Transcontinental dispersal, common ancestry or convergent evolution? New phyllocoptines (Eriophyidae) from American and South African relict conifers

摘要

One new genus, three new species and two records of previously described phyllocoptines are reported from American and South African relict conifers. A new monotypic genus Costolobus n. gen. (Epitrimerus-like phyllocoptines with large ridged frontal lobe and bv I missing) is erected for the new species, Costolobus widdringtonis n. gen., n. sp., from South African endemic Widdringtonia wallichii Endl. ex Carriere (Cupressaceae). Two new species, Epitrimerus papillatus n. sp. and Glossilus calocedris n. sp., are described from Araucaria araucana (Araucariaceae) from Chile and Calocedrus decurrens (Cupressaceae) from USA. Two other phyllocoptine species, Calepitrimerus convergens (Keifer 1966) and Phyllocoptes libocedri (Keifer 1939), are recorded from relict North American cupressacean hosts Calocedrus decurrens and Sequoiadendron giganteum collected in California. The genus Glossilus Navia & Flechtmann 2000 is recorded from North America for the first time; a rediagnosis of this genus is provided. Morphological similarity of the Epitrimerus-like phyllocoptines from gymnosperms is briefly discussed. Contemporary distribution of morphologically similar phyllocoptines on relic conifers in geographically remote regions can be explained by 1) their possible common ancestry followed by transcontinental dispersal and coevolution with hosts or by 2) multiple host-shifts from dicots in different continents and convergent morphological evolution. Comparative studies of the whole complex of eriophyoids inhabiting conifers are necessary to reveal phylogenetic structure of this ecological group of mites. Considering that numerous independent host-shifts from dicots to conifers happened in the past in different clades of Eriophyidae s.l., the mites from conifers might be used as "islands" around which their relatives from angiosperms could be grouped using various phylogenetic tools. Such an approach may be useful for future phylogenetic studies of Eriophyoidea.