I have a lot of Iris rot this year. What is the cause?

Question:I know of two causes. One simple old age and two those flies or whatever that lay eggs on the leaves which hatch into grubs and eat the rhizome alive and cause it to get mushy.

Amazingly I had beautiful flowers coming out of absolute mush. These would fall still gorgeous as the base of the plant died seemingly very quickly.

I have ripped up all the infected plants and destroyed them but I have found no evidence of maggots. Should I see worms this time of year?

I am really upset. These are my prized possessions. I have bought these iris from all over the country via Ebay.

I guess I should have used bone meal. I forgot this year. Would that help?

What do the flies look like? Are they tiny knat like?

Should I try to savage some of the plants. That is cut away the mush part and replant the healthy parts.

Or should I destroy them all to make sure no parasites make it to adulthood?

Answers:
my cousins name was iris, and she died of old age, just wait. she was a funny woman with a big butt.