Tamarixia radiata. These wasps FEED on the citrus psyllid which causes citrus greening (HLB).
I opened the container and placed these little guys next to my citrus within minutes of it being delivered. They shipped with a cool pack too. They are TINY. Perhaps you can see them of the slip of paper inside the container? Below are the details and instructions.
Apply here for your own wasps to release on your citrus.
Read more about the wasps here.
