Amerodectes Valim and Hernandes, 2010

Mironov, Sergey V. & Galloway, Terry D., 2021, Feather mites of the subfamily Pterodectinae (Acariformes: Proctophyllodidae) from passerines and kingfishers in Canada, Zootaxa 5016 (1), pp. 1-55 : 4-5

Genus Amerodectes Valim and Hernandes, 2010

Type species: Proctophyllodes (Pterodectes) gracilis Trouessart, 1885 , by original designation.

Diagnosis. Both sexes. Moderately elongated pterodectines. Full set of hysterosomal setae, full set of leg setae occurring in pterodectines ( Park & Atyeo 1971a). Setae c2 on humeral shields or on striated tegument. Setae c3 lanceolate.

Male. Opisthosomal lobes of moderate length, 1.5–2 times longer than wide at base, rounded or slightly attenuate apically, without wide membranous margins. Setae ps3 situated lateral to adanal suckers, approximately at their level or slightly posterior. Opisthoventral shields at level of adanal suckers well developed, inner margins of these shields without any angular extension posterior to bases of setae ps3. Ventral surface of opisthosomal lobes sclerotized in distal half; with narrow sclerotization along only distal margin in A. bilineatus ( Berla, 1958) , A. storkani ( Černý, 1974) , and A. thraupicola ( Černý, 1974) . Setae h3 variable in form, setiform, narrowly lanceolate, spiculiform. Aedeagus sword-shaped, not extending beyond lobar apices. Genital papillae anterior to branches of genital arch. Genital apparatus without pre- and paragenital apodemes. Adanal shields absent (except A. thraupicola ).

Female. Setae ps2, ps3 always setiform and arranged in large trapezoid, setae ps2 at level of posterior end of anal opening or posterior to it. Setae h2 spindle-shaped, without filiform apex (with short filiform apex in A. turdinus ).

Remarks. Amerodectes is the most species-rich genus of the Pterodectes complex and to date has included 40 species ( Mironov et al. 2008a; Valim & Hernandes 2010; Mironov & González-Acuña 2011; Hernandes et al. 2016, 2018; Mironov & Chandler 2017). According to the previous taxonomic concept ( Mironov et al. 2008a; Valim & Hernandes 2010), discrimination of the three closely related genera of the Pterodectes complex, Amerodectes , Metapterodectes and Tyrannidectes , was based on their leg chaetotaxy, namely, on the presence of absence of trochanteral setae sR III and solenidion σ III. Previously, the main diagnostic features to distinguish the genus Amerodectes from the two other genera included the simultaneous presence of setae sR III and genual solenidia σ III, while in Tyrannidectes , setae s R III are absent, and in Metapterodectes , both the setae and solenidia are absent. Recent molecular phylogenetic study of proctophyllodids and trouessartiids from the New World ( Pedroso et al. 2021) has shown that arrangement of pterodectine mite species in the genera Amerodectes , Metapterodectes and Tyrannidectes based on these characters of leg setation, does not completely correlate with the position of these species among clusters uniting typical species of these genera (a type species and closely related ones). Thus, it was shown that some species, which could be referred to Amerodectes based on chetotatic criteria, appeared among species constituting the genus Tyrannidectes , while some species from the latter appeared in Metapterodectes . Based on reevaluation of previous criteria and searching of new diagnostic characters, the genus Amerodectes can be now characterized in the following combination of features: in males, the ventral side of the opisthosomal lobes is sclerotized in the distal part, and the opisthoventral shields lack any angular extension posterior to setae ps3 ( Figs. 1B , 3A , 4 ); in females the pseudanal setae ps2 and ps3 are always filiform and in trapezoidal arrangement ( Fig. 2B ). In species referred to Amerodectes according our revised concept, setae sR III and solenidia σ III are always present, while in species of the genera Metapterodectes and Tyrannydectes, these setal structures may be present or absent.

All Amerodectes species can be arbitrarily arranged in two groupings based on the structure of setae h 3 in males; in one group, these setae are relatively long, filiform or rod-like, and distinctly exceeding the distance between scapular setae se, and in the other, these setae are narrowly lanceolate or spiculiform and distinctly shorter than the distance between setae se. A key to all previously known species of the New World, except those described in the past decade, was provided by Mironov and González-Acuña (2011), and a world checklist and a key to most of North American species were given by Mironov and Chandler (2017).

In the present work, we describe four new Amerodectes species found on passerines in Canada. On the other hand, based on the renewed diagnosis, we transfer the following four species from the world list of Amerodectes species ( Mironov & Chandler 2017; Hernandes et al. 2018) to the genus Tyrannidectes : A. pitangi (Mironov, 2008) , A. caribaeus Mironov and González-Acuña, 2011 , A. charitomenos Hernandes, 2018 , and A. vireonis Hernandes and Pedroso, 2016 .

Figures

FIGURE 1. Amerodectes tretiakae sp. n., male. A—dorsal view, B—ventral view.

FIGURE 2. Amerodectes tretiakae sp. n., female. A—dorsal view, B—ventral view.

FIGURE 3. Amerodectes tretiakae sp. n., details.A—opisthosoma of male, ventral view, B–D—legs I–III of male, respectively, E—tibia and tarsus IV of male, F—tibia and tarsus IV of female, G—spermatheca and spermaducts. Abbreviations: bs—basal sclerite of genital apparatus, co—copulatory opening, ga—genital arch, hs—head of spermatheca, os—opisthoventral shield, pd—primary spermaduct, sd—secondary spermaducts.

FIGURE 4. Amerodectes species, ventral view of male opisthosoma. A—Amerodectes xanthocephali; B—A. spizellae, C—A. dumetellae, D—A. hribari.