Sawflys....

Rose slugs and other worms on plants come from eggs laid by winged adults. Some have more than one generation per year, or different species may lay eggs at different times in the season.

If leaves or growth tips disappear suddenly, think rabbits or deer (in addition to the worms that you obviously have).

I have fought off Rose Slugs( Sawfly larvae) here since May.
Taking them off the rose bushes & spraying safers insecticide soap and they just keep coming!

So I just recently sprayed with Spinosad to try and get them under control.
( I spray after sun goes down because Spinosad can harm bees while still wet.)

They say Rose Slugs can not crawl back on the bush
after being removed BUT I wonder sometimes...
They could however bury back into the soil and start the process all over again...

Here Rose Slugs are stripping leaves right off the stems & fairly quickly... Some of our roses are in cages so its not animals...We mainly only have rabbits in the neighbors yard..Our yard is closed in by fencing but they still get in once in awhile.

But yes your damage could be a combination of insect and animal...???

1. Sawfly larvae WILL climb back on plants if they are knocked off. I'm curious where you got the information that they wouldn't - I ask because I would like to send that source a correction

2. There is more than one species of sawfly whose larvae feed on roses and, as michaelg said, at least one of them has multiple generations per year. I've never found their damage to be any more than cosmetic, but YMMV.

If you really feel the need to control them, any of the systemic insecticides used on roses will do. But I would strongly recommend you consider leaving it up to natural predators.

Well if Rose Slugs can crawl up a rose bush then
that may explain why I'm not getting anywhere because they are really bad here this year...

I'll try and find that source Nikki.. Matter of fact I've read that in more than one article on Rose Slugs...

All I know is what goes on here in our garden and Rose Slugs can strip off a lot of leaves and cause a lot of unsightly damage...

I don't know -- it looks to me like the aftermath of grasshoppers.

Jeri

I don't know -- it looks to me like the aftermath of grasshoppers.

Jeri

Whether they can or can't crawl back up, new crops of them hatch out all the time. Like aphids, Japanese, Fuller, Curculio and other beetles as well as all other insects which suck or chew the plants, you have to continually battle them during their "season" using whatever methods you've selected. I'm not recommending any method nor attempting to encourage you to go "nuclear" on them, but the less toxic your method, the more interactive you have to be with the control. With more generations regularly hatching from eggs, and more eggs being deposited as long as conditions favor their reproduction, new "slugs" are appearing daily or every few days.

So, if you're knocking them off, picking them off or washing them off, you have to be diligent at it. Pick, knock or wash them off daily or every few days as your time, energy and infestation dictate.

Or, go with an organic control like the bacterial Spinosad, which knocks down all of the hatched slugs at once for two weeks. That has to be sprayed twice monthly unless it's all washed off by a heavy rain. Yes, it can kill the predators, too, but all "insecticides" will.

The point is, you have to determine whether you want to constantly battle them or take stronger measures against them. They not only cause unsightly damage, but ANYTHING which reduces the green leaf area of the rose, inhibits, reduces its ability to feed itself. Reduce the leaf surface area sufficiently and you inhibit the plant's immune system, weaken the plant,by causing it be malnourished, making it more susceptible to other damaging factors such as fungal attacks and potential freeze damage in winter, if that is a possibility where you live. Kim

The below Clemson article states Rose Slugs can not climb back up on to the rose bush after being dislodged.

But I wouldn't count on it... I see them on canes here
so climbing doesn't seem to be a problem for them.
Probably are very slow though... Turtle warp speed....

Here is a link that might be useful: Clemson

That's exactly correct, Jim. I've done the experiment myself placing a larva on the ground next to the bush.

I have a feeling those observations apply to the early instars, which ARE legless slug-like creatures and do not get around all that well. The later instars - the ones that would tend to be the most noticeable - have legs and use them quite effectively.

There are numerous species of sawflies - most plants seem to have at least one species that can use it as a host. Roses have three.

Hi Jeri
We don't get grasshoppers here in London, UK not where I am anyway. I've never seen a grasshopper in London. Maybe I'm wrong if anyone can give more info on that. There are no animals either such as rabbits or deer. The odd occasional fox but nothing else. There are squirrels on the huge oak tree at the end of the garden.
So the consensus is that rose slugs do climb around from plant to plant. I'm going to get some organic insecticide today and start spraying. Will that counter against any type of sawfly larvae?

Higgs

Spinosad is effective on sawfly larvae...

Spinosad is toxic to bees when wet.
So, I spray right after the sun goes down so the spray has time to dry...

Remember all gardens are different. In some gardens rose slugs may only cause minor damage, some others moderate to severe damage. It depends.

Here some damage on our Dogwood bushes from Dogwood Sawfliy larvae... I do not worry to much about these bushes...lol

{{gwi:314601}}

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Ok this Heirloom Rose own-root band was planted by me
about 3.5 weeks ago.
I recently found rose slug damage and 2 mature sized rose slugs on it.
So that leads me to believe Rose Slugs can crawl up into a rose bush...

{{gwi:306801}}

This post was edited by jim1961 on Tue, Aug 20, 13 at 8:29

Link is below but I found this short video on You Tube of a close-up of a rose slug eating a leaf...

Here is a link that might be useful: Rose Slug eating video