This can apply to winter whites, campbells, russian hybrids and chinese.
Not sure how common it is for roborovskis to get diabetes :/
I rarely give fruit to mine anyway, but it is extremely rare for either Treo or Bacardi (especially with his brother having diabetes)
They normally will only have it once every few months at most.
so oscar will be fine, but as you don't know his family history of diabetes, just feed very rarely