PSOCOMORPHA, Roesler, 1944

Yoshizawa, Kazunori, 2002, Phylogeny and higher classification of suborder Psocomorpha (Insecta: Psocodea: ‘ Psocoptera’), Zoological Journal of the Linnean Society 136 (3), pp. 371-400 : 387-394

MONOPHYLY OF PSOCOMORPHA AND RELATIONSHIPS OF INFRAORDERS AND SUPERFAMILIES

Mockford (1967) proposed three autapomorphies supporting the monophyly of suborder Psocomorpha : a hooked nodulus formed by truncated spines fused at their base ( Fig. 34 ); thickened pterostigma; enlargement of mesothorax ( Fig. 17 ). The present analysis strongly supports this monophyly. However the third is not regarded as autapomorphic at the suborder level. The following additional characters were also found to support monophyly: rounded vertex ( Fig. 2 ); absence of stipito-galeal muscle ( Fig. 11 ); presence of proximal minute process at apex of first axillary sclerite ( Figs 29, 30 ); presence of nodus ( Fig. 38 ). By most parsimonious optimization of the character states, two additional character states are regarded as autapomorphies of Psocomorpha : two-segmented tarsus and broad pulvillus. However, these characters are quite variable within the suborder.

Six monophyletic infraorders are recognized in the present analysis ( Table 1), four of which have been widely accepted since Pearman (1936) first established the higher taxonomic system. Two new infraorders, Archipsocetae and Hemipsocetae , are proposed. Both are represented by only one family which was formerly included in Homilopsocidea and Psocetae , respectively ( Table 1).

Archipsocidae is regarded as the basalmost clade of Psocomorpha ( Fig. 75 ). It has long been assigned to Homilopsocidea . However, it possesses the following plesiomorphic character states that exclude it from this infraorder: prothorax strongly bulged dorsally; pterothorax weakly bulged dorsally; narrow membranous region of metaepisternum; posteroproximal corner of forewing angled; proximal median plate mobilized, not fused with second axillary sclerite. Only one derived character state, broad precoxal bridge of mesothorax ( Fig. 23 ), is shared between Archipsocidae and families of Homilopsocidea , and possibly indicates closer relationships between them. However, the musculature associated with the precoxal bridge is completely different ( Figs 20, 21 ) and similarity of the precoxal bridge should be regarded as convergence.

A narrow internal ridge of the epistomal suture and a strongly bulged pterothorax support the monophyly of Psocomorpha , excluding Archipsocidae . The former character is reversed in some families of the suborder ( Elipsocidae , Mesopsocidae , and all families of Caeciliusoidea ). Among the families of Psocomorpha (excluding Archipsocidae ) Hemipsocidae is placed at the basalmost clade. It was regarded as a member of Psocetae based on the following character states: male paraproct with distal process; female paraproct with distal cylindrical projection ( Fig. 54 ); narrow mesothoracic precoxal bridge ( Fig. 22 ). Although the third is plesiomorphic, the first two are apomorphic, and possibly indicate a close relationship between Hemipsocidae and Psocetae . However, as discussed in the next paragraph, monophyly of the clade containing Psocetae (excluding Hemipsocidae ), Homilopsocidea , Epipsocetae , and Caeciliusetae is well supported by stable, or nonhomoplastic autapomorphies. Consequently, the similarities observed between Hemipsocidae and Psocetae are regarded as symplesiomorphies or homoplasies (ambiguous, although the latter is more likely because similar structures are independently derived in some other taxa, such as some species of Lachesilla ).

The remaining infraorders − Psocetae , Homilopsocidea , Epipsocetae , and Caeciliusetae − comprise a monophyletic group and autapomorphies supporting this clade include: (1) the broad membranous region of the metaepisternum ( Fig. 17 ); (2) fusion of the proximal median plate to the second axillary sclerite ( Fig. 32 ); (3) posteroproximal margins of folded forewings separated from each other ( Fig. 32 ). These three character states are hypothesized to have been derived only once, and no convergence or reversals were detected by the present analysis. This is especially significant where (2) is a functionally very important character state for wing folding, and regarded as a reliable autapomorphy, strongly supporting the monophyly of Psocetae + Homilopsocidea + Epipsocetae + Caeciliusetae .

Homilopsocidea + Epipsocetae + Caeciliusetae is supported by only one autapomorphy: divided dorsoventral flight muscle of the mesothorax ( Fig. 20 ). In Psocetae , Hemipsocetae and outgroups, one dorsoventral flight muscle is inserted into the base of the trochantin ( Fig. 19 ). In contrast, dorsoventral flight muscles of Homilopsocidea , Epipsocetae and Caeciliusetae are divided into two, one of which is inserted into the precoxal bridge and the other into the trochantin ( Fig. 20 ). As already discussed above, only one highly homoplastic character may possibly contradict this clade.

Monophyly of Caeciliusetae + Epipsocetae is supported by an elongate and posteriorly hollowed mandible ( Fig. 7 ), ball-shaped galea ( Fig. 9 ), and narrowed or reduced external valve of the gonapophyses. A somewhat triangular labial palpus is also widely observed, possibly providing further evidence of monophyly. Since most synapomorphies supporting Caeciliusetae + Epipsocetae are presumably strongly associated with feeding behaviour, similar structures might easily have occurred independently. However, the members of Caeciliusetae are mostly living-foliage dwellers whereas those of Epipsocetae are found in leaf litter or on stone or bark surfaces. Their food sources are considered to be different, making it difficult to establish that the similarities of mouthparts are convergences associated with function. Consequently, similarities of mouthparts observed between Caeciliusetae and Epipsocetae are regarded here as synapomorphic.

Infraorder Archipsocetae

Archipsocidae is the only representative of this infraorder, distributed in tropical regions. Monophyly is strongly supported by the following autapomorphies: broad precoxal bridge and related unique musculature ( Fig. 21 ); forewing veins and membrane covered with long setae ( Fig. 35 ); forewing marginal crossing setae ( Fig. 35 ); reduction of venation ( Fig. 35 ); absence of preapical tooth on pretarsal claw ( Fig. 27 ); lack of parameres; absence of ventral valve of gonapophyses ( Fig. 68 ). Monophyly is also well supported by their behaviour. All known species of this family live on bark or dead leaves beneath webbing sheets in groups and subsociality is also known ( New, 1987). External appearance is very similar.

Infraorder Hemipsocetae

The family Hemipsocidae is the only representative of this infraorder. It is a small family, recorded from all zoogeographical regions, but its distribution is restricted to tropical or warm areas. All species are dead-foliage dwellers. Monophyly is strongly supported by: absence of the epistomal suture; apically broadened first axillary sclerite; two-branched M vein (not used for analysis), and CuA 1 –M crossvein ( Fig. 40 ). Although absence of aedeagus ( Fig. 44 ) does not unambiguously support this clade, this character state is possibly an additional autapomorphy.

Infraorder Psocetae

Includes three families, Psilopsocidae , Psocidae , and Myopsocidae , all of which are bark or stone surface dwellers. Monophyly is well supported by: the ctenidia-based broad setae on the hind tibiae ( Fig. 25 ); bare fore- and hindwings ( Fig. 36 ), and single-lobed egg guide extended from the ventral margin of the subgenital plate ( Figs 52, 55 ).

Mockford (1961) assigned Psilopsocidae , one of the least known and controversial families, to Psocetae . Psilopsocidae shares the above-mentioned apomorphic character states with Psocidae and Myopsocidae , and can apparently be included in this infraorder.

The areola postica of Psilopsocidae is always separate from the M vein, whereas it is connected with it in Psocidae and Myopsocidae ( Fig. 36 ). The latter state is apomorphic, and possibly supports the monophyly of Psocidae + Myopsocidae . However, a fossil species of Myopsocidae in which the areola postica is separate is known ( Mockford, 1996); if the venation of the fossil specimen represents the ancestral condition, monophyly is not justified. However, three apomorphic character states − paramere absent ( Fig. 45 ); dorsal valve of gonapophyses with ventral swelling ( Fig. 62 ); gonapophyses and egg guide forming the ovipositor − are shared by Psocidae and Psilopsocidae , and support their sister-group relationship.

Psilopsocidae contains only one genus and seven named species. Smithers (1995a, b, 1997) reported a unique and characteristic nymphal wood-boring behaviour in final instar nymphs of Psilopsocus mimulus . In addition, all psilopsocid species of which the nymphal stage is known possess a more or less sclerotized abdominal tip, and thus all are probably woodborers ( Smithers, 1995a). If this behaviour is widely observed throughout the family, monophyly is strongly supported by this highly derived behaviour and associated morphological characters. In the present analysis, a rounded aedeagus was considered to be an autapomorphy of this family.

Psocidae is one of the largest families of Psocoptera , distributed in all zoogeographical regions. Monophyly is supported by the following autapomorphic character states: presence of an articulation between hypandrium and clunium ( Fig. 42 ); presence of the posterior lobe of the external valve of the gonapophyses ( Fig. 55 ). Position of anterior tentorial pit and shape of pulvillus may possibly support the monophyly, but they are highly homoplastic.

Myopsocidae is distributed in all zoogeographical regions. The very long dorsal valve of the gonapophyses ( Fig. 54 ) supports monophyly. Although forewing markings were not used for this analysis, those of this family are unique and characteristic ( Fig. 36 ), and possibly provide further evidence supporting monophyly. Male genital characters show great diversity among genera and, as mentioned by Mockford (1961), male genital structures of some myopsocid genera are similar to those of Psilopsocidae , and may possibly support their sister-group relationship. To confirm Mockford’s findings, a transformation series of male genital characters within the family must be undertaken.

Infraorder Homilopsocidea

This infraorder contains ten families assigned to four superfamilies. When Pearman (1936) first proposed Homilopsocidea , he expressed some doubts about its soundness. Badonnel (1951) also found the infraorder to be heterogeneous. Mockford (1976) transferred Hemipsocidae to Psocetae . Later, Mockford (1993) stated that “with the hemipsocids excluded, it seems to consist of a series of related families except that the peripsocid stand apart from the others, especially in structure of male genitalia” ( Fig. 48 ).

The present cladistic analysis shows that this infraorder comprises related families except Archipsocidae which is here assigned to its own infraorder and stands apart from Homilopsocidea . Peripsocidae is here assigned to Homilopsocidea ; the specialized male phallosome of the family is apparently an autapomorphic modification and thus provides no information about its phylogenetic position.

Monophyly is supported by the following two apomorphic character states: presence of egg guide extending from dorsodistal margin of the subgenital plate ( Fig. 51 ) and the dorsal swelling of the dorsal valve of the gonapophyses ( Figs 65−67 ).

Elipsocidae is regarded here as the sister group of all remaining homilopsocid families. Badonnel & Lienhard (1988) suggested a sister-group relationship between Elipsocidae and Mesopsocidae based on the reduction of wing setae. Specifically, hindwing margins of both families are bare except between R 2+3 and R 4+5 ( Fig. 40 ). This condition is apomorphic but highly homoplastic, and similar conditions are observed also in Stenopsocidae and Dasydemellidae (Caeciliusetae) . Moreover, when the entire hindwing margin is setose, marginal setae between R 2+3 and R 4+5 are usually stronger than those in other sections (e.g. Trichopsocidae ). Forewing ciliation of Elipsocidae is plesiomorphic. Monophyly of the clade containing the remaining homilopsocid families (including Mesopsocidae ) is supported by an apomorphic character state which is more reliable than wing ciliation: presence of rod-like sclerites on the endophallus ( Fig. 46 ). Thus, the similar condition of hindwing marginal setae observed in Elipsocidae and Mesopsocidae should be regarded as homoplasy.

The remaining families are divided into two clades: Lachesilloidea and Trichopsocidae + Pseudocaeciliidae + Calopsocidae + Bryopsocidae + Peripsocidae + Philotarsidae + Mesopsocidae . Monophyly of the latter is supported by a sclerotized dorsal valve and ventral and dorsal valves of the gonapophyses tightly united to form the ovipositor ( Fig. 55 ). These character states are unique, and observed throughout all taxa within the clade. The latter clade also comprises two monophyletic groups, Pseudocaecilioidea and Peripsocoidea . Monophyly of each superfamily is discussed below.

Superfamily Elipsocoidea

The family Elipsocidae is the only representative of this superfamily, distributed in all zoogeographical regions, and all members are bark or stone surface dwellers.

Elipsocidae mostly retains the plesiomorphic conditions of the Homilopsocidea . Monophyly is supported by three character states: broad internal ridge of the epistomal suture ( Fig. 3 ), hindwing marginal setae restricted between R 2+3 and R 4+5, and three-segmented tarsus. The latter character state is extremely homoplastic. Male and female genital structures are very similar throughout Elipsocidae , but some are plesiomorphic and the polarity of others remains uncertain. Further study is therefore required to confirm the monophyly.

Superfamily Lachesilloidea

Monophyly is supported by three apomorphic character states: elongate preepisternum of prothorax ( Fig. 16 ), bare hindwing margin, and narrowed external valve of gonapophyses ( Fig. 68 ). The systematic position assigned for Eolachesilla by previous authors has been controversial: Lachesillidae ( Badonnel, 1967; Mockford & Sullivan, 1986) or Elipsocidae ( New & Thornton, 1981). The present analysis suggests a closer relationship between the genus and Lachesillidae , rather than Elipsocidae .

Ectopsocidae is distributed in all zoogeographical regions. Monophyly is strongly supported by the following autapomorphies: absence of areola postica in forewing ( Fig. 38 ); hindwing Rs and M connected by crossvein ( Fig. 38 ); presence of ball-shaped lobe on meta-epimeron (not used in the analysis); absence of preapical tooth of pretarsal craws.

Lachesillidae is also distributed in all zoogeographical regions. Monophyly of the family excluding Eolachesilla is strongly supported by: the position of anterior tentorial pit, the absence of the ventral valve of the gonapophyses and reduction of the dorsal valve of the gonapophyses ( Fig. 68 ). Eolachesilla lacks these apomorphic character states and monophyly including Eolachesilla is therefore uncertain. In this paper, this genus is declared incertae sedis, and it should be noted that Eolachesilla may represent its own family.

Superfamily Pseudocaecilioidea

Monophyly of Trichopsocidae + Pseudocaeciliidae + Calopsocidae is supported by: apically broadened first axillary sclerite ( Fig. 15 ); position of the anterior tentorial pit; forewing veins with two rows of setae, and absence of preapical tooth. The latter three characters are highly homoplastic. Presence of eversible vesicles on the abdomen may also provide further support for this superfamily, although the state of this character is ambiguous at the basal node of the clade. The male phallosome and female gonapophyses of these three families are similar but they are symplesiomorphic. Trichopsocidae , Pseudocaeciliidae , and Calopsocidae are all living-foliage dwellers. This feature is apomorphic, and provides further evidence for the monophyly of the Pseudocaecilioidea .

The present analysis posits that within Pseudocaecilioidea , Pseudocaeciliidae and Calopsocidae comprise a monophyletic group. Smithers (1967) suggested close affinity of these families but later ( Thornton & Smithers, 1984) doubted this, mentioning that similarities between them were largely due to their retention of primitive features, the two synapomorphies being bilobed subgenital plate and twosegmented tarsi. Most of shared characters suggested in the earlier paper are plesiomorphic or homoplastic, including the two character states that Thornton & Smithers (1984) suggested as apomorphic. Monophyly is well supported by the following character states: crossing marginal setae of forewing ( Fig. 37 ); hindwing veins with one row of setae; presence of an articulation between clunium and hypandrium ( Fig. 43 ); presence of hypandrial lateral bristles ( Fig. 43 ); ventral valve of gonapophyses with dorsal lobe ( Fig. 66 ).

Trichopsocidae is a small family, containing one genus and eight species, distributed in all zoogeographical regions except the Orient. Monophyly is supported by secondary loss of the distal extension of the subgenital plate. An additional apomorphic feature, hindwing Rs and M + Cu separate basally ( Fig. 37 ), is observed in one exemplar, but it is uncertain whether this character state is widely observed throughout this family.

Pseudocaeciliidae is the largest family among Homilopsocidea , and is distributed in all zoogeographical regions. No autapomorphy supporting monophyly was found in the present study. Thus, the family is regarded here as a paraphyletic group. Calopsocidae is regarded as a highly specialized clade within it. I declare the family Pseudocaediliidae incertae sedis, and further phylogenetic study of Pseudocaeciliidae + Calopsocidae is required to confirm their relationships.

Calopsocidae is known only from the Oriental and Melanesian regions. Monophyly is well supported by a sharply angled vertex that is deeply emarginated medially, and presence of numerous secondary veins in the forewing (not used in the analysis). A somewhat elongate mandible, ball-shaped galea, and presence of a preapical tooth on the pretarsal claw also support monophyly.

Superfamily Peripsocoidea

Monophyly is supported by the following apomorphic character states: single-lobed egg guide ( Fig. 59 ); strongly sclerotized and square-shaped dorsal valve of the gonapophyses ( Fig. 67 ).

The family Bryopsocidae is represented by one species, Bryopsocus townsendi ( Smithers, 1969) , known from New Zealand. Smithers (1969) originally described the species under the genus Austropsocus of the family Philotarsidae . Thornton, Wong & Smithers (1977) subsequently erected a new genus, Bryopsocus , in the family Philotarsidae , designating A. townsendi as type species of the genus. Mockford (1984) extensively studied philotarsid and pseudocaeciliid genera, and concluded that Bryopsocus is intermediate between Philotarsidae and Pseudocaeciliidae . Thus, he founded the monotypic family Bryopsocidae for the genus, and considered it to be the sister group to Pseudocaeciliidae + Calopsocidae . This conclusion was based on ‘extent of character sharing’ ( Mockford, 1984) but he did not discuss their polarity.

Judging from published descriptions and illustrations, Bryopsocidae possesses all the apomorphies supporting the monophyly of Homilopsocidea . One character state, dorsal extension of the subgenital plate (character 55), is difficult to assess from published illustrations, but a transverse line was clearly drawn near the base of the egg guide ( Smithers, 1969; fig. 192) which most probably indicates that the egg guide extends from the dorsal surface. Thus, the family is regarded as a member of Homilopsocidea .

Bryopsocidae also appears to share the apomorphies of Peripsocoidea listed above. These character states are not observed in Pseudocaecilioidea . However, Bryopsocidae has long rod-like sclerites on the endophallus that are similar to those of Pseudocaeciliidae and Calopsocidae . This may suggest closer affinities, as suggested by Mockford (1984). However, similar structures are also observed in some taxa within Lachesilloidea and Peripsocidae and, consequently, similarity of the endophallic sclerites observed in Bryopsocidae and Pseudocaeciliidae should be regarded as a symplesiomorphy. Thus, Bryopsocidae is regarded as a member of this superfamily.

Within the Peripsocoidea , Bryopsocidae occupies the basalmost clade. Monophyly of Peripsocidae + Philotarsidae + Mesopsocidae is well supported by a squareshaped female epiproct ( Fig. 50 ). Bryopsocidae shares three-segmented tarsi with Philotarsidae and Mesopsocidae , although this character state is highly homoplastic.

In the present analysis, phylogenetic relationships among Peripsocidae , Philotarsidae , and Mesopsocidae were not resolved because no decisive autapomorphy supporting the clade comprising two of the three families was detected. However, as discussed above, state 1 of character 39 and state 1 of character 48 can be regarded as autapomorphies supporting the monophyly of Philotarsidae + Mesopsocidae .

Peripsocidae is distributed in all zoogeographical regions. Members are mostly bark or stone surface dwellers, but some are collected from dead foliage. Monophyly is well supported by absence of areola postica in the forewing ( Fig. 38 ) and strap-like paramere ( Fig. 48 ). Because of the first character, Peripsocidae was once classified with Ectopsocidae , but is only distantly related to it.

Philotarsidae is distributed in all zoogeographical regions. Members are all bark or stone surface dwellers. Monophyly is supported by only one decisive apomorphic character, presence of ventral setae on the forewing. Position of the anterior tentorial pit, crossing marginal setae of forewing, more than one row of setae on forewing veins, and apically rounded aedeagus possibly provide further evidence of monophyly, but they are highly homoplastic or their states at the basal node of the family are ambiguous.

Mesopsocidae is widely distributed in all zoogeographical regions and is particularly abundant in the Afrotropical and Palearctic regions. Members are mostly bark or stone surface dwellers, although one species is known to be associated with termites. Monophyly is supported by the following apomorphic character states: broad internal ridge of the epistomal suture; glabrous fore- and hindwings; apically broadened ventral valve of the gonapophyses ( Fig. 67 ).

Infraorder Epipsocetae

Monophyly is well supported by the following apomorphic character states: anterior tentorial pit separated from ventral margin of cranium ( Fig. 5 ); labrum with a pair of longitudinal sclerotized lines ( Fig. 5 ); forewing veins with more than one row of setae ( Fig. 39 : reversed in Epipsocidae ); presence of A 2 vein ( Fig. 39 : reversed in Epipsocidae ); hindwing veins with two rows of setae ( Fig. 39 ); dorsal and external valves of gonapophyses (partly) fused ( Fig. 63 ). A long gena and broad lacinial tip possibly support monophyly, but these continuous, quantitative characters were not used for the analysis.

Spurostigma of the family Cladiopsocidae is regarded as the basalmost clade of the infraorder, and monophyly of Epipsocetae excluding Spurostigma is supported by one stable autapomorphy, forewing veins Rs and M connected by a crossvein.

Ptiloneuridae is regarded as the second basalmost clade of Epipsocetae . The family is known from the Afrotropical, Nearctic and Neotropical regions. Monophyly is supported by three, highly homoplastic character states: epistomal suture absent dorsally, presence of ventral setae of forewing, and threesegmented tarsus. Although not used for the cladistic analysis, highly modified male genital structures appear to be autapomorphic. However, they are extremely variable within the family and thus it is very difficult to decide their homology. I have examined only two species of this family and further morphological study of the male genitalia will provide further support for the validity of the autapomorphy.

The remaining exemplars, Epipsocidae , Dolabellopsocidae and Cladiopsocus of the family Cladiopsocidae , comprise a monophyletic group; a stable autapomorphy, complete fusion of external and dorsal valves of the gonapophyses, supports its monophyly. Within this clade, Epipsocidae and Dolabellopsocidae are considered to comprise a subclade, supported by only one autapomorphy: absence of ventral valve of gonapophyses. This feature is considered as derived independently three times in Psocomorpha .

Dolabellopsocidae is known only from the Neotropical region. Monophyly is supported by only one, highly homoplastic, character state, broad pulvillus. Diagnostic characters proposed by Eertmoed (1973) are mostly plesiomorphic, highly homoplastic or not consistent within the family. Further studies are required to confirm its validity.

Epipsocidae is distributed in all zoogeographical regions. Monophyly is supported by three autapomorphies: epistomal suture absent dorsally, absence of A 2 vein in forewing, and presence of ventral setae of forewing.

Cladiopsocidae also is known only from the Neotropical region. As discussed above, the family is regarded as polyphyletic in the present analysis and character states suggesting nonmonophyly can be regarded as stable. In contrast, diagnostic characters proposed by Eertmoed (1973) are mostly plesiomorphic, highly homoplastic or not consistent within the family. As the present analysis strongly suggests polyphyly I postpone division and declare it incertae sedis because I have examined only two species. Cladiopsocidae probably will be divided into at least two independent families in a future study.

Infraorder Caeciliusetae

Monophyly is supported by the following apomorphic character states: elongate preepisternum of prothorax ( Fig. 16 ); campaniform sensilla on the radius divided into two groups; absence of preapical tooth of the pretarsal claw; reduction of external valve of the gonapophyses.

Superfamily Asiopsocoidea

This superfamily is represented by only one bark dwelling family, Asiopsocidae , known from the Nearctic, Neotropical and Palearctic regions. Although it does not have to be established to translate the cladogram to the Linneaean system, I herein maintain this widely accepted superfamily. Monophyly is supported by two unique apomorphic character states, broadened subapical region of the lacinia ( Fig. 12 ) and reduced and membranous dorsal valve of the gonapophyses.

Superfamily Caeciliusoidea

This superfamily comprises three families: Stenopsocidae , Amphipsocidae , and Caeciliusidae . A welldeveloped internal ridge of the epistomal suture and presence of abdominal eversible vesicles support monophyly. The derived male and female external genitalia are remarkably uniform throughout, and most possibly indicate closer relationships among caeciliusioid families. Members are living-foliage dwellers, providings further evidence of monophyly.

Phylogenetic relationships are very difficult to establish because of uniformity of external characters throughout the superfamily. As mentioned by Mockford (1978), the external genitalia are remarkably uniform. However, the external valve of the gonapophyses of Dasydemellinae is rather well developed, whereas it is greatly reduced in the other taxa. The former character state is regarded as autapomorphic in the present analysis, although it does not, unfortunately, provide information about interfamilial phylogenetic relationships. Only one highly homoplastic character state, presence of ventral setae on the forewing, supports the monophyly of Amphipsocidae s.l. + Caeciliusidae .

Stenopsocidae is distributed in the Afrotropical, Palearctic, Oriental, and Australian regions. Monophyly is well supported by the presence of the R 1 –R 2+3 crossvein ( Fig. 40 ), M–CuA 1 crossvein ( Fig. 40 ), and lateral pouch of the spermathecal sac ( Fig. 40 ).

Mockford (1993) raised the status of Dasydemellidae from subfamilial level within the Amphipsocidae . Monophyly of Amphipsocidae s.l. is supported by apomorphic ciliation of the forewing and a pair of concavities on the vertex. Autapomorphy was found for Dasydemellinae and monophyly of Amphipsocinae is also supported by apomorphic ciliation of the hindwing. In the present analysis, Kodamaius , which has been assigned at various times to Amphipsocidae ( Smithers, 1990) , Stenopsocidae ( Smithers, 1972; Badonnel, 1981) and Caeciliusidae ( Mockford, 1993, 1999; Yoshizawa, 1997), is assigned to the clade comprising Dasydemellinae and Amphipsocinae but included in neither. Thus, there are two options for the taxonomic treatment of these taxa: either all three should be placed within a single family or treated as independent. A morphological gap is observed between Dasydemellinae and the other taxa, especially in the shape of the external valve of the gonapophyses. As mentioned above, the taxonomic position of Kodamaius was ambiguous due to its unique forewing venation. However, these morphological gaps cannot be considered as evidence of family level hierarchy, because the external valve, similar to that of Dasydemellinae , is also observed in some species of Stenopsocidae and forewing venation is variable within Amphipsocinae . Therefore, it is more practical to treat the taxa as a single family, Amphipsocidae s.l. (Yoshizawa, 2001). Members are widely distributed in all zoogeographical regions.

Caeciliusidae is the largest family of Psocomorpha , and is widely distributed in all zoogeographical regions. Monophyly was not supported by any autapomorphy. Mockford (1978, 1999) proposed some apomorphic character states but they were not confirmed in the present study or are too homoplasious. The family is possibly paraphyletic. I declare it incertae sedis until the phylogenetic relationships within it can be established.

Figures

Figure 75. Phylogenetic relationships among families of Psocomorpha. Monophyly of shaded bar is not supported.

Figures 28–34. (28–30) right first axillary sclerite of Paramphientomus sp. (28), Peripsocus quercicola (29) and Pseudocaecilius kagoshimensis (30); (31–32) mesothorax and forewing of Hemipsocus chloroticus (31) and Psococerastis nubila (32), dorsal view; (33–34) nodulus of Paramphientomum sp. (33) and Psococerastis nubila (34). Abbreviations: 2ax = second axillary sclerite; dmp = distal median plate; fw = forewing; pmp = proximal median plate.

Figures 15–27. (15–16) prothorax of Psococerastis nubila (15) and Ectopsocus sp. (16), lateral view; (17) thorax of P. nubila, lateral view; (18) metapleuron of Hemipsocus chloroticus, lateral view; (19–21) mesothoracic dorso-ventral flight muscle of Paramphientomum sp. (19), Stenopsocus sp. (20) and Parachipsocus pacificus (21); (22–23) mesothoracic precoxal bridge and trochantin of Psococerastis nubila (22) and S. sp. (23); (24–25) apex of hind tibia of S. sp. (24) and Psocus sp. (25); distal tarsomere and claws of Psocus sp. (26) and S. sp. (27). Abbreviations: aes = anepisternum; cx = coxa; em = epimeron; es = episternum; kes = katepisternum; pb = precoxal bridge; pes = preepisternum; tr = trochantin.

Figures 1–14. (1–5) Head of Echmepteryx lunulata (1) and Psococerastis nubila (2), lateral view; E. lunulata (3), P. nubila (4) and Epipsocopsis sp. (5), anterior view; (6–7) mandible of P. nubila (6) and Matsumuraiella radiopicta (7), anterior view; (8–12) maxilla of P. nubila (8) and M. radiopicta (9), lateral view; Paramphientomum sp. (10) and P. nubila (11), showing muscles attached to galea, anterior view; Notiopsocus aldretei (12), showing apex of lacinia; (13–14) labium of P. nubila (13) and Stenopsocus sp. (14), posterior view. Abbreviations: ata = anterior tentorial arm; cly = clypeus; fr = frons; g = galea; l = lacinia; lr = labrum.

Figures 35–40. Fore– (left) and hindwing (right) of Pararchipsocus pacificus (35), Lichenomima muscosa (36), Philotarsus quercicola (37), Ectopsocus sp. (38), Triplocania spinosa (39) and Stenopsocus sp. (40). Abbreviations: ap = areola postica; ps = pterostigma.

Figures 49–60. (49–50) female epiproct of Elipsocus abdominalis (49) and Haplophallus sp. (50), dorsal view; (51–55) female genitalia of E. abdominalis (51), Psocidus sp. (52) and Stenopsocus sp. (53), lateral view, Lichenomima muscosa (54) and P. sp. (55), ventral view; (56–59) apex of subgenital plate of E. abdominalis (56), Ectopsocus sp. (57), Heterocaecilius fuscus (58) and Mesopsocus unipunctatus (59); (60) spermatheca of Stenopsocus sp. Abbreviations: epr = epiproct; dv = dorsal valve; ev = external valve; pp = paraproct; sg = subgenital plate; vv = ventral valve.

Figures 61–68. Gonapophyses of Hemipsocus chloroticus (61), Psocus sp. (62), Triplocania spinosa (63), Amphipsocus mangifera (64), Elipsocus abdominalis (65), Heterocaecilius fuscus (66), Mesopsocus unipunctatus (67) and Lachesilla sp. (68), ventral view. Abbreviations: dv = dorsal valve; ev = external valve; vv = ventral valve.

Figures 41–48. (41–43) male genitalia of Idatenopsocus orientalis (41) and Trichadenotecnum sexpunctatum (42), lateral view, and Heterocaecilius fuscus (43), posterior view; (44–48) phallosome of Hemipsocus chroloticus (44), Psocus sp. (45), Het. fuscus (46), Haplophallus sp. (47) and Peripsocus quercicola (48). Abbreviations: a = aedeagus; cl = clunium; ep = endophallus; hy = hypandrium; pp = paraproct; pr = paramere.