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1.
Genes (Basel) ; 15(3)2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38540382

RESUMEN

The emergence of culicoid-transmitted bluetongue and Schmallenberg viruses in several European countries demonstrated the ability of indigenous biting midge species to transmit pathogens. Entomologic research programs identified members of the Obsoletus Group (Culicoides subgenus Avaritia) as keyplayers in disease epidemiology in Europe. However, morphological identification of potential vectors is challenging due to the recent discovery of new genetic variants (haplotypes) of C. obsoletus sensu stricto (s.s.), forming distinct clades. In this study, 4422 GenBank entries of the mitochondrial cytochrome c oxidase subunit I (COI) gene of subgenus Avaritia members of the genus Culicoides were analyzed to develop a conventional multiplex PCR, capable of detecting all vector species and clades of the Western Palearctic in this subgenus. Numerous GenBank entries incorrectly assigned to a species were identified, analyzed and reassigned. The results suggest that the three C. obsoletus clades represent independent species, whereas C. montanus should rather be regarded as a genetic variant of C. obsoletus s.s. Based on these findings, specific primers were designed and validated with DNA material from field-caught biting midges which achieved very high diagnostic sensitivity (100%) when compared to an established reference PCR (82.6%).


Asunto(s)
Ceratopogonidae , Animales , Ceratopogonidae/genética , Reacción en Cadena de la Polimerasa Multiplex , Complejo IV de Transporte de Electrones/genética , Haplotipos , Insectos Vectores/genética
2.
Viruses ; 15(12)2023 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-38140539

RESUMEN

Due to globalisation and climate change, mosquito-borne pathogens are emerging in new areas on all continents, including Europe, which has recently faced outbreaks of dengue, chikungunya and West Nile fever. The present study complements previous investigations to evaluate the circulation of mosquito-borne viruses in Germany, with the aim of identifying potential vector species and risk areas. Mosquitoes collected from 2019 to 2021 and identified to species or species group level were screened for viruses of the families Flaviviridae, Peribunyaviridae and the genus Alphavirus of the family Togaviridae. In total, 22,528 mosquitoes were examined, thus providing the most comprehensive study on West Nile virus (WNV) circulation so far in the German mosquito population. Usutu virus (USUV) RNA was detected in six samples, Sindbis virus (SINV) RNA in 21 samples and WNV RNA in 11 samples. Samples containing RNA of USUV and WNV consisted of mosquitoes collected in the East German federal states of Brandenburg, Saxony and Saxony-Anhalt, while samples with RNA of SINV originated from more widespread locations. Although minimum infection rates have remained relatively low, the intensity of virus circulation appears to be increasing compared to previous studies. Continuous mosquito screening contributes to the early detection of the introduction and spread of mosquito-borne pathogens.


Asunto(s)
Culex , Culicidae , Flavivirus , Fiebre del Nilo Occidental , Virus del Nilo Occidental , Humanos , Animales , ARN Viral/genética , Mosquitos Vectores , Flavivirus/genética , Virus del Nilo Occidental/genética , Alemania/epidemiología
3.
Microorganisms ; 11(11)2023 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-38004718

RESUMEN

Biting midges of the genus Culicoides occur almost globally and can regionally and seasonally reach high abundances. Most species are hematophagous, feeding on all groups of vertebrates, including humans. In addition to being nuisance pests, they are able to transmit disease agents, with some viruses causing high morbidity and/or mortality in ruminants, horses and humans. Despite their impact on animal husbandry, public health and tourism, knowledge on the biology and ecology of culicoid biting midges and their interactions with ingested pathogens or symbiotic microorganisms is limited. Research is challenging due to unknown larval habitats, the insects' tiny size, the inability to establish and breed most species in the laboratory and the laborious maintenance of colonies of the few species that can be reared in the laboratory. Consequently, the natural transmission of pathogens has experimentally been demonstrated for few species while, for others, only indirect evidence of vector potential exists. Most experimental data are available for Culicoides sonorensis and C. nubeculosus, the only species kept in western-world insectaries. This contribution gives an overview on important biting midge vectors, transmitted viruses, culicoid-borne viral diseases and their epidemiologies and summarizes the little knowledge on interactions between biting midges, their microflora and culicoid-borne arboviruses.

4.
Parasit Vectors ; 16(1): 369, 2023 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-37853399

RESUMEN

BACKGROUND: Although haemosporidian parasites may cause considerable health and economic problems in aviaries, there is limited understanding of the vectors transmitting them. Mosquito-borne Plasmodium species are responsible for the deaths of numerous exotic (= immunologically naïve) birds in zoos every year, while native birds are adapted to the parasites and largely protected by an effective immune response. METHODS: Mosquitoes were collected in bird/animal parks, wetlands and private gardens in various regions of Germany from 2020 to 2022. Females were pooled with up to 10 specimens according to taxon, location and date. Extracted DNA was screened for avian Haemosporida-specific mitochondrial rDNA using real-time polymerase chain reaction (PCR). Positive samples were amplified by a Plasmodium/Haemoproteus-specific nested PCR targeting the partial cytochrome b gene, followed by sequencing of the PCR product for species identification. Sequences were checked against GenBank and MalAvi databases. RESULTS: PCR of 2633 pools with 8834 female mosquitoes signalled infection with Plasmodium in 46 pools and with Haemoproteus in one pool. Further amplification and sequencing demonstrated the occurrence of Haemoproteus majoris lineage PARUS1 (n = 1) as well as several Plasmodium species and lineages, including Plasmodium relictum SGS1 (n = 16) and GRW11 (n = 1), P. matutinum LINN1 (n = 13), P. vaughani SYAT05 (n = 10), P. circumflexum TURDUS01 (n = 3), P. cathemerium PADOM02 (n = 1) and Plasmodium sp. SYBOR02 (n = 1) and PLOPRI01 (n = 1). The infections were detected in Culex pipiens sensu lato (n = 40), Culiseta morsitans/fumipennis (n = 6) and Aedes cinereus/geminus (n = 1). CONCLUSIONS: Although the overall Plasmodium minimum infection rate (5.2) appears to be low, the results demonstrated not only the ongoing circulation of Plasmodium parasites in the German mosquito population, but also the occurrence of eight distinct Plasmodium lineages, with three of them (PADOM02, SYBOR02, PLOPRI01) being detected in Germany for the first time. This study highlights the importance of conducting mosquito-borne pathogen surveillance studies simultaneously targeting vectors and vertebrate hosts, as certain species may be detected more readily in their vectors than in their vertebrate hosts, and vice versa.


Asunto(s)
Aedes , Haemosporida , Malaria Aviar , Parásitos , Plasmodium , Femenino , Animales , Mosquitos Vectores/parasitología , Plasmodium/genética , Haemosporida/genética , Aves/parasitología , Malaria Aviar/parasitología
5.
Environ Microbiol ; 25(12): 3064-3074, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37658745

RESUMEN

Symbiotic bacteria can alter host biology by providing protection from natural enemies, or alter reproduction or vectoral competence. Symbiont-linked control of vector-borne disease in Anopheles has been hampered by a lack of symbioses that can establish stable vertical transmission in the host. Previous screening found the symbiont 'Candidatus Tisiphia' in Anopheles plumbeus, an aggressive biter and potential secondary vector of malaria parasites and West Nile virus. We screened samples collected over 10-years across Germany and used climate databases to assess environmental influence on incidence. We observed a 95% infection rate, and that the frequency of infection did not fluctuate with broad environmental factors. Maternal inheritance is indicated by presence in the ovaries through FISH microscopy. Finally, we assembled a high-quality 1.6 Mbp draft genome of 'Ca. Tisiphia' to explore its phylogeny and potential metabolic competence. The infection is closely related to strains found in Culicoides biting midges and shows similar patterns of metabolism, providing no evidence of the capacity to synthesize B-vitamins. This infection offers avenues for onward research in anopheline mosquito symbioses. Additionally, it provides future opportunity to study the impact of 'Ca. Tisiphia' on natural and transinfected hosts, especially in relation to reproductive fitness and vectorial competence and capacity.


Asunto(s)
Anopheles , Ceratopogonidae , Rickettsiaceae , Animales , Mosquitos Vectores , Ceratopogonidae/microbiología , Clima
6.
Parasit Vectors ; 16(1): 307, 2023 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-37653421

RESUMEN

BACKGROUND: After several years without bluetongue disease, a ruminant illness caused by Culicoides-borne bluetongue virus (BTV), two new autochthonous cases were reported in 2018 in Germany. By contrast, Schmallenberg virus (SBV), another Culicoides-borne virus pathogenic to ruminants, has continuously circulated in Germany since its first emergence in 2011. The disease outbreaks have triggered numerous studies on the biology of the Culicoides vectors, but many ecological details are still obscure. METHODS: Culicoides biting midge species were collected with UV-light traps on 10 farms in Germany, with one trap inside and one trap outside barns on each of the farms. Traps were run once a week for 24 h from January to December 2019. Collected biting midges were morphologically identified, counted and statistically evaluated, with a focus on the Obsoletus Group and the Pulicaris Complex of the ceratopogonid genus Culicoides, which are believed to contain the major virus vectors. Temperature and relative humidity recorded at each trap were linked to the quantity of caught Culicoides. Correlations between relative Culicoides abundance and presence of livestock or type of husbandry were also investigated. RESULTS: A total of 38,886 Culicoides biting midges were trapped, with most of them belonging to the Obsoletus Group (51.0%) and the Pulicaris Complex (38.8%). The majority of captured specimens were collected in traps inside the barns. Obsoletus Group individuals were caught from late January to the last week of December while Pulicaris Complex individuals were captured from the end of March to early December. The lowest average temperatures at which members of the two groups were collected were 10.7 °C and 12.8 °C, respectively. While temperature had a statistically significant effect on the activity of both the Obsoletus Group and the Pulicaris Complex, relative humidity only significantly affected the activity of the latter. The presence of livestock significantly influenced the number of captured Obsoletus Group, but not of Pulicaris Complex specimens. Inside the barns, no statistical difference was found between numbers of caught Obsoletus Group and Pulicaris Complex specimens in livestock holdings with deep litter and manure scraper or slatted floor husbandry systems. CONCLUSIONS: The almost year-round presence of Obsoletus Group biting midges and the demonstrated high relative abundance of other potential Culicoides vector species inside barns suggest a high risk of indoor virus transmission to ruminants should BTV or SBV circulate locally. Appropriate structural, organisational and vector control measures to reduce biting midge exposure should be implemented.


Asunto(s)
Virus de la Lengua Azul , Lengua Azul , Ceratopogonidae , Humanos , Ovinos , Animales , Alemania/epidemiología , Frío , Ganado
7.
Sci Rep ; 13(1): 12384, 2023 07 31.
Artículo en Inglés | MEDLINE | ID: mdl-37524770

RESUMEN

Worldwide, citizen scientists help to map the distribution of native and introduced mosquito species in a variety of programs, contributing to environmental research and management decisions. Participant background, behavior, and engagement may vary depending on the project design, especially between those using digital apps and those using physical samples, which in turn may impact the quality and representativeness of the data collected. During the analysis of the responses to a survey directed at citizen scientists participating in  a digital and an analog program, we found significant differences in the respondents' demographic backgrounds. Diverse participant motivations and varying sentiments towards mosquitoes were observed, indicating differing susceptibility in response to the program messages. The results can be translated into recommendations to further strengthen the appeal of citizen science projects and to promote and sustain public engagement in environmental research.


Asunto(s)
Ciencia Ciudadana , Culicidae , Animales , Humanos , Motivación , Encuestas y Cuestionarios , Demografía
8.
J Health Monit ; 8(Suppl 3): 33-61, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37342429

RESUMEN

Background: Endemic and imported vector- and rodent-borne infectious agents can be linked to high morbidity and mortality. Therefore, vector- and rodent-borne human diseases and the effects of climate change are important public health issues. Methods: For this review, the relevant literature was identified and evaluated according to the thematic aspects and supplemented with an analysis of surveillance data for Germany. Results: Factors such as increasing temperatures, changing precipitation patterns, and human behaviour may influence the epidemiology of vector- and rodent-borne infectious diseases in Germany. Conclusions: The effects of climatic changes on the spread of vector- and rodent-borne infectious diseases need to be further studied in detail and considered in the context of climate adaptation measures.

9.
Med Vet Entomol ; 37(3): 523-533, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-36988560

RESUMEN

Since the first detection of the Asian tiger mosquito Aedes albopictus (Diptera: Culicidae) eggs in Germany in 2007, several populations of this species have established in Germany. Although colloquially Ae. albopictus is called an 'invasive species', it is not considered 'invasive' and therefore to be controlled according to the European Union (EU) Environmental and Nature Protection Act since evidence of displacement of native species is missing. To test the competitive potential of Ae. albopictus towards mosquito species native to Germany, laboratory experiments were conducted with larvae of this species and indigenous Cx. pipiens complex species/biotypes. First instar larvae of Ae. albopictus and of one of the native taxa were exposed to different temperatures and fed with different food sources. The ratio of individuals developing into adults as well as the time the larvae needed for development were taken as a measure of competitive outcome. In addition, the size of emerging adults was compared between control and experimental groups. Regarding developmental time, no significant differences were found between treatments and controls while significant differences were found regarding developmental rate and average wing size of individuals. Because no evidence of competitive repression of the native species was found, Ae. albopictus cannot be included in the EU list of invasive species.


Asunto(s)
Aedes , Culex , Animales , Larva , Alemania , Especies Introducidas
10.
Viruses ; 14(12)2022 12 14.
Artículo en Inglés | MEDLINE | ID: mdl-36560791

RESUMEN

West Nile virus (WNV) is a zoonotic flavivirus transmitted by mosquitoes as a biological vector. Because of its biting behavior, the widespread snow-melt mosquito Aedes punctor could be a potential bridge vector for WNV to humans and nonhuman mammals. However, little is known on its role in transmission of WNV. The aim of this study was to determine the vector competence of German Ae. punctor for WNV lineages 1 and 2. Field-collected larvae and pupae were reared to adults and offered infectious blood containing either an Italian WNV lineage 1 or a German WNV lineage 2 strain via cotton stick feeding. Engorged females were incubated for 14/15 or 21 days at 18 °C. After incubation; surviving mosquitoes were dissected and forced to salivate. Mosquito bodies with abdomens, thoraces and heads, legs plus wings and saliva samples were investigated for WNV RNA by RT-qPCR. Altogether, 2/70 (2.86%) and 5/85 (5.88%) mosquito bodies were found infected with WNV lineage 1 or 2, respectively. In two mosquitoes, viral RNA was also detected in legs and wings. No saliva sample contained viral RNA. Based on these results, we conclude that Ae. punctor does not play an important role in WNV transmission in Germany.


Asunto(s)
Aedes , Culex , Fiebre del Nilo Occidental , Virus del Nilo Occidental , Animales , Humanos , Femenino , Virus del Nilo Occidental/genética , Mosquitos Vectores , ARN Viral , Mamíferos
11.
Parasitol Res ; 121(12): 3701-3704, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36178512

RESUMEN

Aedes koreicus is an invasive mosquito species originating from East Asia. It has recently been introduced into several countries in Southern, Central and Eastern Europe as well as Central Asia in many of which it has successfully established populations. The biology and ecological requirements of the species are largely unknown, but it is considered as a potential vector of pathogens that requires careful monitoring. We report here the first detection of Ae. koreicus in the Czech Republic, based on a citizen report.


Asunto(s)
Aedes , Culicidae , Animales , Especies Introducidas , Mosquitos Vectores , República Checa , Europa Oriental
12.
Pathogens ; 11(9)2022 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-36145422

RESUMEN

Anopheles algeriensis Theobald, 1903, considered a competent vector of Plasmodium parasites, is a mosquito species widely distributed in the Mediterranean area but rare in Northern and Central Europe. The disappearance of its suitable breeding sites in Italy is having a detrimental effect on the occurrence of this species once common along the Southern coasts and on the islands. Recently, molecular investigations have renewed interest in this species, highlighting a genetic heterogeneity among European populations. In this study, An. algeriensis populations from Italy, Germany, Romania, and Sweden were analyzed by molecular typing of the intergenic transcribed spacer 2 (ITS2). The mitochondrial cytochrome c oxidase subunit I (COI) was also analyzed from specimens collected in Southern Italy. With the aim of investigating the population structure of this species, the obtained data were compared to all publicly available ITS2 and COI sequences of An. algeriensis, adding specimens from Spain and Portugal. The analyses of both markers indicate a split between Iberian populations (Spain for ITS2 and Spain/Portugal for COI) and those from the rest of Europe, revealing two cryptic species. The analysis of the COI barcode revealed a third clade representing a cryptic species present in Danube Delta (Romania). The high levels of genetic divergence among the clades of An. algeriensis indicate that this taxon represents a species complex, potentially harboring several distinct cryptic species.

13.
Parasitol Res ; 121(9): 2587-2599, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35857094

RESUMEN

Aedes albopictus is a highly invasive mosquito species that has become widespread across the globe. In addition, it is an efficient vector of numerous pathogens of medical and veterinary importance, including dengue, chikungunya and Zika viruses. Among others, the vector potential of mosquitoes is influenced by their microbiome. However, this influence is very dynamic and can vary between individuals and life stages. To obtain a rough overview on the microbiome of Ae. albopictus populations in Germany, pooled female and pooled male individuals from seven German locations were investigated by total RNA sequencing. The mosquito specimens had been collected as larvae in the field and processed immediately after adult emergence, i.e. without females having fed on blood. RNA fragments with high degrees of identity to a large number of viruses and microorganisms were identified, including, for example, Wolbachia pipientis and Acinetobacter baumannii, with differences between male and female mosquitoes. Knowledge about the natural occurrence of microorganisms in mosquitoes may be translated into new approaches to vector control, for example W. pipientis can be exploited to manipulate mosquito reproduction and vector competence. The study results show how diverse the microbiome of Ae. albopictus can be, and the more so needs to be adequately analysed and interpreted.


Asunto(s)
Aedes , Infección por el Virus Zika , Virus Zika , Animales , Femenino , Humanos , Especies Introducidas , Masculino , Metagenoma , Mosquitos Vectores , ARN
14.
Parasit Vectors ; 15(1): 250, 2022 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-35820942

RESUMEN

BACKGROUND: Aedes japonicus is a mosquito species native to North-East Asia that was first found established outside its original geographic distribution range in 1998 and has since spread massively through North America and Europe. In the Czech Republic, the species was not reported before 2021. METHODS: Aedes invasive mosquitoes (AIM) are routinely surveyed in the Czech Republic by ovitrapping at potential entry ports. This surveillance is supported by appeals to the population to report uncommon mosquitoes. The submission of an Ae. japonicus specimen by a citizen in 2021 was followed by local search for aquatic mosquito stages in the submitter's garden and short-term adult monitoring with encephalitis virus surveillance (EVS) traps in its surroundings. Collected Ae. japonicus specimens were subjected to nad4 haplotype and microsatellite analyses. RESULTS: Aedes japonicus was detected for the first time in the Czech Republic in 2021. Aquatic stages and adults were collected in Prachatice, close to the Czech-German border, and eggs in Mikulov, on the Czech-Austrian border. Morphological identification was confirmed by molecular taxonomy. Genetic analysis of specimens and comparison of genetic data with those of other European populations, particularly from Germany, showed the Prachatice specimens to be most closely related to a German population. The Mikulov specimens were more distantly related to those, with no close relatives identifiable. CONCLUSIONS: Aedes japonicus is already widely distributed in Germany and Austria, two countries neighbouring the Czech Republic, and continues to spread rapidly in Central Europe. It must therefore be assumed that the species is already present at more than the two described localities in the Czech Republic and will further spread in this country. These findings highlight the need for more comprehensive AIM surveillance in the Czech Republic.


Asunto(s)
Aedes , Aedes/genética , Animales , República Checa , Alemania , Haplotipos , Especies Introducidas
15.
PLoS One ; 17(2): e0262850, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35176044

RESUMEN

Since 2012, the citizen science project 'Mückenatlas' has been supplementing the German mosquito monitoring programme with over 28,000 submissions of physical insect samples. As the factors triggering people to catch mosquitoes for science are still unknown, we analysed the influence of mass media reports on mosquito submission numbers. Based on a theoretical framework of how mass media affect citizen responsiveness, we identified five possible influencing factors related to citizen science: (i) project awareness and knowledge, (ii) attention (economy), (iii) individual characteristics of citizen scientists and targeted communication, (iv) spatial differences and varying affectedness, and (v) media landscape. Hypotheses based on these influencing factors were quantitatively and qualitatively tested with two datasets: clipping data of mass media reports (online, television, radio and print) referring to or focussing on the 'Mückenatlas', and corresponding data of 'Mückenatlas' submissions between 2014 and 2017. In general, the number of media reports positively affected the number of mosquito submissions on a temporal and spatial scale, i.e. many media reports provoke many mosquito submissions. We found that an already heightened public and media awareness of mosquito-relevant topics combined with a direct call-to-action in a media report title led to a maximum participation. Differences on federal state level, however, suggest that factors additional to quantitative media coverage trigger participation in the 'Mückenatlas', in particular the mosquito affectedness of the resident population. Lastly, media types appear to differ in their effects on the number of submissions. Our results show under which circumstances the media presence of the 'Mückenatlas' is most effective in activating people to submit mosquito samples, and thus provide advice for designing communication strategies for citizen science projects.


Asunto(s)
Ciencia Ciudadana/estadística & datos numéricos , Medios de Comunicación/estadística & datos numéricos , Participación de la Comunidad/métodos , Monitoreo del Ambiente/métodos , Conocimientos, Actitudes y Práctica en Salud , Malaria/prevención & control , Control de Mosquitos/métodos , Humanos , Malaria/psicología
16.
Viruses ; 13(12)2021 12 09.
Artículo en Inglés | MEDLINE | ID: mdl-34960732

RESUMEN

Mosquitoes collected from mid-December 2020 to early March 2021 from hibernacula in northeastern Germany, a region of West Nile virus (WNV) activity since 2018, were examined for WNV-RNA. Among the 6101 mosquitoes tested in 722 pools of up to 12 specimens, one pool of 10 Culex pipiens complex mosquitoes collected in early March 2021 in the cellar of a medieval castle in Rosslau, federal state of Saxony-Anhalt, tested positive. Subsequent mosquito DNA analysis produced Culex pipiens biotype pipiens. The pool homogenate remaining after nucleic acid extraction failed to grow the virus on Vero and C6/36 cells. Sequencing of the viral NS2B-NS3 coding region, however, demonstrated high homology with virus strains previously collected in Germany, e.g., from humans, birds, and mosquitoes, which have been designated the East German WNV clade. The finding confirms the expectation that WNV can overwinter in mosquitoes in Germany, facilitating an early start to the natural transmission season in the subsequent year. On the other hand, the calculated low infection prevalence of 0.016-0.20%, depending on whether one or twelve of the mosquitoes in the positive pool was/were infected, indicates a slow epidemic progress and mirrors the still-hypoendemic situation in Germany. In any case, local overwintering of the virus in mosquitoes suggests its long-term persistence and an enduring public health issue.


Asunto(s)
Culicidae/virología , Mosquitos Vectores/virología , Fiebre del Nilo Occidental/virología , Virus del Nilo Occidental/aislamiento & purificación , Animales , Culicidae/clasificación , Culicidae/fisiología , Alemania , Humanos , Mosquitos Vectores/clasificación , Mosquitos Vectores/fisiología , Estaciones del Año , Fiebre del Nilo Occidental/transmisión , Virus del Nilo Occidental/clasificación , Virus del Nilo Occidental/genética
17.
Parasit Vectors ; 14(1): 575, 2021 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-34772448

RESUMEN

BACKGROUND: The Korean bush mosquito Aedes koreicus was recently reported to have established a population in western Germany (Wiesbaden) in 2016. The species is difficult to distinguish morphologically from its close relative, the invasive Japanese bush mosquito Ae. japonicus, which is already widely distributed in many parts of Germany, including the area colonised by Ae. koreicus. Genetic confirmation of morphologically identified "Ae. japonicus" collection material, however, had only been done exceptionally before the German Ae. koreicus population became known. METHODS: Dried archived "Ae. japonicus" specimens both from the municipality of Wiesbaden and from deliberately and randomly selected distribution sites all over Germany were re-examined morphologically and genetically for admixture by Ae. koreicus. Moreover, cemeteries in the greater Wiesbaden area were sampled in 2019 and 2020 to check for Ae. koreicus spread. Korean and Japanese bush mosquitoes submitted to the German citizen science mosquito monitoring scheme "Mueckenatlas" in 2019 and 2020 were also subjected to particularly thorough species identification. The ND4 DNA sequences generated in this study in the context of species identification were phylogenetically compared to respective GenBank entries of Ae. koreicus. As a by-product, several genetic markers were evaluated for their suitability to identify Ae. koreicus. RESULTS: Aedes koreicus specimens could be identified in mosquito collection material and submissions from Wiesbaden from 2015 onwards, suggesting establishment to have happened in the same year as Ae. japonicus establishment. Detections of Ae. koreicus from 2019 and 2020 in Wiesbaden indicate a negligible enlargement of the populated area as described for 2018. Two Ae. koreicus specimens were also submitted from the city of Munich, southern Germany, in 2019 but further specimens could not be identified during immediate local inspections. Comparison of ND4 sequences generated in this and other studies demonstrate a high degree of homology, suggesting that this DNA region is not informative enough for clarification of origins and relationships of Ae. koreicus populations. For genetic identification of Ae. koreicus, PCR primers used for classical CO1 barcoding were found to lead to mismatches and produce no or incorrect amplicons. Alternative CO1 primers or a validated ND4 marker should be used instead. CONCLUSIONS: Aedes koreicus is probably introduced into Germany every now and then but rarely succeeds in becoming established. As with most European populations, the German population is characterised by a limited expansion tendency. Since Ae. koreicus is a potential vector, however, Asian bush mosquitoes found at new places should be examined quite carefully and known distribution areas of Ae. japonicus regularly checked for the presence of Ae. koreicus.


Asunto(s)
Aedes/fisiología , Especies Introducidas/estadística & datos numéricos , Aedes/clasificación , Aedes/genética , Aedes/crecimiento & desarrollo , Distribución Animal , Animales , Femenino , Alemania , Masculino , Mosquitos Vectores/clasificación , Mosquitos Vectores/genética , Mosquitos Vectores/crecimiento & desarrollo , Mosquitos Vectores/fisiología , Filogenia , República de Corea
18.
Insects ; 12(9)2021 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-34564256

RESUMEN

By any measure, such as abundance, species diversity or geographic range, the Simulium ornatum species group is one of the most successful Palearctic taxa of black flies. To explore potential diversity in this group in the Tian Shan range of Central Asia, we focused on Kyrgyzstan, in which three nominal morphospecies have been recorded. Among our samples, we morphologically identified S. mesasiaticum Rubtsov and a second possible species tentatively identified as S. ferganicum Rubtsov. By analyzing banding patterns of the larval polytene chromosomes, we discovered two fixed inversions, two sex-linked rearrangements, and 19 autosomal rearrangements, including supernumerary B chromosomes. The chromosomal data indicate minimal diversity of only one or two species across the surveyed area of nearly 50,000 km2. Mitochondrial DNA (CO1) sequences fell into three distinct clusters, possibly representing separate species. The chromosomal, molecular, and morphological data indicate that Kyrgyz populations are unique within the S. ornatum group, but the data sets are not entirely congruent. Thus, reconciling data sets and assigning existing names is tentative. Simulium mesasiaticum is linked with undifferentiated sex chromosomes, one of the three CO1 clades, and higher elevations, whereas S. ferganicum is tenuously associated with differentiated sex chromosomes, a separate CO1 clade, and lower elevations. These associations leave one Kyrgyz larva, which is in a third CO1 clade, unlinked to a formal species name. Our analyses also indicate that S. ornatum Meigen sensu stricto, contrary to previous reports, does not occur in Kyrgyzstan and should be deleted from the country's faunal list.

19.
Sci Rep ; 11(1): 10007, 2021 05 11.
Artículo en Inglés | MEDLINE | ID: mdl-33976240

RESUMEN

Culicoides are vectors of pathogens mainly of veterinary importance. To establish targeted vector control measures, it is paramount to comprehend the ecological factors determining their distribution. Therefore, we used emergence traps to sample eight biotopes and assess their potential as breeding sites. Part one of the study investigates agricultural habitats, part two compares four biotopes of a forest-dominated area with less anthropogenic influence, including a physicochemical analysis of soil moisture, pH value and organic content. Thirteen culicoid species were collected, with a strong dominance of the Obsoletus Complex on meadows, and with Culicoides punctatus (MEIGEN), Culicoides pictipennis (STAEGER) and the Obsoletus Complex, to be the most abundant species in the natural habitats. Several co-existing species were found, some of them not having been described before. Our results suggest that ungrazed meadows seem unsuitable as breeding sites. Only the influence of livestock creates adequate conditions for certain midge species. The alder on fen site contained most culicoid species with the highest species diversity. Our study clearly indicates that knowledge of species-specific preferences for environmental habitat conditions (choice of breeding site) in connection to soil conditions is crucial to understand the biology and phenology of midges and their role as vectors of pathogens.

20.
Insects ; 12(5)2021 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-33919337

RESUMEN

Urbanization has been associated with a loss of overall biodiversity and a simultaneous increase in the abundance of a few species that thrive in urban habitats, such as highly adaptable mosquito vectors. To better understand how mosquito communities differ between levels of urbanization, we analyzed mosquito samples from inside private homes submitted to the citizen science project 'Mückenatlas'. Applying two urbanization indicators based on soil sealing and human population density, we compared species composition and diversity at, and preferences towards, different urbanization levels. Species composition between groups of lowest and highest levels of urbanization differed significantly, which was presumably caused by reduced species richness and the dominance of synanthropic mosquito species in urban areas. The genus Anopheles was frequently submitted from areas with a low degree of urbanization, Aedes with a moderate degree, and Culex and Culiseta with a high degree of urbanization. Making use of citizen science data, this first study of indoor mosquito diversity in Germany demonstrated a simplification of communities with increasing urbanization. The dominance of vector-competent species in urban areas poses a potential risk of epidemics of mosquito-borne diseases that can only be contained by a permanent monitoring of mosquitoes and by acquiring a deeper knowledge about how anthropogenic activities affect vector ecology.

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