GREATER MILWAUKEE ROSE SOCIETY
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Growing Great Roses
Pests
This page was most recently updated on 3/20/2013
Learn your tolerance level for each of these pests.  You may be comfortable squishing, knocking off, or capturing these bugs.  You may want to bring in chemical sprays. Or perhaps you will be satisfied with introducing beneficial predators.  Learn what works best for you.

Aphids:
  • Appear on the new growth
  • First sign:  small white flecks on growth
  • Suck sap from growth

Thrip:
  • Microscopic, wind-borne insects
  • Burrow into the very center of the bloom
  • Cause small brown blemishes on the petals of white and pastel-colored blooms. 
  • Appear in mid-June; generally disappear by August. 

Spider mites:
  • Appear at the base of the rose plant
  • Live on the underside of the leaves; not always noticeable at first. 
  • Leaves dry out and fall off
  • A strong spray of water on the underside of the leaves will help dislodge the spider mites and lessen the problem.
  • However, you will need to keep repeating this process.

Japanese Beetles:
  • Are large and easy to see.
  • Most commonly found on pastel, fragrant roses
  • Will eat the blooms and leaves
  • Do not crush beetles; releases a pheromone that will attract even more beetles to your garden.
  • Knock off into soapy water and dispose.  Japanese beetle traps will only attract more to your garden.