Praying Mantid Egg Cases, Tenodera aridifolia

With or Without Twigs Attached: There is no real difference between the egg cases with twigs and those without. It is simply a matter of how the grower harvests the egg cases. If egg cases are to be part of a classroom project and will be handled by younger students, choose the cases with twigs attached for easier handling and less chance of damaging the cases.

Outdoor release instructions for praying mantid egg cases – with or without the twig:

You can attach the egg case(s) to a twig or a plant using a twist-tie or wire tie.  Carefully wrap the wire around the egg case and tie it to a branch in warm location with indirect (filtered) sunlight. Do not hang in the direct sun.  A hanging egg case, especially one that swings or moves with the wind, is safer from birds and other predators.

Note that if your egg case(s) have enough remaining twig, you may be able to omit the twist tie.  If there is enough length to the twig and you have the right sized V-junction between branches or between the branch and trunk so that the egg case can be safely and securely placed in that area, you may be able to position the egg case by wedging the twig and egg case perpendicular to the trunk and branch of the tree or shrub.     

Hatching requires at least 10 to 15 days of continuous warm weather but can take as long as 8 weeks to commence.  Once hatching begins, the young will emerge from the egg cases and will rapidly look for something to eat.  If there are not pest insects nearby, they may resort to cannibalizing their siblings. 

Don’t expect to see any praying mantids emerge.  Once hatching commences, it will be complete within a few hours and the newly hatched mantids disappear rapidly into the vegetation looking for food.  This beneficial is well camouflaged and can seem to disappear – they leave very little evidence of hatching.

Indoor release instructions for praying mantid egg cases – with or without the twig:

Hatching praying mantids indoors can be a fun project for the entire family.  Did you know that many people keep praying mantids as indoor pets?  People compare them to cats in behavior.  If you are interested in raising a a mantid as a pet, there are many websites that can help you to build and maintain a mantid habitat.  However, if you wish to hatch them indoors and release them into the garden, here are some instructions that will help you optimize results.

Make sure that the egg cases are exposed to some humidity or they may dry out.  Dried out egg cases are a leading cause of poor or no hatching from your egg case.  

Any container that has ventilation will do for hatching indoors – the container does not need to be large.  Many people use a brown paper bag to hatch their mantids.  You will want a container that has a lid or that can be closed – if you want to make a lid, use a fine gauge mesh to allow ventilation and provide a place to secure the egg case(s).  It is more fun to be able to view the hatching, so use a translucent container.  For paper bags you can add a viewing window by cutting out a hole in the bag and taping plastic wrap over the hole to create a window. 

Many people recommend that you hang the egg case from the top of the container – this is supported by science as the praying mantids actually rely upon gravity to aid hatching.  You can also, carefully glue the egg case to the inside vertical wall of the container.  Use a low heat glue gun if you wish to attach the egg case with glue.  In either case, the egg cases should be no more than about 4 inches from the bottom of the container.

Again, make sure that the egg cases have some humidity.  A quick spritz with water can help, just don’t allow the egg cases to get wet and remain wet or mold may develop. In addition, as soon as the nymphs begin to emerge, they need water.  One way to cope with both issues is to place a moderately wet paper towel or some moistened coconut fiber in the bottom of the container.  Make sure to keep these moist! 

Praying mantids are cannibalistic, so release them as soon as they begin to hatch or make sure that they have something to consume.  It will take only about 2 hours for all of the nymphs to emerge.  Note that hatching may begin in as few as 10 days (with continuous warm temperatures) or it can take up to 8 weeks.