Here is a great project for any person that loves the outdoors and if you have kids even better. What I’m going to teach you is how to hatch a praying mantis egg case in your own garden so you can enjoy these beautiful and very unusual insects.
I want to start out by saying I’m not a professi0nal entomologist. I’m just a backyard hobbyist that loves to learn and try new things. All the photos and videos in this post are mine and were taken in my gardens here in Brooklyn Park Minnesota. My praying mantis experiment began in April when I was dreaming about the Spring and praying for the snow to melt.
Praying mantis hatch out of egg cases called oothecas. These egg cases start out as a foam and eventually harden. Inside the egg case there can be up to two hundred young nymphs born depending on the species.These egg cases can be bought online through garden supply stores and on Ebay. My recommendation if you can afford it is to buy at least two egg cases just to increase you chance of success. You also want to buy from a reputable place because there are people trying to sell wild collected ooths online that never hatch. I bought my mantis egg cases from a company called Bug Sales and was very happy with the service and all my ooths hatched. I bought 5 Chinese mantis egg cases for around $30 and that includes shipping. The picture below is what a ootheca looks like.
If you live in the United States the two most common praying mantis available are the Chinese mantis (Tenodera sinensis) and the Carolina mantis (Stagmomantis carolina). I went with Chinese praying mantis because they were available but both have almost identical needs when it comes to hatching and rearing the young. If you live in the south you may be able to collect adult mantises and egg cases from the wild. Unfortunately here in Minnesota it is rare to find a wild mantis. I’m 44 years old and have seen about a half dozen wild praying mantises in my life.
Depending upon where you live and what the temperatures are outside I would recommend you hatch some of your oothecas indoors and place a few outdoors and compare your results. I kept the ooths indoors at a temperature of 78 degrees fahrenheit and after about a month they hatched. A couple of times a week I would lightly mist the egg case. I did a post which gets into all the details of hatching oothecas here so I won’t get into great detail here. The photo below is a couple of my egg cases I hatched indoors.
The photo below is a Chinese praying mantis ootheca I placed in my garden which just hatched.
If you hatched your oothecas in the garden and the temperatures are above 60 F and there are lots of prey insects for the mantis to feed on you are good to go.
Now it’s up to you to monitor them and move a few into different areas of your yard. If the young nymphs don’t have bugs to eat they will eat each other. When mine were real small I would find them several hundred feet from where they had hatched. As months went by I did find a few larger nymphs at two different neighbors houses.
You may get over a hundred praying mantis nymphs from one egg case depending on the species so if you plan on raising them indoors your going to need individual containers to house the nymphs and your going to need a constant supply of wingless fruit flies to feed your mantis. As the mantis grow you need to increase the size of the food to house flies or meal worms or crickets. This can be quite labor intensive feeding all these babies. My advice is to make sure the conditions are right outside and just keep a few as pets indoors.
My Chinese praying mantis took four months to reach adult size outside. I did run into some real low temperatures in May down to 42 F at night and 50’s during the day and that slowed down the first hatch of insects here in Minnesota.
The life span of a wild praying mantis is between 10-12 months depending on the climate. Here in Minnesota I would say 6-8 months is more realistic. Once the praying mantis have their final moult they are ready for breeding.
Your going to need a male and a female praying mantis which may seem obvious but in the case of stick insects they can breed without the opposite sex present. There are several differences between the males and females but an easy way is to look at the wings. The wing of the males will extend past their abdomen while the females wing does not quite reach the end of the abdomen. The males use their wings to search for females.
Another way is to count the segment on their abdomens. The female praying mantis will have 6 segments and the males will have 8 segments.
If you plan on breeding your praying mantis indoors I would suggest you use a large cage or even a small room. You should feed your female well before introducing the male to the enclosure. The female praying mantis is known for killing the male after mating so to reduce this chance remove the male after mating and make the sure the female is well fed. You should also monitor the mantises behavior when you introduce them. If the male seems agitated and the female is acting aggressive I would separate them and try introducing them the next day.
After a successful mating the female Chinese praying mantis will begin to lay her oothecas. Chinese praying mantis can lay up to 7 egg cases in a season.
It’s October 16th and the leaves are changing colors and the gardening season is coming to an end. The temperatures have dipped into the low 40F at night and I’ve noticed the bee’s and flies are gone. I spent several hours searching for my adult mantises in hopes of bringing them inside for the winter. My search was unsuccessful and not only did I not find a single mantis I did not find a single ootheca (egg case) either.
I learned a lot and had a blast raising these praying mantises this season and I’ll certainly do it again next year. I hope you enjoyed this post and would love to hear your comments and I encourage you to learn about the wonderful insects around you.