Evidence incriminating midges (Diptera: Ceratopogonidae) as potential vectors of Leishmania in Australia

The first autochthonous Leishmania infection in Australia was reported by Rose et al. (2004) and the parasite was characterised as a unique species. The host was the red kangaroo (Macropus rufus) but the transmitting vector was unknown. To incriminate the biological vector, insect trapping by a variety of methods was undertaken at two field sites of known Leishmania transmission. Collected sand flies were identified to species level and were screened for Leishmania DNA using a semi-quantitative real-time PCR. Collections revealed four species of sand fly, with a predominance of the reptile biter Sergentomyia queenslandi (Hill). However, no Leishmania-positive flies were detected. Therefore, alternative vectors were investigated for infection, giving startling results. Screening revealed that an undescribed species of day-feeding midge, subgenus Forcipomyia (Lasiohelea) Kieffer, had a prevalence of up to 15% for Leishmania DNA, with high parasitemia in some individuals. Manual gut dissections confirmed the presence of promastigotes and in some midges material similar to promastigote secretory gel, including parasites with metacyclic-like morphology. Parasites were cultured from infected midges and sequence analysis of the Leishmania RNA polymerase subunit II gene confirmed infections were identical to the original isolated Leishmania sp. Phylogenetic analysis revealed the closest known species to be Leishmania enriettii, with this and the Australian species confirmed as members of Leishmania sensu stricto. Collectively the results strongly suggest that the day-feeding midge (F. (Lasiohelea) sp. 1) is a potential biological vector of Leishmania in northern Australia, which is to our knowledge the first evidence of a vector other than a phlebotomine sand fly anywhere in the world. These findings have considerable implications in the understanding of the Leishmania life cycle worldwide.     

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.     

New insights on diversity,morphology and distribution of Culicoides Latreille 1809 (Diptera: Ceratopogonidae) from Northeast Spain

The present work provides an improvement on the knowledge of the diversity, morphology and distribution of Culicoides species in Catalonia (NE Spain). Data derived from morphology and sequencing allowed to detect the presence of 13 species non previously found in the surveillance area, updating the number of species recorded in Catalonia up to 53. Of special interest among the newly recorded species are: 1) C. yemenensis, new record for Europe, 2) C. coluzzii and C. sejfadinei, being new records for the Iberian Peninsula, and 3) C. pseudopallidus which is new record for Spain. Regarding the current distribution of Culicoides species, two eco-zones were detected in the region, the first eco-zone had species with typical northern Palaearctic (European) distribution whereas the second had species with typical southern Palaearctic (African) distribution, which were apparently influenced by mean high temperature of the warmest month and annual precipitation rate.     

First report of Culicoides boyi (Diptera: Ceratopogonidae) in France

Culicoides boyi Nielsen, Kristensen & Pape 2015 (Diptera: Ceratopogonidae), described in Denmark in 2015, is reported in France. This species is closely related to Culicoides pulicaris (Linnaeus 1758) and can only be distinguished from this species by a subtle variation in spot wing pattern and by calculation of maxillary palpal ratio.     

Bloodmeal analysis reveals avian Plasmodium infections and broad host preferences of Culicoides (Diptera: Ceratopogonidae) vectors

Changing environmental conditions and human encroachment on natural habitats bring human populations closer to novel sources of parasites, which might then develop into new emerging diseases. Diseases transmitted by host generalist vectors are of special interest due to their capacity to move pathogens into novel hosts. We hypothesize that humans using forests for recreation are exposed to a broad range of parasites from wild animals and their vectors. A corollary of this is that new vector-host, parasite-host, and vector-parasite associations could eventually develop. Thus, we expect to observe atypical vector-host associations. Using molecular bloodmeal analysis via amplification of the mtDNA COI gene we identified the vertebrate hosts of Culicoides (Diptera: Ceratopogonidae) species in a sub-urban forest of Southwestern Germany. Bloodmeals were also checked for haemosporidian infections by amplifying a fragment of the mtDNA cyt b gene. We identified a total of 20 Culicoides species, thirteen of which fed on humans. From 105 screened bloodmeals we obtained high quality sequences for 77 samples, 73 (94.8%) originated from humans, two from livestock (Bos taurus and Equus caballus), and two from wild birds (Sylvia atricapilla and Turdus merula). We found that four Culicoides species previously assumed to feed exclusively on either birds (C. kibunensis) or domestic mammals (C. chiopterus, C. deltus, C. scoticus) fed also on humans. A total of six Culicoides abdomens were infected with avian haemosporidian parasites (Plasmodium or Haemoproteus), four of those abdomens contained blood derived from humans. Our results suggest that parasites of wild animals may be transferred to humans through infectious bites of Culicoides vectors. Further, we show that Culicoides vectors believed to be a specialist on specific vertebrate groups can have plastic feeding preferences, and that Culicoides are susceptible to infection by Plasmodium parasites, though vector viability must still be experimentally demonstrated.     

First Record of Culicoides oxystoma Kieffer and Diversity of Species within the Schultzei Group of Culicoides Latreille (Diptera: Ceratopogonidae) Biting Midges in Senegal

The Schultzei group of Culicoides Latreille (Diptera: Ceratopogonidae) is distributed throughout Africa to northern Asia and Australasia and includes several potential vector species of livestock pathogens. The taxonomy of the species belonging to this species group is confounded by the wide geographical distribution and morphological variation exhibited by many species. In this work, morphological and molecular approaches were combined to assess the taxonomic validity of the species and morphological variants of the Schultzei group found in Senegal by comparing their genetic diversity with that of specimens from other geographical regions. The species list for Senegal was updated with four species: Culicoides kingi, C. oxystoma, C. enderleini and C. nevilli being recorded. This is the first record of C. oxystoma from Africa south of Sahara, and its genetic relationship with samples from Israel, Japan and Australia is presented. This work provides a basis for ecological studies of the seasonal and spatial dynamics of species of this species group that will contribute to better understanding of the epidemiology of the viruses they transmit.     

Description of Culicoides pseudoheliconiae sp.n. from Peruvian Amazon and revalidation of Culicoides contubernalis Ortiz & Leon (Diptera: Ceratopogonidae)

A new species of the Culicoides hylas species group, Culicoides pseudoheliconiae Felippe-Bauer is described and illustrated based on female specimens from Peruvian Amazon, and Culicoides contubernalis Ortiz & Leon from Ecuador is resurrected and redescribed as a valid species. A systematic key, table with numerical characters of females of species of the Culicoides hylas group are given.     

Simuliid blackflies (Diptera: Simuliidae) and ceratopogonid midges (Diptera: Ceratopogonidae) as vectors of Mansonella ozzardi (Nematoda: Onchocercidae) in northern Argentina

Mansonella ozzardi, a relatively nonpathogenic filarial parasite of man in Latin America, is transmitted by either ceratopogonid midges or simuliid blackflies. In the only known focus of the disease in north-western Argentina the vectors have never been incriminated. This study investigated the potential vectors of M. ozzardi in this area. The only anthropophilic species of these Diptera families biting man at the time of the investigation were Simulium exiguum, S. dinellii, Culicoides lahillei and C. paraensis. Using experimentally infected flies S. exiguum and both species of Culicoides allowed full development of microfilariae to the infective stage, with C. lahillei being a more competent host than S. exiguum. Based on these data, biting rates and natural infectivity rates it is probable that at the begininning of the wet season C. lahillei is the main vector of M. ozzardi and both C. paraensis and S. exiguum secondary vectors. Additionally, it was found that a single dose of ivermectin was ineffectual in eradicating M. ozzardi from infected individuals in this area.     

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.     

Five new species of Culicoides (Diptera: Ceratopogonidae) of the Nansei Islands.

Five new species of Culicoides of the Nansei Islands are described: C. sasai sp.n. from Amami-oshima Is., C. toshiokai sp.n. from Ishigaki Is., C. iriomotensis sp.n. from Iriomote Is., C. flavipunctatus sp.n. from Yonaguni Is., and C. yaeyamaensis sp.n. from the latter three islands. C. toshiokai sp.n. and C. iriomotensis sp.n. are tree-hole breeders, such as C. dendrophilus Amosova, which is common in similar habitats extending from Okinawa to Honshu.