A new species of Acalitus (Acari: Eriophyoidea) on Viguiera dentata and the first record of Acalitus comptus Flechtmann on Sphagneticola trilobata from Mexico

A new species of eriophyoid mite in the genus Acalitus is described and illustrated. Acalitus viguierae sp. nov. infests Viguiera dentata (Cav.) Spreng. and causes erineum on the lower surface of the leaves. Compared with other Acalitus species described from different host plants within the supertribe Helianthodae, it differs morphologically. The previously known species Acalitus comptus, originally described on Sphagneticola trilobata (L.) Pruski from Guadeloupe, is also recorded on the same host plant in Mexico. DNA fingerprinting for both species is reported and compared with available sequences of Acalitus simplex and Acalitus phloeocoptes. Pairwise comparison of mitochondrial COI gene sequences revealed 16.3% genetic divergence between Acalitus viguierae sp. nov. and Acalitus comptus, while divergence values between the sequences obtained in this study and previously published congeneric sequences ranged from 21.1% to 28.1%. Maximum Likelihood phylogenetic analysis showed that the four analysed species from the genus Acalitus clustered into a single, well-supported clade, with A. comptus and A. viguierae sp. nov. clearly placed within the genus.