BULLETIN DE L'INSTITUT ROYAL DES SClENCES NATURELLES DE BELG IQUE ENTOMOLOGIE, 73: 135-176, 2003 BULLETIN VAN HET KONINKLIJK BELGISCH INSTITUUT VOOR NATUURWETENSCHAPPEN ENTOMOLOGIE, 73: 135-176, 2003 A review of feather mites of the Rhytidelasma generic group (Pterolichoidea Pterolichidae ), specific parasites of panots (Aves Psittaciformes) by S.V. MIRONOV and T.M. PEREZ Abstract both sexes, the idiosoma is distinctly elongated and usual­ ly parallel-sided, ve1tical setae vi absent; males are smal­ A systematic review of all currently recognized genera and species of ler in size than females; in males, the opisthosomal lobes the Rhytidelsama generic group (Pterolichidae: Pterolichinae) repre­ senting specific ectoparasites of parrots Psittaciformes is presented. are usually provided with a pair of leaf-like terminal Four new genera are established within the generic group: Cacatoli­ lamellae having several transverse crests on dorsal sur­ chus gen. n. with the type species Pteroliclws (Pseudalloptes) spathu­ face, the anal discs are sunounded by very large striated liger TROUESSART, 1884; Neorhytidelasma gen. n. with the type species Rhytidelasma cornigera ATYEO & PeREZ, 1988; Kakapolichus gen. n., membranes, corollae of the discs without indentations, with the type species Kakapolichus strigopis sp. n. fro m the Kakapo the genital apodemes are formed by enlarged epimerites Strigops harboptilus; Psillrichobius gen. n. with the type species IVa, legs I-III not hypertrophied, legs IV slightly thick­ Psiltrichobius eclectus sp. n. fro m the Pesquet's Psillrichas Parrot ened , and tarsi IV wi fulgidus. Diagnosis of the genus Rhytidelsama GAUD, 1966 is rede­ th large claw-like process on para­ fined. Two new species belonging to this genus are described from xial surface of the segment. Taxonomically, this group psittacids of the Old World: Rhytidelasma aprosmictis sp. n. from the apparently might warrant treatment as a tribe within the Red-winged Parrot Aprosmictis eiJ'Ihroptesus and R. lanceolata sp. n. subfamily Pterolichinae. There are no doubts of the from the Masked Shining Parrot Prosopeia persona/a. According to the results of the taxonomic review, the Rhytidelasma generic group now monophyly of this group (GAUD & ATYEO, 1996); how­ includes 33 species and 9 genera. Identification keys for all genera and ever, any formal ranking of this group should be made in species of the generic group are presented. Currently known host­ the frame of general revision of Pterolichidae which is a parasite associations of the Rhytidelasma generic group are briefly analyzed. We conclude that this group of feath er mites demonstrates task for a separate study. obvious traces of co-evolutionary relationships with their hosts. The genus Rhytidelasma GAUD, 1966 was originally based on single species Rhytidelasma grammophylla Key words: feather mites, Pterolichidae, Rhytidelasma, systematics, new taxa, Psittaciformes, host-parasite associations (GAUD & MoucHET, 1959). In further investigations of African feather mites, GAUD ( 1980) described 3 new Rhytidelasma species a nd also included in this genus 8 species formerly described by TROUESSART (1 884) within Introduction the conglomerate genus Pterolichus Robin, 1877. Subse­ quent investigations of the Rhytidelasma group were not The pterolichid feather mites associated exclusively with extensive. ATYEO and coauthors (ATYEO et al. 1988; Psittaciformes are represented by three morphologically ATYEO & PEREZ 1988a-b) explored Rhytidelasma species distinct generic groups belonging to th e subfamily Ptero­ associated with some groups of South American parrots lichinae (GAUD & ATYEO, 1996; MIRONOV et al., 2003). and recognized five s pecies groups within this complex Among these, the Rhytidelasma group takes second place of mites. These authors a lso noted that species of large­ by the number of known taxa and currently includes 29 sized pauots, such as Ara LACEPEDE and Aratinga SPLX, species arranged into 5 genera. In ecological aspects, mites may simultaneously harbor representatives of several of the Rhytidelasma group are typical representatives of species groups. Exploring pterolichids from pauots of the morphoecological type adapted to inhabit the plumage the Old World, ATY EO & GAUD (199 1) established the feathers with large and h ard vanes (MJRONOV, 1987; DA­ new genus Lorilichus ATYEO & GAUD, 1991, which unites BERT & MmoNov, 1999). These medium and small-sized pterolichine mites specific to lories and lorikeets (Psitta­ elongated mites commonly occupy narrow and low coni­ cidae: Loriinae). Later on, in their global generic revision dors formed by barbs in the ventral surface of vanes. This of feather mites of the World, GAUD & ATYEO (1996) group of feather mites is widely distributed in both hemi­ established three new monotypic genera belonging to spheres and associated with all families and most tribes of the group in question: Arhytidelasama GAUD & ATYEO, parrots recently recognized (MIRONOV et al. 2003). 1996, Coracopsobius GAUD & ATYEO, 1996, and Psitto­ Mites of the Rhytidelasma group are characterized by colus GAUD & ATYEO, 1996. Summarizing the results of the fo ll owing combination of morphological features: in these investigations, it is possible to state that systematic 136 S.V. MIRONOV and T.M. PEREZ \I study of Rhytidelasma group mites is still in its early Notes to the idiosomal chaetotaxy stage. An additional problem for continuing the explora­ tion of the Rhytidelasma group is the paucity of keys to A characteristic evolutionary tendency observed within most currently known species. the Rhytidelasma generic group is loss of certain hyster­ The main goals of the present study include a taxo­ osomal setae in most derived genera. When one compares nomic review of all cutTently known species of the Rhy­ application of idiosomal chaetotaxy in different taxa of tidelasma generic group, description of new genera and the Rhytidelasma group there is clear discordance in species recognized in the course of this study, creation of nomenclature of obviously homologous setae in different identification keys, and brief analysis of host-parasite genera of the group (ATYEO et al., 1988; ATYEO & GAUD, associations of these mites with the Psittaciformes. 1991 ; GAUD & ATYEO, 1996). Therefore, it is necessary to discuss here this problem and provide a basis for the chaetotaxy concept used for the Rhytidelasma group in the present study. In genera having the most archaic Material and methods chaetome within the group (Psittrichobius gen. n., Kaka­ polichus gen. n., Neorhyridelasma gen. n.), the hystero­ The main part of the material used in the present study soma caiTies 12 pairs of dorsal and lateral setae (including was botTowed in a loan from the University of Georgia humeral setae cp), which is one pair less than in the (Athens, USA). Other sources of the examined material maximum set of 13 pairs observed in the most early are the feather mite collections deposited in the Zoologi­ derivatives of Pterolichidae, for example Opisthocoma­ cal Institute, Russian Academy of Sciences (Saint Peters­ cants DUBfNIN, 1955 and Struthiopterolichus Dubinin, burg, Russia) and in the Instituto de Biologia, Univer­ 1955. In derived genera, such as Arhytidelsama and Lor­ sidad Nacional Aut6noma de Mexico (Mexico City, ilichus, only 10 pairs of these setae are present. However, Mexico). it is quite obvious that certain homologous setae receive Mite specimens used for light microscope study were different designations in recent taxonomic papers. mounted on slides in Hoyer's medium (EvANS, 1992). There are two principal problems in applying setal Diagnoses of genera and descriptions of new species are nomenclatme in the Rhytidelasma group. The first ques­ given in the standard formats used for pterolichine taxa of tion concems the nomenclahu·e for the pairs of setae respective ranks (ATYEO et al., 1988; ATYEO & GAUD, sih1ated lateral to macrochetae h2 on the lateral margins 1991 ). The general morphological terms, leg and idioso­ of the body. These setae occur in all taxa of the Rhytide­ mal chaetotaxy follow GAUD & ATYEO (1996). All lasma group. In males, the position of these setae in measurements in the descriptions are given in micro­ relation to the transverse level of setae h2 varies and most meters (J..Lm). Since the number of specimens in most commonly they are slightly posterior to h2 (Figs. 1, 4, 11 , type series was restricted, for the sake of consistency a 52, 73), while in females, these setae are always slightly full set of measurements is given only for the holotype anterior to this level (Figs. 7, 9, 14, 16, 64, 95). GAUD & (male) and one paratype (female). The range ofidiosomal ATYEO (1991) examined species having only one pair of size (length, width) is displayed for other paratype speci­ setae in the named places and concluded that these setae mens. Scientific names of birds and supraspecific sys­ are j2. However, in the two unique species, Rhytidelasma tematics of patTots used in the present study follow punctata MIRONOV et a!., 2003 and Psittrichobius eclectus " Handbook of the Birds of the World" (DELHOYO et al. sp. n., there are two setae in these places near the margins 1997). of the opisthosoma. Among these, the larger pair of setae Abbreviations used in collection data and to point out that occurs in all representatives of the Rhytidelasma group an origin of materials and institutions, where type materi­ always occupies in males a slightly posterior position with als of new species