common name Rock-Crawler, Ice-crawler, Ice-bug
Likely as G. c. campodeiformis: cold damp locations near mountain tree lines and glacial bogs.
Slightly elongate and depressed body, cursorial legs, and head somewhat resembling Blattidae. Tarsi are five-jointed and tibia have spines, also similar to Blattidae. Eyes are quite reduced and ocelli are absent. Adults are wingless and all life stages have hypognathous, mandibulate mouthparts. These insects have filiform antennae and simple antenniform cerci, usually with eight segments, and no styli. Females possess a typically Tettigonid ovipositor and males have asymmetrical genitalia
The subspecies G. campodeiformis nahanni and G. c. athapaska are separated by about 320 km by the Liard Plateau. Kamp (1979) describes how the two populations were likely one continuous population that was separated in the late Pleistocene by the Cordilleran glaciers, and continued to evolve in isolation. He believes individuals survived the glaciation protected in the Liard and Nahanni valleys. Many experiments on G. c. campodeiformis have been performed, although little is known about the ecology of this genus, probably due to its isolation from human populations and lack of economic significance.
Grylloblatta species are nocturnal, and can frequently be found foraging on the surface of ice or snow. During the day they hide under rocks or in tunnels, migrating vertically when necessary to keep their body temperature constant. Most Grylloblatta species prefer temperatures slightly above freezing, and but some species can withstand temperatures considerably below or above that. Species that have been studied in detail show that they also prefer environments with very high humidity. Nymphs take several years to mature, likely because of the climate's effect on their metabolism.
E. M. Walker described this genus in 1914. The order that contains Grylloblatta is Grylloblattodea, but can also be found as Grylloblattaria and Notoptera, depending on the source and date.
Rare and isolated populations, but probably not immediately threatened.
Mouthparts throughout genus are similar, so diet composition in G. campodeiformis campodeiformis is probably typical to the genus, of which adults and juveniles are mainly carnivorous. These insects mainly eat wingless crane flies, collembola, microcoryphia, oribatid mites, diptera, aphids, and staphylinids. Juveniles also mainly consume other arthropods. They have also been observed eating moss and decaying vegetation.
Rocky Mountains of Alberta and British Columbia, extending into Montana and Idaho.
|genus page author||Taylor, C.||2004 |