Snow-scorpionfly
Guides
Boreus brumalis
mid-winter boreus, snow scorpionfly
Boreus brumalis, commonly known as the mid-winter boreus or snow scorpionfly, is a small, wingless insect in the family Boreidae. Despite its common name, it is neither a scorpion nor a fly, but belongs to the order Mecoptera. Adults are active during winter months and can be observed running across snow and ice. This species is found in North America, including the northeastern United States. Males possess distinctive upward-curving genitalia that resemble a scorpion's stinger, though the insect cannot sting. Snow scorpionflies are believed to be ancient relatives of fleas.
Boreus coloradensis
snow scorpionfly
Boreus coloradensis is a species of snow scorpionfly in the family Boreidae, described by Byers in 1955. Despite their common name, these insects are neither scorpions nor true flies. Adults are active during winter months and have been observed on snow, ice, and moss. They belong to one of the smallest insect orders, Mecoptera, and are believed to be ancient relatives of fleas.
Boreus elegans
snow scorpionfly
Boreus elegans is a species of snow scorpionfly in the family Boreidae, described by Carpenter in 1935. Like other members of its genus, it is adapted to cold environments and is active during winter months when most other insects are dormant. The species is found in North America. Snow scorpionflies are characterized by their reduced wings and distinctive jumping ability.
Boreus nix
snow scorpionfly
Boreus nix is a species of snow scorpionfly in the family Boreidae, first described by Carpenter in 1935. It belongs to an unusual group of insects adapted to cold environments, with adults active during winter months when most other insects are dormant. The species is documented from North America, though specific details about its biology and ecology remain limited in published literature.
Boreus reductus
Snow scorpionfly
Boreus reductus is a wingless species of snow scorpionfly in the family Boreidae, order Mecoptera. Adults are active during winter months and can be observed hopping across snow and ice. Unlike many Mecoptera, this species lacks functional wings entirely. Adults and larvae feed on mosses and liverworts. Males possess enlarged, upward-curving genitalia that resemble a scorpion's stinger, giving the group its common name. The species engages in a distinctive mating behavior where males carry females on their backs.
Caurinus
snow scorpionflies
Caurinus is a genus of snow scorpionflies in the family Boreidae, containing two described species: Caurinus dectes from Washington and Oregon, and Caurinus tlagu from Alaska. These tiny, flea-like insects are among the most unusual members of Mecoptera, with a fossil lineage dating back over 145 million years to the Jurassic. They are non-parasitic and feed on leafy liverworts in coastal forest habitats.
Caurinus dectes
snow scorpionfly
Caurinus dectes is a species of snow scorpionfly in the family Boreidae, endemic to western North America. It is one of only two species in the genus Caurinus, distinguished by its extremely small size (approximately 2 mm), reduced wings, and flea-like appearance. The species is univoltine, with a life cycle adapted to cool, moist coastal forest environments where it feeds on leafy liverworts.
Hesperoboreus
Hesperoboreus is a genus of snow scorpionflies (Mecoptera: Boreidae) established by Norman Penny in 1977. Members of this genus are small, wingless insects adapted to cold environments. The genus is distinguished from the related Boreus by morphological features of the male genitalia. Very few observations exist, with only three records documented on iNaturalist as of the knowledge cutoff.
Hesperoboreus brevicaudus
Hesperoboreus brevicaudus is a species of scorpionfly in the family Boreidae, commonly known as snow scorpionflies. The species was described by George Byers in 1961 and is one of several western North American species in the genus Hesperoboreus. Like other boreids, adults are active during cold months and are often found on snow. The specific epithet brevicaudus refers to the relatively short abdomen characteristic of this species.
Mecoptera
Scorpionflies, Hangingflies, Snow scorpionflies
Mecoptera is a small order of holometabolous insects comprising approximately 600 extant species in nine families worldwide. The group includes scorpionflies (Panorpidae), hangingflies (Bittacidae), and snow scorpionflies (Boreidae). Males of the largest family, Panorpidae, possess enlarged genital structures that resemble scorpion stingers, giving the group its common name. The order exhibits close phylogenetic relationships with Siphonaptera (fleas) and Diptera (true flies), with some studies suggesting fleas may be derived from within Mecoptera, rendering the order potentially paraphyletic. Modern mecopterans are primarily found in moist environments, though the Boreidae are adapted to cold montane regions where adults walk on snowfields.