Systematic Entomology (2009), 34, 533–558 The species-level phylogeny of archostematan beetles—where do Micromalthus debilis and Crowsoniella relicta belong? THOMAS HORNSCHEMEYER¨ Department of Morphology and Systematics, Johann-Friedrich-Blumenbach-Institute for Zoology and Anthropology, Georg-August-University Gottingen,¨ Gottingen,¨ Germany Abstract. A species-level phylogenetic analysis comprising 37 of the 45 known extant species of archostematan beetles and a total of 110 morphological characters from adults and larvae is presented. For the first time, characters of the male genitalia are included in a phylogenetic analysis of Archostemata. The dataset is analysed with parsimony as well as with Bayesian algorithms. Analyses with differently arranged datasets, with larval characters included or excluded, and including or excluding Micromalthus debilis and Crowsoniella relicta are conducted. The resulting hypothesis of the species-level phylogeny of Archostemata confirms Cupedidae and Ommatidae as monophyletic taxa. Within Cupedidae, the South American Paracupes and the North American Priacma together are the sister group to all remaining Cupedidae. Among the latter, the identification of a clade comprising Rhipsideigma, Cupes capitatus and Tenomerga leucophaea renders Tenomerga polyphyletic. Ascioplaga scalena comb. nov. is transferred from Adinolepis. Characters of the male genitalia support phylogenetic affinities of Micromalthus debilis with Ommatidae and of Crowsoniella relicta with Cupedidae. Introduction and 36 species; and the monotypic families Crowsoniellidae, Micromalthidae and possibly Jurodidae (Lawrence & Newton, Archostemata is one of four suborders of beetles (Coleoptera) 1995; Kirejtshuk, 1999; Hornschemeyer,¨ 2005). (e.g. Crowson, 1960; Lawrence & Newton, 1995), and consti- Crowsoniella relicta and Micromalthus debilis are remark- tutes the smallest and the least investigated of these suborders. able for different reasons. Crowsoniella relicta is known only Recent investigations of the basal phylogeny of Coleoptera from three male specimens collected in 1973 in Italy by place Archostemata as sister group to all other extant beetles Roberto Pace (Pace, 1975). With a total length of approx- (i.e. the Adephaga and Myxophaga and Polyphaga: Beutel & Haas 2000; Caterino et al., 2002; Hughes et al., 2006). There imately 1.5 mm, the species is comparatively small for an are other interpretations, for example with Polyphaga as sister archostematan beetle. Furthermore, there are many special mor- group to all other beetles and Archostemata as sister group to phological features, for example missing alae, modified and Adephaga or Myxophaga (e.g. Baehr, 1976; Kukalova-Peck´ & reduced mouth parts, and smooth elytra without the other- Lawrence, 1993, 2004), or together with Myxophaga as sister wise characteristic archostematan window punctures. Nothing group to Adephaga + Polyphaga (Hunt et al., 2007). How- is known about its biology, and, although many have tried, it ever, at present the position as sister group to the remaining has not been possible to collect additional specimens. Micro- Coleoptera seems to be the best supported. malthus debilis is of a similar small size and also shows numer- Currently, 45 extant archostematan species are known ous modifications. However, in habitus it is very different worldwide, and five families are recognized: Ommatidae, con- from C. relicta. The biology and many aspects of the anatomy taining two genera and six species; Cupedidae with nine genera of larvae and adults are quite well known. Micromalthus debilis shows the most complex life cycle among Coleoptera, Correspondence: Thomas Hornschemeyer,¨ Department of Morphol- comprising four externally different larval forms, including ogy and Systematics, Johann-Friedrich-Blumenbach-Institute for Zool- ogy and Anthropology, Georg-August-University Gottingen,¨ Berliner a paedogenetic larva, an arrhenotokous reproductive path- Strasse 28, 37073 Gottingen,¨ Germany. E-mail: [email protected] way and a thelytokous pathway (Pollock & Normark, 2002). © 2009 The Author Journal compilation © 2009 The Royal Entomological Society 533 534 T. H¨ornschemeyer Whether the adults are capable of reproducing is still uncertain QMBA:Queensland Museum, South Brisbane, Australia. (for summary and references see Hornschemeyer,¨ 2005). SMTD:Staatliches Museum fur¨ Tierkunde, Dresden, Another aberrant, probably archostematan, species is Germany Sikhotealinia zhiltzovae (Lafer, 1996), currently placed in its TMSA:Transvaal Museum, Pretoria, South Africa. own family Jurodidae (Kirejtshuk, 1999). It is known only UMRM:Wilbur R. Enns Entomology Museum, University from the holotype and shows a combination of polyphagan-like of Missouri, Columbia, USA. wing venation and morphological characteristics of abdomen, USNM:National Museum of Natural History, Washington thorax and head that are otherwise found in Adephaga and D.C., USA. Archostemata. WAM:Western Australian Museum, Perth, Australia. The phylogeny of Archostemata has so far been studied only ZFMK:Zoologisches Forschungsinstitut und Museum Alexan- at the family or genus level, with moderate taxon sampling der Koenig, Bonn, Germany. (e.g. Hornschemeyer¨ et al., 2002; Beutel & Hornschemeyer,¨ ZMHB:Museum fur¨ Naturkunde der Humboldt-Universitat¨ 2002a, b; Hornschemeyer¨ et al., 2006; Beutel et al., 2008), and zu Berlin, Institut fur¨ Systematische Zoologie, Berlin, the phylogenetic relationships of C. relicta, M. debilis and S. Germany. zhiltzovae are still not satisfactorily resolved. Hornschemeyer¨ ZSMC:Zoologische Staatssammlung Munchen,¨ Munchen,¨ et al. (2002) and Beutel & Hornschemeyer¨ (2002a) found M. Germany. debilis to be the sister group of Cupedidae, and C. relicta as the sister group of Ommatidae. This position of C. relicta In addition to specimens from scientific collections, the is in agreement with Crowson (1975), who associated it author received specimens for preparation from the following with Tetraphalerus, at least partially because of the presence persons: Dr R. G. Beutel (Jena, Germany; p-BEUT), Dr M. of lateral antennal grooves on the heads of Crowsoniella Hauser (Urbana, USA; p-MH), Dr J. F. Lawrence (Gympie, and Tetraphalerus. The close relationship of M. debilis to Australia), S. Lubkin (Ithaca, USA), Dr M. A. Perotti (Bangor, Cupedidae is based mainly on larval characters. Beutel & UK), Dr D. A. Pollock (Portales, USA), Dr R. Staals (Pretoria, Hornschemeyer¨ (2002b) and Hornschemeyer¨ et al. (2006) also South Africa), Dr W. Steiner (Washington, USA), Dr D. K. determined M. debilis to be closely related to Cupedidae. Young (Madison, USA). However, Crowsoniella turned out as sister group to M. debilis Specimens now in the collection of the author are labelled + Cupedidae. Beutel et al. (2008) included extinct taxa in their with p-ThH. analysis and established a clade comprising some fossil groups, Altogether, more than 400 specimens from 37 species of S. zhiltzovae, C. relicta and M. debilis. This clade was the sister Archostemata were investigated. group to Cupedidae. Even though the character sampling of In the following, the species are listed in alphabetical that study was very comprehensive, the problem remained that order. The information is arranged as follows: genus species: most support for this clade was due to loss of characters. biogeographic realm; collection, type status (if applicable). The present study aims to reconstruct the species-level phy- logeny of Archostemata based on a comprehensive morpho- Adinolepis apodema (Neboiss, 1987): Australasian; WAM, logical dataset utilizing characters from structures such as the Holotype. male genitalia that so far have not been used in analyses Adinolepis eumana (Neboiss, 1960): Australasian; NMV, of archostematan phylogeny, and comprising as many extant Holotype, ANIC, Paratype species as possible. Adinolepis mathesonae (Neboiss, 1960): Australasian; NMV, Holotype; ANIC. Adinolepis youanga (Neboiss, 1960): Australasian; NMV, Materials and methods Holotype; ANIC, Paratype; ANIC; p-ThH. Ascioplaga mimeta (Neboiss, 1984): Australasian; QMBA; Material p-MH. Ascioplaga scalena (Neboiss, 1984) comb. nov. (previ- Specimens from the following collections were examined. ously in Adinolepis): Australasian; ANIC, Holotype. Ascioplaga sciasma (Neboiss, 1984): Australasian; BPBM, ANIC:Australian National Insect Collection, Canberra Holotype; QMBA. City, Australia. Crowsoniella relicta (Pace, 1975): western Palearctic; BMNH:The Natural History Museum, London, England. MSNV, Holotype; Paratype. BPBM:Bernice P. Bishop Museum, Honululu, Hawaii. Cupes capitatus (Fabricius, 1801): Nearctic; FMNH; FMNH:Field Museum of Natural History, Chicago, USA. SMTD; USNM; p-ThH. LACM:Natural History Museum of Los Angeles County, Distocupes varians (Lea, 1902): Australasian; ANIC, Los Angeles, USA. Holotype; ANIC; p-ThH. MCZC:Museum of Comparative Zoology, Cambridge, USA. Micromalthus debilis (LeConte, 1878): Nearctic; SMTD; MSNV:Museo Civico di Storia Naturale, Verona, Italy. MTEC, Dominican Amber, foss.; UMRM. MTEC:Montana Entomology Collection, Bozeman, USA. Omma mastersii (Macleay, 1869): Australasian; ANIC. NMV:Museum Victoria, Entomology, Melbourne, Australia. Omma sagitta (Neboiss, 1989): Australasian; BMNH. © 2009 The Author Journal compilation © 2009 The Royal Entomological Society, Systematic Entomology, 34, 533–558 Species-level phylogeny of Archostemata 535 Omma stanleyi (Newman, 1839: Australasian; ANIC; mimeta (Hornschemeyer¨ et al., 2006) were