THE FAMILIES OF SPRINGTAILS (COLLEMBOLA) OF
BRITISH COLUMBIA

by

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

Key to Families of Collembola

1. Abdomen elongate, first four segments with clear intersegmental incisions; furca often reduced or absent (Suborder Arthropleona)....................................... 2

- Abdomen more or less globular, first four segments without intersegmental incisions; furca always well developed (Suborder Symphypleona)............... 9

2. First thoracic segment with some setae (Section Poduromorpha)..................... 3

- Dorsal part of first thoracic segment reduced, and without setae (Section Entomobryomorpha)................................................................................. 7

3. Dentes more than 3 times as long as manubrium, apically ringed.......... Poduridae

- Dentes much shorter, not apically ringed............................................................4

4. Sensorial organ of third antennal segment with large sensorial clubs, usually partly hidden by finger-like papillae; pseudocelli present..................... Onychiuridae

- Third antennal segment usually with small, exposed sensillae; pseudocelli absent
.................................................................................................................. 5

5. Mouthparts adapted for chewing, not projecting or cone-like; mandibles with granulated molar plate, clearly visible in cleared specimens ..........................
........................................................................................... Hypogastruridae

- Mouthparts adapted for sucking, usually projecting and cone-like; mandibles absent or reduced, more or less saw-like, without molar plate...................... 6

6. Either mucro with three large dorsal teeth, or post-antennal organ star-shaped, triradiate .................................................................................... Odontellidae

- Mucro never with three dorsal teeth; post-antennal organ never triradiate...................................................................................... Neanuridae

7. Body without scales, setae simple or at most sparsely ciliate; post antennal organ present, simple unlobed; furca often reduced or absent..................................
.................................................................................................... Isotomidae

- Body often with scales, longer body setae usually densely ciliated and dilated in apical part; post antennal organ usually absent, but a small lobed organ is present in a few genera; fourth abdominal segment often much longer than third ....................................................................................................................8

8. Fourth antennal segment shorter than third; mucro elongate, with many setae ..................................................................................................Tomoceridae

- Fourth antennal segment at least as long as third; mucro usually short, with at most one seta ................................................................................ Entomobryidae

9. Head prognathous; mandibles absent; body less globular; small species, less than 0.3 mm long......................................................................... Mackenziellidae

- Head hypognathous; mandibles present; body clearly globular; larger species, usually much more than 0.3 mm long......................................................... 10

10. Antennae distinctly shorter than head; minute, blind, pale species
...................................................................................................... Neelidae

- Antennae longer or at least as long as head; larger species, usually with eyes and pigmented................................................................................. Sminthuridae

 

FAMILY DESCRIPTIONS

Family Brachystomellidae

This is a small family with 96 species worldwide, and is especially diverse in humid climates where species live in damp soil and litter. Some are associated with fungal fruiting bodies and probably feed on spores. The Brachystomellidae is related to the Neanuridae, and like that family, has reduced mouthparts; mandibles in branchiostomellids are completely absent. They feed on food particles suspended in liquids. Two thirds of the species belong to Brachystomella, which contains the only two species of the family known in B.C., B. parva (Schaeffer) and B. stachi Mills.

Family Hypogastruridae

The 580 species of the cosmopolitan family Hypogastruridae generally live in the upper soil and decomposing litter, but also live under bark, along the seashore, in commercial mushroom plantations and in sewage treatment plants. The furcula is short or absent; in North American species it never reaches past the end of the abdomen when extended. The mandibles are well developed and bear a molar plate.

 

In B.C., 38 species are recorded, two of which are undetermined Ceratophysella. C. denticulata (Bagnall) can be common and is usually associated with disturbed habitats. In Australia, it is collected frequently in cities and farmland, and is evidently introduced from Europe; it may be introduced to B.C. as well. Hypogastrura, a widespread, mostly Holarctic genus, makes up almost half the family in B.C. There are 18 species in the province, including H. viatica (Tullberg), a dark violet species that swarms in large numbers, especially along the shores of brackish estuaries. H. arborea Fjellberg is known only from the Carmanah Valley on Vancouver Island where it lives in ground litter and thick moss on the branches of the Sitka Spruce canopy. In the subgenus Cyclograna, H .c. horrida Yosii and a few other species have spectacular spines on the head; this unusual group is particularly abundant in B.C. Willemia arida Fjellberg is at home in the soil of dry grasslands in the southern B.C. interior. Microgastrura minutissima (Mills) turns up in huge numbers in soil samples on the coast and Xenylla humicola (O. Fabricius), a dark blue, cosmopolitan species, is often found around marshy ponds.

 

 

Family Neanuridae

This diverse family of 1160 named species is found around the world, especially in damp habitats. Species live in the soil and litter, under bark and stones and in rotting logs where they feed mostly on fungal hyphae. Some are carnivorous. The mouthparts are reduced: the mandibles lack molar plates and the maxillae are modified for piercing; food is sucked into the mouth.

There are 39 species reported in B.C. Friesea are adapted for feeding on rotifers, tardigrades and springtails and their eggs; there are eight species in BC. Morulina has long spines or tubercles. M. multatuberculata (Coleman) lives in BC. Anurida maritima (Guérin-Méneville) is abundant in intertidal habitats all around the north temperate regions and A. tullbergi Schött, another cosmopolitan species, lives along seashores and lake margins. Pseudachorutes columbicus Rusek is endemic to B.C., recorded only from southern Vancouver Island.

 

 

Family Odontellidae

Related to the Neanuridae, the family Odontellidae also has piercing and sucking mouthparts. The antennae are conical. The family is small, with 100 species, but the genus Odontella is cosmopolitan and is diverse in wet forests. There are ten species known in the family from B.C., seven in Odontella and four in Xenyllodes.

Family Onychiuridae

The onychiurids are diverse and widespread; over 600 species are described. Most live in the soil or humus layer (cave species are also known) and are characterized by reduced body structures. They are usually colourless, have no eyes and lack a furcula. The absence of the jumping organ is compensated by the presence of pseudocelli, body pores that secrete noxious, defensive fluids. These chemicals can be toxic to predators such as ants.

Thirty-nine species are known from B.C., 24 of these are in the large genus Onychiurus. One of these, O. cocklei (Folsom), is the most famous B.C. springtail -- otherwise known as the Golden Snowflea, it swarms on the snow in masses of yellow. It was first collected by J.W. Cockle of Kaslo, B.C., a hotelier and dynamic amateur entomologist who flourished in the late 1800s and early 1900s. O. voegtlini Christiansen and Bellinger also is an exception to the rule that members of this family are soil dwellers – it lives on bark of Douglas-fir trees in B.C. Tullbergia is a large genus in the province, with 11 species; T. obtusochaeta (Rusek) and T. vancouverica (Rusek), both from southern Vancouver Island, are endemic to B.C. (This genus is of interest, too, because it is abundant on subantarctic islands). Other onychiurans found only in B.C. (at least so far) are Multivesicula columbica Rusek and M. punctata Rusek, Onychiurus eisi Rusek. Sensiphorura marshalli Rusek is named for Valin Marshall, a B.C. soil biologist, who first collected the species in coastal forests on Vancouver Island. It is not known from anywhere else.

Suborder Metaxypleona

Contains one family and one species.

 

 

Family Poduridae

The Poduridae contains a single, well-known species, Podura aquatica Linnaeus. It is, perhaps, the most familiar and easily recognized springtail. Common on the surface of standing water around the Northern Hemisphere, large numbers often swarm in summer in the sheltered corners of ponds and slow streams. It is no more than 1.3 mm long and is usually blue-black with reddish appendages; sometimes it is entirely red-brown. Its antennae are shorter than the head and there are eight eyes on each side. All abdominal segments are distinctly separate. The furcula is extremely long, reaching the collophore when at rest. The cuticle is coarsely granulate.

Suborder Entomobryomorpha

Contains four families in British Columbia.

Family Entomobryidae

This large family of 1365 species represents 21 per cent of all described springtail species. Most live in leaf litter on the soil surface, under tree bark, on vegetation, in the forest canopy or in caves. They are elongate, active forms; many have cuticular scales. In North America, those species without scales tend to live in trees.

Thirty-two species are known in B.C. The largest genus recorded in the province is Entomobrya, with 12 species. E. nivalis Linnaeus swarms and some other species frequently enter houses, where they do no harm.

Sinella contains seven species in the province. S. curviseta Brook is common in some wastewater treatment plants where it is considered beneficial in the breakdown of organic matter.

Family Isotomidae

Most species in the family Isotomidae live in the soil or litter. There are 1028 described species; 70 are recognized in B.C. Many genera are cosmopolitan. Cryptopygus is an example: it is abundant and dominant in the subantarctic and three species also live in B.C. The two largest B.C. isotomid genera are Isotoma with 22 species and Folsomia with 15. Isotoma species are common and widespread. I. notabilis Schaeffer is abundant in gardens, fields and forests in Europe and North America. I. spatulata Chamberlain has spatulate setae; it lives in ant nests. I. viridis Bourlet preys on other small invertebrates. Folsomia candida Willem is reared and used for standard toxicological tests worldwide. F. inoculata Stach uses its heavily sclerotized mouthparts for feeding on wood; it is recorded from Europe and Sicamous Creek in the B.C. interior.

The genus Agrenia often inhabits stream edges. A. bidenticulata (Tullberg) frequently gathers in large swarms; the only Canadian record for A. agilis Fjellberg is from the type locality in Garibaldi Park; that park, too, is the only locality in the world for A. atroviridis Fjellberg. Tetracanthella pacifica Rusek and Marshall has been found only in B.C. Metisotoma grandiceps (Reuter) preys on other Collembola -- it uses specialized, grasping antennae to capture its victims.

Family Oncopoduridae

There are only two genera and 40 species in the Oncopoduridae. All are rare soil or cave-dwelling forms. Oncopodura has 39 named species. An undetermined species of Oncopodura from Vancouver Island is the only record for the family in Canada.

Family Tomoceridae

The Tomoceridae is a family of long, slender species; 115 occur worldwide. Some species are large and conspicuously active above the soil surface and so are frequently seen in gardens and other places. They live in a wide range of habitats, from soil and leaf litter to the bark of trees and on vegetation. There are many species that live on trees or in caves; pigment and eyes in the latter forms are reduced. They have long antennae, and typically segment 3 is longer than segment 4, allowing some species to coil the ends of the antennae. Many species have scales on the cuticle.

There are ten species recorded in B.C., all in the genus Tomocerus. T. vulgaris (Tullberg) is probably the largest springtail in the province.

Suborder Neelipleona

Minute, globular; thorax segments expanded. One family worldwide; one species in B.C.

 

Family Neelidae

There are 25 species of neelids worldwide; all are tiny, globular soil or cave dwellers, rarely longer than half a millimetre. All species are blind and have antennae that are shorter than the head. The body segmentation is indistinct, but much of the fusion and expansion of the body is in the thorax, rather than in the abdomen, where the rest of the globular springtails are enlarged. Little is known about their habits. Megalothorax minimus Willem, which ranges around the northern parts of the world; is the only species recorded in B.C. It is the smallest springtail known from the province and is common in the soil of clearcut forests.

Suborder Symphypleona

Globular springtails, the basal abdominal segments fused, the abdomen enlarged. Furca always well developed. Seven families in B.C.

Family Arrhopalitidae

This family, related to the Katiannidae, has only two genera, although one, Arrhopalites, contains 73 species. Collophora has 6 species. They are small and white, with reduced eyes (rarely 8 on each side) and live in the soil, litter and caves. In B.C. Arrhopalites is the only genus; it has seven species.

Family Bourletiellidae

Found in the Northern Hemisphere, the tropics and Australia, the Bourletellidae is a small family of 176 species. In Australia, where the family is common, several genera are adapted to hot, dry landscapes. Two species are recorded from B.C.: Pseudobourletiella spinata (MacGillivray) and Bourletiella hortensis (Fitch). The latter is a cosmopolitan nursery pest and lives on the foliage and flowers in many gardens in many countries. It may be introduced in B.C. It and some other bourletiellids have courtship displays or dances where the males and females interact before the spermatophore is transferred. The males of some species, like those in the Sminthurididae and Mackenziellidae, have hooked spines on the antennae that are used to hold the female during mating.

Family Dicyrtomidae

The Dicyrtomidae is predominately a family of the Oriental region; there are 161 described species. One character separates these species from all other symphypleonids – the fourth antennal segment is always less than half the length of the third and there are never clasping structures present. The antennae are elbowed between segments 2 and 3; most other Symphypleona families have the bend between segments 3 and 4.

These springtails live mainly on the surface of the soil and litter in various types of forests. Many species are patterned in colours. Two genera are reported in B.C. The sole record of Dicyrtoma is of an undetermined species from the interface between the Sitka Spruce forest and sand dunes on the Brooks Peninsula, Vancouver Island. Four species of Ptenothrix are known in the province.

Family Katiannidae

Widespread, but mostly from the Southern Hemisphere, the family Katiannidae has 162 named species. They are small springtails, less than 1.5 mm long, mostly living in forests. Abdominal segments 5 and 6 are not fused. There are rarely fewer than 8 eyes on each side of the head. All six species in B.C. are in the genus Sminthurinus.

Family Mackenziellidae

Named after the Mackenzie River in northern Canada where it was first discovered, the family Mackenziellidae contains only one species. Mackenziella psocoides Hammer has since been collected in Germany, Norway, the Canary Islands and the interior of B.C. All records are from dry moss. Only a quarter of a millimetre long, the body is elongate, oval and somewhat flattened, adapted for crawling through narrow spaces in moss mats. Males have clasping organs on the antennae similar to those of the Sminthuridiadae. Both sexes have lost the mandibles and outer part of maxilla.

 

Family Sminthuridae

These 181 known species of the globular springtails occur mainly in the Northern Hemisphere and in the tropics. Almost all live above the soil layer in leaf litter and low vegetation. Courtship displays occur. Only one species, an undetermined one in the genus Sminthurus, has been recorded in B.C. The following families formerly were subfamilies or other categories in a broader concept of the family Sminthuridae.

Sminthuridids are small springtails, usually less than 1 mm long. The 126 species are distributed throughout the world, and many species live on the surface of water. Strong differences between males and females are their most striking feature. In males, antennal segments 2 and 3 are strongly modified for clasping the female antenna during mating. Abdominal segments 5 and 6 are fused. B.C. has eight species; five are in the genus Sminthurides. These species, such as S. aquaticus (Bourlet) and S. sexpinnatus Denis, are often associated with freshwater ponds.