Families
- Grylloblattidae - rock crawlers
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Identification guide
- wings absent
- long, multisegmented cerci
- projecting ovipositor
- male genitalia asymmetrical
Physical Features:
Adults and Immatures |
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- Antennae slender, filiform
- Mouthparts mandibulate, hypognathous
- Body cylindrical
- Tarsi 5-segmented
- Secondarily wingless
- Cerci long, 8-segmented
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Common names & synonyms
Ice Bugs
Phylogeny
Taxonomic Category |
Scientific Name |
Common Name |
Phylum |
Arthropoda |
Arthropods |
Class |
Insecta |
Insects |
Order |
Orthoptera |
Grasshoppers, crickets, walking sticks, mantids, cockroaches, & rock crawlers |
Suborder |
Grylloblattodea |
Icebugs, Rock crawlers |
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The name Grylloblattodea, derived from the
Greek "gryll" meaning cricket and "blatta"
meaning cockroach, refers to the blend of
cricket-like and roach-like traits found in these
insects.
Geographic distribution
Rare. Found in caves or near ice or snow at high elevations in mountains of Asia and North America.
Natural history
Rock crawlers are a small and obscure group of insects found only at high elevations in the mountains of China, Siberia, Japan, and western United States and Canada. Cave-dwelling species have been found in Korea and Japan. These omnivorous insects scavenge for food on the surface of snowfields, under rocks, or near melting ice. They are active only at cold temperatures and move downward toward permafrost during warm seasons. As their ordinal name implies, rock crawlers have a blend of physical characteristics from both crickets (gryllo-) and cockroaches (blatta-). Some taxonomists include these insects as a suborder or family within Orthoptera. Others believe these insects are the only survivors of a primitive lineage that gave rise to other orthopteroid orders.
A Few Facts
- Rock crawlers were first discovered around 1906; the first formal description of the order was published in 1915.
- Grylloblattodea is the smallest order of insects. Only 25 species have been described in the entire world.
- Rock crawlers cannot tolerate warm temperatures. Most species are active below freezing and usually die above 10 degrees Celsius.
- Due to the cold temperature at which they live, growth and development is very slow. Rock crawlers may require up to seven years to complete a single generation.
- No grylloblattids have ever been found in the Southern Hemisphere.
How to encounter
Gryllobattodea are found in cold areas, often in mountains, under rocks and in litter in forests, and in caves. In summer, the North American species
feed at night on insects frozen on the surface of snow fields; they are somewhat omnivorous. Western North America,
Japan, Korea, China, Siberia.
Grylloblattodea are unknown as fossils. Although some researchers consider grylloblattids to be related to the Protorthoptera complex dating
back to the Carboniferous.
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