Blackwell Science, LtdOxford, UKZOJZoological Journal of the Linnean Society0024-4082The Linnean Society of London, 2002 136 Original Article K. YOSHIZAWAPHYLOGENY OF PSOCOMORPHA (‘PSOCOPTERA’) Zoological Journal of the Linnean Society, 2002, 136, 371–400. With 75 figures Phylogeny and higher classification of suborder Psocomorpha (Insecta: Psocodea: ‘Psocoptera’) KAZUNORI YOSHIZAWA Systematic Entomology, Graduate School of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan Downloaded from https://academic.oup.com/zoolinnean/article/136/3/371/2631270 by guest on 31 August 2021 Received January 2002; accepted for publication May 2002 Phylogenetic relationships among all 24 families of suborder Psocomorpha (Insecta: Psocodea: ‘Psocoptera’) are inferred based on adult morphology. Monophyly of Psocomorpha is strongly supported by six autapomorphies. The presently accepted four infraorders − Psocetae, Homilopsocidea, Epipsocetae and Caeciliusetae − are regarded as monophyletic, but Archipsocidae and Hemipsocidae, previously assigned to Homilopsocidea and Psocetae, respec- tively, are regarded as the basalmost clades of the suborder. Based on the results of the cladistic analysis, a higher classification for Psocomorpha is proposed. Six infraorders (two new − Archipsocetae, Hemipsocetae − and the four aforementioned) are recognized. Four new superfamilies are recognized within Homilopsocidea: Elipsocoidea, Lachesilloidea, Pseudocaecilioidea and Peripsocoidea. Two superfamilies are recognized within Caeciliusetae: Asiopsocoidea and Caeciliusoidea. Descriptions of taxa above family level are provided. © 2002 The Linnean Society of London, Zoological Journal of the Linnean Society, 2002, 136, 371−400 ADDITIONAL KEYWORDS: – new infraorder – superfamily – phylogeny – Psocomorpha – Psocoptera – systematics. INTRODUCTION 1991) that his phylogenetic system needed revision. Psocomorphans exhibit a range of fascinating The order Psocoptera (psocids, booklice or barklice) is behaviours, including stridulation, aggregation, sub- a small order of insects, comprising c. 4110 described sociality and nesting. Investigation into the evolution- species (García Aldrete, 1996). They range from 1 ary aspects of these behaviours requires a reliable to 10 mm in length and are characterized by a well- phylogenetic system. developed postclypeus, long antennae, pick-like In the present paper, I infer the phylogenetic rela- lacinia, reduced prothorax and well-developed tionships among families of Psocomorpha based on pterothorax. adult morphology. Six infraorders (two of them new) Psocomorpha is the largest suborder in Psocoptera, are recognized. In addition, six superfamilies are containing 24 of the 37 psocopteran families. Psoco- recognized: two within Caeciliusetae and four (new) morphan families are classified into four groups: Epip- within infraorder Homilopsocidea. socetae, Caeciliusetae, Homilopsocidea and Psocetae. This taxonomic system was first proposed by Pearman (1936) and remains widely adopted with some minor HISTORY OF THE HIGHER CLASSIFICATION alterations. OF PSOCOMORPHA Phylogenetic relationships within Psocoptera were The presently accepted taxonomic categories above first extensively studied by Smithers (1972). However, family level within Psocoptera were first proposed by in his proposed dendrogram, some lineages were Pearman (1936). Unlike earlier efforts based on a few based on plesiomorphic or homoplastic character prominent characters such as wing venation and states; nearly 20 years later he admitted (Smithers, number of tarsomeres, his classification was based on an analysis of a wide range of external morpholo- gical characters. He proposed eight family groups (infraorders of the present paper) in Psocoptera, of Correspondence: E-mail: [email protected] which four − Epipsocetae, Caecilietae (= Caeciliuse- © 2002 The Linnean Society of London, Zoological Journal of the Linnean Society, 2002, 136, 371–400 371 372 K. YOSHIZAWA Table 1. History of the higher classification of Psocomorpha Downloaded from https://academic.oup.com/zoolinnean/article/136/3/371/2631270 by guest on 31 August 2021 tae), Homilopsocidea, and Psocetae − are presently dendrogram were defined by symplesiomorphic or assigned within Psocomorpha (Table 1). homoplastic characters and his phylogenetic classifi- Roesler (1944) proposed three suborders in Psocop- cation has not been accepted. tera, corresponding to the presently accepted The classifications adopted by Smithers (1996) and Trogiomorpha, Troctomorpha, and Psocomorpha Lienhard (1998) are based on Badonnel (1951) and (= Eupsocida sensu Roesler). In Psocomorpha, he rec- include the previous updates. A few years prior to this ognized three family groups: Epipsocetae, Psocetae Mockford (1993) raised the status of Dasydemellidae, and Caecilietae (= Caeciliusetae). Psocetae and formerly a subfamily of Amphipsocidae, but this was Homilopsocidea of Pearman’s system were included in not followed by Smithers and Lienhard. Psocetae (sensu Roesler). He also grouped or split Within the family groups of Psocomorpha, the fol- some of Pearman’s families, as shown in Table 1. lowing phylogenetic hypotheses have been proposed: The taxonomic system proposed by Badonnel (1951) is a combination of those of Pearman and Roesler. He (1) Pseudocaeciliidae and Calopsocidae comprise a retained all Pearman’s families and family groups, monophyletic group (Smithers, 1967; Thornton & and arranged them into Roesler’s suborders. Smithers, 1984) Badonnel’s system has been widely accepted with only (2) Elipsocidae and Mesopsocidae comprise a mono- two modifications: Smithers (1967) transferred Calop- phyletic group, with Philotarsidae the sister group socidae from Caeciliusetae to Homilopsocidea and (Badonnel & Lienhard, 1988). Mockford (1976) transferred Hemipsocidae from (3) Caeciliusidae, Stenopsocidae, and Amphipsocidae Homilopsocidea to Psocetae. comprise a monophyletic superfamily, Caeciliusoidea, The monograph by Smithers (1972) is the most with Asiopsocidae the sister group (Mockford & García extensive study of the higher classification of Psocop- Aldrete, 1976). tera. He also investigated the phylogenetic relation- (4) Bryopsocidae is the sister group of the clade com- ships among all families and genera of Psocoptera. prising Pseudocaeciliidae and Calopsocidae (Mockford, However, as mentioned above, some lineages in his 1984). © 2002 The Linnean Society of London, Zoological Journal of the Linnean Society, 2002, 136, 371–400 PHYLOGENY OF PSOCOMORPHA (‘PSOCOPTERA’) 373 (5) Closer relationships between Philotarsidae and 4.0b8 (Swofford, 2001). A heuristic search was per- (a) Mesopsocidae or (b) Elipsocidae, are also possible formed with TBR and the addition sequences ‘random’ (Mockford, 1984). options (1000 replications) chosen. Character states (6) Lachesillidae and Elipsocidae may be phylogenetic were optimized using MacClade 4.0 (Maddison & sister groups (Mockford & Sullivan, 1986). Maddison, 2000). The cladogram was translated to (7) Ectopsocus and its close allies appear to be closer a phylogenetic system following the annotated to the lachesillids than to Peripsocus (Mockford, 1972). Linnaean system method (Wiley, 1981). Eertmoed (1973) proposed phenetic relationships for the Epipsocetae group − a classification which has CLADISTIC ANALYSIS become widely accepted. EXEMPLARS In this section, I list the criteria for selecting exem- Downloaded from https://academic.oup.com/zoolinnean/article/136/3/371/2631270 by guest on 31 August 2021 MATERIAL AND METHODS plars from each family with minimum reduction of morphological diversity. Lists of the taxa examined in this study or selected Outgroup exemplars were selected from the remain- from the literature are available at http:// ing two psocopteran suborders, Trogiomorpha and insect3.agr.hokudai.ac.jp/psoco-web/data/index.html. Troctomorpha. As the former is regarded as monophyl- All internet resources in this paper are also available etic and apparently distantly related to Psocomorpha, from the author on request. Terminology mainly fol- only one primitive exemplar, Echmepteryx lunulata, lows Matsuda (1965, 1970, 1976) and Smithers (1991). was selected from it. Mockford (1967) regarded Dried and wet specimens were used for the study. Amphientomidae of Troctomorpha as the sister group For the observation of external structures, the mate- of Psocomorpha and two exemplars, Paramphiento- rial was placed in a 5% solution of KOH at 45°C for mum yumyum and Tineomorpha sp. (from Malaysia), 1–3 h depending on size. It was then washed with dis- were selected from this family because the sister tilled water and stored in 80% ethanol. Dissected group has the strongest effect upon estimating the structures were stained with Delafield’s Hematoxylin, character states of the ingroup node (Maddison et al., then observed and illustrated. For the study of inter- 1984). Two other exemplars, Tapinella sp. (from nal structures, the wet material was dissected in 80% Taiwan) and Troctopsocidae Gen. sp. (from Malaysia), ethanol, and stained with methylene blue. A Leica were selected from other troctomorphan families, each MZ12 stereoscopic microscope was mainly used for of which is regarded as distantly related to Amphien- observation and illustration. For extremely small tomidae. The list, selected on the basis of the four rules structures, the material was slide-mounted in euparal in the preceding section, is as follows: and an Olympus BX50 compound light microscope used for observation and illustration.