Setting on a planet divided between a primitive human culture with emerging psi powers, an insectoid (ecological, biological) hive race and a "digger" (underground) race. Keeping balance by attrition (war, raids and invasion). I can't remember the type of "digger" race, not sure if it was reptilian based or other.
Main character is a young female who finds herself developing powers that are out of the accepted norm. Secondary character is a human space explorer (scientist, scout).
I read two books in this series a while ago. The first presented the girl, her society, the balance with the aliens and was involved in her rejection by her society; the consequences to her tribe for not keeping balance; her flight with the survivors; meeting the scout and leaving the planet via psi powers.
The second book was about hiding on a human world; learning to fit in; using and abusing psi powers and rise to power; with a hint that the third book might be returning to the original planet.
I vaguely remember that this book may be written in an open universe, but am not positive.