Preying mantis egg cases, also known as oothecae, can regularly be bought from insect breeders. For anyone who wants to keep preying mantids as pets they make an ideal way to start. The reason is that preying mantis don’t tend to live too long so buying an adult means you may only have your pet for a few months, maybe less. On the other end of the scale, baby mantids can be quite fragile and difficult to raise unless you have some experience.
The egg case, or ootheca, though is the best way to start. They are easy to care for. They should yield 100+ babies when they hatch and so even if you lose half of them before they become adults you will still have a good number of mantids. And because you have them from babies, you will have your pets for the longest time possible.
OK, so with that said, assuming you have managed to get hold of an ootheca, what on earth do you do next?
Over the years I have tried a variety of different rearing techniques until coming up with the method that seems to work best for me.
Building The Incubator
You will need:
– Glass or plastic container of around 30cm in all directions with a close-fitting lid
– Heat mat (available from specialist reptile shops)
– Plenty of fine twigs
– Some water
– Your egg case
There are two things to appreciate when it comes to understanding the rearing of baby praying mantids. Firstly, mantis oothecae really like a warm, humid environment if they are to hatch properly. Secondly, the babies, when they hatch, are not only quite fragile but also carnivorous so will readily set about eating their siblings.
So take your container and stuff the twigs in to create a fine mesh in which the baby mantids can hide, stand and change their skins when they hatch. The more densely-packed these twigs are (within reason) the more hiding places there will be.
Next carefully place the ootheca near the top of the cage with plenty of space beneath it. When it hatches the babies fall out on a long thread so they need to space to drop some distance after emerging.
Finally add a little water to help increase the humidity, close the lid and then place the cage half on and half off your heat mat.
Now you wait…
When Your Praying Mantis Egg Case Hatches
One day you will look into the cage to find dozens or even hundreds of babies running around. These first few weeks are crucial to the success of your project.
Firstly, try to keep the container reasonably humid without it getting sopping wet. You will have so many babies that you won’t really want to go cleaning them out so it is better to add a little water at a time than to throw in a whole load and need to try and remove some.
Secondly, as previously mentioned, these babies are carnivorous so will try to eat each other. This is one reason why we provided so many hiding places to reduce this but it is nature at work. To lessen this even further try adding some food for the babies to eat.
Personally I use fruit flies and/or hatchling pinhead crickets and try to ensure there is *always* plenty of food available for the babies.
Keep the babies in this way until they are around an inch or so in length and they will then be over the hardest time so can be caged up individually. If you find you have too many babies left at this time, you can simply leave them together a little longer to let nature takes it’s course or you can sell off the excess to other keepers.