BT will not work on rose slugs...Not sure about Neem... Try safers soap or Spinosad...Be careful of the Spinosad as it can kill bees...Follow directions for success! Yes you must check your roses more often and when you see the first signs of damage take action either by handpicking them off or spray...

There is a version of Sluggo that is OMRI

I don’t believe that will work for rose slugs though.

Thank you, I didn't realize that rose slugs weren't caterpillars. I am hoping that my need oil might work. I think I also have some spinosaid around.

Greetings, I have an update about my rose slug problem. I think that predatory wasps are eating them. I unscientifically identified that my predatory wasps are

Genus Polistes - Paper Wasps.

Rose slugs are the larvae of the European sawfly. Look underneath the leaves & smoosh them!

Thanks JM... I have so many rose leaves that I would be out there forever. I checked my leaf undersides and the nasty rose slugs are gone. I am not sure if the wasps took the slugs or if the slugs moved to their next development stage. I think this has been a small battle in a long war against the slugs.

Rose slug damage is very distinct — they nibble at the upper layer or leaf cuticle so if you start to see this damage, look in the general vicinity of the damaged leaves & you should find them. They don’t travel very far.

Cool photos, looks like a yellow jacket wasp to me! Eek!

I had to be very patient to get those pics...lol.. The jacket went from leaf to leaf in search of insects took him awhile to find it...lol

That's so cool!

When I missed covering my pots with landscape fabric and was away for a couple of days the Slugs came out in full force. However, those that had their soil covered with the fabric we're virtually untouched.

The insects that create the rose slugs fly around.

Yes, that's true, but they fall off the leaves and pupate in the soil. I've had my beds covered since last year for midge and it seems to have prevented the sawfly from emerging, as well. My pots are now on the other side of my house from last year and they are the only ones affected. Those pots with new plantings and soil that are isolated also did not get them yet. I'm covering the soil on everything again. I hate to spray.