Equine Culicoides hypersensitivity in Florida: biting midges collected in light traps near horses

Twenty-three species of Culicoides were trapped near pruritic horses during a 2-year survey in Florida. Nearly 99% of the biting midges collected were represented by Culicoides insignis Lutz, C. edeni Wirth and Blandon, C. stellifer (Coquillett), C. niger Root and Hoffman, C. haematopotus Malloch and C. venustus Hoffman. The relative contribution to the total catch by each of these species varied among collection sites. Seasonally, different species attain their largest population sizes at different times. Association of species collected in light traps with the seasonality of lesion development on the horses suggests that more than one species must be involved in causing Culicoides hypersensitivity in horses from Florida. Nulliparous females were present in most months that females of the same species were active; in some cases, species were trapped in each month of the year, particularly at the more southerly sites. The species of biting midge most likely to be involved in Culicoides hypersensitivity in horses in Florida are C. insignis, C. stellifer and C. venustus based upon their mammalophilic behaviour and seasonality.     

Culicoides aspirated from cattle in Costa Rica, Honduras, Panama and Puerto Rico, and their role as potential vectors of bluetongue viruses

Abstract. In 1991, as part of an epidemiological study of bluetongue viruses (BTV) in the Central American and Caribbean region, eight farms located in Costa Rica, Honduras, Panama and Puerto Rico were sampled for Culicoides spp. attacking cattle. Using cattle bait, 3884 biting midges were collected with an electric aspirator during both crepuscular periods. The predominant species captured was Culicoides insignis Lutz (95%), followed by C.furens (Poey) (3.4%), C.filarifer Hoffman/ C.ocumarensis Ortiz (0.9%), C.lahillei (Iches) (0.7%), C.arubae Fox and Hoffman (<0.1%) and C.gorgasi Wirth and Blanton (<0.1%). Blood-engorged specimens from some of these species were collected and comprised: 18% of all C.insignis , 36% of C.furens , 37% of filarifer/ocumarensis and 25% of C.lahillei. No engorged C.arubae or C.gorgasi were caught. These results confirm earlier findings pointing to C.insignis, C.furens and C.filarifer/ ocumarensis as potential vectors of BTV in the region.     

Species diversity and seasonal abundance of Culicoides biting midges in northwestern Argentina

The species diversity and seasonal abundance of biting midges of the genus Culicoides (Diptera: Ceratopogonidae) were studied in northwestern Argentina during the period 2003–2005. A total of 5437 Culicoides specimens were collected using CDC light traps in three areas of the mountainous rainforest area. The most common species were Culicoides paraensis (Goeldi) and C . insignis Lutz, Culicoides lahillei (Iches), C . venezuelensis Ortiz & Mirsa, C . debilipalpis Lutz and C . crescentis Wirth & Blanton were also collected. Culicoides paraensis was abundant during the summer, and C . insignis and C . lahillei during late summer and early fall. Accumulated rainfall was the climatic variable most related to fluctuation in abundance of C . paraensis .     

Bluetongue epidemiology in the Caribbean region: serological and entomological findings from a pilot sentinel system in Trinidad and Tobago

When monitored by the agar gel immunodiffusion test for antibody to bluetongue viruses, a sentinel flock of twenty-five lambs remained seropositive through the year, whereas in a sentinel herd of twenty calves only two individuals seroconverted and these became negative again within 2 months. A light trap operated with the calf herd yielded high numbers of Culicoides insignis Lutz (over 18,000 per trap night) along with C. filariferus Hoffman, C. pusillus Lutz, C. leopoldi Ortiz, C. foxi Ortiz, C. limai Barretto, C. diabolicus Hoffman and C. guyanensis Floch and Abonnenc. Culicoides were trapped at the sheep station which had housed the lambs 3 years following the sentinel study. No virus was isolated from pools of C. insignis, C. filariferus and C. pusillus. Six other species were collected in insufficient numbers to warrant attempted virus isolations.     

Description of the Pupa of Culicoides crucifer Clastrier (Diptera: Ceratopogonidae)

The pupa of Culicoides crucifer Clastrier is described, illustrated and photomicrographed by using binocular microscope and phase-contrast microscopy from material collected in an artificial container in Manaus, Brazil. The pupa shows features typical of pupae occurring in calm and clean waters, and it is compared with its similar congeners of the subgenus Haematomyiidium, Culicoides annuliductus Wirth and Culicoides debilipalpis Lutz.     

Seasonal abundance of livestock‐associated Culicoides species in northeastern Brazil

Culicoides biting midges (Diptera: Ceratopogonidae) are of great medical and veterinary importance because the haematophagous females of some species can transmit diseases to humans and animals. In order to determine the presence and seasonal abundance of the bluetongue virus (BTV) vector Culicoides insignis Lutz at domestic animal sheds in northeastern Brazil, insects were collected once a month between January and December 2010. Light traps were set from 18.00 to 06.00 hours at a pigsty, chicken coop and bovine corral. Culicoides insignis accounted for 81% of the 22 316 specimens collected. Other well‐represented species were: Culicoides paucienfuscatus Barbosa (3246 individuals), Culicoides diabolicus Hoffman (308), Culicoides leopoldoi Ortiz (224) and Culicoides duartei Tavares and Luna Dias (221). The remainder accounted for 4% of the total sample. Culicoides insignis occurred mostly at the cattle corral, 98.2% in the rainy season. This study confirms the presence and close association of C. insignis with cattle in Maranhão state, northeastern Brazil and emphasizes the risk of bluetongue infections spreading in the area.     

海南霸王岭发现库蠓属二新种(双翅目:蠓科)

2009年在海南霸王岭(19.0°N,109.0°E)的昆虫调查采集中,采获许多蠓类,经分类研究,发现其中有二种库蠓新种,分别命名为霸王岭库蠓Culicoides bawanglingensis Yu,Wang and Chen,sp.nov.和曲囊库蠓Culicoides reduncutheca Yu,Wang and Tan,sp.nov.。这2种库蠓属新种的模式标本珍藏于医学昆虫标本馆(北京丰台东大街20号,100071)。     

Epidemiology of bluetongue in Central America and the Caribbean: initial entomological findings

Abstract. Forty-four species of Culicoides (Diptera: Ceratopogonidae) were caught in insect light traps during the first 2 years of studies on the epidemiology of bluetongue virus in the Caribbean and Central America. Traps were operated near sentinel ruminants which were bled monthly for serologic evaluation and then virus isolation. More than 570,000 individuals were identified. Culicoides insignis Lutz accounted for 90% of the catch, C.filarifer Hoffman/C.ocumarensis Ortiz 5%, C.furens Poey 3% and C.pusillus Lutz 2%. Other species accounted for less than 1% of the total catch. Sentinel ruminants became seropositive when C.insignis populations were high at many study sites. At a few sites C.pusillus and C.filarifer I C.ocumarensis were predominant or were present in large numbers during seroconversions of sentinels. Virus isolations were obtained from sentinel ruminants during times when these same species were present in large populations.     

Bluetongue epidemiology in the Caribbean region: serological and entomological evidence from a pilot study in Barbados

Variation in the percentage of lambs seroconverting to bluetongue viruses was seen between sites and years in Barbados. Transmission at some sites was nearly absent whereas all lambs at one site became seropositive. The agar gel immunodiffusion test for bluetongue gave consistent results in series of serum samples from 112 of 121 sentinel lambs. Collections of biting midges in association with sheep yielded six species: Culicoides insignis Lutz, C. pusillus Lutz, C. phlebotomus (Williston), C. furens (Poey), C. jamaicensis Edwards and C. trilineatus Fox. The first two species comprised 92% of those caught during a sentinel lamb study and were the predominant species trapped for virus isolation. No viruses were recovered from 5517 C. insignis, 614 C. pusillus, three C. trilineatus and two C. furens placed into pools during two brief intensive trapping operations.     

Ecology of Culicoides (Diptera: Ceratopogonidae) in southcentral Florida and experimental Culicoides vectors of the avian hematozoan Haemoproteus danilewskyi Kruse

To determine the vectors of Haemoproteus danilewskyi in blue jays (Cyanocitta cristata) in southcentral Florida (USA), we conducted a 2 yr study from January 1993 to December 1995 of the presence and seasonal abundance of Culicoides spp. Of the 14 species of Culicoides captured in Centers for Disease Control light traps, 10 were ornithophilic. Of these, C. edeni, C. knowltoni, C. stellifer, C. beckae, and C. arboricola were most abundant, representing 46% of the total collection and 99% of the ornithophilic collection. The presence of C. stellifer in Bennett trap collections represents a new biting record for this species on passerine birds. We experimentally challenged the most abundant ornithophilic species to determine which were capable of supporting sporogonic development of H. danilewskyi. Culicoides edeni, C. knowltoni, and C. arboricola supported sporogonic development of H. danilewskyi.     

The bloodsucking biting midges of Argentina (Diptera: Ceratopogonidae)

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.     

Culicoides in relation to transmission of African Horse Sickness virus in The Gambia

Twelve light trap collections made near overnight shelters of horses and donkeys in four villages in the Central River Division of The Gambia captured fourteen species of biting midge of the genus Culicoides . Five species new to The Gambia were identified. This brought the number of recognized species of Culicoides (after a revision of C. schultzei ) to twenty-nine in The Gambia. Species known or suspected as vectors of African horse sickness virus (AHSV) and bluetongue virus (BTV) comprised 83% of female captures, 65% of captures being C. imicola or its sibling species , C. miombo . Captures of female Culicoides in the late dry season were almost as large as in the early dry season, despite the extreme heat and dryness at this time of the year.
Tests on batches of formalin-preserved female midges, using AHSV or BTV antigen capture ELISAs, did not show the presence of any virus amongst 2286 females in 240 aliquots. Nearly all Gambian equines are reportedly seropositive to AHSV and these results suggest that virus challenge from Culicoides vectors may be a factor in the health of Gambian horses and donkeys.     

Description of Culicoides lisicarruni (Diptera: Ceratopogonidae), a new species from Cundinamarca, Colombia

A new species of Culicoides of the subgenus Diphaomyia Vargas from high altitudes of the Andes in Colombia is described and photographied. The species is compared with its similar congener Culicoides marinkellei Wirth & Lee. Data on the collecting site and notes on the species daily activity are also provided.     

Stabling and the protection of horses from Culicoides bolitinos (Diptera: Ceratopogonidae), a recently identified vector of African horse sickness

The stabling of horses at night reportedly offers protection from African horse sickness and the most significant vector of the disease, Culicoides imicola Kieffer, has been shown to be exophilic. In certain high-lying regions of South Africa, however, C. bolitinos Meiswinkel, may be the major vector of the disease but its entry behaviour into stables is unknown. Accordingly, in the eastern Free State province of South Africa, light trap catches of C. bolitinos inside stables and outside, were compared. Two horse-baited stables, one traditional, and one modern, were used and combinations of stable (old/new), ceiling fans (on/off) and accessibility to Culicoides (stable doors open/closed or windows gauzed/ungauzed) were investigated as treatments. A total of 111,452 Culicoides of 26 species was collected on 60 trap nights; C. bolitinos was dominant (89.1% overall) with C. imicola second in abundance (2.9%). Outside catches were greater on warmer, drier, evenings but were suppressed by high wind speeds. Catches of C. imicola inside stables with doors open, or with windows ungauzed, were less than the numbers captured outside. In contrast, more C. bolitinos were caught in open stables than outside, i.e. open structures may protect horses from the exophilic C. imicola, but may increase attack rates from the endophilic C. bolitinos. The closing of doors and the gauzing of windows, however, led to a 14-fold reduction in numbers of C. bolitinos and C. imicola entering stables. A well-gauzed 'traditional' stable was as effective as a closed 'modern' stable. Ceiling fans had no suppressant effect.     

Intradermal Challenge of Icelandic Horses in Norway and Iceland with Extracts of Culicoides spp.

A skin test survey was carried out in Icelandic horses in Norway and Iceland using extracts of Culicoides spp. as antigen. Eleven horses with recurrent seasonal dermatitis reacted with an immediate hypersensitivity response to intradermal challenge with antigen. All except one of thirty-three clinically normal horses in Norway showed a negative response in skin tests. These findings indicate that Culicoides spp. may be the major cause of the disease in Norway. Only one of the 110 horses tested in Iceland showed any skin test reaction (weak), demonstrating that the horses were not sensitized to Culicoides allergen. The disease has never been reported in Iceland.     

Virus recovery rates for wild-type and live-attenuated vaccine strains of African horse sickness virus serotype 7 in orally infected South African Culicoides species

Previously reported virus recovery rates from Culicoides (Avaritia) imicola Kieffer and Culicoides (Avaritia) bolitinos Meiswinkel (Diptera, Ceratopogonidae) orally infected with vaccine strain of African horse sickness virus serotype 7 (AHSV-7) were compared with results obtained from concurrently conducted oral infections with five recent AHSV-7 isolates from naturally infected horses from various localities in South Africa. Culicoides were fed sheep bloods spiked with 10(7.6) TCID(50)/mL of a live-attenuated vaccine strain AHSV-7, and with five field isolates in which virus titre in the bloodmeals ranged from 10(7.1) to 10(8.2) TCID(50)/mL). After an extrinsic incubation of 10 days at 23.5 degrees C, virus recovery rates were significantly higher in C. imicola (13.3%) and C. bolitinos (4.2%) infected with the live-attenuated virus than in midges infected with any of the field isolates. The virus recovery rates for the latter groups ranged from 0% to 9.5% for C. imicola and from 0% to 1.5% for C. bolitinos. The C. imicola population at Onderstepoort was significantly more susceptible to infection with AHSV-7 isolated at Onderstepoort than to the virus strains isolated from other localities. Results of this study suggest that tissue culture attenuation of AHSV-7 does not reduce its ability to orally infect competent Culicoides species and may even lead to enhanced replication in the vector. Furthermore, oral susceptibility in a midge population appears to vary for geographically distinct isolates of AHSV-7.     

Two new species and new records of biting midges of the genus Culicoides from northwestern Argentina (Diptera: Ceratopogonidae)

The following two new species of Culicoides from the Argentinean Yungas are described, illustrated and placed to subgenus or species group and compared with related congeners: Culicoides calchaqui Spinelli & Veggiani Aybar and Culicoides willinki Spinelli & Veggiani Aybar. Culicoides daedaloides Wirth & Blanton is recorded for the first time for Argentina and Culicoides pseudoheliconiae Felippe-Bauer is firstly mentioned from the northwestern region of the country.     

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

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 horses were screened for midges, each region sampled randomly for 5 min using a handheld mouth aspirator (pooter). Observations were confined to the hour immediately before and after sunset. Culicoides spp. were obtained from every body region, of which the four most abundant species – Culicoides chiopterus (Meigen), Culicoides punctatus (Meigen), the species complex Culicoides obsoletus (Meigen), and Culicoides dewulfi Goetghebuer – all were proven or potential vectors for arboviral diseases in livestock. Culicoides spp. activity was distinctly bimodal across the day, surging at sunset and 1 h after sunrise. Midges were inactive between 11:00 and 16:00 hours, these hours marking the time of day when horses can be pastured most safely but, thereafter, to avoid escalating attacks, would have to be stabled protectively. Around sunset, the mean attack rate of the four most abundant species ranged from 3.0 to 11.7 midges per min; of these, C. dewulfi and C. chiopterus were reared out of the dung of experimental horses. The Netherlands is home to the world's densest horse population (11 per km²), of which half are estimated to stay outdoors permanently with no access to protective housing. In the absence of a preventive vaccination policy, it is difficult to envisage how horses in northern Europe will be protected from infection during an outbreak of a Culicoides‐transmitted disease like African horse sickness.     

Descriptions of a new species and the pupae of two known species of Culicoides Latreille (Diptera: Ceratopogonidae) from India

Pupa, and adult male and female of Culicoides pseudosimilis n. sp., and pupae of two known species, C. selangorensis Wirth & Hubert, and C. dryadeus Wirth & Hubert, are described and illustrated. An identification key to the Indian species of Clavipalpis and Shermani species group of male Culicoides is also provided.     

Description of Culicoides (Mataemyia) felippebauerae sp. n., Forcipomyia musae immatures, and occurrence of F. genualis, breeding in banana stems in Brazilian Amazonia (Diptera: Ceratopogonidae)

The following three species of Ceratopogonidae were collected breeding in the rhizomatous herb Phenakospermum guyannense Endl., 1833 in the vicinity of Manaus, Brazil, a new species, Culicoides (Mataemyia) felippebauerae Spinelli, Forcipomyia (Forcipomyia) genualis (Loew), and F. (Phytohelea) musae Clastrier & Dellécole. C. (M.) felippebauerae is described and illustrated as adult, pupa, and fourth instar larva, the adult compared with the adult of C. barthi Taveres and Souza and larva and pupa with those of C. dicrourus Wirth & Blanton and C. macieli Tavares & Ruiz, the only species with known immatures in the subgenus. The pupa and fourth instar larva of F. (P.) musae are described and illustrated and compared with immatures of F. (P.) edwardsi Saunders.