The following information is based on my experiances ONLY.
This is a very beautiful specie of mantids. Subadults to adults are often beautiful green colours or even greenish-blue. This specie is relatively rare, due to the fact that they are hard to keep/ keep alive. I originally got 8 nymphs since then, i have one left. This is to the fact that there are no good care sheets (at least none that I have being able to find) on line.
I have tried o keep them at 50%, 40%, 30% humidity, but they still kept on dieing. At day time, the mantids were kept at 20- 23°C, at night 18- 20°C. I was feeding them every 2nd day, with Fruit Flys, Meal Worms, and Crickets.
I took one mantis, and placed it into a cage which was completely dry. I decided to see how it will do with ~0% humidity. The only way it was gaining moisture, is by eating Fruit flys and Meal Worms, etc. The cage, was actually a 32 Oz cup, which seem more then enaph for an L3 mantis. All of the rest i kept at 20- 30% humidity. Currently, the mantis that i have kept at ~0% humidity, is the only survivor from the eight! The rest just seemed to rot from even such low humidity.
Now, almost 2 month later, that L3 nymph is growing fast :)! During this time, I have never offered him any water. I feel that the only way to keeping this specie, is to never offer them any water.
Sexing your mantids
Males will have 5 or more segments on their abdomen, females less then 5 segments on their abdomen.
As the mantis grows it will shed its skin several times, becoming almost twice larger as before at each stage, until it matures. A general rule, the terrarium's walls on each side should be no smaller then the full grown mantis's length times 2, and The distance from top to bottom should be at least 3 times the size of the mantis. Since both the skin of the mantis and the molt will stretch every so slightly.
Temperatures and Humidity.
They seem to do best at 20- 25°C. Although, i have not tried higher temperatures yet!
I have tried to hatch many oothecas of B. Mendica, but I was always getting mold problems with them. Recently, I got a tip from one of my friends, that they need to be kept at ~0% humidity, with out misting them EVER, until they will hatch. That ootheca have not hatched yet, so I will be adding more information as time progresses.
Breeding Your Mantids.
Did not have a chance to do so, will inform if or when I have.