Group appendiculata Diagnosis. Both sexes. Hysteronotal setae d2, e2 present. Setae c2 long, spiculiform. Setae sR of trochanters III spiculiform, usually longer than tarsi I, II and slightly enlarged in basal part. DHA present. Male. Opisthosoma strongly attenuate posteriorly, opisthosomal lobes fused along midline forming heavily sclerotized median septa, only distal ends of lobes separated by narrow terminal cleft not extending beyond level setae h2. Epimerites IVa present, with anterior ends not extending to genital apparatus. Paragenital apodemes absent. Translobar apodemes present. Terminal lamellae ovate and attenuate apically (Figs. 3E, 16A) or enlarged with concave posterior margin and shaped as a fish-tail (Fig. 16D). Female. Setae f2 present. Remark. The group currently incorporates 9 species, including one described herein; 3 species have been recorded in the New World (Santana 1976; Gaud & Atyeo 1986). Included species: Trouessartia ampulicaudata sp. n., T. appendiculata (Berlese, 1886), T. exima Gaud and Atyeo 1986, T. gladifera Gaud and Atyeo 1986, T. longiseta Gaud & Atyeo 1986, T. modesta Gaud and Mouchet, 1958, T. piscicauda Gaud, 1957, T. santanai Gaud and Atyeo, 1986, and T. sophiae Gaud and Atyeo, 1986.

Published as part of Mironov, Sergey V. & Galloway, Terry D., 2019, Feather mites of the genus Trouessartia Canestrini (Acariformes: Trouessartiidae) from swallows (Passeriformes: Hirundinidae) in Canada, pp. 1-39 in Zootaxa 4568 (1) on page 5, DOI: 10.11646/zootaxa.4568.1.1, http://zenodo.org/record/2599119