Flower thrips feed on flower buds and tips of the branches killing the flower cluster. The scapes have corky lesions. Use rotenone or Sevin.
Mites cause the leaves to turn yellow and have a dusty appearance. Heavy infestations form fine webbing. Applications of rotenone control the pest.
Slugs leave a slime trail which looks like part of the leaf was varnished. Use baits containing Mesurol or metaldehyde.
Japanese beetle can be controlled with sprays of methoxychlor, Sevin, or rotenone.