Taxonomic review and phylogenetic analysis of central EuropeanEresusspecies (Araneae: Eresidae)

Ladybird spiders (Eresusspp.) have attracted scientific interest since the 18th century, but taxonomical knowledge of the genus is unsatisfactory. Early classification based on colour and size variation divided EuropeanEresusinto numerous species. These were later lumped into one predominant morphospecies,Eresus niger/E. cinnaberinus, which could be found from Portugal to Central Asia. Here, we perform a major revision ofEresusfrom northern and central Europe using morphological, phenological, habitat, distribution and molecular data. Three species,E. kollari,E. sandaliatusandE. moravicussp. n. were distinguished. The nameE. niger(originallyAranea nigra) cannot be used as the nameA. nigrawas used for a previous spider species. The nameE. cinnaberinusis considered anomen dubium. The three species differ in size, colour pattern, shape of prosoma and copulatory organs, phenology, and have slightly different habitat requirements. No morphologically intermediate forms were recorded. In contrast to distinct morphology and phenology, the genus is genetically complex. Genetically, the mitochondrial haplotypes ofE. sandaliatusandE. moravicussp. n. are monophyletic, whereas those ofE. kollariare paraphyletic. Eastern central EuropeanE. kollariis likely a hybrid lineage betweenE. sandaliatusand the monophyletic western central EuropeanE. kollari. Because eastern and western EuropeanE. kollariare morphologically and phenologically indistinguishable, we did not formally split them. However, detailed population‐based research in the future may partitionE. kollariinto additional species.