Hypogastrura (Hypogastrura)

Belongs within: Hypogastruridae.

The type subgenus of the genus Hypogastrura are springtails with a well-developed unguiculus, short and rounded postantennal organ lobes that do not surround an accessory boss, and lacking an eversible sac between the third and fourth antennal segments.

Snow sausages

Published 8 December 2025

I’ve noted elsewhere that springtails can basically be divided between three main groups: the round blobby ones, the long thin ones, and the ones that look like sausages. The subjects of this post, in the genus Hypogastrura, are among the ones that look like sausages.

About 170 species of Hypogastrura have been described to date from around the world, some of them being themselves cosmopolitan in distribution. The family Hypogastruridae is distinguished from others in the poduromorphs (the sausage-shaped springtails) by the presence of a granulate molar plate at the base of the mandibles and the absence of pseudocelli on the head (Fjellberg 1992). Hypogastrura is distinguished by a well-developed furcula (the spring-tail of the springtail), eyes with eight ocelli each, apical teeth on the mandible, and presence of a lobed postantennal organ (a sensory organ situated near the base of the antennae). Christiansen & Bellinger (1980) recognised four subgenera within Hypogastrura, among which members of the type subgenus had a well-developed unguiculus (a claw-like structure on the legs), short lobes on the postantennal organ, and lacked an eversible sac on the antennae. The remaining subgenera seem to have subsequently been considered separate genera, but one might still question whether Hypogastrura is mostly defined by the absence of derived features of other genera.

Hypogastrura species seem to primarily feed on fungi growing on decaying plant matter such as wood or leaf litter. One species, H. hargrovei, possesses unusually protracted mouthparts suggesting a distinct diet from other species in the genus (Skarżyński 2007). The nature of that diet remains unknown but such mouthparts are associated in other micro-arthropods with a more fluid-feeding lifestyle.

Hypogastrura may be most familiar in northern parts of the world through the formation by some species of dense aggregates on the surface of snow in winter, earning them the label of ‘snow fleas’. Movement across snow may assist the springtails in dispersing between localised ‘islands’ of suitable food sources. Some snow-associated springtails exhibit cyclomorphosis, the production of different morphologies at different times of year (Leinaas 1981). Individuals of cyclomorphotic Hypogastrura species found during winter have enlarged teeth on the branches of the furcula that provide a better grip on the cold, slippery substrate for jumping. The difference is strong enough that such seasonal forms have sometimes been mistaken for distinct species. In H. lapponica, summer individuals live under tree bark and are only reluctant jumpers, whereas winter individuals live openly and jump freely. Truly, these are the snow bunnies of the arthropod world.

Systematics of Hypogastrura (Hypogastrura)

<==Hypogastrura Bourlet 1839 (Hypogastrura) (see below for synonymy)CB80
    |  i. s.: ‘Achorutes’ hyperborea Boheman 1866 (n. d.)CB80
    |         H. (H.) punctata Coleman 1941 (n. d.)CB80
    |         H. (H.) reticulata Börner 1909CB80
    |         ‘Achorutes’ schneideri Schäffer 1896CB80
    |         ‘Achorutes’ theeli Tullberg 1876CB80
    |--H. viatica groupCB80
    |    |--*H. (H.) viatica (Tullberg 1872) [=Achorutes viaticus, *Neogastrura viatica]CB80
    |    |--H. (H.) aequepilosaCB80
    |    |--H. (H.) alta Christiansen & Bellinger 1980CB80
    |    |--H. (H.) antra Christiansen & Bellinger 1980CB80
    |    |--H. (H.) boldoriiCB80
    |    |--H. (H.) bulba Christiansen & Bellinger 1980CB80
    |    |--H. (H.) distincta (Axelson 1902) [=Achorutes distincta]CB80
    |    |--H. (H.) gami (Wray 1952) [=Achorutes gami]CB80
    |    |--H. (H.) gracilis (Folsom 1899) [=Achorutes gracilis]CB80
    |    |--H. (H.) helena Christiansen & Bellinger 1980CB80
    |    |--H. (H.) humi (Folsom 1916) [=Achorutes humi]CB80
    |    |--H. (H.) itaya Kinoshita 1916CB80
    |    |--H. (H.) litoralis (Linnaniemi 1909) [=Achorutes purpurascens var. litoralis]CB80
    |    |--H. (H.) perplexa Christiansen & Bellinger 1980 [=Achorutes macgillivrayi Folsom 1916 non Dalla Torre 1895]CB80
    |    |--H. (H.) purpurescens (Lubbock 1868)CB80
    |    |--H. (H.) sensilis (Folsom 1919) [=Achorutes sensilis]CB80
    |    |--H. (H.) spitsbergensis (Stach 1962)CB80
    |    `--H. (H.) tullbergi (Schäffer 1900) (see below for synonymy)CB80
    |--H. manubrialis groupCB80
    |    |--H. (H.) assimilis (Krausbauer 1898) [=Achorutes assimilis]CB80
    |    |--H. (H.) brevispina (Harvey 1893) [=Achorutes brevispina]CB80
    |    |--H. (H.) christianseni Yosii 1960CB80
    |    |--H. (H.) devia Christiansen & Bellinger 1980CB80
    |    |--H. (H.) essa Christiansen & Bellinger 1980CB80
    |    |--H. (H.) manubrialis (Tullberg 1869)CB80 (see below for synonymy)
    |    |--H. (H.) matura (Folsom 1916) [=Achorutes matura]CB80
    |    |--H. (H.) pannosa (Macnamara 1922) [=Achorutes pannosa]CB80
    |    |--H. (H.) promatro (Wray 1950) [=Achorutes promatro]CB80
    |    |--H. (H.) ripperi Gisin 1952CB80
    |    |--H. (H.) tigrina (Harvey 1900) [=Achorutes tigrina, *Anachorutes tigrina]CB80
    |    |--H. (H.) utahensis (Wray 1953) [=Achorutes utahensis]CB80
    |    `--H. (H.) vernalis (Carl 1901) [=Achorutes vernalis]CB80
    |--H. nivicola groupCB80
    |    |--H. (H.) frigidaCB80
    |    |--H. (H.) harveyi (Folsom 1902) [=Achorutes harveyi]CB80
    |    |--H. (H.) nivicola (Fitch 1846) (see below for synonymy)CB80
    |    |--H. (H.) notha (Macnamara 1922) [=Achorutes notha]CB80
    |    `--H. (H.) socialis (Uzel 1891) [=Achorutes socialis]CB80
    |--H. packardi groupCB80
    |    |--H. (H.) copiosa (Folsom 1916) [incl. H. gigas Maynard 1951, H. ulmea Maynard 1951]CB80
    |    |--H. (H.) funesta Christiansen & Bellinger 1980CB80
    |    |--H. (H.) indiana Christiansen & Bellinger 1980CB80
    |    |--H. (H.) macrotuberculata (Hammer 1953)CB80
    |    |--H. (H.) madera Christiansen & Bellinger 1980CB80
    |    |--H. (H.) packardi (Folsom 1902) [=Achorutes packardi; incl. A. dentata Folsom 1902, H. furcata Maynard 1951]CB80
    |    `--H. (H.) sparta Christiansen & Bellinger 1980CB80
    `--H. trybomi groupCB80
         |--H. (H.) ireneae (Wray 1953) [=Achorutes ireneae]CB80
         |--H. (H.) lima Christiansen & Bellinger 1980CB80
         |--H. (H.) maynardi Christiansen & Bellinger 1980 [=H. montana Maynard 1951 non Achorutes montanus Becker 1905]CB80
         |--H. (H.) oregonensis (Yosii 1960) [incl. *Biacanthella neomexicana Scott 1961]CB80
         `--H. (H.) trybomi (Schött 1893) [=Achorutes trybomi]CB80

Hypogastrura Bourlet 1839 (Hypogastrura) [=Neogastrura Stach 1949; incl. Anachorutes Bagnall 1949, Biacanthella Scott 1961, Schoturus MacGillivray 1893]^CB80

Hypogastrura (Hypogastrura) manubrialis (Tullberg 1869)^CB80 [=Achorutes manubrialis^CB80; incl. A. neglectus Börner 1901^W39, H. manubrialis var. neglecta^W39, A. schoetti Reuter 1895^W39]

Hypogastrura (Hypogastrura) nivicola (Fitch 1846) [=Podura nivicola, *Schoturus nivicola; incl. Achorutes diversiceps Lintner 1896]^CB80

Hypogastrura (Hypogastrura) tullbergi (Schäffer 1900) [=Achorutes dubius (preoc.); incl. A. tullbergi var. concolor Carpenter 1900, H. tullbergi var. setosa Schött 1923]^CB80

*Type species of generic name indicated

References

[CB80] Christiansen, K., & P. Bellinger. 1980. The Collembola of North America north of the Rio Grande: A taxonomic analysis vol. 1. Introduction; general; families Poduridae and Hypogastruridae. Grinnell College: Grinnell (Iowa).

Fjellberg, A. 1992. Collembola of the Canary Islands. I. Introduction and survey of the family Hypogastruridae. Entomologica Scandinavica 22: 437–456.

Leinaas, H. P. 1981. Cyclomorphosis in Hypogastrura lapponica (Axelson, 1902) (=H. frigida [Axelson, 1905] syn. nov.) (Collembola, Poduridae). Morphological adaptions and selection for winter dispersal. Zeitschrift für Zoologische Systematik und Evolutionforschung 19: 278–285.

Skarżyński, D. 2007. Hypogastrura hargrovei sp. n., a new species of the family Hypogastruridae (Collembola) with highly modified mouthparts. Insect Systematics and Evolution 38: 201–204.

[W39] Womersley, H. 1939. Primitive Insects of South Australia: Silverfish, springtails, and their allies. South Australian Branch of the British Science Guild: Adelaide.