Carausius morosus female on
ivy Hedera sp.
[photo by P.
Brock ©] |
Description
Male (rare) 48.5-61mm, female 70-84mm. Usually
parthenogenetic 
, stick-like, medium sized wingless insects with medium length
antennae. Colour various shades of dull green or brown, sometimes with darker
mottling. In adult females the inside base of the forelegs are bright red. The
thorax has a number of small tubercles (knobs). The thinner, shorter males are
brown. It is believed that those reared in captivity are genetic females with
male characteristics, but sterile, which are more frequent when these insects
are kept at unusually high temperatures.
Life History and behaviour
Females drop their eggs to the ground. The
eggs are round, brown with a yellow knob, which hatch into fragile-looking brown
nymphs after about 4-6 months. These moult six times, taking about 4-7 months to
mature; adults live 4-6 months, laying several hundred eggs.
When disturbed, nymphs and adults may sway from side to side and may emit a
fluid from the mouthparts. They may, however, simply drop to the ground. After
all, this is the classic twig mimic, which can remain motionless for hours on
end. It has been in culture in Europe since the late 1800s.
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