I'm unaware of even an unofficial estimate. They are widespread and certainly not an endangered species.
there are approximately 1,800 species of praying mantis.
1800 known species of praying mantids.
4
there is only one in the world
The praying mantis (Mantis religiosa) is not endangered anywhere. There are many other types of mantises, sometimes called "praying mantises" colloquially, around the world though, and some of them are endangered.
Praying Mantises eat many small insects, including grubs.
yes, and no at the same time. There are some extremely endangered species of praying mantises as of 2011. Yet there are still many species that are thriving in the eastern united states and in Australia.
the praying mantis eats all of the slugs and other bugs such as ants and pests that eat your flowers and plants.
They lay about 3-4 eggs in a month after maried.
Many insects breathe through spiracles, holes in their exoskeletons. See the related link for more information. Red blood cells collect oxygen that happens to enter the tubes. This is a passive form of respiration, so oxygen is not actually pulled in, it just happens to be there. Most insects breath this way, and that is why they don't get very big.
last year the mantises must have laid more eggs and over 200 mantis come out of one egg!
female mantids lay up to 5 oothecas each ooth containing 200 to 400 eggs but only a quarter will survive till adulthood
Dozens at least, maybe more.
I suggest you that you check the sites. it has so many variates.
So many variates are available in market those are not expansive with updated features.