An ootheca in a foam mass produced by a praying mantis to house it’s eggs. Ootheca can vary immensely; some can be a few millimetres long, whilst some can stretch up to around 8cm long. There are some species, which will lay large, round foamy ootheca, whereas some will lay short, think, tough ootheca. The amount of nymphs and ootheca hatches also varies; some can hatch up to 10, whereas some can hatch up to 400. Some mantids will only lay 1 or 2 ootheca, whereas some can lay up to 20 in their lives.
There are several different methods of hatching praying mantis ootheca, however I find by far the best method the “string” method.
This is very easy, and this was the method I used to hatch my very first ootheca. First of all, you need to see which type of ootheca you are incubating. It is much easier with larger, foamier ootheca such as Sphodromantis, Hierodula or Idolomantis. However, species such as Creobroter, Phylocrania and Iris Oratoria can be slightly more difficult, as the ootheca are much longer, thinner, and tougher.
Anyway, here it goes. First of all thread a piece of cotton through a needle, (the smaller, sharper the needle the better.) Find a suitable piece of foam at the very top of the ootheca in which you can thread your cotton through, without damaging any eggs. This is very easy with the large ootheca, as the foam is very thick. However, with the thinner ootheca, you might have to sacrifice one or two eggs if you can get through the foam at the top. Alternatively, if the ootheca has been laid on a twig, then you can thread the cotton through the twig.
Once the threading is done, you now need to hang it up for incubation. Depending on the species, you need to incubate them at different temperatures; you can see the care sheets for more information on this. The best container to hang the ootheca in is a small cup, or cricket tub. I always use the cricket tub just because it is slightly ventilated, and I have a lot of them! But either will do fine. By incubating the ootheca in a small container, when the ootheca hatches, the tub can be easily transferred, and put in a larger container/enclosure.
Incubation methods
Bluetack – The ootheca can be stuck onto a surface with bluetack for incubation. However, this will often fall down as the tack looses is “tackiness” when wet.
Superglue – The ootheca can be stuck onto a surface with superglue. This can be another good method, but make sure to use a small amount so the ootheca doesn’t absorb any glue, thus killing off the eggs.
Pin – Instead of threading cotton, you can pin up your ootheca. Although, this might be hard with small ootheca, and you face a chance of killing more eggs.
When hanging/threading the ootheca, please be aware of one factor. The front of the ootheca can be easily defined by a line running down the middle of it. When attaching the ootheca to a surface (if it has not already been laid on a surface), make sure that you do not fix the front of the ootheca. Otherwise, nymphs could face a struggle coming out of the ootheca.