There is no simple answer to this question. First, both species and subspecies need to be defined, and this varies between people, and there may be different traditions for different taxonomical groups.

Secondly, there are no strict threshold that can be used for distinguishing taxonomic levels, the genetic distances between species varies between taxonomic groups, and also within groups. this may be due to varying mutation rate, and/or speciation rate.

Svante is absolutely right. There is a widely spread misbeliefs that you can simply look at a distance value (anyway what kind of genetic distance p? K2P or other these all differ) and can determine species or subspecies or any category.

All such measures have to be analysed taxonomically thoroughly before drawing far reaching conclusions, especially if you are using one gene fragment.

and one more thing, with ITS it that it often have insertions and/or deletions, which create gaps in the alignment. This makes it very hard to calculate genetic distance. How the gaps are treated can drastically change the estimated distances.

Sure ITS it is almost impossible to align properly in more distant taxa.

Thank so much for you help