Knowledgebase

Control of Rose Sawfly Larvae #873638

Asked June 18, 2024, 3:06 PM EDT

We had thousands of Sawfly Larvae on our large Lillan Gibson rose this year. I have have been fairly successful picking them off in past seasons, but their numbers were overwhelming. Preumambly we now have thousands of the little buggers in the soil around the plant. Is there some treatment we can use to get at them before they emernge next spring? Maybe diatamtious earth or some other natural treatment? I am not fond of insecticide, but could be persuaded. Thanks in advance for your thoughts.

Hennepin County Minnesota

Expert Response

Hi Henry,

They are such a gross pain ! Hand pick and spray with insecticidal soap. I would experiment with raking around the soil underneath the plants several times after the worms are gone to see if you can disturb the eggs that were laid there. I would also try covering the ground underneath with something you think the worms might not be able to get through. If you have many bushes you might want to try a few different techniques to see what helps.

https://ipm.ucanr.edu/PMG/GARDEN/PLANTS/INVERT/roseslug.html#:~:text=Handpick%20larvae%20or%20clip%20off,%2C%20neem%20oil%2C%20or%20spinosad.

https://extension.umn.edu/yard-and-garden-insects/sawflies

I hope this helps,

Sally Granath

St. Louis County MG

An Ask Extension Expert Replied June 22, 2024, 7:55 AM EDT
Thank you  Sally Granath!  I think I'll try putting down newspaper around the rose and see if that helps. 


On Sat, Jun 22, 2024 at 6:55 AM Ask Extension <<personal data hidden>> wrote:
The Question Asker Replied June 22, 2024, 1:48 PM EDT

Loading ...