Parasitic wasp
For every wild collected ootheca, there is always a chance that the ootheca has been infested by parasitic wasp larvae. In this region in
Texas, the
Stagmomantis ootheca became a favorite target for this parasitic wasp to deposit their eggs inside the ootheca using the
long ovipositor.
So far I have seen only one kind of parasitic wasp in this region, but I am not an expert in parasitic wasp so maybe there are more than
one species. The parasitic wasp infested in
Stagmomantis ootheca is likely of Podagrion sp. This species of parasitic wasp appear to
be only infesting
Stagmomantis ootheca, as I have never seen wild collected oothecae of other local species such as Thesprotia
graminis
and Brunneria borealis oothecae being infested.
Parasitic wasp eggs usually develop faster than Stagmomantis egg which required a cool period to hatch. The parasitic wasp larvae
consume the mantis eggs within the ootheca. In Texas, the parasitic wasp hatches out earlier than mantis hatchling too.
The parasitic wasps do not hatch the same way as mantis hatchlings, instead of emerging from the ootheca seam,  the parasitic
wasp hatching out by making a circular hole from either the side and bottom of the ootheca, but seldom from the seam.
Therefore, when incubating wild collected ootheca, be sure to keep the ootheca in a closed system. Parasitic wasp is small enough to
escape between the gaps on mesh screen lid, and may infest the other viable ootheca.
(notice the long ovipositor)