Systematic Entomology (2007), 32, 502–538 DOI: 10.1111/j.1365-3113.2006.00374.x Phylogeny of Psephenidae (Coleoptera: Byrrhoidea) based on larval, pupal and adult characters CHI-FENG LEE1 , MASATAKA SATOˆ2 , WILLIAM D. SHEPARD3 and M A N F R E D A . J A¨CH4 1Institute of Biodiversity, National Cheng Kung University, Tainan 701, Taiwan, 2Dia Cuore 306, Kamegahora 3-1404, Midoriku, Nagoya, 458-0804, Japan, 3Essig Museum of Entomology, 201 Wellman Hall, University of California, Berkeley, CA 94720, U.S.A., and 4Natural History Museum, Burgring 7, A-1010 Wien, Austria Abstract. We conducted the first comprehensive phylogenetic analysis of Pse- phenidae, based on 143 morphological characters of adults, larvae and pupae and coded for 34 taxa, representing three outgroups and 31 psephenid genera, including four undescribed ones. A strict consensus tree calculated (439 steps, consistency index ¼ 0.45, retention index ¼ 0.75) from the two most-parsimonious cladograms indicated that the monophyly of the family and subfamilies is supported, with the exception of Eubriinae, which is paraphyletic when including Afroeubria. Here a new subfamily, Afroeubriinae (subfam.n.), is formally estab- lished for Afroeubria. The analysis also indicated that the ‘streamlined’ larva is a derived adaptive radiation. Here, suprageneric taxonomy and the evolution of some significant characters are discussed. Keys are provided to the subfamilies and genera of Psephenidae considering larvae, adults and pupae. Introduction type specimens and the association of adults and immature stages by rearing, five new genera were proposed for Ori- Psephenidae, the ‘water penny’ beetles, are characterized by ental taxa and a well-resolved phylogenetic tree was ob- the peculiar larval body shape (Figs 4–7). The phylogeny of tained for genera within the family (Lee et al., 1999a, b, c, this family has been difficult to understand because of two 2000a, b, 2001, 2003a) by using larval, pupal and adult char- past problems. One was taxonomic confusion, caused acters. Thus, it seems promising to conduct a phylogenetic especially by Pic (1916, 1918, 1923, 1934, 1938, 1944). study of the whole family by combining characters of adults Although he assigned all eubriine species to Macroeubria, and immature stages. Drupeus, Grammeubria, and Ectopria, Drupeus belongs to Pic’s problems have been solved by revisionary studies a genus of Ptilodactylidae (Satoˆ, 1983), and Grammeubria (Appendix 1) (Ja¨ch & Lee, 1994; Lee & Yang, 1995, 1996; has been synonymized with Ectopria (Satoˆ, 1985). The Lee et al., 1998). In addition, successful associations of second problem is a lack of association of adults and immature stages with adults by rearing have been made for immature stages. Identification of the Psephenidae is mostly Homoeogenus (Lee & Yang, 1993), Schinostethus (Lee et al., based on adult stages, but larvae are more easily available, 1993), Nipponeubria (Lee & Satoˆ, 1996), Macroeubria (Lee as they are long-lived and common in streams. If associated et al., 1997), Granuleubria (Lee & Yang, 1999), Mubrianax with adults, larval characters would contribute significantly (Lee et al., 1999b), Jinbrianax (Lee et al., 1999c), Odontanax to phylogenetic studies. Unfortunately, few species have had (Lee et al., 2000a), Jaechanax (Lee et al., 2000b), Afrobrianax larval–adult associations, especially for those from the (Lee et al., 2003a), and Microeubria (Lee & Yang, 2002) Oriental Region. For example, the subfamily Eubrianacinae, allowing the inclusion of larval, pupal and adult characters comprising some 40 species, had been regarded as mono- in phylogenetic studies. So far, only Costa et al. (1999) has generic, with larvae only of Eubrianax edwardsii (LeConte) discussed the phylogenetic position of Psephenidae, based described (Blackwelder, 1930). After a re-examination of on one representative of each subfamily, indicating that only one synapomorphy, flattened larvae, can support the mono- Correspondence: Chi-Feng Lee, Institute of Biodiversity, phyly of the family. This claim is questionable, because their National Cheng Kung University, Tainan 701, Taiwan. E-mail: phylogenetic analysis did not include some genera of [email protected] Elmidae that share this same state (e.g. Fig. 4B, C). # 2007 The Authors 502 Journal compilation # 2007 The Royal Entomological Society Phylogeny of Psephenidae 503 The suprageneric taxonomy of Psephenidae has been (Ptilodactylidae: Araeopidinae), Cladotominae (Ptilodacty- confused, mainly because of dissimilarity between adults lidae), Chelonariidae, Psephenidae, Dryopidae, Lutrochi- of subfamilies and incorrect association of immature stages dae and Elmidae was suggested by the presence of and adults. Members of Eubrianacinae had been placed in a ventrally hinged operculum of segment IX. The presence the family Dascillidae, until Blackwelder (1930) described of plumose setae on the mouthparts was regarded as a the larva of Eubrianax edwardsii (LeConte) and assigned it possible synapomorphy of Chelonariidae, Psephenidae, to Psephenidae. Psephenoides immsi, the first member of Lutrochidae and Elmidae. The presence of three retractable Psephenoidinae, was described by Gahan (1914). It was anal gill-tufts was considered as a significant synapomorphy placed in Psephenidae, partly on account of the similar of the latter three families. The monophyly of Psephenidae habits of the adults and the great similarity of the larvae of and Elmidae was supported by the flexible, pilose mandib- Psephenidae and Psephenus. Champion (1920, 1924) trans- ular appendage. Costa et al.’s (1999) phylogenetic analysis ferred the genus to Scirtidae (¼ Helodidae) because adults of of Byrrhoidea using 32 taxa and 72 characters (43 from Psephenoids are more similar to members of Scirtidae than adults, 28 from larvae, one from pupae) is consistent with those of Psephenus.Bo¨ving (1926, 1929) and Bo¨ving & Lawrence’s (1987) analysis. Sister-group relationships Craighead (1931) transferred Psephenoides to Dryopidae between Cneoglossidae and Psephenidae were supported because of the similarity of the larvae of Psephenoides and by one adult character, the presence of paired glandular Helichus (Dryopidae) in that both had anal gills in contrast openings on abdominal tergites. to ventral gills in Psephenus. At that time, larvae of some Hinton (1966) discussed phylogenetic relationships eubriines had been identified erroneously as Helichus by between subfamilies of Psephenidae based on the respira- Kellicott (1883). This confusion still existed when Hinton tory systems of the immature stages, arguing that Psephe- (1939) proposed that Psephenidae should contain three sub- ninae had the most primitive respiratory systems of all families: Psepheninae, Psephenoidinae and Eubrianacinae, subfamilies. However, his discussion focused on the auta- based on the comparative anatomy of the larvae, pupae and pomorphic respiratory system of each subfamily, which adults. The first true larva for Eubriinae was recognized provided no information on the relationships between when Bertrand (1939) correctly described the life history of subfamilies. Thus, when he drew the phylogeny of Psephe- Eubria palustris Germar. Hinton (1955, 1966) formally nidae (Hinton, 1966: fig. 16), the cladogram united all included Eubriinae in Psephenidae when discussing the subfamilies. Although all subfamilies were represented in respiratory adaptations of the larvae and pupae. This Costa et al.’s (1999) phylogenetic analysis of Byrrhoidea, assignment has been followed by Lawrence & Newton subfamily relationships within Psephenidae were not dis- (1995), but other researchers have disagreed. For example, cussed. Bertrand (1972) treated Eubrianacinae as a subfamily of the In this study, we tested monophylies of the family Dascillidae, and raised Psephenoidinae and Eubriinae up to Psephenidae and its subfamilies and clarified the relation- the family level – Psephenoididae and Eubriidae. Eubriidae ships between subfamilies based on adult and immature was also adopted by some other researchers, e.g. Brigham stages, using most of the known genera. (1981). Crowson (1960) was the first to discuss the phylogenetic position of the Psephenidae. Psephenidae was attributed to Materials and methods the superfamily Dryopoidea (¼ Byrrhoidea), which was split into two main lineages. Psephenidae, Heteroceridae, Terminology Dryopidae, Limnichidae and Elmidae were one lineage united by the synapomorphy of five or six lateral ocelli in The terminology for hind wing venation is based on larvae. Eulichas (Eulichadidae), Ptilodactylidae, Chelonar- Kukalova´-Peck & Lawrence (1993, 2004). Terms for larval iidae and Eurypogonidae represented a second lineage structure follow Lee et al. (2001) for Eubrianacinae and Lee united by the synapomorphy of a single lateral ocellus. et al. (2003c) for Psepheninae. However, there are autapo- Later, Crowson (1978) thought that Psephenidae should be morphic arrays of marginal fringes within Psephenidae. grouped with Elmidae, Lutrochidae, Heteroceridae and Especially in some eubriine genera, the marginal fringes Limnichidae, due to the presence of the specialized hydro- are highly developed: there are four layers of setae on the fuge pubescence that enables the adults to move freely into outward margin of larvae. These setae are named based on water. The reduced and nonfunctional adult mouthparts their position. For example, the setae of the most outward and the strongly onisciform larvae were considered autapo-