The anal secretory apparatus of Eriophyoidea and description of Phyllocoptes bilobospinosus n. sp. (Acariformes: Eriophyidae) from Tamarix (Tamaricaceae) from Ukraine, Crimea and USA

A new vagrant phyllocoptine species, Phyllocoptes bilobospinosus n. sp. (Eriophyidae, Phyllocoptinae), found on tamarisks ( Tamarix tetrandra Pallas , T. smyrnensis Bunge , T. ramossisima Ledeb) in Donbass (Ukraine), Crimea, and USA is described based on conventional light microscopy and confocal laser scanning microscopy. Apart from two distinct areas of ventral cuticle bearing large, spike-like microtubercles, the new species possesses a thin translucent supracapitular plate (situated below the frontal lobe of the prodorsal shield), a short longitudinal ventral ridge anterior to the anal lobes, and unusual internal tube-like structures associated with the rectum. Careful examination of purposefully made slide mounts of partially cleared specimens revealed that adults of P. bilobospinosus possess a complex of structures associated with the rectum, including a hypertrophied, four-lobed putative anal gland and four thin tubes connected with a rectal sac. Similar tubular structures previously described in aberoptine mites of the genus Aberoptus from Brazilian Cesalpiniaceae are discussed. The synonymy of genera Aberoptus Keifer and Aceria Keifer is rejected and a new combination, Aberoptus inusitatus (Britto & Navia (in Britto et al . 2008)) n. comb. , is proposed. A brief review of the anal glands of Eriophyoidea is given, including a discussion on homology and the variety of forms of the anal secretory apparatus among eriophyoid genera. Further research is needed on the anatomy of anal glands in Eriophyoidea, including transmission electron microscopy based histological analyses and additional studies of eriophyoids with well-developed secretory structures associated with the rectum. These methods will lead to a much better understanding of the evolution and homology of the anal secretory apparatus, which may render it useful for future phylogenetic studies.