Life cycle of Mantis Species from Resaca de la Palma State Parks (Part 10)
2.7 Molting process
All mantids need to molt to grow by a process called ecdysis. Depending on the species and gender, most species of mantis require
about 6-9 molts to attain adulthood.
Before molting, a mantis tends to become sluggish, loses interest in food, rejects any advancing prey by striking it off and hangs
upside down at the highest spot in the cage with all four middle and hind legs widely spread apart.
Molting occurs during both day and night. Most mantises will look for a secluded area with the least interference by other nymphs, but if
too many nymphs are housed together, molting could occur anywhere.
This exoskeleton is analogous to the bone structure for the mantis and protects vital organs and tissues within. Unlike humans, where
tissues continue to grow as we age, the exoskeleton does not allow for further body expansion during growth. Therefore, to increase in
size, the mantis must shed its current exoskeleton in favor of a new ‘skin’ underneath.
The method of mantis molting is similar to insects in the order Orthoptera. The mantis will hang upside down with its legs widely
spread apart working as suspenders for its body, usually from an elevated location. It will then begin to expand its body by taking in air
or raising its internal blood pressure.
|Figure 2.7-1: S. carolina nymph position prior to molting
The exoskeleton on the prothorax is the first to split open as the mantid’s new body continues to expand. The head is usually the first to
emerge from the old exoskeleton, followed by the prothorax. Both are pushed through the gaping hole of the exoskeleton on the
prothorax. Next to emerge are the legs, starting with the middle legs, followed by the hind legs. The abdomen is the last to be freed
from the exoskeleton.
|Figure 2.7-2: S. carolina expanding wings the last molt (Adult female)
The new exoskeleton is soft and expandable. The newly molted mantis will take the opportunity of this malleable exoskeleton to
expand its body to the maximum possible size before the new exoskeleton hardens. The newly molted, lighter colored mantis will
eventually harden and retain its original, usually darker coloring.
This process repeats several times during the mantis’ lifecycle until it reaches adulthood and bares wings and will no longer molt. The
final exoskeleton will stay with the mantis for the rest of its lifespan enduring weathering over time, which explains the deep scars or
marks on the mantis’ body, especially with aging wild adult mantis particularly with broken wings. It is notably a common sight during
late summer months when most adult mantises are nearing the end of their lifecycle.
Molting is considered one of the most crucial stages during the mantis’ lifetime, especially the final molt, when the mantis achieves its
full grown state. However, a mantis is also at its most vulnerable and is basically defenseless to enemies such as spiders, ants,
lizards, etc. during molts. Therefore, mantises will try to regain fortitude after molting as quickly as possible. Depending upon the stage
of the mantis, molting could take as little as a few minutes to more than an hour. The molt from first instar to second, which was the
first molt, usually only occurs over few minutes, whereas the final molt requires considerably more time to complete due to the need
for expansion of the two pairs of wings.
Occasionally, mismoltings occur where the mantis is trapped inside its own (old) exoskeleton. Some mantids are able to survive the
ordeal with only slightly deformed legs, resulting from the mismolt and are able to fix the deformed leg with future molts. Infrequently,
some are not as fortunate and become entangled in the process of mismoltings, which could be fatal. Mantids are capable of surviving
another molt with a single deformed middle or hind leg, but mismolting with trapped front legs in its old exoskeleton is generally fatal.
The mantis may survive, but failure to use the deformed front legs to hunt for prey would eventually lead to death due to starvation.
|Figure 2.7-2: An unfortunately S. carolina (adult female) failed on final molt
with trapped front legs and partially expanded wings
Sometimes the final molt results in wrinkled or unfolded wings, which may impede flight and mating as shown in the adult female
specimen in the following photograph.
|Figure 2.7-3: S. carolina (adult female) without properly folded wings