3. Diagnostic characters
• Elongate, wingless insects that as adults are
2–3.5 cm long.
• Head is flattened and prognathous.
• Mouth parts mandibulate and filiform
antennae.
• The compound eyes are reduced to a few
ommatidia or are entirely absent. There are
no ocelli.
4. • The thoracic segments are more or less
identical, though the prothorax is slightly
larger than the other two.
• The six legs are similar in structure, each with
a large coxa and a five-segmented tarsus.
• The abdomen has 10 obvious segments and
the 11th is represented by the epiproct and
paraprocts.
5. • The ovipositor of females comprises three
pairs of valves.
• The cerci are long, eight-segmented
structures.
6. Habitat
• Cryptozoic insects, generally found in cold wet
locations, often at relatively high altitudes,
under stones, in rotting logs or leaf litter of
cool temperate forests.
• insects are active by both day and night.
• In korea, they were found in caves.
• They favor low temperatures (optimally
around 4◦C) and go underground during
warmer months.
7. • In winter they probably remain active,
occupying the air space between the snow
and ground surface.
• Interestingly, they have very limited ability to
withstand below-freezing temperatures.
8. Feeding habit
• They are typically predaceous, eating a variety
of other insects, dead or alive, but also ingest
some plant material.
9. Reproduction
• The black eggs are laid singly, and embryonic
development takes from a few months to 3
years.
• There are eight juvenile stages, and
development may take up to 7 years.
