Cantharis 1X (Q) (30ml)SBL Cantharis Vesicatoria(Mother tincture) Common Name: Spanish Fly Blister Beetle This beetle lives on honeysuckle and olive trees in western Asia and southern Europe. The Spanish fly produces a toxic substance called cantharidin. Cantharidin is a strong poison that primarily affects the urinary tract and causes burning pain and vomiting. Causes & Symptoms for SBL Cantharis Vesicatoria (Mother tincture) It is well indicated in complaints occur