Psocodea

Mating pair of Rhyopsocus eclipticus (male on left), copyright Diane Young.

Belongs within: Paraneoptera.
Contains: Psocathropetae, Trogioidea, Lepidopsocidae, Psocomorpha, Nanopsocetae, Amphientometae.

The Psocodea include the barklice, small insects that mostly feed on fungi and other micro-organisms, as well as the true parasitic lice. It is now generally accepted that the latter are a derived subgroup of the former. The most basal division in the Psocodea is between the clades Trogiomorpha and Psocina; Trogiomorpha have antennae with more than twenty segments and a strong posterior spine on the paraproct (the lateral sclerites alongside the anus) whereas Psocina have fewer antennal segments and lack the paraproct spine. Psocina also have the hypopharyngeal filaments fused for at least part of their length whereas they remain separate in Trogiomorpha. Trogiomorpha are divided between the Psocathropetae and Atropetae, with the Atropetae having a short, broad head, a conical sensillum on the inner side of the second segment of the maxillary palp, and no nodulus on the fore wing (if present) (New & Lienhard 2007). Within the Psocina, members of the Troctomorpha lineage have antennae with at least some segments secondarily annulated, wings lacking a pterostigma and often a triangular or T-shaped sclerite on the large subgenital plate (Mockford 1993).

Characters (from Rasnitsyn 2002, for Psocidea): Size small, rarely medium. General appearance highly variable depending on free living or parasitic habit and mode of parasitism. Head with clypeus strongly convex to house cibarial muscles (secondarily less developed in some parasitic forms). Mandible chewing (reverted and thus tearing instead of biting in elephant louse, reduced in sucking lice). Lacinia free of remaining maxilla, rod-like. Hypopharynx with two ovoid sclerites. Pronotum small. Wings often lost, when present roof-like at rest, rather poor in venation, coupled in flight except in some Palaeozoic species with homonomous wings. Legs cursorial or, in parasites, clinging, with tarsus l-3-segmented (4-segmented in some extinct forms). 1st abdominal sternum lost. Ovipositor present or lost. Aedeagus lost in living species. Cercus lost. Extant forms with abdominal ganglia fused in single ganglionic mass and with 4 or less Malpighian tubes. Ovaries polytrophic. Chromosomes holokinetic.

<==Psocodea [Copeognatha, Corrodentia, Psocida, Psocidea, Psocoptera]
    |--Trogiomorpha [Trogiina] Y02
    |    |--Psocathropetae NL07
    |    `--Atropetae [Trogiformia] NL07
    |         |--Trogioidea NL07
    |         |--Lepidopsocidae NL07
    |         `--Psoquillidae [Psoquilloidea] L02
    |              |--Balliella Badonnel 1949 M93
    |              |    `--*B. ealensis Badonnel 1949 M93
    |              |--Psoquilla Hagen 1865 [incl. Heteropsocus Verrill 1902] L02
    |              |    |--*P. marginepunctata Hagen 1865 NL07 (see below for synonymy)
    |              |    `--P. infuscata Badonnel 1949 B49
    |              |--Eosilla NL07
    |              |    |--*E. (Eosilla) jacobsoni Ribaga 1908 NL07
    |              |    `--E. (Empheriella) denervosa NL07
    |              `--Rhyopsocus Hagen 1876 [incl. Deipnopsocus Enderlein 1903, Rhyopsocopsis Pearman 1929] M93
    |                   |--*R. eclipticus Hagen 1876 [incl. R. phillipsae Sommerman 1956] M93
    |                   |--R. afer (Badonnel 1948) [=Deipnopsocus afer] B49
    |                   |--R. bentonae Sommerman 1956 M93
    |                   |--R. bicornis Badonnel 1986 B86
    |                   |--R. disparilis (Pearman 1931) M93 (see below for synonymy)
    |                   |--R. maculosus M93
    |                   |--R. micropterus Mockford 1971 M93
    |                   |--R. orthatus B86
    |                   |--R. pandanicola Thornton, Lee & Chui 1972 NL07
    |                   |--R. peregrinus (Pearman 1929) L98 [=*Rhyopsocopsis peregrina NL07]
    |                   |--R. phillipsae Sommerman 1956 S56
    |                   |--R. spheciophilus (Enderlein 1903) L98 [=*Deipnopsocus speciophilus NL07]
    |                   `--R. texanus (Banks 1930) (see below for synonymy) M93
    `--Psocina R02
         |--Psocomorpha Y02
         `--Troctomorpha [Amphientomiformia, Amphientomomorpha, Troctopsocoidea] Y02
              |--Nanopsocetae YL10
              `--Amphientometae YL10

Psocodea incertae sedis:
  Tshekarcephalus [Tshekarcephalidae] R02
    `--T. bigladipotens R02
  Surijokopsocus [Surijokopsocidae] R02
  Sinopsocus oligovenus Lin 1976 L02
  Diploperipsocus phagococcus Li & Mockford 1993 L02
  Mascaropsocus spinosus Badonnel & Pearman 1971 SN08
  Miotroctes Pierce 1960 YL10
    `--M. rousei Pierce 1960 YL10
  Westphalopsocus Azar, Nel et al. in Nel, Roques et al. 2013 [Westphalopsocidae] NR13
    `--*W. pumilio Azar, Nel et al. in Nel, Roques et al. 2013 NR13
  Zygopsocus [Zygopsocidae] NR13

*Psoquilla marginepunctata Hagen 1865 NL07 [incl. *Heteropsocus dispar Verrill 1902 NL07, M93, P. dispar B49]

Rhyopsocus disparilis (Pearman 1931) M93 [=Deipnopsocus spheciophilus var. disparilis M93, R. spheciophilus disparilis MG56]

Rhyopsocus texanus (Banks 1930) [=Deipnopsocus texanus; incl. R. pescadori García Aldrete 1984, R. squamosus Mockford & Gurney 1956] M93

*Type species of generic name indicated

REFERENCES

[B49] Badonnel, A. 1949. Psocoptères de la Cote d'Ivoire. Mission Paulian-Delamare (1945). Revue Française d'Entomologie 16: 20–46.

[B86] Badonnel, A. 1986. Psocoptères de Colombie (Insecta, Psocoptera). Spixiana 9 (2): 179–223.

[L02] Li F. 2002. Psocoptera of China vol. 1. Science Press: Beijing.

[L98] Lienhard, C. 1998. Faune de France. France et Régions Limitrophes. 83. Psocoptères Euro-Méditerranéens. Fédération Française des Sociétés de Sciences Naturelles: Paris.

[M93] Mockford, E. L. 1993. North American Psocoptera (Insecta). Sandhill Crane Press, Inc.

[NR13] Nel, A., P. Roques, P. Nel, A. A. Prokin, T. Bourgoin, J. Prokop, J. Szwedo, D. Azar, L. Desutter-Grandcolas, T. Wappler, R. Garrouste, D. Coty, D. Huang, M. S. Engel & A. G. Kirejtshuk. 2013. The earliest known holometabolous insects. Nature 503: 257–261.

[NL07] New, T. R., & C. Lienhard. 2007. The Psocoptera of Tropical South-east Asia. Brill: Leiden.

[R02] Rasnitsyn, A. P. 2002. Superorder Psocidea Leach, 1815. In: Rasnitsyn, A. P., & D. L. J. Quicke (eds) History of Insects pp. 125–133. Kluwer Academic Publishers: Dordrecht.

[SN08] Schmidt, E. R., & T. R. New. 2008. The Psocoptera (Insecta) of Tasmania, Australia. Memoirs of Museum Victoria 65: 71–152.

[S56] Sommerman, K. M. 1956. Two new species of Rhyopsocus (Psocoptera) from the U.S.A., with notes on the bionomics of one household species. Journal of the Washington Academy of Sciences 46 (5): 145–149.

[Y02] Yoshizawa, K. 2002. Phylogeny and higher classification of suborder Psocomorpha (Insecta: Psocodea: ‘Psocoptera’). Zoological Journal of the Linnean Society 136: 371–400.

[YL10] Yoshizawa, K., & C. Lienhard. 2010. In search of the sister group of the true lice: a systematic review of booklice and their relatives, with an updated checklist of Liposcelididae (Insecta: Psocodea). Arthropod Systematics and Phylogeny 68 (2): 181–195.

Last updated: 27 August 2020.