Well, I've found it to be somewhat more of an individual thing, as to the female sometimes waiting until the second shed, it's hard to give an absolute answer one way or another. But i.e., this is what FR was basically referring to. This second shed often coincides with the right time the females follicles tend to be ready to be fertilized.
I can also relate to exactly what he was talking about in regards to palpating the female, as I have done it many times before, but basically, I just keep introducing them to each other after the first post brumation shed, and continue doing so about every week or so until something happens. After all, if you introduce them fairly early, and continue doing this, something is bound to take place in the middle somewhere..LOL!
To palpate a female, I use some pressure starting about half way down her length with the tip of the thumb pressing in her ventral surface(belly). As you gently glide your thumb down her belly with a little pressure, you can feel your thumb going past some soft lumps, these are the unfertilized eggs referred to.
hope this helps, ~Doug
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"Better to be silent and thought a fool, than to open mouth and remove any doubt!"