Identification

• Damaged plants will grow healthy leaves.foglie di rose image by marco c. from Fotolia.com
  
  Check the undersides of chewed leaves for sawfly larvae. According to the University of Minnesota Extension, the larvae are light green with orange heads and can reach 3/4 inch in length. Three species of sawflies feed on rose foliage: roseslug (Endelomyia aethiops), bristly roseslug (Cladius difformis) and curled rose sawfly (Allantus cinctus).
  
  

Damage

• Sawfly larvae eat most of a leaf's green tissue, leaving behind a thin layer of clear or brown tissue and veins. The leaf will be left with a "window-pane" or skeleton-like appearance.
  
  

Scouting

• Scout for sawfly larvae in early May. The University of Minnesota Extension reports that roseslugs feed through June and don't return until the next season. The curled rose sawfly also has one generation yearly; but the bristly roseslug has several generations in one summer.
  
  

Control I

• The University of Minnesota Extension advises controlling sawflies at the larval stage since some adults, such as bristly roseslugs, feed on roses and lay eggs on stems or leaves, launching their next generation.
  
  

Control II

• If the number of larvae is small, they can be picked off by hand, dislodged with a stick, or removed with running water. According to the Iowa State University Extension, larger numbers can be controlled with insecticides, such as insecticidal soap, carbaryl (Sevin) or permethrin (Eight).