The actinoids exhibits more number of oxidation states in general than the lanthanoids. This is  because

 the 5f orbitals are more buried than the 4f orbitals

the 5f orbitals extend further from the nucleus than the 4f orbitals 

 there is a similarity between 4f and 5f orbitals in their angular part of the wave function

the actinoids are more reactive than the lanthanoids