: Ceratopogonidae

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Maria Luiza Felippe-Bauer

2000-12-01

Full Text Available A description and illustrations of Monohelea maya, new species, based on male and female characteristics are provided. The specimens were collected in the special biosphere Reserves of Ria Lagartos and Ria Celestun, Yucatan State, Mexico.

Culicoides and the Tartar Steppe: Il Deserto dei Tartari Culicoides and the spread of blue tongue virus.

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Houin, R

2008-12-01

Culicoides were described for the first time in England in 1713, but named by Latreille in 1809 only. Even so, they were better known as Ceratopogon until Kieffer reintroduced the name Culicoides. The family name became Ceratopogonidae, the description by Meigen (1803) being better adapted to that systematic level. Culicoides were considered simply as biting insects until it was found that they can carry filaria and viruses. In 1944, du Toit in Transvaal described their role in the transmission of blue-tongue virus. Blue-tongue disease has since extended progressively northward from South Africa, disseminated by Culicoides imicola. At the end of the 20th century, it reached the southern shores of the Mediterranean sea, and has since threatened the southern Europe. Surveillance and prevention procedures were put in place, but fortress Europe was taken breached when a different strain of the virus entered through Belgium in 2006. Transmitted by local Culicoides species that were aggressive and abundant, the disease spread quickly, in a disastrous epizootic southward through more than half of France. Westward, infected insects have been carried by wind over the Channel, introducing the disease to England.

Sources of variation in an enzyme-linked immunoassay of bluetongue virus in Culicoides variipennis (Diptera: Ceratopogonidae).

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Tabachnick, W J; Mecham, J O

1991-03-01

An enzyme-linked immunoassay for detecting bluetongue virus in infected Culicoides variipennis was evaluated using a nested analysis of variance to determine sources of experimental error in the procedure. The major source of variation was differences among individual insects (84% of the total variance). Storing insects at -70 degrees C for two months contributed to experimental variation in the ELISA reading (14% of the total variance) and should be avoided. Replicate assays of individual insects were shown to be unnecessary, since variation among replicate wells and plates was minor (2% of the total variance).

Infection of guinea pigs with vesicular stomatitis New Jersey virus Transmitted by Culicoides sonorensis (Diptera: Ceratopogonidae).

Science.gov (United States)

Pérez De León, Adalberto A; O'Toole, Donal; Tabachnick, Walter J

2006-05-01

Intrathoracically inoculated Culicoides sonorensis Wirth & Jones were capable of transmitting vesicular stomatitis New Jersey virus (family Rhabdoviridae, genus Vesiculovirus, VSNJV) during blood feeding on the abdomen of six guinea pigs. None of the guinea pigs infected in this manner developed clinical signs of vesicular stomatitis despite seroconversion for VSNJV. Guinea pigs infected by intradermal inoculations of VSNJV in the abdomen also failed to develop clinical signs of vesicular stomatitis. Three guinea pigs given intradermal inoculations of VSNJV in the foot pad developed lesions typical of vesicular stomatitis. Transmission by the bite of C. sonorensis may have facilitated guinea pig infection with VSNJV because a single infected C. sonorensis caused seroconversion and all guinea pigs infected by insect bite seroconverted compared with 50% of the guinea pigs infected by intradermal inoculation with a higher titer VSNJV inoculum. The role of C. sonorensis in the transmission of VSNJV is discussed.

Microgeographic and temporal genetic variation in populations of the bluetongue virus vector Culicoides variipennis (Diptera: Ceratopogonidae).

Science.gov (United States)

Tabachnick, W J

1992-05-01

Seven Colorado populations of the bluetongue virus vector Culicoides varipennis (Coquillett) were analyzed for genetic variation at 19-21 isozyme loci. Permanent populations, which overwinter as larvae, showed little temporal genetic change at 19 loci. PGD and MDH showed seasonal changes in gene frequencies, attributable to selection at two permanent populations. Two temporary populations showed low heterozygosity compared with permanent populations. Independent estimates of gene flow, calculated using FST and the private allele method, were Nm* = 2.15 and 6.95, respectively. Colorado C. variipennis permanent populations showed high levels of gene flow which prevented significant genetic differentiation due to genetic drift. Temporary populations showed significant gene frequency differences from nearby permanent populations due to the "founder effect" associated with chance colonization.

Identity and diversity of blood meal hosts of biting midges (Dipterea: Ceratopogonidae: Culicoides Latreille) in Denmark

DEFF Research Database (Denmark)

Lassen, Sandra; Nielsen, Søren Achim; Kristensen, Michael

2012-01-01

biting midges were sorted and head and wings were removed for morphological species identification. The thoraxes and abdomens including the blood meals of the individual females were subsequently subjected to DNA isolation. The molecular marker cytochrome oxidase I (COI barcode) was applied to identify......: Twenty-four species of biting midges were identified from the four study sites. A total of 111,356 Culicoides biting midges were collected, of which 2,164 were blood-fed. Specimens of twenty species were identified with blood in their abdomens. Blood meal sources were successfully identified by DNA...

Dermatozoonosis by Culicoides' bite (Diptera, Ceratopogonidae in Salvador, State of Bahia, Brazil: IV - A clinical study

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Italo A. Sherlock

1965-01-01

Full Text Available A observação de 211 pacientes com reação intensa à picada do Culicoides, que procuraram tratamento na Clínica dermatológica do Hospital das Clínicas da Universidade da Bahia, durante os anos de 1959 e 1962, permitiu o estudo clínico dessa Dermatozoonose, cujos dados são aqui apresentados. A lesão parece ser de natureza alérgica e devido ao aspecto polimorfo pelo qual se apresenta, essa Dermatose pode lembrar o Prorigo, a Escabiose, as Lesões liquenoide; quando a manifestação é mais intensa torna-se uma verdadeira eczematização; quando há infecção secundária, lembra o impetigo folicular. O estudo histológico da lesão revelou ser ela a de uma inflamação crônica, com vascularites e preivascularites dermo-epidérmica, provàvelmente de natureza alérgica. Para que haja a formação da lesão, são necessários: a substância inoculada pelo inseto e o componente alérgico do indivíduo. Não se conhece a natureza da substância inoculada pelo inseto e as seguintes hipóteses são apresentadas para explicá-la: substâncias enzimáticas ou a histamina existentes nas glândulas salivares do Culicoides. Após a picada do Culicoisdes forma-se no local uma pequena área eritematosa que logo após se transforma em pápula; as pápulas podem desaparecer ou transformarem-se em vesículas; estas ao se romperem dilaceram a superfície cutânea, descamam-na ou pode advir uma infecção secundária e transformam-se em pústulas.

Fauna de insectos hematófagos del sur del Parque Natural Nacional Chiribiquete, Caquetá, Colombia

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Jorge A. Molina

2000-12-01

Full Text Available Como parte del estudio para el manejo y la conservación del Parque Natural Nacional Chiribiquete, desarrollado por la Fundación Puerto Rastrojo, se realizó un inventario de la fauna entomológica hematófaga en la estación biológica de Puerto Abeja (rio Mesay, municipio de Solano, departamento de Caquetá. Se calcularon los índices de similitud de Jaccard y el indice de diversidad de Shannon-Weaver y se determinaron los patrones de picadura de los dipteros diurnos para los seis tipos de bosques evaluados. Se registraron 31 especies de Culicidae, 1 de Triatominae, 1 de Ceratopogonidae, 2 de Simuliidae, 10 de Phlebotominae y 6 de Tabanidae. Se obtuvieron tres nuevos registros de especies de Culicidae para Colombia: Sabethes glaucodaemon, Trichoprosopon espini y Uranotaenia pallidoventer; y se amplió el registro de varios insectos hematófagos en el departamento de Caquetá. Se presentan los patrones de actividad de las especies diurnas y su relación con los tipos de bosque y se sugieren posibles medidas de control para evitar enfermedades transmitidas por diferentes vectores, resaltando la importancia epidemiológica de las especies capturadas que presentan capacidad vectorial.

Characterization of Viral Communities of Biting Midges and Identification of Novel Thogotovirus Species and Rhabdovirus Genus

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Sarah Temmam

2016-03-01

Full Text Available More than two thirds of emerging viruses are of zoonotic origin, and among them RNA viruses represent the majority. Ceratopogonidae (genus Culicoides are well-known vectors of several viruses responsible for epizooties (bluetongue, epizootic haemorrhagic disease, etc.. They are also vectors of the only known virus infecting humans: the Oropouche virus. Female midges usually feed on a variety of hosts, leading to possible transmission of emerging viruses from animals to humans. In this context, we report here the analysis of RNA viral communities of Senegalese biting midges using next-generation sequencing techniques as a preliminary step toward the identification of potential viral biohazards. Sequencing of the RNA virome of three pools of Culicoides revealed the presence of a significant diversity of viruses infecting plants, insects and mammals. Several novel viruses were detected, including a novel Thogotovirus species, related but genetically distant from previously described tick-borne thogotoviruses. Novel rhabdoviruses were also detected, possibly constituting a novel Rhabdoviridae genus, and putatively restricted to insects. Sequences related to the major viruses transmitted by Culicoides, i.e., African horse sickness, bluetongue and epizootic haemorrhagic disease viruses were also detected. This study highlights the interest in monitoring the emergence and circulation of zoonoses and epizooties using their arthropod vectors.

Characterization of Viral Communities of Biting Midges and Identification of Novel Thogotovirus Species and Rhabdovirus Genus

Science.gov (United States)

Temmam, Sarah; Monteil-Bouchard, Sonia; Robert, Catherine; Baudoin, Jean-Pierre; Sambou, Masse; Aubadie-Ladrix, Maxence; Labas, Noémie; Raoult, Didier; Mediannikov, Oleg; Desnues, Christelle

2016-01-01

More than two thirds of emerging viruses are of zoonotic origin, and among them RNA viruses represent the majority. Ceratopogonidae (genus Culicoides) are well-known vectors of several viruses responsible for epizooties (bluetongue, epizootic haemorrhagic disease, etc.). They are also vectors of the only known virus infecting humans: the Oropouche virus. Female midges usually feed on a variety of hosts, leading to possible transmission of emerging viruses from animals to humans. In this context, we report here the analysis of RNA viral communities of Senegalese biting midges using next-generation sequencing techniques as a preliminary step toward the identification of potential viral biohazards. Sequencing of the RNA virome of three pools of Culicoides revealed the presence of a significant diversity of viruses infecting plants, insects and mammals. Several novel viruses were detected, including a novel Thogotovirus species, related but genetically distant from previously described tick-borne thogotoviruses. Novel rhabdoviruses were also detected, possibly constituting a novel Rhabdoviridae genus, and putatively restricted to insects. Sequences related to the major viruses transmitted by Culicoides, i.e., African horse sickness, bluetongue and epizootic haemorrhagic disease viruses were also detected. This study highlights the interest in monitoring the emergence and circulation of zoonoses and epizooties using their arthropod vectors. PMID:26978389

The effect of high frequency sound on Culicoides numbers collected with suction light traps

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Gert J. Venter

2012-04-01

Full Text Available Culicoides midges (Diptera: Ceratopogonidae, are involved in the transmission of various pathogens that cause important diseases of livestock worldwide. The use of insect repellents to reduce the attack rate of these insects on livestock could play an important role as part of an integrated control programme against diseases transmitted by these midges. The objective of this study was to determine whether high frequency sound has any repellent effect on Culicoides midges. The number of midges collected with 220 V Onderstepoort white light traps fitted with electronic mosquito repellents (EMRs, emitting 5-20 KHz multi-frequency sound waves, was compared with that of two untreated traps. Treatments were rotated in two replicates of a 4 x 4 randomised Latin square design. Although fewer midges were collected in the two traps fitted with EMRs, the average number collected over eight consecutive nights was not significantly different. The EMRs also had no influence on any of the physiological groups of Culicoides imicola Kieffer or the species composition of the Culicoides population as determined with light traps. The results indicate that high frequency sound has no repellent effect on Culicoides midges. There is therefore no evidence to support their promotion or use in the protection of animals against pathogens transmitted by Culicoides midges.

Endophagy of biting midges attacking cavity-nesting birds.

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Votýpka, J; Synek, P; Svobodová, M

2009-09-01

Feeding behaviour, host preferences and the spectrum of available hosts determine the role of vectors in pathogen transmission. Feeding preferences of blood-feeding Diptera depend on, among others factors, the willingness of flies to attack their hosts either in the open (exophagy) or in enclosed places (endophagy). As far as ornithophilic blood-feeding Diptera are concerned, the biting midges (Diptera: Ceratopogonidae) and blackflies (Diptera: Simuliidae) are generally considered to be strictly exophagous. We determined which blood-sucking Diptera enter nest cavities and feed on birds by placing sticky foil traps inside artificial nest boxes. A total of 667 females of eight species of biting midges of the genus Culicoides (Latreille, 1809) were captured on traps during 2006-2007, with Culicoides truncorum (Edwards, 1939) being the dominant species. DNA blood analyses of blood-engorged females proved that midges actually fed on birds nesting in the boxes. Three species were identified as endophagous: Culicoides truncorum, Culicoides pictipennis (Staeger, 1839), and Culicoides minutissimus (Zetterstedt, 1855). Our study represents the first evidence that ornithophilic biting midges are endophagous. The fact that we caught no blackflies in the bird boxes supports the exophagy of blackflies. We believe that our findings are important for surveillance programmes focusing on Diptera that transmit various bird pathogens.

First molecular identification of the vertebrate hosts of Culicoides imicola in Europe and a review of its blood-feeding patterns worldwide: implications for the transmission of bluetongue disease and African horse sickness.

Science.gov (United States)

Martínez-DE LA Puente, J; Navarro, J; Ferraguti, M; Soriguer, R; Figuerola, J

2017-12-01

Culicoides (Diptera: Ceratopogonidae) are vectors of pathogens that affect wildlife, livestock and, occasionally, humans. Culicoides imicola (Kieffer, 1913) is considered to be the main vector of the pathogens that cause bluetongue disease (BT) and African horse sickness (AHS) in southern Europe. The study of blood-feeding patterns in Culicoides is an essential step towards understanding the epidemiology of these pathogens. Molecular tools that increase the accuracy and sensitivity of traditional methods have been developed to identify the hosts of potential insect vectors. However, to the present group's knowledge, molecular studies that identify the hosts of C. imicola in Europe are lacking. The present study genetically characterizes the barcoding region of C. imicola trapped on farms in southern Spain and identifies its vertebrate hosts in the area. The report also reviews available information on the blood-feeding patterns of C. imicola worldwide. Culicoides imicola from Spain feed on blood of six mammals that include species known to be hosts of the BT and AHS viruses. This study provides evidence of the importance of livestock as sources of bloodmeals for C. imicola and the relevance of this species in the transmission of BT and AHS viruses in Europe. © 2017 The Royal Entomological Society.

Transmission of vesicular stomatitis New Jersey virus to cattle by the biting midge Culicoides sonorensis (Diptera: Ceratopogonidae).

Science.gov (United States)

Perez de Leon, Adalberto A; Tabachnick, Walter J

2006-03-01

Laboratory-reared Culicoides sonorensis Wirth & Jones were infected with vesicular stomatitis virus serotype New Jersey (family Rhabdoviridae, genus Vesiculovirus, VSNJV) through intrathoracic inoculation. After 10-d incubation at 25 degrees C, these insects were allowed to blood feed on four steers. Two other steers were exposed to VSNJV through intralingual inoculation with 10(8) tissue culture infective dose50 VSNJV. All six steers became seropositive for VSNJV. The results demonstrate the ability of C. sonorensis to transmit VSNJV to livestock. Only the animals intralingually inoculated with VSNJV showed clinical signs in the form of vesicles at the site of inoculation. Uninfected C. sonorensis allowed to feed on the exposed animals did not become infected with VSNJV. Animals infected by C. sonorensis showed a slower antibody response compared with intralingually inoculated animals. This is probably because of different amounts of virus received via insect transmission and syringe inoculation. A significant difference was found in the serum acute-phase protein alpha-1-acid glycoprotein in animals that received VSNJV through C. sonorensis transmission. These animals had previously been exposed to insect attack in the field compared with intralingually inoculated animals and C. sonorensis-infected animals that had been protected from insect attack. The failure to observe clinical signs of vesicular stomatitis through transmission of VSNJV by C. sonorensis may explain widespread subclinical infections during vesicular stomatitis epidemics.

Genetic variation in laboratory and field populations of the vector of bluetongue virus, Culicoides variipennis (Diptera: Ceratopogonidae).

Science.gov (United States)

Tabachnick, W J

1990-01-01

Laboratory colonies and several natural populations of the biting midge Culicoides variipennis (Coquillett) were analyzed for genetic variation at 21 electrophoretic loci. The laboratory colonies maintained high levels of genetic variation measured by average expected heterozygosities (He = 0.142 +/- 0.008), although levels were lower than those observed in field collections (He = 0.198 +/- 0.009). A field population from Colorado, analyzed five times over a 1-yr period, showed a consistent trend in the change in gene frequencies at two loci. Genetic comparisons between natural populations were consistent with the existence of two subspecies. C. variipennis variipennis and C. variipennis sonorensis Wirth & Jones.

Quantifying Dispersal of European Culicoides (Diptera: Ceratopogonidae) Vectors between Farms Using a Novel Mark-Release-Recapture Technique

DEFF Research Database (Denmark)

Kirkeby, Carsten; Bødker, Rene; Stockmarr, Anders

2013-01-01

Studying the dispersal of small flying insects such as Culicoides constitutes a great challenge due to huge population sizes and lack of a method to efficiently mark and objectively detect many specimens at a time. We here describe a novel mark-release-recapture method for Culicoides in the field...

Spatial uniformity in depth optima of midges: evidence from sedimentary archives of shallow Alpine and boreal lakes

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Tomi P. Luoto

2012-01-01

Full Text Available In this study, water depth optima, i.e. habitat preferences within a depth gradient, were estimated for mutual midge (Diptera: Nematocera; Ceratopogonidae, Chironomidae taxa in surface sediment intralake data sets from eastern Finland and Austrian Alps and in a regional data set across Finland. The aim was to investigate how the optima and tolerances differ in these data sets and to discuss whether the possible causal factor for deviance is related to local adaptation, taxa representativeness, or some other factor. A total of 20 mutual taxa were found from the data sets and the estimated optima and tolerances were highly similar, with the exception of three taxa, which had deviating optima in the Austrian lake. The reason for these differences was most likely that the optima were poorly estimated in the Austrian lake due to low abundances and number of occurrences of these taxa. No evidence for intraspecific niche separation or local habitat adaptation was found between the Austrian and Finnish sites, although, interspecific variation in habitats was evident. Therefore, water depth optima estimated from representative number of specimens may be applicable for various ecological, limnological, and paleolimnological purposes. However, when the optima are applied outside the data set’s coverage, the results should be interpreted with caution. In addition, the given optima are not applicable in sites deeper than the sites in the data sets.

Passage of ingested Mansonella ozzardi (Spirurida: Onchocercidae) microfilariae through the midgut of Aedes aegypti (Diptera: Culicidae).

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Vaughan, Jefferson A; Bell, Jeffrey A; Turell, Michael J; Chadee, Dave D

2007-01-01

When virus and microfilariae are ingested concurrently by a mosquito, microfilariae (mf) may penetrate the mosquito midgut and introduce virus directly into the mosquito hemocoel, allowing mosquitoes to become infectious much sooner than normal and enhancing transmission of viruses by mosquitoes. Mansonella ozzardi (Manson) is a benign filarial nematode parasite of humans in Latin America and is transmitted by black flies (Diptera: Simuliidae) and biting midges (Diptera: Ceratopogonidae). Because M. ozzardi and dengue are sympatric, we wanted to know whether M. ozzardi mf had the ability to penetrate the midgut of Aedes aegypti (L.) (Diptera: Culicidae) and thus play a potential role in the enhancement of dengue transmission. To test this, the F1 progeny from locally collected Ae. aegypti were fed on M. ozzardi-infected human males in an endemic village in northern Trinidad. Mosquitoes were dissected at various times after feeding and examined for mf in the midguts and thoraces. Microfilariae penetrated the midguts of 43% of 63 mosquitoes that ingested mf. Overall, 11% of mf penetrated the midgut by 17 h after being ingested. The intensity of midgut penetration was positively correlated to the numbers of mf ingested. Because midgut penetration is a key requirement for mf enhancement to occur, the potential exists that M. ozzardi could be involved in the enhancement of dengue virus transmission.

Determinants of abundance and effects of blood-sucking flying insects in the nest of a hole-nesting bird.

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Tomás, Gustavo; Merino, Santiago; Martínez-de la Puente, Josué; Moreno, Juan; Morales, Judith; Lobato, Elisa

2008-05-01

Compared to non-flying nest-dwelling ectoparasites, the biology of most species of flying ectoparasites and its potential impact on avian hosts is poorly known and rarely, if ever, reported. In this study we explore for the first time the factors that may affect biting midge (Diptera: Ceratopogonidae) and black fly (Diptera: Simuliidae) abundances in the nest cavity of a bird, the hole-nesting blue tit Cyanistes caeruleus, and report their effects on adults and nestlings during reproduction. The abundance of biting midges was positively associated with nest mass, parental provisioning effort and abundance of blowflies and black flies, while negatively associated with nestling condition. Furthermore, a medication treatment to reduce blood parasitaemias in adult birds revealed that biting midges were more abundant in nests of females whose blood parasitaemias were experimentally reduced. This finding would be in accordance with these insect vectors attacking preferentially uninfected or less infected hosts to increase their own survival. The abundance of black flies in the population was lower than that of biting midges and increased in nests with later hatching dates. No significant effect of black fly abundance on adult or nestling condition was detected. Blood-sucking flying insects may impose specific, particular selection pressures on their hosts and more research is needed to better understand these host-parasite associations.

Farms, pastures and woodlands: the fine-scale distribution of Palearctic Culicoides spp. biting midges along an agro-ecological gradient.

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Rigot, T; Drubbel, M Vercauteren; Delécolle, J-C; Gilbert, M

2013-03-01

The spatial epidemiology of Bluetongue virus (BTV) at the landscape level relates to the fine-scale distribution and dispersal capacities of its vectors, midges belonging to the genus Culicoides Latreille (Diptera: Ceratopogonidae). Although many previous researches have carried out Culicoides sampling on farms, little is known of the fine-scale distribution of Culicoides in the landscape immediately surrounding farms. The aim of this study was to gain a better understanding of Culicoides populations at increasing distances from typical dairy farms in north-west Europe, through the use of eight Onderstepoort-type black-light traps positioned along linear transects departing from farms, going through pastures and entering woodlands. A total of 16 902 Culicoides were collected in autumn 2008 and spring 2009. The majority were females, of which more than 97% were recognized as potential vectors. In pastures, we found decreasing numbers of female Culicoides as a function of the distance to the farm. This pattern was modelled by leptokurtic models, with parameters depending on season and species. By contrast, the low number of male Culicoides caught were homogeneously distributed along the transects. When transects entered woodlands, we found a higher abundance of Culicoides than expected considering the distance of the sampling sites to the farm, although this varied according to species. © 2012 The Authors. Medical and Veterinary Entomology © 2012 The Royal Entomological Society.

Aproximación a La Caracterización Ecológica de La Quebrada Fucha en La Reserva Forestal de los Cerros Orientales en La Localidad de San Cristóbal. (Bogotá, Colombia

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Mónica Restrepo Villamil (Página 96-113

2009-07-01

Full Text Available En este trabajo se presentan los resultados obtenidos en la práctica de campo realizada el día 10 de octubre de 2008, en la quebrada Fucha en una reserva forestal protegida por la Empresa de Acueducto y Alcantarillado de Bogotá en los cerros orientales de la localidad de San Cristóbal. El objetivo principal de este estudio fue realizar una aproximación a la caracterización de este sistema acuático, para lo cual, se colectaron insectos acuáticos (entomofauna y perifiton, se caracterizaron los suelos de la ribera y se realizaron análisis de las variables fisicoquímicas de la zona. Los insectos acuáticos que se encontraron sumaron un total de 188 individuos, en donde las familias más abundantes fueron Simuliidae y Ceratopogonidae con 60 individuos cada una (32% c/u y las de menor abundancia fueron Odontoceridae, Lepharoceridae y Pyralidae con 1 individuo c/u (0.53% c/u; por otra parte, se encontraron 14 géneros de perifiton. El sistema presenta una diversidad media de acuerdo al índice de Shannon (1.55. La principal fuente de energía del sistema es la materia orgánica disuelta, por lo que la vía que predomina es la detrítica.

Handling small arbovirus vectors safely during biosafety level 3 containment: Culicoides variipennis sonorensis (Diptera:Ceratopogonidae) and exotic bluetongue viruses.

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Hunt, G J; Tabachnick, W J

1996-05-01

Equipment and procedures are described for biosafety level 3 (BL-3) containment work with small, zoophilic arthropods. BL-3 classified pathogens always must be manipulated in biological safety cabinets. Procedures, including physical barriers and handling methods, that prevent the escape of potentially virus-infected insects are discussed, and the use of a monitoring system for insect security is explained. The inability to recover escaped minute, flying insects poses a major difference from similar work with larger insects, such as mosquitoes. Methods were developed for the safe and secure handling of Culicoides variipennis sonorensis Wirth & Jones infected with exotic bluetongue viruses during BL-3 containment.

Molecular differentiation of Culicoides biting midges (Diptera: Ceratopogonidae) from the subgenus Culicoides Latreille in Denmark

DEFF Research Database (Denmark)

Lassen, S. B.; Nielsen, S. Achim; Skovgård, H.

2012-01-01

complexes are hard to distinguish. We evaluated the use of the mitochondrial DNA cytochrome oxidase I gene (COI) barcode region in the identification of species within the subgenus Culicoides. COI barcode sequence divergence within species was ... impunctatus, and Culicoides grisescens. Additionally, this study confirms the existence of Culicoides halophilus as a valid taxon and presents the first Culicoides deltus barcode sequences. Three additional groups of specimens were identified: Culicoides dk1 with a COI barcode diverging by 14.3% to 17.2% from...... other subgenus Culicoides species and Culicoides Kalix and Culicoides dk3, which diverged by 5.9% from each other and showed 12.5% to 17.6% divergence in COI barcode to subgenus Culicoides specimens....

Torix group Rickettsia are widespread in Culicoides biting midges (Diptera: Ceratopogonidae), reach high frequency and carry unique genomic features.

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Pilgrim, Jack; Ander, Mats; Garros, Claire; Baylis, Matthew; Hurst, Gregory D D; Siozios, Stefanos

2017-10-01

There is increasing interest in the heritable bacteria of invertebrate vectors of disease as they present novel targets for control initiatives. Previous studies on biting midges (Culicoides spp.), known to transmit several RNA viruses of veterinary importance, have revealed infections with the endosymbiotic bacteria, Wolbachia and Cardinium. However, rickettsial symbionts in these vectors are underexplored. Here, we present the genome of a previously uncharacterized Rickettsia endosymbiont from Culicoides newsteadi (RiCNE). This genome presents unique features potentially associated with host invasion and adaptation, including genes for the complete non-oxidative phase of the pentose phosphate pathway, and others predicted to mediate lipopolysaccharides and cell wall modification. Screening of 414 Culicoides individuals from 29 Palearctic or Afrotropical species revealed that Rickettsia represent a widespread but previously overlooked association, reaching high frequencies in midge populations and present in 38% of the species tested. Sequence typing clusters the Rickettsia within the Torix group of the genus, a group known to infect several aquatic and hematophagous taxa. FISH analysis indicated the presence of Rickettsia bacteria in ovary tissue, indicating their maternal inheritance. Given the importance of biting midges as vectors, a key area of future research is to establish the impact of this endosymbiont on vector competence. © 2017 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

Laboratory survival and blood feeding response of wild-caught Culicoides obsoletus Complex (Diptera: Ceratopogonidae) through natural and artificial membranes.

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Goffredo, M; Romeo, G; Monaco, F; Di Gennaro, A; Savini, G

2004-01-01

In late summer 2002, live wild-caught midges of the Obsoletus Complex were collected using blacklight traps placed at a horse stable in Teramo (Abruzzo, Italy). For the survival study under laboratory conditions, 1,500 Obsoletus Complex midges were kept at 17 degrees C-25 degrees C and provided only with a sucrose solution. Of these, 150 (10%) survived for at least 40 days and 3 midges were still alive after 92 days. In addition, 10 midges survived 10 days at 4 degrees C. For the feeding trials, 40 blood-meals (9,440 midges) were administered, 27 of which were successful (67.5%); the feeding rate ranged from 0.3% to 16.7%, with a total of 592 engorged midges. Similar feeding rates (U Mann-Whitney test=129.5 p>0.05) were obtained when natural (day-old chicken skin) and artificial (stretched parafilm) membranes were used. To infect the insects, a field strain of bluetongue (BT) virus (BTV) serotype 2 isolated from the spleen of a sheep during the 2000 Italian outbreak was added to the blood-meal. Two different viral solutions, with titres of 10(6)TCID(50)/ml and 10(7)TCID(50)/ml, were prepared. Uninfected blood was significantly more appetising (U Mann-Whitney test=88.5 pdays. During the incubation period, the dead insects were collected daily and analysed for evidence of virus infection. Of the 251 engorged midges, 54 (21.5%) died in the feeding chambers or during sorting on the chill table, 136 died within the first 10 days and 61 survived longer. BTV was isolated only from those which died just after feeding (52.6%; 10/19) or 24 h later (47.8%; 11/23). Considering the small number of midges tested after 10 days of incubation, the prevalence of infection detected in this study (95% probability) would have been higher than 4.74%. These preliminary results appear very promising as this is the first time that midges of the Obsoletus Complex have been successfully fed under laboratory conditions.

Inventário Taxonômico das Coleções Paleoentomológicas do Museu Dom José e da Universidade Estadual Vale do Acaraú, Sobral-CE

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Maria de Jesus Gomes de Sousa

2016-01-01

Full Text Available Uma realidade ainda observada em instituições que mantêm coleções paleontológicas, como museus e universidades, é o não conhecimento dos espécimes que compõem seus acervos, onde o seu estudo poderia trazer muitas respostas à taxonomia e filogenia. Este trabalho vem apresentar uma classificação taxonômica geral dos exemplares de insetos fósseis pertencentes às coleções do Museu Dom José e da Universidade Estadual Vale do Acaraú, em Sobral, Ceará e, neste contexto, exibe espécimes ainda não descritos na literatura, provenientes da Formação Santana, da Bacia do Araripe. Realizou-se uma extensa pesquisa bibliográfica e os espécimes foram observados através de anatomia comparada em literatura especializada. Ao todo, foram 39 amostras analisadas, com representantes de sete ordens (Blattoptera, Coleoptera, Diptera, Ephemeroptera, Hemiptera, Odonatoptera e Orthoptera. Os táxons registrados foram: Araripegryllus femininus, Araripegryllus sp., Cratoelcana damianii, Cratolocustopsis sp., Hallex xestocephalus(?, Hallex brevipes(?, Mesoblattina sp., Nothomacromia sensibilis, Paracearagryllus poliacanthus, Protoligoneuria limai, Vulcanoia sp., além de um coleóptero estafilinídeo, um díptero Ceratopogonidae inédito, um Coleorrhyncha Progonomicidae e um heteróptero cimicomorfa e cicadomorfas indeterminados. Estudos de coleções são sempre bem-vindos, pois geram conhecimento e perguntas para serem respondidas com novos trabalhos.

Fly proof net shed for livestock: A novel concept of physical barrier for integrated management of Culicoides spp. (Diptera: Ceratopogonidae

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B. W. Narladkar

2014-11-01

Full Text Available Aim: An age old and time tested technique of mosquito net requiring no energy, used by humans since prehistoric period was the inspiration behind this novel technique of fly proof net shed for livestock. With the aim to develop similar type of net shed for animals, which will protect them at night from biting of range of insects from Culicoides midges to mosquitoes, research was undertaken. Materials and Methods: Net shed with pitch roof (gable type was erected for use of livestock. The open inlet area was covered with 40 mesh size wire net. The roof at attic level was fitted with hurricane type of ventilator. Shed was used for animals at night hours only. vane anemometer was used for estimation of temperature and wind related parameters. Thermal humidity index (THI and air changes were calculated as per the standard formulas. Based on these parameters suitability of shed was judged. Results: It was observed that, due to netting of the shed population of Culicoides and other flies and incidences of their bites at night hours were considerably lowered. As a result, animals were found comfortable, and their body movements undertaken for wiping off these flies were significantly reduced from 196.50 to 22.16. All it accrued to increased milk yield to the tune of 18.97% in the net shed buffaloes as against control shed. Studies on suitability and comfort to animals were tested by estimating THI and air changes per hour in the net shed, which also revealed the estimates in comfortable regimen and ventilation, remained not much affected despite of netting. Other parameters studied for testing its more accuracy by taking other species of animals as kids, for them also, shed was found suitable through estimation of various physiological and behavioral parameters. Finally, the efficacy of shed was judged on the basis of cost effectiveness. Highly encouraging results on the above said parameters endorsed the effectiveness of the technique. Conclusion: A net shed with pitch roof (gable type fitted with hurricane type ventilator at its top serves the purpose of a physical barrier to minimize host-pest contact. Observations recorded in the experiment are sound enough to conclude and to recommend the use of net shed for livestock.

[Field efficacy of repellent formulation containing para-menthane-3,8-diol and lemongrass against Culicoides pachymerus (Diptera: Ceratopogonidae) in Colombia].

Science.gov (United States)

Santamaría, Erika; Cabrera, Olga Lucía; Zipa, Yaneth; Pardo, Raúl Hernando

2012-09-01

Culicoides pachymerus is a major pest species for the inhabitants of the western Boyacá province of Colombia. The effect of a repellent lotion based on p-menthane-3,8-diol (16%) and lemongrass oil (2%) was evaluated against the bites of C. pachymerus. The repellent lotion was compared simultaneously with a control (no treatment) by human landing catches of C. pachymerus on the forearms of paired volunteers situated near human dwellings. Protection percentage and protection time for 3 to 6 h after repellent application was calculated. The test was repeated ten times. Only two females of C. pachymerus were collected on arms with the repellent treatment. In contrast, the mean biting rate in the untreated control was 47.7 midges/person/10 min. Mean protection percentage of the repellent was 100% up to 4 h and 99.5% up to 5 h. Protection time was 332.2 and 338.2 min in the two replicates where bites of C. pachymerus were confirmed. In the remaining eight replicates protection time exceeded the test duration. The repellent showed high efficacy against C. pachymerus, up to 5 h post-application.

Community analysis of the abundance and diversity of biting midge species (Diptera: Ceratopogonidae) in three European countries at different latitudes.

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Möhlmann, Tim W R; Wennergren, Uno; Tälle, Malin; Favia, Guido; Damiani, Claudia; Bracchetti, Luca; Takken, Willem; Koenraadt, Constantianus J M

2018-03-27

The outbreaks of bluetongue and Schmallenberg disease in Europe have increased efforts to understand the ecology of Culicoides biting midges and their role in pathogen transmission. However, most studies have focused on a specific habitat, region, or country. To facilitate wider comparisons, and to obtain a better understanding of the spread of disease through Europe, the present study focused on monitoring biting midge species diversity in three different habitat types and three countries across Europe. Biting midges were trapped using Onderstepoort Veterinary Institute light traps at a total of 27 locations in Sweden, the Netherlands and Italy, comprising farm, peri-urban and wetland habitats. From July 2014 to June 2015 all locations were sampled monthly, except for during the winter months. Trapped midges were counted and identified morphologically. Indices on species richness, evenness and diversity were calculated. Community compositions were analysed using non-metric multidimensional scaling (NMDS) techniques. A total of 50,085 female midges were trapped during 442 collection nights. More than 88% of these belonged to the Obsoletus group. The highest midge diversity was found in Sweden, while species richness was highest in the Netherlands, and most specimens were trapped in Italy. For habitats within countries, diversity of the trapped midges was lowest for farms in all countries. Differences in biting midge species communities were more distinct across the three countries than the three habitat types. A core midge community could be identified, in which the Obsoletus group was the most abundant. Variations in vector communities across countries imply different patterns of disease spread throughout Europe. How specific species and their associated communities affect disease risk is still unclear. Our results emphasize the importance of midge diversity data at community level, how this differs across large geographic range within Europe, and its implications on assessing risks of midge-borne disease outbreaks.

Aquatic macroinvertebrates associated with Eichhornia azurea (Swartz Kunth and relationships with abiotic factors in marginal lentic ecosystems (São Paulo, Brazil

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CV. Silva

Full Text Available Marginal lakes are characterised by their having high biological diversity due to the presence of aquatic macrophytes in their coastal zones, providing habitats for refuge and food for animal community members. Among the fauna components associated with macrophytes, aquatic macroinvertebrates are important because they are an energy source for predators and fish. In six lakes and two different seasons (March and August 2009, the ecological attributes of aquatic macroinvertebrate community associated with Eichhornia azurea were compared and the controlling environmental factors were identified. Since the attributes of macroinvertebrate community are strictly associated with abiotic variables of each distinct habitat, our hypothesis was that each site associated with the same floating aquatic macrophyte (E. azurea should have a typical composition and density of organisms. We identified 50 taxa of macroinvertebrates, with greater taxa richness for aquatic insects (37 taxa divided into eight orders; the order Diptera being the most abundant in the two study periods. On the other hand, higher values of total taxa richness were recorded in August. Dissolved oxygen and pH presented the greatest number of significant positive correlations with the different taxa. The animals most frequently collected in the six lakes in March and August 2009 were Hirudinea, Oligochaeta, Hydrachnidae, Conchostraca, Ostracoda, Noteridae, Ceratopogonidae, Chironomidae, Culicidae, Caenidae, Pleidae, Aeshnidae, Libellulidae, Coenagrionidae and Nematoda. Only densities of Trichoptera, Ostracoda and Conchostraca presented the highest significant differences between lakes in both study periods and considering the composition of macroinvertebrates no significant differences were registered for macroinvertebrate composition.

Impact of potash mining in streams: the Llobregat basin (northeast Spain as a case study

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Ruben Ladrera

2016-12-01

Full Text Available Potash mining is significantly increasing the salt concentration of rivers and streams due to lixiviates coming from the mine tailings. In the present study, we have focused on the middle Llobregat basin (northeast Spain, where an important potash mining activity exists from the beginning of the XX century. Up to 50 million tonnes of saline waste have been disposed in the area, mainly composed of sodium chloride. We assessed the ecological status of streams adjacent to the mines by studying different physicochemical and hydromorphological variables, as well as aquatic macroinvertebrates. We found extraordinary high values of salinity in the studied streams, reaching conductivities up to 132.4 mS/cm. Salt-polluted streams were characterized by a deterioration of the riparian vegetation and the fluvial habitat. Both macroinvertebrate richness and abundance decreased with increasing salinity. In the most polluted stream only two families of macroinvertebrates were found: Ephydridae and Ceratopogonidae. According to the biotic indices IBMWP and IMMi-T, none of the sites met the requirements of the Water Framework Directive (WFD; i.e., good ecological status. Overall, we can conclude that potash-mining activities have the potential to cause severe ecological damage to their surrounding streams. This is mainly related to an inadequate management of the mine tailings, leading to highly saline runoff and percolates entering surface waters. Thus, we urge water managers and policy makers to take action to prevent, detect and remediate salt pollution of rivers and streams in potash mining areas.

Benthic macroinvertebrates as bioindicators of water quality in an Atlantic forest fragment

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Augusto Oliveira

2010-12-01

Full Text Available The objective of this study was to evaluate benthic macroinvertebrate communities as bioindicators of water quality in five streams located in the "Reserva Particular do Patrimônio Natural" (RPPN Mata Samuel de Paula and its surroundings, in the municipality of Nova Lima near the city of Belo Horizonte, Minas Gerais State, southeastern Brazil. This region has been strongly modified by human activities including mining and urbanization. Samples were collected in the field every three months between August 2004 and November 2005, totaling six samplings in the rainy and dry seasons. This assessment identified one area ecologically altered while the other sampling sites were found to be minimally disturbed systems, with well-preserved ecological conditions. However, according to the Biological Monitoring Work Party (BMWP and the Average Score Per Taxon (ASPT indices, all sampling sites had excellent water quality. A total of 14,952 organisms was collected, belonging to 155 taxa (148 Insecta, two Annelida, one Bivalvia, one Decapoda, one Planariidae, one Hydracarina, and one Entognatha. The most abundant benthic groups were Chironomidae (47.9%, Simuliidae (12.3%, Bivalvia (7.5%, Decapoda (6.1%, Oligochaeta (5.2%, Polycentropodidae (3.7%, Hydropsychidae (2.5%, Calamoceratidae (1.8%, Ceratopogonidae (1.7%, and Libellulidae (1.2%. The assessment of the benthic functional feeding groups showed that 34% of the macroinvertebrates were collector-gatherers, 29% predators, 24% collector-filterers, 8% shredders, and 5% scrapers. The RPPN Mata Samuel de Paula comprises diversified freshwater habitats that are of great importance for the conservation of many benthic taxa that are intolerant to organic pollution.

Culicoides species abundance and potential over-wintering of African horse sickness virus in the Onderstepoort area, Gauteng, South Africa

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Gert J. Venter

2014-11-01

Full Text Available In South Africa, outbreaks of African horse sickness (AHS occur in summer; no cases are reported in winter, from July to September. The AHS virus (AHSV is transmitted almost exclusively by Culicoides midges (Diptera: Ceratopogonidae, of which Culicoides imicola is considered to be the most important vector. The over-wintering mechanism of AHSV is unknown. In this study, more than 500 000 Culicoides midges belonging to at least 26 species were collected in 88 light traps at weekly intervals between July 2010 and September 2011 near horses in the Onderstepoort area of South Africa. The dominant species was C. imicola. Despite relatively low temperatures and frost, at least 17 species, including C. imicola, were collected throughout winter (June–August. Although the mean number of midges per night fell from > 50 000 (March to < 100 (July and August, no midge-free periods were found. This study, using virus isolation on cell cultures and a reverse transcriptase polymerase chain reaction (RT-PCR assay, confirmed low infection prevalence in field midges and that the detection of virus correlated to high numbers. Although no virus was detected during this winter period, continuous adult activity indicated that transmission can potentially occur. The absence of AHSV in the midges during winter can be ascribed to the relatively low numbers collected coupled to low infection prevalence, low virus replication rates and low virus titres in the potentially infected midges. Cases of AHS in susceptible animals are likely to start as soon as Culicoides populations reach a critical level.

Monitoring of biting midges (Diptera: Ceratopogonidae: Culicoides Latreille) on farms in Sweden during the emergence of the 2008 epidemic of bluetongue

DEFF Research Database (Denmark)

Nielsen, Søren Achim; Nielsen, Boy Overgaard; Chirico, Jan

2010-01-01

In light of the emergence of bluetongue in northern Europe, populations of Culicoides species were monitored in 2007-2008 by means of Onderstepoort blacklight suction traps operating at livestock farms in Sweden. The location of the 22 sampling sites ranged from about latitude 55°N to about 68°N....... A total of 61,669 male and female Culicoides were captured, of which, 52,319 were trapped outside the farms and 9,350 in byres or livestock sheds. Thirty-three Culicoides species were recorded, of which, 30 were new to Sweden. The species and their relative abundance and spatial distribution on sites...... are presented. Two species incriminated as vectors of bluetongue virus, viz. Culicoides obsoletus (about 38%) and Culicoides scoticus (about 36%), were predominant and common in the environment of livestock farms practically all over the Swedish mainland, penetrating far north to at least 65°N. The two species...

Delineation of Culicoides species by morphology and barcode exemplified by three new species of the subgenus Culicoides (Diptera: Ceratopogonidae) from Scandinavia

DEFF Research Database (Denmark)

Nielsen, Søren Achim; Kristensen, Michael

2015-01-01

new species initially separated by DNA barcoding with mitochondrial COI can be distinguished by morphological characters. In this context a key to Scandinavian subgenus Culicoides using wing and maxillary palp characters is presented. The key is including the three new species Culicoides boyi...... is considered, as well as the evolutionary relationships between species within this genus remains problematic. In recent years molecular barcoding has assisted substantially in the identification of biting midges in the multiple entomological survey projects which were initiated in many European countries...... following the bluetongue outbreak in 2006–2009. These studies revealed potentially new species and “species-complexes” with large genetic and morphological variability. Here we use molecular barcoding, together with morphological analysis, to study subgenus Culicoides Latreille from Scandinavia with focus...

Taxonomic problems in the subgenus Meloehelea Wirth of the genus Atrichopogon Kieffer (Diptera: Ceratopogonidae) inferred from both morphological and molecular characters

Czech Academy of Sciences Publication Activity Database

Tóthová, A.; Knoz, J.; Sonnek, R.; Bryja, Josef; Vaňhara, J.

2008-01-01

Roč. 19, č. 1 (2008), s. 1-12 ISSN 0785-8760 R&D Projects: GA ČR(CZ) GD524/05/H536 Institutional research plan: CEZ:AV0Z60930519 Keywords : taxonomy * biting midges * 16S rDNA Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.410, year: 2008 http://www.entomologicafennica.org/Volume19/abstracts19_1.htm

Treatment of horses with cypermethrin against the biting flies Culicoides nubeculosus, Aedes aegypti and Culex quinquefasciatus.

Science.gov (United States)

Papadopoulos, E; Rowlinson, M; Bartram, D; Carpenter, S; Mellor, P; Wall, R

2010-04-19

An in vitro assay was used to assess the efficacy of the proprietary pyrethroid insecticide cypermethrin applied to horses (Deosect spray, 5.0%, w/v Fort Dodge Animal Health) against the biting midge Culicoides nubeculosus (Meigen) (Diptera: Ceratopogonidae) and the mosquitoes Aedes aegypti Linneaus and Culex quinquefasciatus Say (Diptera: Culicidae). Hair was collected from the back, belly and legs of the horses immediately prior to treatment and 7, 14, 21, 28 and 35 days after treatment, and also from untreated controls. In laboratory assays groups of 10 adult female C. nubeculosus, Ae. aegypti or C. quinquefasciatus were exposed to 0.5g of hair for 3min. In all cases, little or no mortality was observed in insects kept in contact with the pre-treatment samples or the untreated controls. With post-treatment samples for C. nubeculosus, mortality was close to 80% 7 days after treatment and then declined gradually; mean mortality was still at around 50% for hair collected 35 days after treatment. In general, Ae. aegypti and C. quinquefasciatus appeared to be less susceptible to cypermethrin than C. nubeculosus and the attenuation of the toxic effect declined more quickly with time after treatment. There were differences in the toxicity of hair from different body regions, with hair from the back consistently inducing the highest mortality and hair from the legs the lowest; this effect was more pronounced for C. nubeculosus than Ae. aegypti or C. quinquefasciatus. The results demonstrate the potential for topical insecticide treatment to offer protection to horses against biting flies; but highlight the major differences that exist in susceptibility between different insect species.

Algal-mediated ecosystem exchanges in the Eel River drainage network: towards photogrammetric mapping of color to function

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Power, M. E.; Welter, J.; Furey, P.; Lowe, R.; Finlay, J. C.; Hondzo, M.; Limm, M.; Bode, C.; Dietrich, W. E.

2009-12-01

Seasonal algal proliferations in river networks are typically short-lived (weeks-months) but spatially extensive. They mediate important ecological and biogeochemical exchanges within and between ecosystems. We are investigating correspondence of assemblage color with ecosystem function in the nitrogen-limited Eel River of northern California. During summer base flow following winter floods, Eel algal assemblages are dominated by the green macroalga Cladophora glomerata. New growths are green, but blooms turn yellow as Cladophora filaments are colonized by epiphytic diatoms (Cocconeis spp.). Later, proliferations turn rust colored as epiphytic assemblages became dominated by Epithemia spp., diatoms that contain nitrogen-fixing cyanobacterial endosymbionts. Epithemia-encrusted Cladophora occurs at and downstream of reaches draining > 100 km2 (where summer inundated average channel widths > 25 m), coinciding with a threshold increase in concentration of total dissolved nitrogen. Areal nitrogen fixation rates are 14x higher in rusty algal proliferations than in green, and 3-4x higher than in yellow Cladophora mats. Corresponding increases in insect emergence suggest that nitrogen fixed by cyanobacterial endosymbionts is highly edible. Rates of biomass emergence from rusty Cladophora mats are 12-17 times greater than from green mats, and 8-10 times greater from rusty than from yellow Cladophora mats, because larger taxa emerge from rusty mats (Chironominae versus Ceratopogonidae in yellow mats). Photogrammetric detection of spatial coverage and color changes in algal proliferations may help us track nitrogen fluxes they mediate (riverine loading from the atmosphere via fixation, river to the watershed return via insect emergence) that link riverine to aerial, watershed, and potentially nearshore marine ecosystems at reach to basin scales.

Factors affecting numbers of Culicoides in truck traps in coastal Queensland.

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Kettle, D S; Edwards, P B; Barnes, A

1998-10-01

Truck trap collections of Ceratopogonidae were made over a period of 27 months (November 1973-February 1976) at Tingalpa Creek, in southeast Queensland, Australia. Six collections were made on each of 95 days, giving 570 observations and a total of 29,378 Culicoides. Two collections were made before, one at, and three after sunset. Separate analyses were made of the catches of thirteen entities: male and female C. austropalpalis, C. brevitarsis, C. marksi, C. marmoratus and C. victoriae, female C. henryi and C. longior, and total C. bundyensis. Catches were dominated by C. brevitarsis (35.2%) and C. marmoratus (32.3%) and, with C. victoriae, were taken on almost every collecting day over all seasons. Sex ratios (M:F) varied from 0:100 for C. longior to 130:100 for C. marksi. Collections of all entities, except female C. henryi, were greatest (50-70% of the daily catch) at sunset. In winter there was substantial activity in the hour before sunset. Time of day was the most important variable, accounting for 15-45% of the observed variation. Between-day differences were significant for all except C. austropalpalis, C. victoriae and male C. marksi. Culicoides brevitarsis, C. bundyensis and C. longior had highly significant annual cycles, C. victoriae and female C. austropalpalis had significant lunar cycles, and C. longior had a significant tidal cycle. Logarithms of catches of female C. austropalpalis, C. brevitarsis, C. henryi, C. marmoratus, and female and male C. victoriae were inversely related to linear wind speed. Log catches of female C. austropalpalis, C. brevitarsis, C. marmoratus and C. victoriae, and male C. marksi and C. victoriae were positively related to temperature (quadratic).

Culicoides (Diptera: Ceratopogonidae) midges, the vectors of African horse sickness virus--a host/vector contact study in the Niayes area of Senegal.

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Fall, Moussa; Diarra, Maryam; Fall, Assane G; Balenghien, Thomas; Seck, Momar T; Bouyer, Jérémy; Garros, Claire; Gimonneau, Geoffrey; Allène, Xavier; Mall, Iba; Delécolle, Jean-Claude; Rakotoarivony, Ignace; Bakhoum, Mame T; Dusom, Ange M; Ndao, Massouka; Konaté, Lassana; Faye, Ousmane; Baldet, Thierry

2015-01-21

African horse sickness (AHS) is an equine disease endemic to Senegal. The African horse sickness virus (AHSV) is transmitted to the mammalian hosts by midges of the Culicoides Latreille genus. During the last epizootic outbreak of AHS in Senegal in 2007, 1,169 horses died from this disease entailing an estimated cost of 1.4 million euros. In spite of the serious animal health and economic implications of AHS, very little is known about determinants involved in transmission such as contact between horses and the Culicoides species suspected of being its vectors. The monthly variation in host/vector contact was determined in the Niayes area, Senegal, an area which was severely affected by the 2007 outbreak of AHS. A horse-baited trap and two suction light traps (OVI type) were set up at each of five sites for three consecutive nights every month for one year. Of 254,338 Culicoides midges collected 209,543 (82.4%) were female and 44,795 (17.6%) male. Nineteen of the 41 species collected were new distribution records for Senegal. This increased the number of described Culicoides species found in Senegal to 53. Only 19 species, of the 41 species found in light trap, were collected in the horse-baited trap (23,669 specimens) largely dominated by Culicoides oxystoma (22,300 specimens, i.e. 94.2%) followed by Culicoides imicola (482 specimens, i.e. 2.0%) and Culicoides kingi (446 specimens, i.e. 1.9%). Culicoides oxystoma should be considered as a potential vector of AHSV in the Niayes area of Senegal due to its abundance on horses and its role in the transmission of other Culicoides-borne viruses.

Functional validation of Apoptosis Genes IAP1 and DRONC in midgut tissue of the biting midge Culicoides sonorensis (Diptera: Ceratopogonidae) by RNAi

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Background: Culicoides biting midges transmit multiple ruminant viruses, including bluetongue virus and epizootic hemorrhagic disease virus, causing significant economic burden worldwide due to trade restrictions and production loss. To limit the spread of these viruses, control strategies focus on ...

Detection of Leishmania amazonensis and Leishmania braziliensis in Culicoides (Diptera, Ceratopogonidae) in an endemic area of cutaneous leishmaniasis in the Brazilian Amazonia.

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Rebêlo, José Manuel Macário; Rodrigues, Bruno Leite; Bandeira, Maria da Conceição Abreu; Moraes, Jorge Luiz Pinto; Fonteles, Raquel Silva; Pereira, Silma Regina Ferreira

2016-12-01

Biting midges in the genus Culicoides act as vectors of arboviruses throughout the world and as vectors of filariasis in Latin America, the Caribbean, and parts of Africa. Although Culicoides spp. are currently not considered to be vectors of Leishmania protozoa, the high abundance of biting midges in areas with active cutaneous leishmaniasis transmission points to the possibility of Culicoides infection by these pathogens. We used PCR to test captured Culicoides species for natural infection with Leishmania spp. We tested 450 Culicoides females, divided into 30 pools of 15 individuals each, as follows: nine pools of C. foxi (135 specimens), seven pools of C. filariferus (105), seven pools of C. insignis (105), five pools of C. ignacioi (75), and two pools of C. flavivenula (30). PCR confirmed the presence of Leishmania braziliensis DNA in C. ignacioi (0.14%), C. insignis (0.14%), and C. foxi (0.11); and Le. amazonensis DNA in C. filariferus (0.14%) and C. flavivenula (0.50%). We conclude that these Culicoides species can be naturally infected, but vector competence and transmission capability must be confirmed in future studies. Our results warrant further investigation into the role of these biting midge species in the leishmaniasis epidemiological cycle. © 2016 The Society for Vector Ecology.

Sphagnum mosses as a microhabitat for invertebrates in acidified lakes and the colour adaptation and substrate preference in Leucorrhinia dubia (Odonata, Anisoptera)

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Henrikson, B.-I. (Dept. of Zoology, Sect. of Animal Ecology, Univ. of Goeteborg, Goeteborg (Sweden))

1993-01-01

The increase of peat mosses, Sphagnum spp., in acidified lakes leads to a changed microhabitat structure for benthic invertebrates. The importance of this change was investigated for some benthic invertebrates. Comparisons between quantitative samples of Sphagnum and debris within the acidified Lake Stora Haestevatten, in the Lake Gaardsjoen catchment of SW Sweden, showed significantly higher abundances of Chironomidae, Ceratopogonidae, Odonata, Trichoptera, Cladocera and Argyroneta aquatica (Araneae) in Sphagnum. For chironomidae and Cladocera the differences were tenfold. Special reference was made to the libellulid Leucorrhinia dubia which is common in acid lakes. In a laboratory test, late instar larvae of L. dubia were shown to change colour to correspond to the brown and green colour of Sphagnum. This result was completed with a field test where larvae of L. dubia were significantly more common in Sphagnum of the same colour as the larvae. The ability to change colour may have an adaptive value when coexisting with visual predators. Small larvae were more prevalent in Sphagnum and they also showed a preference for this substrate in the laboratory test. Laboratory tests showed mediumsized larvae preferred Sphagnum. Larvae of L. dubia were more successful as predators on Asellus aquaticus in Sphagnum substrate than in debris in the laboratory test. Laboratory predation tests with notonecta glauca, Corixa dentipes, Acilius sulcatus, Hyphydrus ovatus and L. dubia showed that they could all feed on larvae of L. dubia. The complex habitat structure of Sphagnum is probably the reason for the high abundance of invertebrates since it may serve as both shelter against predation and as foraging sites. it is probably important as a key habitat for young instars of, for example, L. dubia. In lakes with large Sphagnum mats, L. dubia can coexist with fish. The expansion of Sphagnum due to acidification will probably benefit many acid-tolerant invertebrate species. (au)

Possible over-wintering of bluetongue virus in Culicoides populations in the Onderstepoort area, Gauteng, South Africa

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Jumari Steyn

2016-10-01

Full Text Available Several studies have demonstrated the ability of certain viruses to overwinter in arthropod vectors. The over-wintering mechanism of bluetongue virus (BTV is unknown. One hypothesis is over-wintering within adult Culicoides midges (Diptera; Ceratopogonidae that survive mild winters where temperatures seldom drop below 10 °C. The reduced activity of midges and the absence of outbreaks during winter may create the impression that the virus has disappeared from an area. Light traps were used in close association with horses to collect Culicoides midges from July 2010 to September 2011 in the Onderstepoort area, in Gauteng Province, South Africa. More than 500 000 Culicoides midges were collected from 88 collections and sorted to species level, revealing 26 different Culicoides species. Culicoides midges were present throughout the 15 month study. Nine Culicoides species potentially capable of transmitting BTV were present during the winter months. Midges were screened for the presence of BTV ribonucleic acid (RNA with the aid of a real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR assay. In total 91.2% of midge pools tested positive for BTV RNA. PCR results were compared with previous virus isolation results (VI that demonstrated the presence of viruses in summer and autumn months. The results indicate that BTV-infected Culicoides vectors are present throughout the year in the study area. Viral RNA-positive midges were also found throughout the year with VI positive midge pools only in summer and early autumn. Midges that survive mild winter temperatures could therefore harbour BTV but with a decreased vector capacity. When the population size, biting rate and viral replication decrease, it could stop BTV transmission. Over-wintering of BTV in the Onderstepoort region could therefore result in re-emergence because of increased vector activity rather than reintroduction from outside the region.

Mining pollution and the diet of the purple-striped Gudgeon Mogurnda Mogurnda Richardson (Eleotridae) in the Finniss River, Northern Territory, Australia

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Jeffree, R.A.; Williams, N.J.

1980-01-01

During the dry season of 1974, collections of the purple-striped Gudgeon Mogurnda Mogurnda were taken from the Finniss River of the Northern Territory; during the wet season, this river receives acidic and metallic pollutants from the formerly mined area of Rum Jungle. The fish consumed a great variety of foods, with high abundances of dytiscidae, chironomidae, ceratopogonidae, trichoptera, odonata, copepoda, decapoda, and pisces. For no food was there a significant regression against habitat descriptors in both of the zones; this emphasizes that pollution effects are more complex than simply depressing or raising the abundances of the dietary species. Five foods were more abundant in the diets of the polluted zone, and three in those of the unpolluted zone. The dietary abundances of two foods, both crustacean, increased in the polluted zone, compared to the unpolluted zone, through the dry season. Two categories of foods: (1) those obtaining oxygen directly from the atmosphere or via a film or bubble of air; and (2) the converse set (aquatic respirers), were contrasted for their usefulness in distinguishing between the zones, by both hierarchical agglomerative and discriminant function analyses. One collection from the polluted zone was reclassified as unpolluted on the basis of its grouping behaviour. The relevance for pollution studies of dietary analysis of euryphagous fish, rather than sampling aquatic fauna directly, is discussed in terms of food substitution, switching, strategies for abundance and recovery by the fauna, and possible effects of the pollutants on the fish as an intervening collector. Downstream patterns of abundance of the invertebrate fauna in this study are broadly similar to those of other studies in which such chemically diverse metals as Pb, Zn, and Cu are the pollutants, but there are differences for some faunal components.

The Influence of Host Plant Extrafloral Nectaries on Multitrophic Interactions: An Experimental Investigation.

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Suzanne Koptur

Full Text Available A field experiment was conducted with outplantings of the native perennial shrub Senna mexicana var. chapmanii in a semi-natural area adjacent to native pine rockland habitat in southern Florida. The presence of ants and the availability of extrafloral nectar were manipulated in a stratified random design. Insect communities were monitored and recorded over a period of six months with a view to addressing three main questions. Do ants provide biotic defense against key herbivores on S. chapmanii? Is the presence of ants on S. chapmanii mediated by EFN? Finally, are there ecological costs associated with the presence of ants on S. chapmanii, such as a reduction in alternative predator or parasitoid numbers? Herbivores on S. chapmanii included immature stages of three pierid butterflies, and adult weevils. Eight species of ants were associated with the plants, and other predators included spiders, ladybugs, wasps, and hemipterans. Parasitic, haemolymph-sucking midges (Ceratopogonidae and parasitoid flies were also associated with the caterpillar herbivores, and possibly the extrafloral nectaries of the plants. The presence of ants did not appear to influence oviposition by butterflies, as numbers of lepidopterans of all developmental stages did not differ among treatments. Significantly more late instar caterpillars, however, were observed on plants with ants excluded, indicating that ants remove small caterpillars from plants. Substantially more alternative predators (spiders, ladybugs, and wasps were observed on plants with ants excluded. Rates of parasitization did not differ among the treatments, but there were substantially fewer caterpillars succumbing to virus among those collected from control plants. We provide a rare look at facultative ant-plant mutualisms in the context of the many other interactions with which they overlap. We conclude that ants provide some biotic defense against herbivores on S. chapmanii, and plants benefit overall

Aquatic insects of New York salt marsh associated with mosquito larval habitat and their potential utility as bioindicators.

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Rochlin, Ilia; Dempsey, Mary E; Iwanejko, Tom; Ninivaggi, Dominick V

2011-01-01

The aquatic insect fauna of salt marshes is poorly characterized, with the possible exception of biting Diptera. Aquatic insects play a vital role in salt marsh ecology, and have great potential importance as biological indicators for assessing marsh health. In addition, they may be impacted by measures to control mosquitoes such as changes to the marsh habitat, altered hydrology, or the application of pesticides. Given these concerns, the goals of this study were to conduct the first taxonomic survey of salt marsh aquatic insects on Long Island, New York, USA and to evaluate their utility for non-target pesticide impacts and environmental biomonitoring. A total of 18 species from 11 families and five orders were collected repeatedly during the five month study period. Diptera was the most diverse order with nine species from four families, followed by Coleoptera with four species from two families, Heteroptera with three species from three families, then Odonata and the hexapod Collembola with one species each. Water boatmen, Trichocorixa verticalis Fieber (Heteroptera: Corixidae) and a shore fly, Ephydra subopaca Loew (Diptera: Ephydridae), were the two most commonly encountered species. An additional six species; Anurida maritima Guérin-Méneville (Collembola: Neanuridae), Mesovelia mulsanti White (Heteroptera: Mesovelidae), Enochrus hamiltoni Horn (Coleoptera: Hydrophilidae), Tropisternus quadristriatus Horn (Coleoptera: Hydrophilidae), Dasyhelea pseudocincta Waugh and Wirth (Diptera: Ceratopogonidae), and Brachydeutera argentata Walker (Diptera: Ephydridae), were found regularly. Together with the less common Erythrodiplax berenice Drury (Odonata: Libellulidae), these nine species were identified as the most suitable candidates for pesticide and environmental impact monitoring due to abundance, position in the food chain, and extended seasonal occurrence. This study represents a first step towards developing an insect-based index of biological integrity for

A key, based on wing patterns of biting midges (genus Culicoides Latreille - Diptera: Ceratopogonidae in the Iberian Peninsula, for use in epidemiological studies

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Rawlings, Peter

1996-12-01

Full Text Available The identity of vectors of disease are often required speedily in epidemiological studies but with a precision which excludes as many other species as possible. Identification keys usually require the examination of many different parts of the suspected vector to pinpoint the species. This consumes considerable time and resources, so epidemiologists tend to ignore them. Asimplified approach to identification is proposed, using the characteristics of a single part of the body (the wings of biting midges of the genus Culicoides. The level of differentiation was epidemiologically valuable. The monoclave could not differentiate all the species from each other but more than one third (20/58 of identifications were for single species, and a further 12/58 identifications gave only two possibilities, making 55.2% of identifications to an accuracy of at most one of two species. The diagnosis of vector species was reached in a maximum of six decision points. The only notable exception to valuable differentiation was the four species in the Culicoides obsoletus group which had almost identical female wing patterns. The ready availability of simple keys, which can be used by anyone without formal training in taxonomy, for all the species of a group in a region should encourage greater standardisation of identifications in all studies, including those not primarily aimed at systematics. These monoclaves can also serve as the primary tools to build computerised image-recognition systems for genera, families and orders of insects.Con frequencia en los estudios epidemiológicos hace falta conocer con rapidez, pero también con precisión, la identidad de los vectores. Por lo general los procedimientos de identificación y las claves exigen el examen de un elevado número de partes diferentes del vector sospechoso. Este enfoque consume mucho tiempo y recursos por lo que tiende a ser evitado por los epidemiólogos. Se propone un sistema simplificado para la identificación, el cual utiliza las caracteristicas de sólo una parte del cuerpo (las alas de los ceratopogónidos del género Culicoides. El nivel de diferenciación es bueno (55.2% de las 58 especies presentes y abarca casi todas las especies implicadas en la transmisión de virus y otros agentes patógenos de animales en la Península Ibérica. El diagnóstico de una especie precisa un máximo de seis criterios. La única excepción importante la constituyen las cuatro especies del grupo Culicoides obsoletus, las hembras de las cuales muestran un diseño alar casi idéntico. La utilización de claves sencillas debería proporcionar una mejor estandarización de la identificación en todos los estudios, incluso los realizados por no sistemáticos. Estas claves pueden servir como el instrumento más importante para desarrollar sistemas informáticos de reconocimiento de géneros, familias y especies de insectos por medio de imágenes.

A comparison of commercial light-emitting diode baited suction traps for surveillance of Culicoides in northern Europe.

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Hope, Andrew; Gubbins, Simon; Sanders, Christopher; Denison, Eric; Barber, James; Stubbins, Francesca; Baylis, Matthew; Carpenter, Simon

2015-04-22

The response of Culicoides biting midges (Diptera: Ceratopogonidae) to artificial light sources has led to the use of light-suction traps in surveillance programmes. Recent integration of light emitting diodes (LED) in traps improves flexibility in trapping through reduced power requirements and also allows the wavelength of light used for trapping to be customized. This study investigates the responses of Culicoides to LED light-suction traps emitting different wavelengths of light to make recommendations for use in surveillance. The abundance and diversity of Culicoides collected using commercially available traps fitted with Light Emitting Diode (LED) platforms emitting ultraviolet (UV) (390 nm wavelength), blue (430 nm), green (570 nm), yellow (590 nm), red (660 nm) or white light (425 nm - 750 nm with peaks at 450 nm and 580 nm) were compared. A Centre for Disease Control (CDC) UV light-suction trap was also included within the experimental design which was fitted with a 4 watt UV tube (320-420 nm). Generalised linear models with negative binomial error structure and log-link function were used to compare trap abundance according to LED colour, meteorological conditions and seasonality. The experiment was conducted over 49 nights with 42,766 Culicoides caught in 329 collections. Culicoides obsoletus Meigen and Culicoides scoticus Downes and Kettle responded indiscriminately to all wavelengths of LED used with the exception of red which was significantly less attractive. In contrast, Culicoides dewulfi Goetghebuer and Culicoides pulicaris Linnaeus were found in significantly greater numbers in the green LED trap than in the UV LED trap. The LED traps collected significantly fewer Culicoides than the standard CDC UV light-suction trap. Catches of Culicoides were reduced in LED traps when compared to the standard CDC UV trap, however, their reduced power requirement and small size fulfils a requirement for trapping in logistically challenging areas or where many

Retrospective analysis of Bluetongue farm risk profile definition, based on biology, farm management practices and climatic data.

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Cappai, Stefano; Loi, Federica; Coccollone, Annamaria; Contu, Marino; Capece, Paolo; Fiori, Michele; Canu, Simona; Foxi, Cipriano; Rolesu, Sandro

2018-07-01

Bluetongue (BT) is a vector-borne disease transmitted by species of Culicoides midges (Diptera: Ceratopogonidae). Many studies have contributed to clarifying various aspects of its aetiology, epidemiology and vector dynamic; however, BT remains a disease of epidemiological and economic importance that affects ruminants worldwide. Since 2000, the Sardinia region has been the most affected area of the Mediterranean basin. The region is characterised by wide pastoral areas for sheep and represents the most likely candidate region for the study of Bluetongue virus (BTV) distribution and prevalence in Italy. Furthermore, specific information on the farm level and epidemiological studies needs to be provided to increase the knowledge on the disease's spread and to provide valid mitigation strategies in Sardinia. This study conducted a punctual investigation into the spatial patterns of BTV transmission to define a risk profile for all Sardinian farmsby using a logistic multilevel mixed model that take into account agro-meteorological aspects, as well as farm characteristics and management. Data about animal density (i.e. sheep, goats and cattle), vaccination, previous outbreaks, altitude, land use, rainfall, evapotranspiration, water surface, and farm management practices (i.e. use of repellents, treatment against insect vectors, storage of animals in shelter overnight, cleaning, presence of mud and manure) were collected for 12,277 farms for the years 2011-2015. The logistic multilevel mixed model showed the fundamental role of climatic factors in disease development and the protective role of good management, vaccination, outbreak in the previous year and altitude. Regional BTV risk maps were developed, based on the predictor values of logistic model results, and updated every 10 days. These maps were used to identify, 20 days in advance, the areas at highest risk. The risk farm profile, as defined by the model, would provide specific information about the role of each

Entomopathogenic Fungus as a Biological Control for an Important Vector of Livestock Disease: The Culicoides Biting Midge

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Ansari, Minshad Ali; Pope, Edward C.; Carpenter, Simon; Scholte, Ernst-Jan; Butt, Tariq M.

2011-01-01

Background The recent outbreak of bluetongue virus in northern Europe has led to an urgent need to identify control measures for the Culicoides (Diptera: Ceratopogonidae) biting midges that transmit it. Following successful use of the entomopathogenic fungus Metarhizium anisopliae against larval stages of biting midge Culicoides nubeculosus Meigen, we investigated the efficacy of this strain and other fungi (Beauveria bassiana, Isaria fumosorosea and Lecanicillium longisporum) as biocontrol agents against adult C. nubeculosus in laboratory and greenhouse studies. Methodology/Findings Exposure of midges to ‘dry’ conidia of all fungal isolates caused significant reductions in survival compared to untreated controls. Metarhizium anisopliae strain V275 was the most virulent, causing a significantly decrease in midge survival compared to all other fungal strains tested. The LT50 value for strain V275 was 1.42 days compared to 2.21–3.22 days for the other isolates. The virulence of this strain was then further evaluated by exposing C. nubeculosus to varying doses (108–1011 conidia m−2) using different substrates (horse manure, damp peat, leaf litter) as a resting site. All exposed adults were found to be infected with the strain V275 four days after exposure. A further study exposed C. nubeculosus adults to ‘dry’ conidia and ‘wet’ conidia (conidia suspended in 0.03% aq. Tween 80) of strain V275 applied to damp peat and leaf litter in cages within a greenhouse. ‘Dry’ conidia were more effective than ‘wet’ conidia, causing 100% mortality after 5 days. Conclusion/Significance This is the first study to demonstrate that entomopathogenic fungi are potential biocontrol agents against adult Culicoides, through the application of ‘dry’ conidia on surfaces (e.g., manure, leaf litter, livestock) where the midges tend to rest. Subsequent conidial transmission between males and females may cause an increased level of fungi-induced mortality in midges

A comparison of a new centrifuge sugar flotation technique with the agar method for the extraction of immature Culicoides (Diptera: Ceratopogonidae) life stages from salt marsh soils.

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Two sampling techniques, agar extraction (AE) and centrifuge sugar flotation extraction (CSFE) were compared to determine their relative efficacy to recover immature stages of Culicoides spp from salt marsh substrates. Three types of samples (seeded with known numbers of larvae, homogenized field s...

Modelling the distributions and spatial coincidence of bluetongue vectors Culicoides imicola and the Culicoides obsoletus group throughout the Iberian peninsula.

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Calvete, C; Estrada, R; Miranda, M A; Borrás, D; Calvo, J H; Lucientes, J

2008-06-01

Data obtained by a Spanish national surveillance programme in 2005 were used to develop climatic models for predictions of the distribution of the bluetongue virus (BTV) vectors Culicoides imicola Kieffer (Diptera: Ceratopogonidae) and the Culicoides obsoletus group Meigen throughout the Iberian peninsula. Models were generated using logistic regression to predict the probability of species occurrence at an 8-km spatial resolution. Predictor variables included the annual mean values and seasonalities of a remotely sensed normalized difference vegetation index (NDVI), a sun index, interpolated precipitation and temperature. Using an information-theoretic paradigm based on Akaike's criterion, a set of best models accounting for 95% of model selection certainty were selected and used to generate an average predictive model for each vector. The predictive performances (i.e. the discrimination capacity and calibration) of the average models were evaluated by both internal and external validation. External validation was achieved by comparing average model predictions with surveillance programme data obtained in 2004 and 2006. The discriminatory capacity of both models was found to be reasonably high. The estimated areas under the receiver operating characteristic (ROC) curve (AUC) were 0.78 and 0.70 for the C. imicola and C. obsoletus group models, respectively, in external validation, and 0.81 and 0.75, respectively, in internal validation. The predictions of both models were in close agreement with the observed distribution patterns of both vectors. Both models, however, showed a systematic bias in their predicted probability of occurrence: observed occurrence was systematically overestimated for C. imicola and underestimated for the C. obsoletus group. Average models were used to determine the areas of spatial coincidence of the two vectors. Although their spatial distributions were highly complementary, areas of spatial coincidence were identified, mainly in

Indoor activity of Culicoides associated with livestock in the bluetongue virus (BTV) affected region of northern France during autumn 2006.

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Baldet, T; Delécolle, J C; Cêtre-Sossah, C; Mathieu, B; Meiswinkel, R; Gerbier, G

2008-10-15

In August 2006, bluetongue virus (BTV) was detected in the Netherlands, Belgium, western Germany, Luxembourg and northern France for the first time. Consequently, a longitudinal entomological study was conducted in the affected region of northern France (Ardennes) throughout the autumn of 2006. Data on the spatio-temporal distribution of Culicoides (Diptera: Ceratopogonidae) associated with livestock were collected and an attempt was made to identify the vector(s) involved in BTV transmission by means of virus detection in wild-caught biting midges. Weekly sampling using standardized Onderstepoort-type blacklight traps were performed simultaneously both outdoors and indoors in one BTV-free and three BTV-affected farms between September and December 2006. Culicoides were sorted according to farm, location (outdoors vs. indoors), time point (in weeks), species and physiological stage. BTV detection was conducted by RT-PCR on monospecific pools of non-bloodfed parous female Culicoides. The principal results showed: (i) the absence of the Mediterranean vector, C. imicola, (ii) the relatively low abundance of C. dewulfi and C. pulicaris, (iii) the widespread occurrence and abundance of C. obsoletus/C. scoticus with longevity and behaviour compatible with BTV transmission, and (iv) all Culicoides pools tested for BTV were negative. In France, the very low levels of BTV-8 circulation were probably due to the limited introduction of the virus from affected neighbouring countries, and not due to the absence of local vector populations. A key finding has been the substantiation, for the first time, that Culicoides, and particularly the potential vectors C. obsoletus/C. scoticus and C. dewulfi, can be active at night inside livestock buildings and not only outside, as originally believed. The endophagic tendencies of members of the Obsoletus group are discussed in light of the prolonged period of BTV transmission during the autumn of 2006 and the risk of BTV overwintering and

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Marlene Villegas-Salas

2017-12-01

Full Text Available Schmallenberg virus affects ruminants, which causes significant economic losses.  The virus is transmitted through vectors of the genus Culicoides; however, other studies do not rule out the possibility of sexual transmission due to its presence in semen. For this reason, the National Service of Animal Health of Costa Rica (SENASA imposed restrictions on the import of semen from animals from the European Union in 2013. Consequently, SENASA conducted a study to determine the presence or absence of antibodies against this virus in bovine, ovine and caprine samples. As a result, no antibodies against this virus were detected in the 748 samples tested. It was concluded that Schmallenberg virus was not circulating in Costa Rican ruminants during the tested period.