The ecological niche of Dermacentor marginatus in Germany

Abstract

The ixodid tick Dermacentor marginatus (Sulzer, 1776) is endemic throughout southern Europe in the range of 33–51 ° N latitude. In Germany, however, D. marginatus was exclusively reported in the Rhine valley and adjacent areas. Its northern distribution limit near Giessen is located at the coordinates 8.32 ° E/50.65 ° N. Particularly with regard to the causative agents of rickettsioses, tularemia, and Q fever, the observed locations as well as the potential distribution of the vector D. marginatus in Germany are of special interest. Applying a dataset of 118 georeferenced tick locations, the ecological niche for D. marginatus was calculated. It is described by six climate parameters based on temperature and relative humidity and another six environmental parameters including land cover classes and altitude. The final ecological niche is determined by the frequency distributions of these 12 parameters at the tick locations. Main parameters are the mean annual temperature (frequency distribution characterized by the minimum, median, and maximum of 6.1, 9.9, and 12.2 °C), the mean annual relative humidity (73.7, 76.7, and 80.9 %), as well as the altitude (87, 240, 1108 m). The climate and environmental niche is used to estimate the habitat suitability of D. marginatus in Germany by applying the BIOCLIM model. Finally, the potential spatial distribution of D. marginatus was calculated and mapped by determining an optimal threshold value of the suitability index, i.e., the maximum of sensitivity and specificity (Youden index). The model performance is expressed by AUC = 0.91.

Diversity, ecology, and seasonality of hard ticks (Acari: Ixodidae) in eastern Croatia

“…Dermacentor marginatus was often restricted to the southeastern parts of some countries, under hot and dry climate conditions similar to the Mediterranean type (Estrada‐Peña and Santos‐Silva ). In this study, 37.0% of D. marginatus was collected on sheep, its main host (Walter et al ), 18.5% on dogs, 11.1% on wild boars, and 33.3% were collected by the dragging‐flagging method in different forest communities. Climatic conditions in the study area belong to the Cfb climate category and may thus better suit D. reticulatus than D. marginatus .…”

The Spatial Distribution of Dermacentor Ticks (Ixodidae) in Germany—Evidence of a Continuing Spread of Dermacentor reticulatus

“…Interestingly, the ecological niche model by Walter et al (40) identified most of Rhineland-Palatinate as suitable habitat for D. marginatus, as well as a large area to the northeast of the distribution limit, including the entire federal state of Hesse and even the southern part of Lower Saxony. In contrast, North Rhine-Westphalia, which is located to the northwest of Giessen, was not identified as a suitable habitat by Walter et al (40). Further studies should continue to examine whether stable populations of D. marginatus are permanently established in North Rhine-Westphalia.…”

Tick-Borne Encephalitis Virus and Its European Distribution in Ticks and Endothermic Mammals

“…In the past 15 years, SDMs have been increasingly used for predicting the potential distribution of infectious diseases as part of risk assessments [ 14 ]. For this, either the distribution of pathogens or disease cases themselves (e.g., West Nile Fever [ 15 ], Usutu virus [ 16 ], or chikungunya virus [ 17 ]) was modelled or—in the case of vector-borne pathogens—solely the vectors such as mosquitoes [ 18 ] or ticks [ 19 ]. In the case of species distribution models for TBE recent publications are focusing only on limited areas e.g., Finland [ 20 ] or the so called DACH region, i.e., Germany, Austria, Switzerland [ 21 ].…”