Particle effect before spawn enemy

Hello, i want to made a dual stick shooter game.

what I would try to do is that before the spawn was created a small particle. But I have no idea how to do.

This is the script that i use for the enemy spawn

public class enemySpawner : MonoBehaviour { public GameObject enemyType; public float spawnRadius = 10.0f; public float spawnDelay = 0.7f;

 void Start () 
 {
     Invoke ("SpawnEnemy",spawnDelay);
 }

 void SpawnEnemy () 
 {
     //Vector3 spawnPosition = transform.position + ((Vector3)Random.insideUnitCircle).normalized * spawnRadius;
     Vector3 spawnPosition = new Vector3 (Random.Range (-17,18),Random.Range (-10,-8),0);
     Instantiate (enemyType, spawnPosition, enemyType.transform.rotation);
     Invoke ("SpawnEnemy", spawnDelay);
 }

 void OnDrawGizmosSelected () 
 {
     Gizmos.DrawWireSphere (transform.position, spawnRadius);
 }

}

thanks for the help!!