DNA barcoding of blackflies (Diptera: Simuliidae) as a tool for species identification and detection of hidden diversity in the eastern regions of Spain

Surveillance and screening of Stomoxyinae flies from Mallorca Island (Spain) reveal the absence of selected pathogens but confirm the presence of the endosymbiotic bacterium Wolbachia pipientis

Adult brachycera biting flies can significantly impact livestock through both direct effects (reduction of food intake, disturbance, painful bites, and blood loss) and indirect effects (pathogen transmission), leading to substantial economic losses and production damage. This study aimed to assess the presence of blood-sucking flies in six mixed-animal farm environments on the island of Mallorca (Balearic Islands, Spain) by employing multiple trapping methods. Additionally, distribution maps of brachycera biting fly species recorded in Spain were created, based on data extracted thorough review of scientific literature and citizen digital databases. Investigation of several pathogens, including equine infectious anemia virus (EIAV), Anaplasmataceae bacteria, and piroplasm protozoa, was carried out using different PCR targets (18S rRNA, 16S rRNA, groESL, and tat genes). Citizen science databases and literature review corroborated the consistent distribution trend for two Stomoxyinae species, underscoring the importance of citizen collaboration as a complement to traditional entomological surveillance. Our study confirmed the presence of two biting Stomoxyinae species: the prevalent stable fly Stomoxys calcitrans across all sampled farms, and the horn fly Haematobia irritans, which turned out to be less abundant. DNA barcoding techniques validated the identification of the two species. Neither EIAV nor bacterial/protozoan pathogens were detected using the selected PCR targets in either fly species. However, Wolbachia pipientis (clustered in the supergroup A together with the only sequence of W. pipientis from the USA) was identified through PCR targeting 16S rRNA, groESL and wsp genes in all pools of H. irritans (n = 13) collected from two of the examined farms. This study represents the first attempt to investigate pathogens in Stomoxyinae biting flies in Spain. The discovery of the endosymbiotic Wolbachia organism in H. irritans represents the first record in Spain and the second from Europe. This finding holds significant implications for future research on the applications of this bacterium in biocontrol programs.

Comparative Study of Potential Habitats for Simulium qinghaiense (Diptera: Simuliidae) in the Huangshui River Basin, Qinghai-Tibet Plateau: An Analysis Using Four Ecological Niche Models and Optimized Approaches

The Huangshui River, a vital tributary in the upper reaches of the Yellow River within the eastern Qinghai-Tibet Plateau, is home to the endemic black fly species S. qinghaiense. In this study, we conducted a systematic survey of the distribution of the species in the Huangshui River basin, revealing its predominant presence along the river's main stem. Based on four ecological niche models-MaxEnt with parameter optimization; GARP; BIOCLIM; and DOMAIN-we conduct a comparative analysis; evaluating the accuracy of AUC and Kappa values. Our findings indicate that optimizing parameters significantly improves the MaxEnt model's predictive accuracy by reducing complexity and overfitting. Furthermore, all four models exhibit higher accuracy compared to a random model, with MaxEnt demonstrating the highest AUC and Kappa values (0.9756 and 0.8118, respectively), showcasing significant superiority over the other models (p < 0.05). Evaluation of predictions from the four models elucidates that potential areas of S. qinghaiense in the Huangshui River basin are primarily concentrated in the central and southern areas, with precipitation exerting a predominant influence. Building upon these results, we utilized the MaxEnt model to forecast changes in suitable areas and distribution centers during the Last Interglacial (LIG), Mid-Holocene (MH), and future periods under three climate scenarios. The results indicate significantly smaller suitable areas during LIG and MH compared to the present, with the center of distribution shifting southeastward from the Qilian Mountains to the central part of the basin. In the future, suitable areas under different climate scenarios are expected to contract, with the center of distribution shifting southeastward. These findings provide important theoretical references for monitoring, early warning, and control measures for S. qinghaiense in the region, contributing to ecological health assessment.

Cytotaxonomic characterization and estimation of migration patterns of onchocerciasis vectors (Simulium damnosum sensu lato) in northwestern Ethiopia based on RADSeq data

BACKGROUND

While much progress has been made in the control and elimination of onchocerciasis across Africa, the extent to which vector migration might confound progress towards elimination or result in re-establishment of endemism in areas where transmission has been eliminated remains unclear. In Northern Ethiopia, Metema and Metekel-two foci located near the Sudan border-exhibit continuing transmission. While progress towards elimination has been faster in Metema, there remains a problematic hotspot of transmission. Whether migration from Metekel contributes to this is currently unknown.

METHODOLOGY/PRINCIPLE FINDINGS

To assess the role of vector migration from Metekel into Metema, we present a population genomics study of 151 adult female vectors using 47,638 RADseq markers and mtDNA CoI sequencing. From additional cytotaxonomy data we identified a new cytoform in Metema, closely related to S. damnosum s.str, here called the Gondar form. RADseq data strongly indicate the existence of two distinctly differentiated clusters within S. damnosum s.l.: one genotypic cluster found only in Metema, and the second found predominantly in Metekel. Because blackflies from both clusters were found in sympatry (in all four collection sites in Metema), but hybrid genotypes were not detected, there may be reproductive barriers preventing interbreeding. The dominant genotype in Metema was not found in Metekel while the dominant genotype in Metekel was found in Metema, indicating that (at the time of sampling) migration is primarily unidirectional, with flies moving from Metekel to Metema. There was strong differentiation between clusters but little genetic differentiation within clusters, suggesting migration and gene flow of flies within the same genetic cluster are sufficient to prevent genetic divergence between sites.

CONCLUSIONS/SIGNIFICANCE

Our results confirm that Metekel and Metema represent different transmission foci, but also indicate a northward movement of vectors between foci that may have epidemiological importance, although its significance requires further study.

First report of Culicoides caucoliberensis in Spain: Exploring molecular phylogeny, host-feeding behaviour and avian haemosporidian parasites

Culicoides biting midges (Diptera: Ceratopogonidae) are vectors of pathogens that affect wildlife and livestock. Understanding the composition and distribution of vector species is crucial for implementing control strategies and preventing the spread of infectious diseases. This study provides a morphological and molecular characterisation of Culicoides caucoliberensis, which represents the first record for Spain, increasing the number of Culicoides species in the country to 85. A total of 213 specimens were collected using Onderstepoort-ultraviolet down-draught light traps on a rocky coastline in the Balearic Islands during two sampling periods in 2022. Phylogenetic analysis showed that C. caucoliberensis forms a monophyletic cluster within the Maritimus group. Host preferences were determined for the first time and showed propensity to feed on the European shag (Phalacrocorax aristotelis). The vector role of C. caucoliberensis for haemosporidian transmission remains unclear since molecular detection of Haemosporidians (Haemoproteus and Plasmodium) was negative for all the pools of parous and engorged females analysed. This study emphasises the importance of conducting entomofauna studies in lesser-known Mediterranean islet landscapes and highlights the need for research on vectors within the One Health framework.

Integrated taxonomy of black flies (Diptera: Simuliidae) reveals unexpected diversity in the most arid ecosystem of Europe

The family Simuliidae includes more than 2000 species of black flies worldwide. Their morphological uniformity creates difficulty for species identification, which limits our knowledge of their ecology and vectorial role. We investigated the systematics of black flies in a semi-arid area of the Iberian Peninsula, an ecologically harsh environment for these organisms. Sampling adult black flies in three different habitats (by means of CDC traps) and in avian nest boxes and collecting immature stages in high-salinity rills provided a representative sample of the component species. A combination of approaches, including morphological, chromosomal, and molecular (based on the mitochondrial cytochrome C oxidase subunit I (COI) and internal transcribed spacer 2 (ITS2) genes) revealed five species: four common species (Simulium intermedium, S. petricolum, S. pseudequinum, and S. rubzovianum) and the first European record for S. mellah. Barcoding gap and phylogenetic analyses revealed that ITS2 is a key marker to identify the species, whereas the COI marker does not provide enough resolution to identify some species or infer their phylogenetic relationships. Morphological and chromosomal features are also provided to identify S. mellah unequivocally. Our study highlights the need for integrated studies of black flies in ecologically extreme habitats to increase our knowledge of their distribution, ecology, and potential risks for public health.

First Record of Phlebotomus (Larroussius) perfiliewi (Diptera: Psychodidae), Vector of Leishmania infantum and Phleboviruses, in Spain

Phlebotomine sand flies are vectors of several diseases of importance for public health, including leishmaniosis, bartonellosis, and sand fly fevers. An entomological survey on blood-feeding Diptera was conducted in June–November 2020–2021 to know the diversity of insect vectors in Mallorca (Balearic Islands, Spain). Among the vectors collected, Phlebotomus (Larroussius) perfiliewi Parrot, 1930 was found being the first record of this species in Spain. Phlebotomus perfiliewi s.l. is one of the main vectors of Leishmania infantum in the Mediterranean Basin and Central Asia. The identification of this species was confirmed by both morphological features and DNA barcoding. Phylogenetic analyses showed that the specimens captured were Ph. perfiliewi s.s. (99.85–100% homologues from Italy and Algeria specimens), with a sequence divergence of 0.17%. The cytochrome c oxidase subunit I gene clearly separates the three species that make up the Ph. perfiliewi species complex. In addition, we also provide a brief discussion about their identification remarks, phylogenetic relationships, and vector status.

The Palearctic blackfly Simulium equinum (Diptera: Simuliidae) as a biting pest of captive nyala antelopes (Tragelaphus angasii)

Blackflies (Diptera: Simuliidae) are cosmopolitan nuisance pests of great economic importance as well as vectors of many pathogens. After reports of massive blackfly biting of captive nyala antelopes in the Vienna Zoo, Austria, this study aimed to identify the species causing multiple skin lesions on the antelope hosts. The Palearctic species Simulium equinum, belonging to the medically and veterinary important Wilhelmia subgenus, was identified as the most likely causative agent. Barcoding and maximum likelihood analysis supported morphological species identification and highlighted the complex phylogeny of the subgenus Wilhelmia. Our study gives first evidence of the multi-host feeding blackfly S. equinum in the Vienna Zoo, thereby raising the question whether other hosts could also be bitten on a regular basis. The preliminary results urge for further analysis of blackfly breeding sites as well as the clarification of the host spectrum to assess the medical and veterinary importance of blackflies in the Zoo.

First record of the mermithid nematode worm Isomermis lairdi parasitizing black flies in Spain

Mermithid nematodes are considered a promising biological control agent to reduce the population density of different blood-feeding vectors, i.e. black flies (Diptera: Simuliidae), which are important pests of medical and veterinary interest worldwide. Immature larvae of black flies were collected in a rill from La Rioja (Northern Spain) in the summer of 2016. Isomermis lairdi Mondet, Poinar & Bernadou, 1977 (Nematoda: Mermithidae) was found parasitizing eleven specimens of Simulium cryophilum s.l. (Rubtsov, 1959) (prevalence of 52%), which represent the first record of this nematode for Spain and the second for Europe. The confirmation of the nematode and the black fly species was carried out by both morphological and molecular approaches using the 18S ribosomal RNA and the cytochrome c oxidase subunit I genes. Phylogenetic analyses indicated that the collected specimens were Isomermis lairdi (99.4-99.9% identity with homologues from Africa) with a sequence divergence of 0.2%. The role of Isomermis lairdi as an alternative tool in the biological control of black flies in Spain should be further explored.

A Survey on Native and Invasive Mosquitoes and Other Biting Dipterans in Northern Spain

PURPOSE

Haematophagous Diptera, such as mosquitoes (Culicidae), biting midges (Ceratopogonidae), and black flies (Simuliidae), are important insects for public and animal health due to their capacity to bite and transmit pathogens. Outdoor recreation areas are usually affected by biting species and provide suitable habitats to both adult and immature stages. This study aimed to determine the species diversity and larval sites of these Diptera groups in two golf courses.

METHODS

A multi-method collection approach using ultraviolet-CDC traps, human landing catches, collection in breeding sites, and ovitraps was implemented during summer 2020 in northern Spain. Insects were determined by morphological features accompanied by DNA barcoding.

RESULTS

A total of ten native mosquito species were recorded either as adults or as larval stages. The invasive species Aedes japonicus was collected only at egg or pupa stage in ovitraps. Culex pipiens s.l. and Culex torrentium were both common mosquito species accounting for 47.9% of the total larval site collections and their larvae might be found in a wide range of natural and artificial sites. Culiseta longiareolata specimens were also prominent (30.1% of the total) and occurred exclusively in man-made water-filled containers. A total of 13 Culicoides species were identified, 10 of which were captured by ultraviolet-CDC traps, particularly members of the Obsoletus complex (Culicoides obsoletus/Culicoides scoticus, 74.9%) and seven species by emergence traps, being the two most abundant C. kibunensis (44.8%) and C. festivipennis (34.9%). Simulium cryophilum was also collected hovering around the operator under field sampling.

CONCLUSION

A comprehensive representation of the blood-sucking Diptera fauna and their larval sites was obtained by the multi-method approach in two Spanish golf courses.

The biology of Simulium erythrocephalum and S. chelevini (Diptera, Simuliidae): Morpho-logical, ecological and molecular data

The subgenus Boophthora is a typical Palearctic taxon, which includes only 6 species, among them. Simulium erythrocephalum has a transpalearctic distribution. In Europe, Adler notes only the species S. erythrocephalum, and Yankovsky – two species S. (Boophthora) erythrocephalum and S. (Boophthora) chelevini. According to morphological characteristics, these species differ in their life stages. We have studied the development of S. erythrocephalum and S. chelevini from three rivers of Volyn region, Ukraine (Styr, Chornoguzka, Putylivka) from 2017 to 2019. We used the EPPO PM7 / 129 standard. Collected samples, 615-bp fragments of the COI gene were sequenced from five individuals of S. erythrocephalum and five individuals of S. chelevini and compared with four samples of S. erythrocephalum from the GenBank. We obtained the nucleotide sequence of S. chelevini. All of the S. erythrocephalum samples from Ukraine had 692 bases, the S. erythrocephalum samples from Armenia had 673 bases. S. erythrocephalum and S. chelevini did not have any intraspecific variations. These intraspecific variations were not larger than the interspecific variations. It has been proved that the populations of S. erythrocephalum and S. chelevini from medium and small rivers of Volyn do not differ in biological, behavioural and genetic characteristics. Comparison of S. erythrocephalum and S. chelevini life stages showed clear differences in 20 morphological features, which are probably manifestations of phenotypic variability. Comparison of species with data from the GenBank from Spain and Armenia on the mitochondrial cytochrome c oxidase subunit I (COI) gene confirmed the opinion that S. erythrocephalum and S. chelevini are one species. On the phylogenetic tree, the data are not grouped, there is no clear separation of the clades. Bootstrap values are 95–100%, which may indicate a significant similarity of all studied samples and the lack of isolation of individual morphotypes from Volyn, Spain and Armenia. To finally confirm the taxonomic position of these two species, additional research is needed covering more individuals from different parts of Europe and analysis of more genes.

Surveillance along the Rio Grande during the 2020 Vesicular Stomatitis Outbreak Reveals Spatio-Temporal Dynamics of and Viral RNA Detection in Black Flies

Vesicular stomatitis virus (VSV) emerges periodically from its focus of endemic transmission in southern Mexico to cause epizootics in livestock in the US. The ecology of VSV involves a diverse, but largely undefined, repertoire of potential reservoir hosts and invertebrate vectors. As part of a larger program to decipher VSV transmission, we conducted a study of the spatiotemporal dynamics of Simulium black flies, a known vector of VSV, along the Rio Grande in southern New Mexico, USA from March to December 2020. Serendipitously, the index case of VSV-Indiana (VSIV) in the USA in 2020 occurred at a central point of our study. Black flies appeared soon after the release of the Rio Grande’s water from an upstream dam in March 2020. Two-month and one-year lagged precipitation, maximum temperature, and vegetation greenness, measured as Normalized Difference Vegetation Index (NDVI), were associated with increased black fly abundance. We detected VSIV RNA in 11 pools comprising five black fly species using rRT-PCR; five pools yielded a VSIV sequence. To our knowledge, this is the first detection of VSV in the western US from vectors that were not collected on premises with infected domestic animals.

Atypical behavior of a black fly species connects cavity-nesting birds with generalist blood parasites in an arid area of Spain

BACKGROUND

The feeding behavior of bloodsucking insects determines the transmission, distribution, host spectrum and evolution of blood parasites in the wild. Conventional wisdom suggests that some vector groups (e.g. black flies, family Simuliidae) are consistently exophagous daytime biters. We aimed to understand more about the exceptions to this pattern by combining targeted trapping and molecular identification of parasites in vectors.

METHODS

In this study, we collected black flies in nest boxes used by European rollers Coracias garrulus in southeastern Spain. We molecularly analyzed 434 individual insects, identifying the black fly species caught in the nest boxes, their potential vertebrate blood meals, and the haemosporidian parasite lineages that they carried.

RESULTS

Only one black fly species, Simulium rubzovianum, appeared to enter the nest boxes of rollers. Among the trapped specimens, 15% contained vertebrate DNA, which always belonged to rollers, even though only half of those specimens were visibly engorged. Furthermore, 15% of all black flies contained Leucocytozoon lineages, indicating previous feeding on avian hosts but probably not on infected adult rollers. The known vertebrate hosts of the recorded Leucocytozoon lineages suggested that large and/or abundant birds are their hosts. Particularly represented were cavity-nesting species breeding in the vicinity, such as pigeons, corvids and owls. Open-nesting species such as thrushes and birds of prey were also represented.

CONCLUSIONS

Our data strongly suggest that S. rubzovianum bites uninfected roller nestlings and infected individuals of other species, potentially incubating adults, inside nest boxes and natural cavities. This simuliid does not appear to have a strong preference for specific host clades. Contrary to the general pattern for the group, and possibly enhanced by the harsh environmental conditions in the study area, this black fly appeared to intensively use and may even have a preference for confined spaces such as cavities for feeding and resting. Preferences of vectors for atypical microhabitat niches where hosts are less mobile may enable social and within-family transmission and parasite speciation in the long term. At the same time, a lack of host preference in concentrated multispecies communities can lead to host switches. Both processes may be underappreciated driving forces in the evolution of avian blood parasites.

The biology of Simulium noelleri and Simulium dolini: morphological, ecological and molecular data

Molecular genetic research has revolutionized the taxonomy and systematics of the Simuliidae family. Simulium noelleri Friederichs, 1920 is a species of blackfly, common in the Holarctic, reported for 33 countries. In 1954, Topchiev recorded it in Ukraine for the first time. Simulium dolini Usova et Sukhomlin, 1989 has been recorded at the borders of Ukraine and Belarus. It was described for the first time by Usova and Sukhomlin in 1989 from the collection from the territory of Volyn region in 1985. Usova and Sukhomlin, Yankovsky, Adler state that S. noelleri and S. dolini are different species by the morphological characteristics that differ in all phases of development. Adults differ in the structure of the genital appendages, palps, the margin and shape of the face and forehead, the colour of the legs; the larva – in the pattern on the frontal capsule, the number of rays in the fans, mandibular teeth and the hypostoma, the structure of the hind organ of attachment; pupae – in the branching way of gills. Molecular data are becoming an increasingly important tool in insect taxonomy. Therefore, we had to check that these two closely related species also have genetic difference. The development of S. noelleri and S. dolini was studied in four small rivers of Volyn region, Ukraine (Chornohuzka, Konopelka, Putylivka, Omelyanivka) in the period from 2017 to 2019. During initial processing of insect samples, we used the standard protocols EPPO PM7/129. We obtained the nucleotide sequence of S. dolini. It was proved that the populations of S. noelleri and S. dolini from medium and small rivers of Volyn differ in biological, morphological, behavioural and genetic characteristics. Comparison of the species S. noelleri with the data of the GenBank confirms the identification of three distinct morphotypes from Volyn, Great Britain and Canada. As a result of the conducted researches, it was confirmed that two close species of S. dolini and S. noelleri from the noelleri species group differ in the structure of mitochondrial DNA, which confirms their independent taxonomic status. Additional studies comprising more individuals from larger areas of Europe are required to verify the taxonomic position of these two species.

Surveillance of a Pest Through a Public Health Information System: The Case of the Blackfly (Simulium erythrocephalum) in Zaragoza (Spain) during 2009-2015

Background: Animals and people in many Spanish regions are increasingly being affected by blackfly bites in the last decade. Because of blackflies, the city of Zaragoza has become in recent years a paradigm of discomfort in Europe, with thousands of citizens affected. The OMI-AP system (Stacks, Barcelona, Spain) implemented by the Government of Aragón, a software that manages the electronic medical history of all patients, has been evaluated in order to document the increase of insect bite recorded by the primary care consultations in Zaragoza after the first outbreak of blackflies occurred in 2011. Methods: An observational, ecological and longitudinal study of insect bites recorded at the primary care consultations was carried out in primary care during the period 2009–2015. Results: The incidence of medical consultations by insect bites in Basic Health Areas (BHA) near to rivers is higher than the furthest BHA. Rural BHA are more affected by insect bites than the urban ones. The increase of medical assistance due to insect bites in Zaragoza since 2011 is correlated with the blackflies bites. Conclusions: This tool was very useful to describe the initial stage of this public health problem. It could be used for guiding public health responses in terms of surveillance and management of this pest.

Simulium reptans (Linnaeus, 1758) and Simulium reptantoides Carlsson, 1962 from the Balkan Peninsula

Simulium reptans (Linnaeus, 1758) and Simulium reptantoides Carlsson, 1962 are two species of the Simulium reptans group whose distribution is unclear because of their confusing taxonomy and systematics. Their genetic variability is well known for populations in northern and central Europe and shows that both species have two forms; however, the genetic variability of these species in southern and eastern Europe is unknown. To identify the status of these two species in southeast Europe, mtDNA was extracted from 19 individuals from 12 localities across the Balkan Peninsula. Phylogenetic analysis confirmed the existence of two species with 7.38-7.94% divergence. Each species was comprised of two clades, with 2.31% and 1.43% interclade divergence for S. reptans and S. reptantoides, respectively. This study revealed the presence of both species across the Balkans and that S. reptans occurs in this area in only one form (S. reptans B), while S. reptantoides is found in two genetic forms (A and B).

Species-specific Identification of Vibrio sp. based on 16S-23S rRNA gene internal transcribed spacer

AIMS

To explore a prokaryotic species-specific DNA marker, 16S-23S rRNA gene internal transcribed spacer (ITS) sequence for identification and classification of Vibrio.

METHODS AND RESULTS

Five hundred and seventy four ITS sequences from 60 Vibrio strains were collected, then the primary and secondary structures of ITS sequence were analysed. The ITS was divided into several subunits, and the species-specificity of these subunits were evaluated by blast. The variable subunit of ITS showed high species-specificity. A protocol to identify a Vibrio species based on ITS analysis was developed and verified. Both the specificity and sensitivity were 100%. The phylogeny analysis of Vibrio based on ITS showed that ITS devised a better classification than 16S rDNA. Finally, an identification method of Vibrio based on ITS sequencing in food samples was developed and evaluated. The results of ITS sequencing were (100%) consistent with the results identified by ISO standard.

CONCLUSIONS

Vibrio could be accurately identified at the species level by using the ITS sequences.

SIGNIFICANCE AND IMPACT OF THE STUDY

The present study suggests that the ITS can be considered as a significant DNA marker for identification and classification of Vibrio species, and it posed a new path to screen the Vibrio in food sample.

Surveillance of Mosquitoes (Diptera, Culicidae) in a Northern Central Region of Spain: Implications for the Medical Community

Mosquitoes are important to public and animal health due to their capacity to transmit diseases. Since the Zika virus was declared a pandemic by the WHO in 2016, and it has been recorded in different regions of Mediterranean Area (included Spain), the Government of La Rioja (Northern Spain) through the Center of Rickettsiosis and Arthropod-Borne Diseases, implemented an entomological surveillance programme of mosquitoes in La Rioja and in a close area of Navarra. This surveillance extended to some of the pathogens that they can transmit. Here we describe the framework of the initial surveillance programme for the detection of mosquitoes and associated human pathogens. We outline the benefits and the limitation of the programme to date, and explore how greater benefits can be achieved, for example using a One Health approach. Entomological surveillance has been carried out with BG-Sentinel traps, human bait technique and other methods such as collecting adults in resting places or immature stages by dipping in several wetlands. Since Aedes albopictus, vector of arbovirus such as Dengue, Chikungunya, and Zika, has not been detected yet in the region, the entomological programme included the surveillance of this exotic species using ovitraps in the most important cities. Morphological identification was supported using the mitochondrial cytochrome C oxidase subunit I and the internal transcribed spacer 2 genes analysis. In 2016 and 2017, more than 6,000 mosquitoes were collected. The mosquito's community included 21 species associated with six genera: Anopheles (n = 4), Aedes (n = 5), Culex (n = 6), Culiseta (n = 4), Uranotaenia (n = 1) and Coquillettidia (n = 1). Eleven species represent new records for La Rioja and Navarra regions. Several species were collected biting humans and a great proportion of the sampled mosquito population are competent vectors of several pathogens, such as West Nile virus. Sequences closely related to mosquito-only flavivirus have been detected in 0.34% of analysed pools. At the same time, the epidemiological surveillance emphasis is placed in the early detection of mosquito-borne diseases in primary health and emergency services. The surveillance programme represents a relevant and necessary assessment of the risk of pathogen transmission in a region, and it allows for the establishment of the appropriate preventive measures.