Strangely I am losing Iris here and there. Even sprayed them. What is getting at them?
what are you spraying with.. if you dont know what you are spraying for???? .... and is it labeled for such??
What kind of iris? Various insects will nibble the foliage and iris borers can burrow into the rhizomatous kind and eventually destroy the plant but no insect will make iris vanish :-) You are either looking at a larger critter or they have rotted away.
I've had deer eat TB iris early in the season.
Underground pests like voles and chipmunks will feast on the roots of Siberian iris and Japanese iris. I lost much of an entire garden (iris and other perennials) about ten years ago to these demons. Then I waged war on them--no prisoners taken. I was successful but have to keep it up or they come back. Those plants that had shreds left took years to recover but they did come back.