Holes In Leaves Due To Sawfly
The sawfly larva is a gray caterpillar with dark stripes. Working at night, it feeds on foliage of many flowers, often skeletonizing the lower leaves, and may defoliate the plant.
If there are just a few, go out after dark and pick them off by hand and (drop)them into a plastic bag for the trash.
For heavier infestations spray the foliage of vulnerable plants with an insecticide product containing Bt (Bacillus thuringiensis) just as the young caterpillars begin feeding. They will ingest the bacteria, sicken, stop eating and die in a matter of days. Repeat the Bt spray if it rains.
Natural Insecticdes
AzaMax will control this pest insect
AzaMax is a natural product with a broad spectrum of pest control and broad plant applications. AzaMax is an anti-feedant and insect growth regulator which control (kills) pests through starvation and growth disruption within two or three days. Therefore this product is used when the bugger is chomping on the foliage. Any of the sprayers can be used to apply AzaMax
For more information about AzaMax go to the Yardener's Tool Shed; click here