FAMILIES OF PSOCOPTERA OF BRITISH COLUMBIA

by
R. A. Cannings and G. G. E. Scudder 
Copyright © 2005 - All rights reserved

Key to Families of Psocoptera

1. Antennae with more than 18 flagellomeres; hypopharyngeal filaments separate, never fused on midline; labial palp with minute basal segment, and rounded distal segment; tarsi 3-segmented (Suborder TROGIOMORPHA).............. 2

- Antennae with fewer than 19 flagellomere; hypopharyngeal filaments fused on midline for at least part of their length; labial palp as above, or with no basal segment .....................................................................................................3

2. Body and forewings covered with scales........................... LEPIDOPSOCIDAE

- Body and forewings not covered with scales.................................... TROGIIDAE

3. Antennae with 13 flagellomeres (rarely fewer); at least some flagellomeres annulated with cuticular sculpture ; labial palp usually with minute basal segment, and rounded distal segment; tarsi usually 3-segmented; males apterous, females apterous or macropterous, forewing, when present, folded flat over back at rest and lacking sclerotized pterostigma
.......................(Suborder TROCTOMORPHA, Family LIPOSCELIDIDAE) - Not recorded in BC so far

- Antennae with 11 flagellomeres (rarely fewer); flagellomeres never annulated, although sometimes with reticulate sculpturation: labial palp without basal segment, consisting of single rounded or triangular segment; tarsi 2- or 3-segmented; forewings usually present, and with sclerotized pterostigma (Suborder PSOCOMORPHA).................................................................. 4

4. Labrum with a pair of line-like sclerotizations running lengthwise, and continuing laterally and onto lateral labral margin; mandibles elongate, excavate posteriorly; tarsi 2-segmented, with claws of fore tarsus each with a preapical denticle............................................................................... EPIPSOCIDAE

- Labrum lacking a pair of longitudinal line-like sclerotizations, but sometimes with a pair of pigmented lines in the same position; if mandibles elongate and excavate, then claws of fore tarsus lacking a preapical denticle.................... 5

5. Mandibles usually elongate and excavated posteriorly; claws of fore tarsus lacking a preapical denticle..................................................................................... 6

- Mandibles short, not excavated posteriorly; claws of fore tarsus usually with a preapical denticle ........................................................................................9

6. Forewing pterostigma with R2+3 crossvein and M-Cula crossvein present; hindwing without setae, or with a few restricted to cell R3 ......................................................................................STENOPSOCIDAE

- Forewing pterostigma with R2+3 crossvein absent, Cula usually free from M, but occasionally fused to M .............................................................................7

7. Ciliation of hindwing margin restricted to cell R3, or absent; fourth segment of maxillary palp longer than second segment; spine on free margin of paraproct relatively large ............................................................ DASYDEMELLIDAE

- Hindwing margin ciliated, except for basal 2/3 of front margin; fourth segment of maxillary palp shorter than or equal in length to second segment; spine on free margin of paraproct small or absent............................................................. 8

8. Setae on veins in distal half of forewing on both dorsal and ventral surface; fourth segment of maxillary palp equal in length to second segment ....................................................................................AMPHIPSOCIDAE

- Setae on veins in distal half of forewing only on dorsal surface; fourth segment of maxillary palp shorter than second segment ...........................CAECILIIDAE

9. Meso-precoxal bridges narrow; meso-trochantius wide basally; vein Cula in forewing usually joined to M, before latter branches into 3, rarely joined by short crossvein; bark inhabiting forms with 2-segmented tarsi
................................................................................................. PSOCIDAE

- Meso-precoxal bridges wide (except in some brachypterous forms; meso-trochantius narrow throughout; vein Cula in forewing absent or not joined to M ..................................................................................................................10

10. Setae of median cell margins of forewing in two series forming crossing pairs; micropterous and brachypterous individuals with numerous, long, backward-directed setae on vertex and thoracic dorsum..................... PHILOTARIDAE

- Crossing pairs of setae absent on median cell margins; forms with reduced wings only moderately ciliate, never with numerous long, backward directed setae on vertex and thoracic dorsum........................................................................ 11

11. Tarsi 2-segmented; forewing with vein Cula present and usually free from M; wings generally unciliated or lightly ciliated ........................LACHESILLIDAE

- Combination of characters not as above ............................................................12

12. Distal inner labral area with 9 or 11 sensilla, or if with only 5, then tarsi 3-segmented .................................................................................................13

- Distal inner labral area with only 5 sensilla; tarsi 2-segmented ............................14

13. Distal inner labral area with 9 sensilla; tarsi 3-segmented; forewing with vein Cula present and free from M; wings often much reduced in females ........................................................................................MESOPSOCIDAE

- Distal inner labral area with 11 sensilla, or if with 5, then tarsi 3-segmented; wings usually with some ciliation; vein Cula in forewing either present or absent, but when present usually free from M, although rarely fused to M a short distance; wings sometimes greatly reduced ........................ .................ELIPSOCIDAE

14. Third valve of ovipositor broad; subgenital plate in female with single distal process (‘egg guide’); endophallus of male with a single pair of sclerites or a median forked sclerite ....................................................... PERIPSOCIDAE

• Third valve of ovipositor slender, sometimes short and thumb-like; subgenital plate in female with 2 distal processes; endophallus of male with several complex sclerites ........................................................... ECTOPSOCIDAE

 

Description of Families

Suborder TROGIOMORPHA

Family LEPIDOPSOCIDAE

Adults generally with wings, these pointed especially when fully developed. Body and forewings generally covered with scales, but occasionally with dense setae. The antennae have more than 18 flagellomeres. The mouthparts have the hypopharyngeal filaments separate, never fused in the midline. The maxillary palp has a forked sensillum on the terminal segment. The labial palp has a minute basal segment, and a rounded distal segment.

The forewings lack a sclerotized pterostigma, but have veins Cu2 and 1A ending separately on the wing margin. The forewings also have vein R1 usually reuniting with vein Rs distally by a crossvein or a short fusion. The R vein is faint near the wing base, and vein Cu1 branches a short distance beyond its separation from vein M. The hindwings have two M veins, arising separately or together from the Rs-M stem.

The tarsi are 3-segmented. The ovipositor in the female lacks the first valvulae, and the second valvulae are short or absent.

Worldwide there are 15 genera and 144 species. twelve species in five genera occur in North America. Two species in two genera so far are reported from Canada, but none of these are known from British Columbia. However, an additional species, Pteroxanium kelloggi (Ribaga) can be expected to occur in the province in coastal areas. This species, in which only brachypterous forms are known, occurs along the Pacific Coast from San Francisco Bay north to the Olympic Peninsula in Washington. It has been found on trunks and branches of conifers and broad-leaf trees, in dead fern leaves, and in dead plant material under stones. P. kelloggi has the fore winglets reaching the basal half of the abdomen, the head has longitudinal purplish bars through each parietal region, and the antennae have 30 flagellomeres.

Family TROGIIDAE

Adults in this family have the wings reduced to small flattened pads which lack venation, or they may be absent altogether. The body and winglets lack scales, but may have abundant setae. The antennae have more than 18 flagellomeres. The mouthparts have the hypopharyngeal filaments separate, never fused in the midline. The labial palps have a minute basal segment, and a rounded distal segment. The tarsi are 3-segmented, with the fore tarsal claws lacking a preapical tooth. The ovipositor of the female has distinct second and third valvulae.

Worldwide there are five genera and 24 species. There are four genera and seven species of Trogiidae in North America. In Canada, two species, Cerobasis questfalica (Kolbe) and Lepinotus reticulatus Enderlein have been recorded in British Columbia. Both have the forewings represented by small winglets. Those of L. reticulatus have a reticulate pattern, hence the specific name. The forewings of Cerobasis questfalica are no more than minute buttons, which just reach the metathorax.

C. questfalica occurs in coastal areas on a variety of trees and shrubs, as well as on stone outcrops. It has 6-9 spurs on the first segment of the hind tarsus, and there is no forked sensillum on the last segment of the maxillary palp. Most populations are parthenogenetic.

Lepinotus reticulatus, which has a worldwide distribution, is pale straw-brown in colour and occurs in a great variety of habitats, including ground litter, birds and mammal nests and granaries. The first segment of the hind tarsus lacks spurs, but the last segment of the maxillary palp has a forked sensillum. It is an obligate parthenogenetic species.

Suborder PSOCOMORPHA

Family AMPHIPSOCIDAE

In this family the head has the inner clypeal shelf broad. The labrum has five distal inner sensillae, lacks central longitudinal sclerites, and also lacks labral stylets. The mandibles are elongate, and excavate posteriorly. The lacinia has a slender, bicuspid tip. The maxillary palp has the fourth segment longer than the second.

The tarsi of the legs are 2-segmented, and the claws of the forelegs lack a preapical denticle. The setae on the veins in the distal half of the forewing are present on both the dorsal and ventral surfaces. These setae on the veins of the forewing are upright, relatively long, and in more than one rank on at least some veins other than the costal vein. The forewings have a pterostigma, but the pterostigma R2+3 crossvein is absent, and vein Cula is usually free from vein M1.

The margin of the hindwings is mostly ciliated, except for the basal two-thirds of the front margin. The pine on the free margin of the paraproct is small or absent.

Worldwide there are 10 genera and 90 species. A single species, Polypsocus corruptus (Hagen) occurs in British Columbia along the Pacific Coast and in eastern North America. This is the only species of Amphipsocidae in North America, and little is known about its biology.

Family CAELIIDAE

Head with the inner clypeal shelf variable in shape. Hypopharyngeal filaments fused in midline for at least part of length. Antennae with no more than 11 flagellomeres. Mandibles elongate and excavate posteriorly. Labrum distally with 5 to 7 inner sensillae. Lacinia with tip variable in shape. Maxillary palp with fourth segment shorter than second.

Forewings with pterostigma, but lacking a pterostigma - R2+3 crossvein, the vein Cula usually being free from the Median vein. Setae on forewing veins slanting towards the apex, relatively short, and usually in one rank except on the costal vein. The setae on the veins in the distal half of the forewing are present only on the dorsal surface. The hindwings have ciliated margins, except for the basal two-thirds of the front margin.

The tarsi are 2-segmented, with the tarsi of the forelegs lacking a preapical denticle. Ventral abdominal resides are present, and the spine on the free margin of the paraproct is small or absent.

Worldwide there are 17 genera and 355 species. Two genera and 31 species occur in North America. Both of these genera are recorded in Canada and British Columbia. So far 10 species are reported in Canada, and six of these are known from British Columbia. Caelilius confluens (Walsh) has been collected on Scotch broom (Cytisus scoparius (L.) Link) in Vancouver, while C. perplexus Chapman and Xanthocaecilius quillayute (Chapman) occur usually on conifers, but also occasionally on broad-leaf trees.

Family DASYDEMELLIDAE

Head with the inner clypeal shelf broad, and hypopharyngeal filaments used in the midline for at least part of length. The antennae have no more than 11 flagellomeres. The labrum with five distal inner sensillae, lacks central longitudinal sclerites, and labral stylets are absent. The mandibles are elongate, and excavate posteriorly. The lacinia has a broad and flat tip or it is only slightly denticulate. The maxillary palp has the fourth segment longer than the second.

The tarsi of the legs are 2-segments, and the claws o the forelegs lack a preapical denticle. Setae on the veins in the distal half of the forewings are present on the dorsal surface only. The setae on the veins of the forewing are upright, relatively long, and in more than one rank on at least some veins other than the costal vein. The forewings have pterostigma, but the pterostigma - R2+3 crossvein is absent, and vein Cula is usually free from vein M1. The hindwings have the marginal ciliation restricted to cell R3 or ciliation may be absent altogether. The abdomen ahs the spine on the free margin of the paraproct relatively large.

The single species in the family in North America, Teliapsocus conterminus (Walsh) is reported from British Columbia. It occurs throughout most of the Untied States and Canada, and inhabits the foliage of both broad-leaf trees and confers, and occasionally occur sin ground litter.

Family ECTOPSOCIDAE

These are small insects, only 1.5 to 2.5 mm long, with the body colour shapes of brown, and the wings clear or variously marked. The head has a fronto-clypeal suture, and the hypopharyngeal filaments are fused in the midline for at least part of their length. There are numerous setae on the head, and these are usually curved either forward or backward. The antennae have no more than 11 flagellomeres. The labrum bears five distal inner sensillae, and the mandibles are short and not excavated posteriorly. The tip of the lacinia is slender and bicuspid, with the lateral cusp usually somewhat broader than the median cusp.

Adults are usually macropterous, but sometimes are brachypterous or micropterous. The forewings, with pterostigma, have sparse to moderate ciliation on the veins and margin, but this is lacking on vein Cula. The hindwings usually lack ciliation, but occasionally it is present on the margin of cell R3, and the hindwings have veins Rs and M joined by a crossvein.

The tarsi are 1-segmented, and the claws of the fore tarsi usually have a preapical denticle. Females have the third valve of the ovipositor slender, and it is sometimes short and thumb-like. The female also has a subgenital plate with two distal processes, while the endophallus of the male aedeagus has several complex sclerites.

Worldwide there are three genera and 124 describes species. Two genera and 13 species are known from north America. Only two species occur in Canada in British Columbia. Ectopsocus briggsi McLachlan is recorded from Vancouver, and E. californicus (Banks) occurs along much of the coast. Both are found on living and dead leaves of broad-leaf trees, and sometimes also on conifers.

Family ELIPSOCIDAE

These are small to medium sized psocids, 1 to 4.5 mm in length. The hypopharyngeal filaments of the head are fused at the midline for at least part of their length, and the antennae have no more than 11 flagellomeres. The labrum usually has 11 inner distal sensillae, but may have fewer with three placoid sensillae alternating with two inner trichoid sensillae. If the latter condition prevails, then there is also an outer series of six trichoid sensillae. The mandibles are short and not excavate posteriorly. The tip of the lacinia is bicuspid, with the lateral cusp generally wider than the median cusp. Both usually being denticulate.

The wings are often sexually dimorphic, with females brachypterous or micropterous. Ciliation on the wings is sparse, often being totally absent on the hindwings. The forewings, with pterostigma, have vein Cula present and free from the Median vein.; Adults have 2- or 3-segmented tarsi, with the claws of the fore tarsi usually having a preapical denticle.

Worldwide there are 21 genera and 74 species. Six genera and 12 species occur in North America. Two genera and six species are known from Canada, all being present in British Columbia. Best known perhaps is Elipsocus quentheri Mockford which occurs throughout the Rocky Mountains and the Cariboo region, occurring on the branches of pines, spruces, firs and aspens.

Family EPIPSOCIDAE

The head has mandibles that are elongate and excavate posteriorly, and the labrum has a characteristic pair of sclerites that run the entire length and are continuos with the sclerotization on each side of the labrum. The labial palps lack a basal segment, and consists of the single element. The hypopharynx has a pair of sclerotized filaments that are fused together in the midline, and separate only near the distal ends. The antennae have generally 11 flagellomeres, which are never annulated.

Although the genus that occurs in British Columbia has females without wings, the very rare males, should they be found, have forewings with a pterostigma without internal crossveins, a short Rx-M crossvein, and only one anal vein.

The legs have 2-segmented tarsi, and the claws of the fore tarsi have a preapical denticle. The pulvillus on these latter claws has an acuminate tip.

Worldwide there are six genera and 89 species. Two genera and three species are reported from North America, with two species known from Canada. Only one of these Bertkauia crosbyana Champion is recorded from southwestern British Columbia. This generally occur sin woodland or forest ground litter, and is presumed to be an obligate thelytokous species. The females are dark brown, paler on the thoracic dorsum, with a dark brown longitudinal stripe throughout the middle of the meso and metanotum.

Family LACHESILLIDAE

Relatively small psocids, 2 to 4 mm in length. The body colour is various shades of brown. The head has the vertex and frons bearing numerous upright or forward directed curved setae of various lengths. The labrum lacks a pair of longitudinal line-like sclerites, but has 5 distal inner sensillae. The mandibles are short and not excavated posteriorly. The tip of the lacinia is slender, bicuspid with the two cusps of about equal size and pointed apically, although the outer cusp can be longer and sometimes with denticles. In the thorax, the meso-precoxal bridge is wide. The wings are usually clear and generally unciliated or lightly ciliated, without crossing pairs of setae on the margins. In the forewing, vein Cula is present and usually free from vein M, while in the hindwings veins Rs and M are joined by a relatively long fusion, which is about equal to or greater than the length of the proceeding segment of Rs. The middle legs have narrow trochantius, and all tarsi are 2-segmented, with the claws of the forelegs usually with a preapical denticle. The ovipositor in the female usually has one, or sometimes only two valvulae.

Worldwide there are four genera and 107 described species. Four genera and 47 species are reported from North America, with 2 of these genera and 14 species known from Canada. Four species of Lachesilla are recorded from British Columbia.

Family MESOPSOCIDAE

Medium to large psocids, 3.0 to 4.5 mm in length. The body has at most short and sparse setae. The labrum has 9 inner distal sensillae, with a median placoid sensilla followed by three trichoid and one placoid sensilla on each side. The mandibles are short and not excavated posteriorly, while the tip of the lacinia is bicuspid, of moderate width, with the outer cusp longer and wider than the inner cusp, both with a roughened surface. The thorax has a wide meso-precoxal bridge. The wings are without ciliation, and lack crossed pairs of seta eon the wing margins. The forewings have vein Cula present and free from vein M, although wings are often reduced in females.

The tarsi are 3-segmented, with the claws of the forelegs having a preapical denticle.

Worldwide there are 5 described genera and 34 specie. Only the genus Mesopsocus with three species occurs in North America. All three species have been reported from Canada, with two of these recorded in British Columbia. M. immunis (Stephens) is an introduced species reported from Vancouver and Victoria on branches of Garry Oak, pine, maple and western red cedar. M. unipunctatus (Müller) occurs in the Rocky Mountains and also the Pacific Coast on both broad-leaf and needle-leaf trees.

Family PERIPSOCIDAE

Moderate sized to small psocids, 2 to 4 mm long. The body is various shades of dusky brown, and the wings usually have diffuse bands and/or spots, although they are occasionally unmarked. The head lacks a fronto-clypeal suture, and the vertex is smooth or has a few minute setae. The labrum has five inner distal sensillae. The mandibles are short and not excavated posteriorly, while the tip of the lacinia is slender and bicuspid with the lateral cusp usually somewhat broader than the median cusp. Adults are usually macropterous, and only rarely micropterous or brachypterous. The forewings usually lack ciliation, but occasionally have sparse setae on the veins and margins. The forewings lack vein Cula. The hindwings lack ciliation and have veins Rs and M fused for a distance. The tarsi are 2-segmented, and the claws of the forelegs usually have a preapical denticle. Females have a subgenital plate with a single distal process or "egg guide", and the ovipositor has broad and setose third valvulae.

Worldwide thee are 2 described genera and 113 species. Two genera and 14 species are reported from North America. Five species of Peripsocus are known to occur in Canada, with three of these recorded from British Columbia. P. phaeopterus (Stephens) is an introduced European species known from Vancouver, where it has been collected on Thuja plicata and Scotch broom. P. alboguttatus (Dalman) occurs over much of the province being reported on maple, alder and Scotch broom. P. subfasciatus (Rambur) inhabits the branches of both broad-leaf and needle-leaf trees.

Family PHILOTARSIDAE

Medium sized psocids, 2 to 3.5 mm long, with the body various shades of brown and grey. The head has moderate setae on the vertex and frons. The antennae have no more than 11 flagellomeres. The labrum has 9 inner distal sensillae. The mandibles are short, and not excavated posteriorly, while the tip of the lacinia is slender and bicuspid, with the lateral cups wider than the median cusp and denticulate at its free edge.

While the mesonotum has moderate setae, they are sparse on the rest of the body. Adults are usually macropterous, although they are occasionally brachypterous, and rarely micropterous. Brachypterous and micropterous forms have numerous long, backward directed setae on the vertex and thoracic dorsum. The forewings have moderate setae on the veins, but setae are abundant on the margins. Setae are moderate or absent on the veins of the hindwings. However, the setae on most of the median margin of the forewing, and part of the hindwing are in two series forming crossing pairs. The forewings have vein Cula present and free from vein M. Adults in most species have 3-segmented tarsi, with the claws of the forelegs usually with preapical denticle.

Worldwide there are 7 described genera and 143 species. Two genera and 5 species are known from North America. Both genera and three of the species occur in Canada. Two species are reported from British Columbia. Philotarsus kwakiutl Mockford is known from Pacific coastal areas from San Francisco north to Vancouver, and inland in the north and central part of the province on branches of conifers. P. picicornis (Fabricius) is recorded from Vancouver on both conifers and Scotch broom.

Family PSOCIDAE

Medium to large psocids, 3.5 to 10 mm long, bark inhabiting species. antennae with no more than 11 flagellomeres. The labrum has 5 to 11 inner distal sensillae, and the mandibles are short and not excavated posteriorly. The forewings, with pterostigma have variable markings, varying from none to extensive banding and blotching. The forewings have vein M three-branched, and generally with vein Cula fused to vein M for some distance, occasionally joined at a point, rarely joined by a crossvein. Adults have 2-segmented tarsi, and claws of the forelegs with moderately large preapical denticle.

Worldwide there are 31 described genera and 494 species. Fourteen genera and 59 species are known from North America. Ten genera and 19 species are reported from Canada, with just three species so far recorded in British Columbia. Amphigerontia bifasciata (Latreille) is found throughout the province on conifers and broad-leaf trees, while the alien A. contaminata (Stephens) is known only from Vancouver on branches of Larix and Thuja. Psocus crosbyi Chapman is a coastal species occurring on broad-leaf trees and shrubs, recorded from Langford.

Family STENOPSOCIDAE

The head has a broad inner clypeal shelf. The labrum, with five distal inner sensillae, lacks central longitudinal sclerites, but labral stylets are present. The mandibles are elongate, and excavate posteriorly. The lacinia has a bicuspid tip, and the second and forth segments of the maxillary palp are equal in length.

The forewings characteristically have the pterostigma - R2+3 crossvein present, and the M-Cu crossvein is also present. The veins in the distal half of the forewing have setae only on the dorsal surface. These setae are relatively short, slanted distal, and generally occur in only one rank. The hindwings lack marginal setae, are at most may have a few in cell R3.

The tarsi of the legs are 2-segmented, and the claws of the forelegs lack a preapical denticle. The abdomen has two or three pairs of ventral spiracles, and the spines on the free margin paraproct are relatively small.

Only one species, Graphospsocus cruciatus (L.) occur sin North America, and this is an alien introduced species occurring on both the east and west coasts. It is recorded from Vancouver.