In overlord 2 after finding the blue minions hive, where can i get ALOT more blue minions?

ive gotten the hive but now i need alot more but cant get any. ive tried killing gnomes but i never get any blue, where can i find alot more blue minions? all i have is 5 blue minions now... can i get help on this???... my xbox gamertag is iDz jobojoey