I think you might be referring to leaf cutter bees. They make circular cuts on leaves (rose leaves  are most often used) and use the leaves to make their solitary nests. They are important pollinators and so, generally, it doesn't make any sense to treat for them. 

https://www.fs.usda.gov/wildflowers/pollinators/pollinator-of-the-month/megachile_bees.shtml 

Not sure what you mean by larva - they aren't part of the leaf cutter bee life cycle to see cutting the  leaves. It is the bee itself. Is there another insect, possibly? Feel free to email me directly or respond through this AE system. Chip Bubl OSU Extension Agent/Columbia (retired) <personal data hidden>