ITS and nrLSU DNA sequence data from four species of Coreomyces (Laboulbeniomycetes)

The genus Coreomyces (Laboulbeniaceae, Laboulbeniomycetes, Ascomycota)
includes minute parasites on water boatmen (Corixidae, Hemiptera,
Insecta). This taxonomic study is primarily based on freshly sampled
corixids infected by Coreomyces from Sweden, although a few samples from
Denmark and Turkey were also included. All records were verified using DNA
sequence data from the internal transcribed spacer region and large
subunit of the nuclear ribosomal DNA repeat region. We recognise four
species, two of which are new to science: Coreomyces confusus H. Sundb. et
al. sp. nov., C. dextrorsus H. Sundb. et al. sp. nov., C. macropus Thaxt.,
and C. corixae Thaxt. C. corixae is a new record for Denmark, Sweden, and
Turkey, while C. macropus is a new record for Denmark and
Sweden. All four species can inhabit two different yet distinct
positions on the host. We observe that morphology is affected by the
position on the host and that different species sharing the same position
on the host tend to be difficult or impossible to separate on morphology
only. We conclude that species circumscriptions in Coreomyces must be
based on the integration of molecular and morphological data.