FAMILIES OF PHTHIRAPTERA OF BRITISH COLUMBIA

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

Key to Families of Phthiraptera

1. Head relatively large; mouthparts mandibulate; ectoparasitic on birds or mammals (Mallophaga)............................................................................................. 2

- Head relatively small; mouthparts styliform and without mandibles; ectoparasites of mammals (Suborder Anoplura) ...................................................................6

2. Antennae filiform and exposed; maxillary palps absent (Suborder Ischnocera)................................................................................................. 3

- Antennae more or less clubbed, usually concealed in grooves; maxillary palps present (Suborder Amblycera) ....................................................................4

3. Antennae 3-segmented; tarsi with a single claw; ectoparasites on mammals ...............................................................................................Trichodectidae

- Antennae 5-segmented; tarsi with two claws; ectoparasites of birds
................................................................................................. Philopteridae

4. Meso- and metanotum fused ............................................................................5

- Meso- and metanotum not fused, with later not fused to tergum I .................................................................................................Menoporidae

5. Tergum I fused with metanotum ...........................................................Richinidae

- Tergum I not fused with metanotum............................................. Laemobothriidae

6. Head with distinct eyes or ocular points behind antennae.................................... 7

- Head without eyes or prominent ocular points..................................................... 9

7. Head with eyes having a distinct lens, but without ocular points ..........................8

- Head with prominent ocular points, but without eyes with lens .............................................................................................Haematopinidae

8. Abdomen compact, about as long as basal width; with setose lateral tubercles on abdomen; forelegs smaller and more slender than middle an hindlegs........................................................................................... Pthiridae

- Abdomen much longer than basal width; without setose lateral tubercles on abdomen; all three pairs of legs subequal .......................................Pediculidae

9. Head and thorax thickly covered with stiff setae; abdomen thickly covered with various setae, scales and spines ............................................Echinophthiriidae

- Head and thorax with only a few fine setae; abdomen without scales .................10

10. Forelegs smaller and more slender than middle and hindlegs; abdominal segment II without paired ventral plates ...................................................................11

- Forelegs subequal to middle legs, both smaller and more slender than hindlegs; abdominal segment II usually with a pair of ventral plates, but if lacking, then antennae and head with ventral hook-like processes................................................................................Enderleinellidae

11. Abdomen with distinct paratergites; forecoxae close together mesally............... 8

- Abdomen without distinct paratergites; forecoxae widely separated from each other........................................................................................ Linognathidae

12. Abdominal segment II with sternum extending laterally on each side to articulate with corresponding paratergites; hindlegs largest ......................Hoplopleuridae

- Abdominal segment II with sternum narrow, not extending laterally; middle legs subequal to hindlegs in size .........................................................Polyplacidae

Description of Families

Suborder ANOPLURA

Family ECHINOPHTHIRIIDAE

These are medium-sized to large mammal lice. The body is densely covered with thick setae, as well as regular setae, scales and pegs. The head lacks distinct eyes or prominent ocular points. The antennae are 3- to 5-segmented. The mesothoracic phragmata in the thorax connect across the dorsum and usually enclose a notal pit; the sternal plate is absent. The middle and hindlegs are large and similar in size and shape, and have blunt claws; the tibial thumb is elaborate, with several short, blade- or peg-like setae at the apex. The forelegs are small and slender, with acuminate claws (except in Echinophthirius which has large forelegs similar to the middle legs). The abdomen is completely membranous, usually with various types of setae, including pegs and scales. Six pairs of spiracles are on the abdomen, all small, distinctive with a long, slender atrial chamber and a long sclerotized rod.

Species in this family occur on aquatic mammals (Pinnipedia and Mustelidae). In North America, 6 species in 4 genera are reported. Four species occur in Canada. Only Antarctophthirius microchir (Trouessart & Neumann) in reported from B.C. It is reported from the Northern sea-lion (Eumetopias jubatus, from Triangle Island and Vancouver. It characteristically has 5 segmented antennae, thorax and abdomen with scale-like setae, and the thoracic sternum has a few long setae on the posterior border.

Family ENDERLEINELLIDAE

These are very small mammal lice, less than 1 mm in length. The head does not have a well developed postantennal angle. Antennae are usually 5 segmented, but if 4-segmented, the terminal segment has 2 sensoria. The thorax usually has well developed sternal plates, but if these are weakly developed or not present, the coxae of each pair of legs are widely separated from each other. The forelegs and middle legs are subequal in size, and shape, both being small and slender, and with a slender claw. The hindlegs are stout, with the tibia-tarsus highly developed and in the form of a stout claw. Paratergites are present on segments 2-4, 2-5 or 2-6, or if absent, the entire abdomen is membranous. Tergal and sternal sclerites are usually poorly developed or completely lacking on the abdomen, which has functioned spiracles on segments 3-4, 3-5, 3-6 or 3-8. Nymphs lack ventral tubercles on the head.

All species in this family are ectoparasites of squirrels. Ten species in 2 genera are reported from North America. Four species occur in Canada, with only one species, Microphthirus uncenatus (Ferris) recorded from Vancouver on the Northern Flying Squirrel (Glaucomys sabrinus). It is recognized by its extremely small size (total length  0.35 mm  0.45 mm), and by the fact that the antennae and the head have characteristic sclerotized hook-like processes, and the second abdominal segment is without ventral plates.

Family HAEMATOPINIDAE

These are relatively large mammal lice. The head is without external evidence of eyes, but has prominent ocular points or lobes behind the antennae. The antennae are 5-segments. The thorax has distinct notal pits, a pair of small sternal apophyseal pits, and strongly sclerotized sternal plate. All legs are similar in size and shape. Each tibia has a flap-like tibial lobe bearing a few spiniform setae. The tibial thumbs are well developed, each with an apical spiniform seta. The abdomen has strongly sclerotized, cap-like paratergites on prominent lateral lobes of segments 2-8 or 3-8. The paratergites are not free from the body wall. The abdominal cuticle is leathery, minutely wrinkled dorsally with weakly sclerotized areas; segmental setae are short and arranged in single transverse rows. Abdominal segments 3-8 have spiracles laterally.

Four species in the genus Haematopinus Leach are reported from North America. Three species occur in Canada, with all three of these recorded from B.C. The horse sucking louse (Haematopinus asini (L.)) recorded from Kamloops and Vancouver on horses is 2.25 to 3 mm long and has the thoracic sternal plates longer than wide and without a median projection, while the head is at least twice as long as the width measured at the ocular points. The shortnosed cattle louse (Haematopinus eurysternus Denny) recorded from Douglas Lake and Kamloops on cattle occurs in the temperate and cold regions of North America, and is 2 to 3.25 mm long and has the thoracic sternal plates longer than wide, with the median and antero-lateral processes blunt and rounded, and the sternum has a median projection; the forehead is short. Shortnosed cattle louse infestations usually appear in the fall and tend to increase overwinter. These infestations occur primarily on the top of the neck, but can appear over the whole body. Eggs, which are glued to hairs, hatch in about 2 weeks, and pass through 3 nymphal instars. The complete life cycle takes about 4 weeks, with males living 10 days or longer and females 16 days or longer. Females lay up to 50 eggs.

The hog louse (Haematopinus seus (L.) is 4.1 to 5.25 mm long, is recorded from Quesnel and Vancouver, and occurs on domestic pigs. In this species of Haematopinus, the sternal plate is wider than long and has distinct sternal pits antero-laterally.

The hog louse takes 29-33 days to complete its life cycle. Eggs are attached to hairs around the ears, and on the neck, shoulders and flanks. They take 12 to 20 days to hatch, and pass through 3 nymphal instars. Females lay 2 to 6 eggs daily for some 35 days, with an average total output of about 80 eggs.

FFamily HOPLOPLEURIDAEE

These are small to medium sized mammal lice. The head is without external indication of eyes, and the antennae are 4- to 5-segmented. The thorax is without notal pits, with the sternal plate well developed and with its posterior apex free. The forelegs are always small, and each has an acuminate claw. The middle legs are similar in shape to the forelegs, but are usually larger. The hindlegs are the largest, with a stout claw, and highly developed tibial thumb. The abdomen usually has tergal, sternal and paratergal plates. Each paratergite has its apex free from the body wall and overlapping that of the succeeding segments. A pair of spiracles is present on abdominal segments 3-8, and each abdominal segment has transverse rows of setae on or off sterna and terga. The sternal plate of the second abdominal segment is prolonged laterally on each side, articulating with the corresponding paratergites.

Species in this family parasitize insectivores and rodents. Sixteen species in 2 genera are reported from North America, seven species are recorded in Canada. Six species are so far recorded from B.C., all in the genus Hoplopleura Enderlein. Hoplopleura acanthopus (Burmeister) in the province is recorded from the southern red-backed vole (Clethrionomys gapperi), the long-tailed vole (Microtus longicaudus), the montane vole (M. montanus), the creeping vole (M. oregoni), the meadow vole (M. pennsylvanicus), Townsend’s vole (M. townsendii), bushy-tailed woodrat (Neotoma cinerea), common pika (Ochotono priniceps), the Norway rat (Ratttus norvegilus), The northern bog lemming (Synaptomys borealis), and the northern pocket gopher (Thomomys talpoides). Hoplopleura arboricola Kellogg & Ferris is recorded from the yellow-pine chipmunk (Tamias amoenus), H. hesperomydis (Osborn) from deer mouse (Peromyscus maniculatus) and Keen’s mouse (P. keeni), While H. pacifica Ewing has been collected off the Norway rat (Rattus norvegicus). Hoplopleura sciuricola Ferris is recorded from Douglas’ squirrel (Tamiasciurus douglasii) on the coast, and the red squirrel (T. hudsonicus) on the coast and in the interior. Hoplopleura trispinosa Kellogg & Ferris has been collected on the northern flying squirrel (Glaucomys sabrinus).

Family LINOGNATHIDAE

Medium sized mammal lice 1 to 2.5 mm in length. The head is without external evidence of eyes, and the antennae are 5-segments. The thorax usually has distinct notal pits, but sometimes these are obscure. Thoracic sternal plates are usually absent, but if present, the posterior apex is not free from the body. Forelegs are small and slender with acuminate claw. Middle and hindlegs are subequal, but larger than the forelegs, and each has a distinct, stout claw, and a well developed tibial thumb with a single, spiniform seta. The abdomen is membranous, with no trace of tergal or sternal plates, except for those associated with the genital and terminal segments. Paratergites are absent or at most represented by small tubercles anterior to each spiracle. Spiracles are present on abdominal segments 3-8, and these spiracles have distinct internal ledges.

Species in this family infest cattle, caribou, deer, elk, goats and sheep. Ten species in 2 genera are reported from North America. Nine species are recorded in Canada and 5 occur in British Columbia. The genus Linognathus Enderlein is represented by 3 species, and the genus Solenopotes Enderlein by 2 species. The sheep foot louse (Linognathus pedalis (Osborn) is reported from domestic sheep at UBC, the dog sucking louse (L. setosus (Von Olfers)) from dogs in Kamloops, Vancouver and Victoria, and the longnosed cattle louse (L. vituli (L.)) from domestic cattle at Canim Lake and Milner. The little blue cattle louse (Solenopotes capillatus Enderlein) is also recorded from domestic cattle at Kamloops and S. ferrisi (Fahrenholz) from mule deer (Odocoilius hemionus columbianus) on the coast.

Family PEDICULIDAE

This family in North America contains one species, the human louse (Pediculus humanus L.). It occurs in British Columbia and worldwide on humans, and elsewhere is also reported from gibbons and the New World monkeys.

The head has distinct external eyes and the thorax has well developed phragnata, with thoracic sternal plates weakly developed or absent. All three pairs of legs are essentially the same size and form, with slender, claws. The abdomen is much longer than the basal width and is membranous, except for the genitalia and terminal segments. The abdomen of the male has small tergites. The abdomen has 6 pairs of spiracles completely enclosed by paratergites.

Two distinct subspecies are now recognized, the body louse (P. humanus humanus) and the head louse (P. humanus capitis de Geer). These subspecies differ as shown below.

	Body louse	Head louse
Size & colour	Larger and lighter Male 2.3-3.0 mm Female 2.4-3.6 mm	Smaller and darker Male 2.1-2.6 mm Female 2.4-3.3 mm
Antennae	Longer and more slender, third segment usually longer than wide.	Shorter and stouter, third segment often as long as wide.
Abdomen	Indentations between abdominal segments less prominent.	Indentations between abdominal segments more prominent.
Position on host body	Below the neck, often on garments next to skin when not feeding.	On neck and head, particularly behind the ears and on back of neck.
Eggs	Glued to body hairs or on clothing worn next to body, particularly along seams.	Glued to head or neck hairs.

 

The human louse occurs on the coast and in the interior.

Family POLYPLACIDAE

Sexually dimorphic, medium to small size mammal lice. Head without eyes, and antennae 5-segmented, the postantennal angles are variable. The thorax is without notal pits, but the sternal plate is usually well developed, rarely absent. The forelegs are small and slender, each with an acuminate claw. Middle and hindlegs are subequal in size and shape, or the hindlegs may be somewhat larger than the middle legs. The abdomen has the paratergites usually well developed, with 6 pairs of spiracles, and with tergal and sternal plates usually well developed. The sternal plate of abdominal segment 2 does not extend laterally to articulate with corresponding paratergites.

In North America, species in this family parasitize lagomorphs and rodents. Twenty-seven species in 5 genera are reported in North America. Twelve species are known from Canada, with 8 species in 5 genera recorded from British Columbia, namely Fahrenholzie Kellogg & Ferris (1 species), Haemodipsus Enderlein (1 species), Linognathoides Cummings (2 species), Neohaematopinus Mjöberg (3 species) and Polyplax Enderlein (1 species).

Fahrenholzie pinnata Kellogg & Ferris has been recorded from the Great Basin pocket mouse (Perognathus parvus) in the South Okanagan, the rabbit louse (Haemodipsus ventricosus (Denny)) from rabbits in Vancouver.

Linognathoides laeviusculus (Grube) is recorded from the Columbian ground squirrel (Spermophilus columbianus) in the British Columbia interior. L. marmotae (Ferris) from the hoary marmot (Marmota caligata), the yellow-bellied marmot (M. flaviventris) and the woodchuck (M. monax), all in the interior. Neohaematopinus ornatus (Kellogg & Ferris) occurs on bushy-tailed woodrats (Neotomes cinera) in the interior, N. sciurinus (Mjöberg) on the native red squirrel (Tamiasciurus hudsonicus) and the introduced eastern gray squirrel (Scrius carolinensis), N. sciuropteri (Osborn) on the northern flying squirrel (Glaucomys sabrinus), and there is a record from the yellow-pine chipmunk (Tamias amoenus) at Aspen Grove. Polyplax spinulosa (Burmeister) is recorded from the black rat (Rattus rattus), and the Norway rat (R. norvegicus) on the coast.

Family PTHIRIDAE

This family contains the public or crab louse (Pthirus pubis (L.)). It occurs on humans throughout the world, and is usually spread by close body contact. It also occurs on other primates. It is occasionally recorded on dogs and other animals, but these latter infestations are probably accidental and not self sustaining.

As the common name suggests it occurs on the pubic area of humans, and its appearance is rather crab-like. Eggs are usually laid attached to the pubic hairs.

The diagnostics are as follows: Medium sized (1.25-1.75 mm), compact, with head short and much narrower than the thorax, and never constricted into a neck. Eyes present laterally as a pair of distinct lenses on large lateral protuberances. Antennae 5-segments, not sexually dimorphic. Thorax short and very wide, lacking sternal plate and notal pit. Forelegs very slender, with acuminate claw. Middle and hindlegs very large and stout, and with stout claw. All coxae set at extreme thoracic margins, each with a large tubercle. Tibial thumbs well developed, each with a spiniform apical seta. Abdomen relatively small, as broad basally as posterior part of thorax. Abdomen membranous except for genitalia segments and lateral lobes. Abdomen without tergal and sternal plates, but segments 5-8 each with prominent, heavily sclerotized paratergal lobes, being very prolonged. Abdomen with 6 pairs of spiracles, the first three crowded together, and the first two being displaced toward the dorsal mason. Segmental setae are arranged in transverse rows.

The crab louse occurs on the coast and in the interior.

Suborder AMBLYCERA

Family LAEMOBOTHRIIDAE

This family of bird lice contains the single genus Laemobothrion, with species being 6.5-11.0 mm in length, and constituting the largest bird lice know. There is an area of sculpturing on the postero-lateral areas of the head, and this has a row of peg-like projections. The antennae are four-segmented and enclosed in bulbous capsules which open ventrally. The mouthparts are well developed, with 4-segmented maxillary palps and distinct labial palps are present. The mesonotum and metanotum are fused, but these are not fused to tergum I. There are two claws on each leg, and the middle and hind tibia have a terminal dorsal patch of microtrichia located distally, together with an anterior patch of microtrichia. The hind femur ventrally, and some abdominal sterna also have patches of microtrichia. There are six pairs of spiracles on the abdomen. The female lacks an anal corona of setae.

Eight species of Laemobothrion are reported from the United States, six in Canada and three in British Columbia. Species generally infest birds of prey. Laemobothrion glutinous Nitzsch is recorded from the turkey vulture (Cathartes aura), L. maximum (Scopoli) from the Swainson’s hawk (Buteo swainsoni), and L. tinnunculi (L.) from the merlin (Falco columbarius) and the American Kestral (Falco sparverius).

Family MENOPONIDAE

Small to large bird lice (1.1-6.0 mm in length), with 4- or 5-segmented antennae. The labrum lacks a pulvinus. The maxillary palps are 4-segmented, and labial palps are present. The mesonotum and metanotum are not fused, and the latter is not fused to tergum I. The mesonotum is without a pair of setae-bearing protuberances. There are two claws on each leg, and the anterior coxae are elongate antero-posteriorly. The female usually has an anal corona of setae.

Worldwide there are some 69 genera, 34 of which occur in the USA, 23 in Canada, and 15 in British Columbia. There are over 600 species worldwide, 249 in the USA, with 85 species recorded in Canada, and 36 to date in British Columbia. Although most species of Menoponidae live on the body of the host and roam freely among the feathers, Piagetiella peralis (Leidy) lives inside the pouch of the white pelican (Pelecanus erythrorhynchos). Some species can become serious pests of domestic fowl. While most species feed on feathers, some are known to consume blood and serum from wounds made by the lice.

Family RICINIDAE

Large to medium sized bird lice (1.6-5.5 mm in length), with 4-segmented antennae enclosed in capsules that open ventrally. The mouthparts are reduced for piercing and sucking, and there are no labial palps. Maxillary palps are present and 4-segmented. The mesonotum, metanotum and tergum I are fused together. There are two claws on each leg, and the anterior coxae are elongate antero-posteriorly. The abdomen has six pairs of spiracles. The female has an anal corona of setae.

The family Ricinidae contains three genera worldwide, only one of which, the genus Ricinus, occurs in Canada. Nine species are reported in Canada, two in British Columbia. They occur on Passerine birds. Picinus diffuses (Kellogg) has been recorded from the Oregon junco (Junco hyemalis) and R. elongates (Olfers) from the Bohemian waxwing (Bombycilla garrulous).

Suborder ISCHNOCERA

Family PHILOPTERIDAE

Small to large bird lice (1.12-9.72 mm in length), with exposed 5-segmented filiform antennae in females; males can have an enlarged basal segment. The mouthparts have prominent mandibles, but maxillary palps are absent. The thorax has the mesothorax and the metathorax fused together. The first pair of legs are smaller than the others, but all legs have two claws. The abdomen has light apparent segments, with six pairs of abdominal spiracles.

This is a large family with over 120 genera worldwide. All occur on birds, where they can be found firmly attached to feathers, their only food.

Sixty genera are recorded in the USA, 41 in Canada and 28 in British Columbia. Of the 490 species in the USA, 166 species known from Canada, and 84 are reported from British Columbia. Several can be poultry pests. These include the slender duck louse (Anaticola crassicornis (Scopoli)) and the chicken head louse (Cuclotogaster heterographus (Nitzsch)).

Family TRICHODECTIDAE

Small to medium sized lice, 0.92-2.73 mm in length, that occur on mammals. The head has a rounded preantennal margin, and the antennae are exposed, 3-segmented, filiform in the female, with often an enlarged basal segment in the male. The mandibles are triangular-shaped, or indented, and prominent. The thoracic segments are as wide as the abdomen. The forelegs are smaller than the other legs, but all end in a single claw. The abdominal shape differs in the two sexes, and the genitalia are prominent.

There are about 20 genera worldwide, 12 in North America, 11 in Canada and 9 in British Columbia. Eighty-two species are recoded in North America, 27 in Canada and 18 in British Columbia. In the genus Bovicola, B. bovis (L.) occurs on ox (Bos taurus), B. caprae (Gurtle) on domestic goat (Capra hircus), B. concavifrons (Hopkins) on elk (Cervus elaphus), and B. ovis (Schrank) on California bighorn sheep (Ovis candensis californiana). Felicicola subrostratus occurs on the domestic cat (Felis catus) and Lorisicola spenceri (Hopkins) on lynx (Lynx canadensis). Two species of Neotrichodectes are reported in British Columbia, N. minutus (Paine) on long-tailed weasel (Mustela frenata oribasus) and N. osborni (Keler) on spotted skunk (Spilogale putorius).

The large genus Trichodectes at present in British Columbia is represented by 4 species. T. canis (DeGeer) occurs on the coyote (Canis latraas), the grey wolf (Canis lupus) and the domestic dog (Canis familiaris), T. ermiueae (Hopkins) on ermine (Mustela erminea) and mink (M. vison), T. octomaculatus Paine on racoon (Procyon lotor vancouverensis), while T. pingius enarctidos Hopkins is reported from the black bear (Ursus americanus). The louse Tricholipenrius lipuroides (Megnin) is recorded from mule deer (Odocoileus hemionus) and coyote (Canis latrans), which T. parallelus (Osborn) is also reported from mule deer. Finally, Werneckiella equi (Denny) is present on the domestic horse (Equus cabalus).