Vi - The iris borers would not be in the bed in the form you are looking for. They start out very small in the mid-fan height area and chew their way down towards the rhizome. They eat other borers on the way down getting as big as your photos. They then go into a cocoon of sorts which would be in the soil until they hatch as moths.
Finding them now in the stage you did is surprising to me. This puts you about three months behind a "normal" iris borer schedule. This and having multiple borers in the same rhizome is unusual at best.
