AMERICAN MUSEUM Novitates PUBLISHED BY THE AMERICAN MUSEUM OF NATURAL HISTORY CENTRAL PARK WEST AT 79TH STREET, NEW YORK, N.Y. 10024 Number 2743, pp. 1-13, figs. 1-4, table 1 August 4, 1982 Redefinition, Revised Phylogeny, and Relationships of Pseudopsinae (Coleoptera, Staphylinidae) ALFRED F. NEWTON, JR.' ABSTRACT New evidence is presented to support transfer vised cladistic analysis of the four genera is pre- of the genera Nanobius, Asemobius, and Zalobius sented with the conclusion that Pseudopsis is the from the Piestinae to Pseudopsinae, currently in- sister group of the remaining genera. The rela- cluding only Pseudopsis. The subfamily is rede- tionships of the subfamily are discussed; a close scribed, a key to genera given, and the natural relationship to the Phloeocharinae rather than to history and distribution briefly reviewed. A re- the Oxytelinae is suggested. INTRODUCTION The subfamily Pseudopsinae, with the sin- paper is intended as a supplement to, rather gle included genus Pseudopsis, has recently than a replacement for, Herman's revisions been thoroughly revised by Herman (1975). (1975, 1977). Thus the treatment is largely The same author shortly thereafter revised limited to making changes in the subfamily the three piestine genera Nanobius, Asemo- description, generic keys, etc. that are re- bius, and Zalobius (Herman, 1977). In the quired by combining all four genera in one latter work Herman cited many similarities subfamily. A cladistic analysis is presented, among these four genera but concluded that combining data from Herman's analyses the available evidence did not adequately (1975, 1977) with new data. support the hypothesis that the four genera constituted a monophyletic unit; Nanobius and its allies were tentatively retained in the MATERIALS AND METHODS Piestinae. In the course ofthis study I have examined The purpose of the present work is to pro- KOH-cleared, chlorazyl black-stained spec- vide new evidence that, in my view, firmly imens of the Pseudopsinae with both dis- establishes a close relationship of the four secting and compound microscopes. All genera and justifies placing them in a single species ofthe subfamily have been examined subfamily, Pseudopsinae sensu novo. This with the exception of most species of the I Research Associate, Department of Entomology, American Museum of Natural History; Curatorial Associate, Entomology Department, Museum of Comparative Zoology, Harvard University. Copyright © American Museum of Natural History 1982 ISSN 0003-0082 / Price $1.35 2 AMERICAN MUSEUM NOVITATES NO. 2743 Pseudopsis sulcata complex, which according tum, elytra, and sometimes head with lon- to Herman (1975) are distinguishable only gitudinal carinae or costae. Vestiture sparse, by details of the aedeagus. Several cleared of simple tapered setae and/or modified and partially dissected specimens were crit- scalelike or clubbed setae. Color reddish ical-point-dried, coated with gold-palladium brown. Body with or without tendency to mixture and examined with a scanning elec- accumulate mud and debris. tron microscope. Labrum with anterior margin truncate or The cladistic methods used here are essen- sinuate, with exposed epipharyngeal lobes, tially those of Herman (1970, 1975, 1977). dorsal surface with long setae. Epipharynx Other subfamilies of the Staphylinidae and with globosetae near anterior margin. Ante- related families such as the Silphidae and clypeus large and apparently permitting ex- Leiodidae have been used as out-groups to trusion of labrum. Supra-antennal ridge car- determine character polarities. inate or not. Epistomal suture present, posteriorly convex, evident externally as ACKNOWLEDGMENTS ridge or groove. Neck more or less distinct, at least laterally. Antenna slender to rela- I thank Dr. Lee H. Herman, Jr., and Dr. tively stout, 11-segmented, without distinct J. Milton Campbell for the gift of specimens club. Mandibles prominent, usually asym- relevant to this study. Dr. Herman and my metrical, apices acute, each with one to four wife, Margaret K. Thayer, have reviewed and teeth along mesial margin; molar lobe absent provided useful comments on the manuscript or thin, with microtrichia on mesial surface; for which I am grateful. The SEM photo- prostheca present. Maxilla with lacinia setose graphs were made with the support of Na- and bearing small apical spine; galea with tional Science Foundation grants BMS- dense brush of setae at apex; and palp four- 7412494 and BMS-7502606, and with the segmented, fourth segment about as long as assistance of Mr. Edward Seling. or longer than third and wide or narrow. La- bium with three-segmented palp; with one to PSEUDOPSINAE, SENSU NOVO three premental sclerites. Hypopharynx (in- cluding ligula) with one to three pairs of api- Pseudopsini Ganglbauer, 1895. cal lobes, the median pair spatulate. Gular Pseudopsinae ofauthors plus Piestinae: Nanobius, sutures separated, divergent anteriorly and Asemobius, and Zalobius (see Herman, 1975, posteriorly; submentum and gula not sepa- 1977 and references therein). rated by suture. Subocular carina present or DIAGNOSIS: The structure ofthe genital seg- absent. ment, with ninth terga dorsally fused in both Pronotal lateral margin rounded, serrate, sexes and with a fine presumed stridulatory or spinose; dorsal surface broadly elevated. file on each side (figs. 1, 2), will distinguish Protergosternal suture present. Procoxal fis- the Pseudopsinae from all other staphylinid sure broadly or narrowly open with exposed subfamilies. The Pseudopsinae are more eas- trochantin, or fissure closed and trochantin ily recognizable by a combination of the concealed. Postprocoxal lobe present. Pro- coarse punctation ofthe head and pronotum; hypomeron with or without microporous longitudinal carinae or costae of the prono- depression. Procoxae with or without shal- tum, elytra and sometimes of the head; 11- low, carina-delimited groove on mesial sur- segmented unclubbed antennae; and either face. Prosternal process carinate or spini- a comb at the apex of the eighth abdominal form. tergum or a deep incision of the posterior Scutellum with apex exposed behind margin of each elytron. pronotum. Elytra with or without posterior DESCRIPTION: Length 1.8 to 7.0 mm. Body emargination; elytral epipleural ridge pres- moderately broad, moderately flattened dor- ent. One or pair of sclerites present anterior soventrally. Head and pronotum weakly to to mesosternum but posterior to and not as- strongly sculptured with reticulate (large, ir- sociated with mesothoracic spiracular peri- regular, subcontiguous) punctures; prono- tremes (fig. 3). Mesosternum carinate or not. 1982 NEWTON: PSEUDOPSINAE 3 41 FIGS. 1, 2. 1. Pseudopsis obtusa, female, right dorsolateral view oftergum IX. 2. Nanobius serricollis, female, left dorsolateral view of tergum IX. Scale line = 0.1 mm. Mesocoxae contiguous or narrowly separated minuta only) 3-3-3. Tarsal empodium bise- by meso- and meta-stemal processes. Hind tose. coxae transverse, contiguous. Abdominal segments II or III to VII each Tibiae with or without longitudinal rows with one or two pairs oflaterosclerites. Terga ofspines. Tarsal formula 5-5-5 or (Pseudopsis II (Pseudopsis) or III to VII with transverse 4 AMERICAN MUSEUM NOVITATES NO. 2743 FIG. 3. Pseudopsis subulata, pro- and meso-thorax, ventral view. subbasal ridge; terga with or without baso- or without transverse subbasal ridge. Ab- lateral ridges or basal, longitudinal carinae; dominal intersegmental membranes with or terga without wing-folding setae or spicules; without pattern; attached to apex or anterior tergum VIII with apical cuticular comb or to apex of preceding segment. median process, or with apex rounded. Spi- Tergum IX ofboth sexes consisting of sin- racles placed in edges of terga II (Pseudopsis) gle large sclerite with fine file on each side or III to VIII. Sternum I represented by strap- (figs. 1, 2), the ridges of the file becoming like sclerite, medially divided or not. Sternite more closely spaced posteriorly. Anterior, II short and fused to sternite III. Sternites II dorsolateral margins of tergum IX with sin- and III with or without median longitudinal uation or shallow emargination which, in carina; sternites III to VII with (Pseudopsis) Pseudopsis at least, marks the opening of a 1982 NEWTON: PSEUDOPSINAE 5 large glandular reservoir. Tergum X ovoid 3(2). Subocular carina present; lateral margin of or triangular, placed in large apical emargi- pronotum coarsely serrate; abdominal nation of tergum IX. terga without longitudinal basal carinae Male. Aedeagus symmetrical or asymmet- ......................... .Asemobius rical, with or without parameres, with or Subocular carina absent; lateral margin of pronotum spinose; abdominal terga III to without basal piece. Aedeagus in repose with VI each with one basal midlongitudinal parameres facing dorsal surface of beetle. carina .................... Zalobius Female. Coxites circular to oval in cross- section and free, or flattened and fused to one another. Styli present and small, or absent. NATURAL HISTORY Intergonopodal sclerite present or absent. All species, as far as known, occupy cool TAXA INCLUDED: The subfamily as rede- temperate montane forested regions (Her- fined here includes four genera: man, 1975, 1977). Pseudopsis and Nanobius Asemobius Horn (one species, A. caelatus species are most commonly found in moist Horn, from western North America) forest floor litter; some Pseudopsis species Nanobius Herman (one species, N. serri- have also been associated