Rose Bush Leaves Are Splitting

Question From: B. Stevens - Coeur d'Alene, Idaho, United States
Q: leaves on rose bushes show splitting, and a fair amount of being chomped on by some little critter. I first noticed it on my Knockout roses, but see that it's spreading to 2 or 3 others. I've never seen this splitting before...irregular in shape, but if you put the leaves together, the splits fit. I treated my roses with Bayer All-In-One about 3 weeks ago as preventative and fertilizer, and did pour diluted solution over the leaves, then rinsed with water, as directed in the instructions. the rose blooms look healthy at this point, but I'm worried about progression of disease, if that's what it is. Thank you!

A: You've got me stumped on this one. Take samples of the damaged leaves along with photos to a local nursery (not a big box) that specializes in roses. Please share with us what you find. Best And Happy Yardening, Nancy.