A review of Ultratenuipalpus (Trombidiformes: Tenuipalpidae) and related genera, with a new species from forest oak Allocasuarina torulosa (Aiton) (Casuarinaceae)

Abstract

ABSTRACTA new species of flat mite (Acari: Tenuipalpidae), Ultratenuipalpus jubatus Otley, Beard and Seeman sp. nov., is described from the green stems of forest oak Allocasuarina torulosa (Aiton) L.A.S. Johnson (Casuarinaceae) in Australia. We reinstate Extenuipalpus as a genus, with E. quadrisetosus (Lawrence, 1940) as the type species, and move Tenuipalpus niekerkae Meyer, 1979 and Tenuipalpus saggitus Meyer, 1993a to Extenuipalpus. We treat Urigersonus as a junior subjective synonym of Ultratenuipalpus, thus returning Urigersonus bunyai (Smiley and Gerson, 1995) to Ultratenuipalpus. The genera Ultratenuipalpus and Extenuipalpus are diagnosed and a key is provided for each genus. Ultratenuipalpus is shown to comprise two groups that generally conform to a biogeographic pattern: those species without seta f2 show a Gondwanan distribution, post-separation from Africa, while those with seta f2 are found in Africa, North America and East Asia. We also show that the pair of pseudanal setae that are modified into genital stylets in the male are setae ps3, not ps1 as previously thought, and therefore setae ps3 are always present in flat mites.