dusky birch sawfly

Dusky birch sawfly larvae on river birch. Photo: Lacy L. Hyche, Auburn University, Bugwood.org

Updated: April 21, 2021

About plant bugs

  • Sawflies resemble caterpillars but they are not. Sawfly larvae have more than 5 pairs of prolegs on the abdomen. Common examples include black-headed ash sawfly, dogwood sawfly, and dusky birch sawfly (see above photo). 
  • Sawflies often have shiny red or blackheads and the bodies often have black spots or stripes, and are 2 to 1 inch long.
  • They like to feed in groups and many may be found together feeding on a branch (called gregarious behavior).
  • In light infestations, damage may appear as defoliation on needles of individual branches or shoots.

Management

  • Heavy infestations may cause complete defoliation of conifers.
  • Manually removing and destroying the sawflies may control light infestations. They usually are closely gathered together feeding in the same area of the plant. 
  • Heavy infestations of young larvae may be sprayed with horticultural oil.
dogwood sawfly larvae
Dogwood sawfly larvae
walnut butternut woolyworm larvae
Butternut woollyworm sawfly larvae on black walnut leaf. Photo: D. Clement, UMD
butternut woollyworm adult
Butternut woollyworm adult on leaf. Photo: Lacy L. Hyche, Auburn University, Bugwood.org