Caterpillar is tiny, now about three weeks old and only 20mm long, feeds on a variety of plants including Poplar tree, Amelanchier bush and Verbena Bonariensis. It looked as if it was cannabalistic but have discovered that the "bits" were casts as the creature grew. Had never seen one before but discovered it is a Vapourer Moth caterpillar.
VERY interersting  moth. Check it out.
 
Anyone else seen these little things?