236 Bulletin ofZoological Nomenclature 63(4) December2006 Case 3354 Tydeus Koch, 1836 (Acari): proposed designation of Tydeus spathulatus Oudemans, 1928 as the type species Henri M. Andre Section des Invertebres non-insectes, Musee royal de I'Afrique centrale, B-3080 Tervuren, Belgium (e-mail: [email protected]) Andrzej Kazmierski Department ofAnimal Morphology, A. Mickiewicz University, Umultowska 89, PL-61-614 Poznan, Poland (e-mail: [email protected]) Abstract. The purpose of this application, under Article 70.3 of the Code, is to propose a new type species for the genus Tydeus Koch, 1836, the type genus ofthe family tydeidae. The nomenclature of this genus is uncertain because of several incorrect designations of type species and a series of misidentifications. One of the two species originally included in the genus has been misidentified, and the types of both species originally included are lost. It is proposed that Tydeus spathulatus Oudemans, 1928 is designated as the type species of Tydeus Koch, 1836. Keywords. Nomenclature; taxonomy; Acari; tydeoidea; tydeidae; Tydeus; Tydeus spathulatus: Tydeus croceus\ Tydeus kochi; tydeid mites. 1. Koch (1836, unnumbered page) established the nominal genus Tydeus(Acari) to incorporate two species, Acarus croceus Linnaeus, 1758 and Tydeus velox Koch, 1836. He did not designate either species as the type. 2. Subsequently, Koch (1842, p. 70) illustrated Tydeus mutabilis Koch, 1838 as an example ofthe genus Tydeus. This action cannot be regarded as a valid type fixation — as this species was not originally included in the genus (Article 67.2 Species eligible for type fixation) and, apart from that, the mere mention ofa species as an example — of a genus is not to be regarded as a type designation (Article 67.5 The term "designation"). 3. Types ofthe two originally included species described by Koch (1836) are lost. 4. Koch'sspecies, veloxandmutabilis, haveneverbeen recorded since theiroriginal description and are considered to be species inquirendae (Kazmierski, 1998; Andre, 2005). 5. The identity ofAcarus croceus Linnaeus, 1758 is dubious as Oudemans (1928) changed hisinterpretation ofLinnaeus's speciesand referred to threediff"erent species under the name croceus (Andre, 2005). Thor (1933, p. 16) published a redescription ofAcarus croceus Linnaeus, 1758, indicating thatit is not the same as Tydeus croceus Koch, 1836. Acarus croceus Linnaeus, 1758 was subsequently designated by Oudemans (1937) as the type species of Calotydeus Oudemans, 1937. 6. The species identified as Acarus croceus Linnaeus, 1758 by Koch (1836) was misidentified. It was renamed as Tydeus kochi by Oudemans (1928, p. 378). Later it ) Bulletin ofZoological Nomenclature 63(4) December 2006 237 was designated without any discussion as the type species of Tydeiis by Vitzthum (1941, p. 800). Baker & Wharton (1952, p. 191) recorded Tydeiis kochi Oudemans, 1928 as the type species of Tydeiis. Subsequently, Baker (1970) figured Tydeits kochi and recorded it as the type species ofthe genus Tydeus. However, the specimens that Baker figured as Tydeus kochi Oudemans, 1928 differ from Tydeus kochi Oudemans, 1928 in the shape of the opisthosomal setae. Currently, there are no specimens of Tydeus kochi in Oudemans's collection housed in Leiden, and the identity of this species is uncertain. Specimens figured by Baker (1970) as Tydeus kochi Oudemans, 1928 are lost. 7. Due to this series of errors and in the absence of well-defined types, the true identity ofthe genus Tydeus is uncertain and two nomenclatural systemscoexist, that of Andre (1980) and that of Kazmierski (1989), which generates nomenclatural instability (Momen & Lundqvist, 1995). 8. Andre (2005) discussed three alternative approaches to this situation and compared the advantages and disadvantages ofselection ofa new type species from the list of three Tydeus species in Oudemans's collection {Tydeus spathulatus Oudemans, 1928, A. croceus Linnaeus, 1758 or T cruciatusOudemans, 1928). Tydeus spathulatus Oudemans, 1928 was considered the best choice. The type of Tydeus spathulatus Oudemans, 1928 is in a good state, properly housed in a well-known museum (National Museum of Natural History, Leiden, The Netherlands) and available for study. The description of Tydeus spathulatus given by Andre (2005) refers to the type specimens that Oudemans purchased from Berlese and collected from Padova in Italy. The 12 specimens originally placed on a single slide were remounted separately. Andre(2005) designated aslectotype thefemale remounted on the slide with the original label handwrittenby Oudemans. The other slides with new labels contain the paralectotypes. 9. The International Commission on Zoological Nomenclature is accordingly asked: (1 to use its plenary power to set aside all previous type species designations for the nominal genus Tydeus Koch, 1836 and to designate Tydeus spathulatus Oudemans, 1928 as the type species; (2) to place on the Official List of Generic Names in Zoology the name Tydeus Koch, 1836 (gender: masculine), type species by designation in (1) above Tydeus spathulatus Oudemans, 1928; (3) to place on the Official List ofSpecific Names in Zoology the namespathulatus Oudemans, 1928, as published in the binomen Tydeus spathulatus (specific name ofthe type species of Tydeus Koch, 1836). References Andre,H.M. 1980. A generic revision ofthe familyTydeidae (Acari: Actinedida). IV. Generic descriptions, keys and conclusions. Bulletin et Annates de la Societe rovale beige d'Entomologie, 116: 103-130, 139-168. Andre, H.M. 2005. In search ofthe true Tydeus. Journal ofNaturalHistory, 39: 975-1001. Baker, E.W. 1970. The genus Tydeus: subgenera and species group with descriptions ofnew species (Acarina: Tydeidae). AnnalsoftheEntomologicalSocietyofAmerica,63: 163-177. Baker, E.W. «& Wharton, G.W. 1952. An Introduction to Acarology. 465 pp. MacMillan, New York. 238 Bulletin ofZoological Nomenclature 63(4) December 2006 Kazmierski, A. 1989. Revision ofthe genus Tydeiis Koch sensu Andre, Homeotydeus Andre and OrthotydeusAndrewithdescription ofa newgenusand fournew species ofTydeinae (Acari: Actinedida: Tydeidae). Mitteihingen aus dem Hamburgischen Zoologischen Museum iindInstitute 86: 289-314. Kazmierski, A. 1998. Tydeinae ofthe world: Generic relationships, new and redescribed taxa and keys to all species. A revision ofthe subfamilies Pretydeinae and Tydeinae (Acari: Actinedida: Tydeidae) - Part IV. Acta Zoologica Cracoviensia, 41: 283^55. Koch, C.L. 1836. Deutschlands Criistaceen, Myriapoden und Arachniden. Ein Beitnig :iir deiitscben Fauna, Heft 4=137. Herrich-Schaffer, Regensburg. Koch, C.L. 1838. Deutschlands Crustaceen, Myriapoden und Arachniden. Ein Beitrag zur deutschen Fauna, Heft 20=160. Herrich-Schaffer, Regensburg. Koch, C.L. 1842. Ubersicht des Arachnidensystems, vol. 3(2). C.H. Zeh'schen Buchhandlung, Niirnberg. Momen,F.& Lundqvist,L. 1995.Thegenus Tydeus(Acari: Prostigmata:Tydeidae)insouthern Sweden: six new species. Acarologia, 36: 41-56. Oudemans, A.C. 1928. Acarologische aanteekeningen XCIV. Entomologische Berichten. 7: 374-382. Oudemans, A.C. 1937. Kritisch historisch Overzicht der Acarologie. Derde Gedeelde, Band C. 1-23, 799-1348 pp. E.J. Brill, Leiden. Thor, S. 1933. Tydeidae, Ereynetidae. Das Tierreich. 6: 1-84. Vitzthum, H. 1941. Acarina. 5 Lieferung. Dr H.G. Bronns Klassen und Ordnungen des Tierreichs, 5: 641-800. Acknowledgement ofreceipt ofthis application was published in BZN 62: 126. Comments on this case are invited for publication (subject to editing) in the Bulletin; they should be sent to the Executive Secretary, LC.Z.N., c/o Natural History Museum, Cromwell Road, London SW7 5BD, U.K. j(e-mail: [email protected]).