Species-level Microbiota of Biting Midges and Ticks from Poyang Lake

Objective The purpose of this study was to investigate the bacterial communities of biting midges and ticks collected from three sites in the Poyang Lake area,namely,Qunlu Practice Base,Peach Blossom Garden,and Huangtong Animal Husbandry,and whether vectors carry any bacterial pathogens that may cause diseases to humans,to provide scientific basis for prospective pathogen discovery and disease prevention and control.Methods Using a metataxonomics approach in concert with full-length 16S rRNA gene sequencing and operational phylogenetic unit(OPU)analysis,we characterized the species-level microbial community structure of two important vector species,biting midges and ticks,including 33 arthropod samples comprising 3,885 individuals,collected around Poyang Lake.Results A total of 662 OPUs were classified in biting midges,including 195 known species and 373 potentially new species,and 618 OPUs were classified in ticks,including 217 known species and 326 potentially new species.Surprisingly,OPUs with potentially pathogenicity were detected in both arthropod vectors,with 66 known species of biting midges reported to carry potential pathogens,including Asaia lannensis and Rickettsia bellii,compared to 50 in ticks,such as Acinetobacter lwoffii and Staphylococcus sciuri.We found that Proteobacteria was the most dominant group in both midges and ticks.Furthermore,the outcomes demonstrated that the microbiota of midges and ticks tend to be governed by a few highly abundant bacteria.Pantoea sp7 was predominant in biting midges,while Coxiella sp1 was enriched in ticks.Meanwhile,Coxiella spp.,which may be essential for the survival of Haemaphysalis longicornis Neumann,were detected in all tick samples.The identification of dominant species and pathogens of biting midges and ticks in this study serves to broaden our knowledge associated to microbes of arthropod vectors.Conclusion Biting midges and ticks carry large numbers of known and potentially novel bacteria,and carry a wide range of potentially pathogenic bacteria,which may pose a risk of infection to humans and animals.The microbial communities of midges and ticks tend to be dominated by a few highly abundant bacteria.

Description of two new species in the genus Forcipomyia(Diptera:Ceratopogonidae) from China

Two new species of biting midges in the genus of Forcipomyia Meigen,1818 are described and illustrated:Forcipomyia(Microhelea) clypedus Liu and Yu sp.nov.and Forcipomyia(Caloforcipomyia)longipenis Yu and Liu sp.nov.,respectively.

Fauna and a new species of the genus Palpomyia(Diptera: Ceratopogonidae) from China

In this paper, 33 known species of Palpomyia are described. A new species of Palpomyia named Palpomyia nanniwana He, Liu and Yu sp. nov. is reported from Shaanxi Province, China.

A new species in the genus Palpomyia(Diptera:Ceratopogonidae) from Qinghai Province,China

Specimens of Ceratopogonidae were collected from the Nachitai District of Qinghai Province.Among them,a new species of the genus Palpomyia was discovered and named Palpomyia nachitai He,Liu and Yu sp.nov.

Detection of arboviruses in Culicoides(Diptera:Ceratopogonidae)collected from animal farms in the border areas of Yunnan Province,China

Biting midges of the genus Culicoides(order Diptera,family Ceratopogonidae)are potential biological vectors for the transmission of certain arboviruses among humans,livestock,and wild animals.This study collected a total of 405 Culicoides individuals from seven animal farms located in five counties in the border areas of Yunnan Province,China,and examined the Culicoides species composition and the major arboviruses carried by the Culicoides species.The collected Culicoides were classified into seven species with variable abundances:Culicoides arakawae(5.43%,22/405),Culicoides homotomus(1.23%,5/405),Culicoides obsoletus(19.75%,80/405),Culicoides orientalis(17.28%,70/405),Culicoides oxystoma(29.38%,119/405),Culicoides peregrinus(5.68%,23/405),and Culicoides nipponensis(21.23%,86/405).Among the seven species,C.oxystoma and C.nipponensis were distributed in all the five counties with abundances of 13.33–44.87%and 10.00–46.83%,respectively,suggesting that these were the dominant species of Culicoides widespread on animal farms in the border areas.PCR was used to detect major arboviruses in the collected Culicoides specimens,including bluetongue virus(BTV),Japanese encephalitis virus,Dengue virus,Zika virus,African swine fever virus,and African horse sickness virus.Among the tested viruses,only BTV serotype 1 was tested positive in C.oxystoma specimens collected from a buffalo farm.Culicoides oxystoma was the dominant species on animal farms in the sampled areas,but it has not previously been documented as positive for BTV in China.The current results thus suggest that C.oxystoma could be an important vector for BTV transmission in these border areas,which,however,needs to be confirmed by further comprehensive experiments.Overall,the present study provides the first profile of Culicoides species on animal farms in the China,Vietnam,and Myanmar border areas,establishes the prevalence of arboviruses carried by these Culicoides species,and suggests the vector potential of C.oxystoma species for the transmission of BTV.

Differential effects of environmental climatic variables on parasite abundances in blue tit nests during a decade

Models on climate change have predicted an increase of temperature over the earth’s surface with potential drastic effects on living organisms.We analyzed the relationships between climatic conditions(temperature,rainfall,and wind speed)and the abundance of blood-sucking flying insects(biting midges and blackflies)and nest-dwelling ectoparasites(mites,fleas,and blowflies)collected from blue tit nests during bird breeding seasons for a period of 10 years.Average temperature,rainfall,and wind speed showed significant differences among years.Temperature and wind speed increased during the period of study while rainfall decreased.Biting midge,blackfly,and blowfly abundances increased across years but not flea and mite abundances.Hatching date decreased and brood size increased across years.Independently of year variation,parasites were related to climatic variables.For example,biting midge,blowfly,mite,and flea abundances were positive and significantly related to average temperature.We also found a positive and significant relationship between abundances of Haemoproteus infections and biting midge abundances during the first year of life of birds out of nests.However,abundance and prevalence of Lankesterella infections in yearlings were positive and significantly related to mite abundances during the year of birth of birds.Leucocytozoon and Lankesterella infections were also significantly related to climatic variables and Haemoproteus and Lankesterella infections increased across years.In addition,body condition of adult females and males were negatively related to flea larvae and blowfly abundance respectively.Nestling body condition was also negatively related to biting midge abundance.Changes in climatic conditions across years could therefore affect several parasites of birds but also to birds themselves.