|Females of Madagascar giant hissing cockroach (Gromphadorhina
portentosa) lay their eggs in a purse-like capsule known as an ootheca.
This ootheca (egg case) is retained within her body (brood pouch) until
the eggs hatch, and the young roaches first see the world as tiny
nymphs. It seems the mother is giving a live birth to babies.
You may occasionally see a female with the egg-case extruded in your
colony. This can be seen all year long. Such a female is in the process
of forming the case as if she is "air drying" it. Healthy
extruded egg-case is solid, two-lines and straight. This behavior is
believed by entomologists to be obtained by the Madagascar hissers
recently in their evolutional process.
Once the extruded egg-case is completely formed and
"ready", she will retract it into a special cavity in the tip
of her abdomen. Nevertheless, when the female is not well fed or under
consistent stresses such as undesirable environmental changes (i.e.,
just shipped from a dealer in other states to your apartment, loud
noises, improper temperature and humidity, or even improper foods
given), she can not produce healthy ootheca. Eggs might be extruded
individually or loosely hanging outside of her body like a skinny arch.
In such incidences, unfortunately they are to be left alone on the
ground. They are sooner or later eaten by cage mates as nutritious good
A female that has been successfully fertilized will retain the eggs
within this cavity in her abdomen for at least 60 days. The eggs left on
the ground, thus can not grow into babies. Incubation of abandoned eggs
in a test tubes or glass container with proper gel nutrient and
consistent oxygen circulation is rather difficult, costly and
inefficient way to save the eggs or solve the source of problem.
During this period, baby Madagascar hissers grows inside of the
egg-cases inside of their mother's abdomen. Be very gentle and nice to
pregnant ladies! They are doing the truly miraculous works within their
As long as you feed the colony mainly with dry dog food or dry cat
food that are rich in protein, you do not need to separate the pregnant
mother from her cage mates --- In another words, her cage mates (male
and females) will eat the newly born babies (soft, tiny, ivory white
with black cute eyes, 1/4 inches) to get much needed protein. So, do not
just feed Madagascar Hissers vegetables and fruits. This is very
NOTE: The ideal environment for Madagascar Hissers is 80 - 95 degree
with at least 90% humidity level. Adding another egg tray for increasing
additional surface is also a good idea. Also do not put them under any
PS. Blaberus Giganteus is also a giant (3+ inches) cockroach. This
beautiful and angelic-looking cockroach also "air dry"
egg-case and retract it inside of the mother's abdomen in healthy