When do sawflies (rose and berberis) stop breeding?

Nollie

I have been plagued with both this year, on the roses for the first time. My berberis are on their third set of foliage and picking them off them and the rose leaves is an endless battle I’m clearly losing. Please tell me when this will be over!

When they finally stop multiplying, I plan to clear up underneath and scrape off and bin the mulch around the plants to try get any over-winterers, then remulch with pine bark chips (allegedly a hostile environment for the grubs) but is this a waste of time?  How do you cope/defeat them?

peteS

@Nollie...it's incredible how they have become such a problem this year. I've been growing roses for about 4-5 years now and never had even the slightest problem from them in that time. But this year they are everywhere. Whether it has been one of those  freak years, and it's a one off I don't know...hope so.

Pianoplayer

Hi @Nollie, I too had a problem this year, and my endless googling indicated that they generally only have one generation per year, so it is unusual that you are still seeing them. I can only assume it is the weird seasonal pattern we have had this year. Stopping the overwintering is a good idea. Good luck!

edhelka

I had them too but they either only had one life cycle or stopped being a problem after July. Maybe you have a different type.

Nollie

It does seem to be a bumper year for them, doesn’t it? Maybe it’s climate change/milder winters? Who knows. I definitely have more than one type, I have certainly seen the all-black bristly rose sawflies (cladius difformis) which has multiple cycles and I have the curled rose sawfly that still seem to be laying - the tiny slugs are cunningly disguised curled up on the underside of leaves so really difficult to spot.

Same bumper year with the Berberis - this year I have had three cycles and normally I only get one.

I take it the bristly rose ones aren’t in the UK then, if you are all only getting one cycle. At least you can all comfort yourselves with that!