Hello,

Thank you for reaching out to us about this!

It is best to leave the ootheca be until is hatches in the Spring. Chinese mantids (Tenodera sinensis) are a non-native species, but they are not an invasive species. They are important general predators in our landscapes that provide valuable and natural pest control services (like feeding on invasive spotted lanternflies). Conservation of beneficial insects, like predatory mantids, is key when it comes to supporting sustainable landscapes and ecosystems. 

You can keep an eye on the ootheca through the coming months and once it has hatched then you can easily place the ootheca into a container to have for educational purposes. You would not have to do anything special with the egg case to preserve it once it hatches. Currently the ootheca has hundreds of immature mantids inside. I would not recommend trying to preserve the ootheca at this time. I would also not recommend placing the ootheca into a container or bringing it indoors. Keep the ootheca outside so it can go through the natural course of climatic changes and seasonal cues. A container could crowd and harm any mantids that try to emerge-- we have unfortunately seen this happen many times; they need their space and are best kept where they were naturally laid outdoors. 

There unfortunately is a lot of misinformation (non-science based information) out there about Chinese mantids, as it has become a controversial topic. But going off of the science-based information and facts, Chinese mantids have not been shown to be a significant environmental threat. Chinese mantids have been in the United States since the late 1800s and have become a part of our local ecology. There are also three other non-native mantis species currently found in Maryland. There unfortunately are records that our one native mantis species, the Carolina mantis (Stagmomantis carolina), has declining populations, but like many of our native species that are declining, the decline is caused by a combination of abiotic (non-living) and biotic (living) factors. The top things we can do to support our native insects is to decrease pesticide use and utilize more sustainable forms of pest control like conserving natural predators and parasitoids. 

There is also research that shows Chinese mantis ootheca are overwintering hosts for different native parasitic wasp species (parasitic wasp species that help to naturally control insect pests like stink bugs). Come spring any parasitic wasps inside the ootheca would emerge with the remaining mantid nymphs. You can spot parasitoid emergence by looking for tiny holes in the ootheca in the late spring/early summer. Very cool to see! 

In other words many Chinese mantid ootheca and other mantid species ootheca may be housing other beneficial insects. Many parasitic wasp species, native bee species, and other beneficial insects seek shelter around this time of year so they may survive the cold winter months and emerge in the spring. Shelter could include ootheca, other insect eggs or hosts, fallen leaves, rock piles, brush piles, plant stems, etc. 

If you would like to preserve the adult mantid, you could place the adult mantid into a container and then into the freezer. I would recommend keeping the adult mantid in the freezer for at least two weeks or until you are ready to pin the specimen. Please note it is best to pin the specimen soon after removing it from the freezer for the best results and to minimize the potential of breakage. Once out of the freezer an insect specimen becomes more and more brittle over time. The specimen is most "pliable" right out of the freezer. Forewarning, insect specimens, especially a large adult mantis may appear like its moving (limbs moving) as it defrosts (once you pull it out of the freezer). Since mantids have a soft abdomen the specimen will likely be stinky once it sits outside the freezer in whatever display case you decide to place it in. The smell is normal and it is generally recommended to place moth balls or crystals (packaged) in the same display case as pinned insect specimens, to deter other insects like dermestid beetles from feeding on the preserved specimens. The moth crystals/balls will need to be replaced once they naturally dissipate. 

Please be sure you reference credible, science-based sources when discussing the life history of the Chinese mantis and other mantid species. We want to ensure we do not encourage the general public to target non-native species like the Chinese mantis. Please feel free to reply if you have any further questions.

Thank you for reaching out!

-M. Potter