Buzzing Homes: Using Citizen Science Data to Explore the Effects of Urbanization on Indoor Mosquito Communities

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

Blood parasites in vectors reveal a united blackfly community in the upper canopy.

Chakarov N, Kampen H, Wiegmann A, Werner D, Bensch S. Blood parasites in vectors reveal a united blackfly community in the upper canopy. Parasites & vectors. 2020;13(1): 309.BACKGROUND: The behaviour of blood-sucking arthropods is a crucial determinant of blood protozoan distribution and hence of host-parasite coevolution, but it is very challenging to study in the wild. The molecular identification of parasite lineages in vectors can be a useful key to understand the behaviour and transmission patterns realised by these vectors.; METHODS: In this study, we collected blackflies around nests of three raptor species in the upper forest canopy in central Europe and examined the presence of vertebrate DNA and haemosporidian parasites in them. We molecularly analysed 156 blackfly individuals, their vertebrate blood meals, and the haemosporidian parasite lineages they carried.; RESULTS: We identified nine species of Simulium blackflies, largely belonging to the subgenera Nevermannia and Eusimulium. Only 1% of the collected specimens was visibly engorged, and only 4% contained remains of host DNA. However, in 29% of the blackflies Leucocytozoon lineages were identified, which is evidence of a previous blood meal on an avian host. Based on the known vertebrate hosts of the recorded Leucocytozoon lineages, we can infer that large and/or abundant birds, such as thrushes, crows, pigeons, birds of prey, owls and tits are the main targets of ornithophilic blackflies in the canopy. Blackfly species contained similar proportions of host group-specific parasite lineages and thus do not appear to be associated with particular host groups.; CONCLUSIONS: The Leucocytozoon clade infecting thrushes, crows, and pigeons present in most represented blackfly species suggests a lack of association between hosts and blackflies, which can increase the probability of host switches of blood parasites. However, the composition of the simuliid species differed between nests of common buzzards, goshawks and red kites. This segregation can be explained by coinciding habitat preferences between host and vector, and may lead to the fast speciation of Leucocytozoon parasites. Thus, subtle ecological preferences and lack of host preference of vectors in the canopy may enable both parasite diversification and host switches, and enforce a habitat-dependent evolution of avian malaria parasites and related haemosporidia

In memory of Professor Dr Werner Mohrig (*17 December 1937 – †26 April 2019)

Der deutsche Zoologe Werner Mohrig verstarb im Alter von 81 Jahren am 26. April 2019 in Gießen (Hessen). Als Professor für Allgemeine Zoologie lehrte er am Zoologischen Institut und Museum der Ernst-Moritz-Arndt-Universität in Greifswald. In dieser Zeit erwarb sich Professor Dr. Mohrig vor allem bei der Ausbildung und Förderung des dipterologischen und immunbiologischen Nachwuchses große Verdienste. Bei den Entomologen ist er vor allem durch seine umfangreichen taxonomisch-systematischen Studien über die niederen Diptera (Cecidomyiidae, Culicidae, Sciaridae) weltweit bekannt. Die vorliegende Arbeit gibt neben dem biographischen Abriss seines Lebens eine Publikationsliste, die 201 wissenschaftliche Arbeiten aus der Entomologie und Immunologie sowie zu anthropologischen und demographischen Problemen zusammenfasst. Den Abschluss bildet eine Liste der von Werner Mohrig beschriebenen Taxa, in der 3 präokkupierte Namen ersetzt und 15 Arten in eine andere Gattung kombiniert werden.The German zoologist Werner Mohrig died on the 26th April 2019, at the age of 81, in Gießen (Hesse). As professor of general zoology he taught at the Zoological Institute and Museum of the Ernst Moritz Arndt University in Greifswald. In this capacity, Professor Dr Mohrig was responsible for the education and training of many young dipterists and immunobiologists. Among entomologists, he is known worldwide for his extensive taxonomic and systematic studies on the lower Diptera (Cecidomyiidae, Culicidae, Sciaridae). In addition to a biographical sketch of his life, this paper lists his 201 scientific papers on entomology and immunology, as well as anthropological and demographic topics. The final part is a list of taxa described by Werner Mohrig, in which 3 preoccupied names are replaced and 15 species names are newly combined with a different genus

Drivers of spatio-temporal variation in mosquito submissions to the citizen science project ‘Mückenatlas’

Intensified travel activities of humans and the ever growing global trade create opportunities of arthropod-borne disease agents and their vectors, such as mosquitoes, to establish in new regions. To update the knowledge of mosquito occurrence and distribution, a national mosquito monitoring programme was initiated in Germany in 2011, which has been complemented by a citizen science project, the ‘Mückenatlas’ since 2012. We analysed the ‘Mückenatlas’ dataset to (1) investigate causes of variation in submission numbers from the start of the project until 2017 and to (2) reveal biases induced by opportunistic data collection. Our results show that the temporal variation of submissions over the years is driven by fluctuating topicality of mosquito-borne diseases in the media and large-scale climate conditions. Hurdle models suggest a positive association of submission numbers with human population, catch location in the former political East Germany and the presence of water bodies, whereas precipitation and wind speed are negative predictors. We conclude that most anthropogenic and environmental effects on submission patterns are associated with the participants’ (recording) behaviour. Understanding how the citizen scientists’ behaviour shape opportunistic datasets help to take full advantage of the available information

Das überörtliche Biotopverbundsystem in Sachsen-Anhalt und seine Berücksichtigung am Beispiel des Regionalen Entwicklungsplanes für die Planungsregion Harz

Das überörtliche Biotopverbundsystem wurde als Fachplanung des Naturschutzes nach fast 10-jähriger Bearbeitungszeit flächendeckend für das Land Sachsen-Anhalt fertiggestellt. Zielstellung ist der Verbund von Lebensräumen zu einem Gesamtsystem, in dem wichtige Vernetzungsbeziehungen für den räumlichen Austausch von Arten und Populationen als Voraussetzung für die Erhaltung der biologischen Vielfalt ermöglicht werden. Das überörtliche Biotopverbundsystem ist die Grundlage des Aufbaus eines landesweiten ökologischen Verbundsystems, dessen Umsetzung eine gemeinschaftliche Aufgabe von unterschiedlichen Fachressorts und weiteren Akteuren ist. Vorgestellt wird die Fachplanung sowie die Integration in die Regionalplanung am Beispiel der Aufstellung des Regionalen Entwicklungsplanes der Planungsregion Harz als ein erster Schritt zur Umsetzung.Saxony-Anhalt’s supra-local system of linked biotopes, an example of sectoral planning in the interests of nature conservation, was completed after a period of preparation of almost ten years and with coverage spanning the entire state territory. It aims to link up natural habitats into one comprehensive system which facilitates the network relationships vital to the territorial exchange of species and populations as a prerequisite to maintaining biological diversity. The supra-local system of linked biotopes is the basis for creating a state-wide network of ecological systems, implementation of which is a joint task involving various political portfolios as well as other actors. This paper outlines the technical planning underlying this scheme and its integration within regional planning. In doing so, it refers for illustration to the process of framing the Regional Development Plan for the Harz planning region, seen as a first step towards implementation

Recently discovered Aedes japonicus japonicus (Diptera: Culicidae) populations in The Netherlands and northern Germany resulted from a new introduction event and from a split from an existing population

BACKGROUND: Originally native to East Asia, Aedes japonicus japonicus, a potential vector of several arboviruses, has become one of the most invasive mosquito species in the world. After having established in the USA, it is now spreading in Europe, with new populations emerging. In contrast to the USA, the introduction pathways and modes of dispersal in Europe are largely obscure. METHODS: To find out if two recently detected populations of Ae. j. japonicus in The Netherlands and northern Germany go back to new importations or to movements within Europe, the genetic makeup of mosquito specimens from all known European populations was compared. For this purpose, seven microsatellite loci from a representative number of mosquito specimens were genotyped and part of their mitochondrial nad4 gene sequenced. RESULTS: A novel nad4 haplotype found in the newly discovered Dutch population of Ae. j. japonicus suggests that this population is not closely related to the other European populations but has emanated from a further introduction event. With five nad4 haplotypes, the Dutch population also shows a very high genetic diversity indicating that either the founder population was very large or multiple introductions took place. By contrast, the recently detected North German population could be clearly assigned to one of the two previously determined European Ae. j. japonicus microsatellite genotypes and shows nad4 haplotypes that are known from West Germany. CONCLUSION: As the European populations of Ae. j. japonicus are geographically separated but genetically mixed, their establishment must be attributed to passive transportation. In addition to intercontinental shipment, it can be assumed that human activities are also responsible for medium- and short-distance overland spread. A better understanding of the processes underlying the introduction and spread of this invasive species will help to increase public awareness of the human-mediated displacement of mosquitoes and to find strategies to avoid it

Oviposition of Aedes japonicus japonicus (Diptera: Culicidae) and associated native species in relation to season, temperature and land use in western Germany

Background: Aedes japonicus japonicus, first detected in Europe in 2000 and considered established in Germany 10 years later, is of medical importance due to its opportunistic biting behaviour and its potential to transmit pathogenic viruses. Its seasonal phenology, temperature and land use preference related to oviposition in newly colonised regions remain unclear, especially in the context of co-occurring native mosquito species. Methods: Focussing on regions in Germany known to be infested by Ae. japonicus japonicus, we installed ovitraps in different landscapes and their transition zones and recorded the oviposition activity of mosquitoes in relation to season, temperature and land use (arable land, forest, settlement) in two field seasons (May-August 2017, April-November 2018). Results: Ae. japonicus japonicus eggs and larvae were encountered in 2017 from June to August and in 2018 from May to November, with a markedly high abundance from June to September in rural transition zones between forest and settlement, limited to water temperatures below 30 degrees C. Of the three native mosquito taxa using the ovitraps, the most frequent was Culex pipiens s.l., whose offspring was found in high numbers from June to August at water temperatures of up to 35 degrees C. The third recorded species, Anopheles plumbeus, rarely occurred in ovitraps positioned in settlements and on arable land, but was often associated with Ae. japonicus japonicus. The least frequent species, Aedes geniculatus, was mostly found in ovitraps located in the forest. Conclusions: The transition zone between forest and settlement was demonstrated to be the preferred oviposition habitat of Ae. japonicus japonicus, where it was also the most frequent container-inhabiting mosquito species in this study. Compared to native taxa, Ae. japonicus japonicus showed an extended seasonal activity period, presumably due to tolerance of colder water temperatures. Higher water temperatures and arable land represent distribution barriers to this species. The frequently co-occurring native species An. plumbeus might be useful as an indicator for potentially suitable oviposition habitats of Ae. japonicus japonicus in hitherto uncolonised regions. The results contribute to a better understanding of mosquito ecology and provide a basis for more targeted monitoring, distribution modelling and risk management of mosquitoes

Can data from native mosquitoes support determining invasive species habitats? Modelling the climatic niche of Aedes japonicus japonicus (Diptera, Culicidae) in Germany

Invasive mosquito species and the pathogens they transmit represent a serious health risk to both humans and animals. Thus, predictions on their potential geographic distribution are urgently needed. In the case of a recently invaded region, only a small number of occurrence data is typically available for analysis, and absence data are not reliable. To overcome this problem, we have tested whether it is possible to determine the climatic ecological niche of an invasive mosquito species by using both the occurrence data of other, native species and machine learning. The approach is based on a support vector machine and in this scenario applied to the Asian bush mosquito (Aedes japonicus japonicus) in Germany. Presence data for this species (recorded in the Germany since 2008) as well as for three native mosquito species were used to model the potential distribution of the invasive species. We trained the model with data collected from 2011 to 2014 and compared our predicted occurrence probabilities for 2015 with observations found in the field throughout 2015 to evaluate our approach. The prediction map showed a high degree of concordance with the field data. We applied the model to medium climate conditions at an early stage of the invasion (2011–2015), and developed an explanation for declining population densities in an area in northern Germany. In addition to the already known distribution areas, our model also indicates a possible spread to Saarland, southwestern Rhineland-Palatinate and in 2015 to southern Bavaria, where the species is now being increasingly detected. However, there is also evidence that the possible distribution area under the mean climate conditions was underestimated

How media presence triggers participation in citizen science—The case of the mosquito monitoring project ‘Mückenatlas‘

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