Destroying gameobject after its been cloned

I know that the script is accessing it after every clone, but how am i meant to delete a asset that is being used in the script? I dont want it in the scene after a few seconds. (player has to dodge them)

Thanks

 var theObject:GameObject;
 var maxPosx:float = 2.898618; // x axis
 var minPosx:float = -1.89557; // x axis
 var delay:float = 0.5; // delay each spawned item by 0.5
 var maxPosy:float = 5.086665; // y axis
 var minPosy:float = 5.086665; // y axis
 
 var lifeTime = 1.0;
  
 function Start(){
     StartCoroutine(spawn());
 }
  
     function spawn() : IEnumerator {
         for (;;) {
            yield WaitForSeconds(delay);
            var theNewPos= new Vector3 (Random.Range(minPosx,maxPosx),Random.Range(minPosy,maxPosy),0);
            var go : GameObject = Instantiate(theObject);
            go.transform.position = theNewPos;
            Destroy(theObject, lifeTime);
         }
 
     }