Almost never--in fact, I can't remember the last time I sprayed for bugs. The reason I avoid bug spray is that it kills off the good bugs along with the bad bugs. It also often creates more problems later in the rose's cycle--like when you get spider mites as a result of having sprayed earlier for rose slugs.

The fly larvae you are talking about is probably sawfly larvae (I think they are called)--which is what the rest of us call rose slugs--small green worms that hide under the leaves of roses and eat away, creating translucent "windows" in the leaves. You can also find them clinging to the edge of the leaf or shaping themselves to the outlines of the rose bud. They are hard to spot at first, until you get used to looking for them.

What to do about them? Pluck them off the rose and toss them into the grass. Then in a couple weeks, the good bugs will come along and eat up the rest. End of problem--and no good bugs killed in the process. (Same is true for aphids, by the way.)

Good luck.

Kate

I'll ditto everything Kate said.

Yes, I think that's what they were called. I will try that method next year. I've never been able to spot anything doing the "act"! It's odd they only pick certain roses, and leave others unscathed? Dont taste as good?

If the damage looks like the linked photo below, then your problem is sawfly larvae. In terms of likely harm to the environment, I think applying an insecticide is a big step up from applying a fungicide. I've reached a point where I can just ignore, barely, sawfly damage. If you can't, then you might consider that spraying a non-systemic insecticide which kills only what it contacts and doesn't persist very long after application would do the least harm. An insecticidal soap would be one possibility.

Here is a link that might be useful: Sawfly

Mother insects probably locate appropriate host plants for their species according to the way the foliage smells and reflects light. Probably the larvae could eat any rose, but some look better to mama than others.

Mike, yes that's the look exactly. I will see if a topical spray will work next year (too late this year, damage is already done)........IF I can catch them in the act. So the mother lays the eggs on the leaves themselves?

Yes, worms don't move around much (with some exceptions like Eastern Tent Caterpillars).

Tare, we all have rose slugs in the rose patch, and most of us find it unnecessary to spray. Just watch for the damage next season and wipe off the worms when they are still tiny. Remember, they are only on the underside of the leaf.

If you need to spray, please just use WATER - it works for all kinds of bugs, including aphids. If you spray poisons on your plants you will be killing the good bug predators that keep the others under control (not to mention killing the bees, who have enough problems already!), and you will end up with more bad bugs, not fewer.

Jackie

I live in zone 5 too and this year has been really bad for what I believe to be Asian Bettles. The eat the blooms and then they start on the leaves. They obviously preferr some roses than others. I add Malathyon (probably spelled wrong) with my weekly fungus spray and seems to work well. However, in a few days a new bunch are back to work.

I've only seen a couple of beetles so far. Not much is blooming right now in this heat wave (They all head to Abe Darby!)

Jackie, I was talking about spraying the worm itself, not the bush. Would that affect other bugs?

I either use a strong jet of water or a soapy spray made with soft soap diluted with lukewarm water. Then I slip off the aphids or whatever bug it is with my fingers. Works for most insects if you are diligent and have spotted them before any harm is done.

No. It helps to encourage birds by providing the proper habitat--in this garden, birds eat most all of the insects without me having to lift a finger.

Well, the worst damaged plants are my potted roses and I dont think any birds really get to them. They arent in the yard area.............

If they're on container-grown roses, that's even easier, because they're raised up a bit. Look for them toward evening, when the weather cools a little.

Take along a glass of chilled wine. Comb through the leaves, looking for fresh damage, and you'll find 'em, little green caterpillar things, on the underside of the leaves.
If you squish 'em, they "pop" satisfactorily, and no beneficial insects (including bees) are harmed in the process.

It's a very soothing thing to do, at the end of a long day.

Jeri

LOL. Ok. I'll wear gloves though! :)

Don't like the idea of having a green thumb, eh? :)

In my garden, it's wasps rather than birds who do the rose slug patrol. If you see them hovering around the foliage, that's what they are looking for.

LOL. Not really!

I actively hunt slugs, snails and grasshoppers. Aphids get taken off with my hands or a spray of water. Anything toxic - never! I''m happy to have a plethora of insects and wildlife and couldn't stand the idea of hurting any of it - except the baddies of course.

Ingrid

Do I spray for bugs?

Heck yes! If there was a nerve gas that was guaranteed to get rid of thrips, I swear I'd use it. I've been alternating Conserve and Avid all season and it's hopeless. The Avid does reasonably well - much better than the Conserve, despite the literature.

Anyway, other than those things, er ... no. I could care less about aphids, Japanese Beetles, rose slugs, and the stupid Katydids that nip the tops off of new buds. The others are right. Anything else you spray and it's just going to start a spider mite invasion - and the remedy for a major one of those is very expensive (Floramite). I could live with them all (and do) if I could just get rid of the d*mn thrips!!!

I don't exhibit roses so they don't have to be perfect. I don't mind some chomps, chews, curls or phews. I shake rose chafers and rose leaf & Japanese beetles into a bucket of soapy water early in the morning, spray aphids and spider mites and rose slugs off leaves with a strong spray from my hose, and ignore almost all the rest. The one time, and only one time that I will use an insecticide is if I get an infestation of midge, which has happened twice. Midge quickly destroys every bud on all the new growth so you end up with a garden of green leaves and no roses. If you do nothing about them they continue to spread each year until all of your roses are impacted. I've tried a variety of organic approaches for midge but nothing has worked but an insecticide. So twice I have had to bite the bullet, apologize to the environment, and spray with a non-organic insecticide. I did it early in the morning before the bees were active, avoided bird baths & feeders, and dressed like a moon man. Both times they did the trick - but I'm always on the lookout for both midge, and an effective alternative treatment. Got any I haven't tried?

Last year I used safers insecticide soap to kill rose slugs as they were very bad.
It has to be sprayed directly on the rose slug, so spraying upper and underside of leaves is important.

This year I'm letting the wasps and birds do the job.
Hopefully in a few years I can achieve a balance in our garden.

Are rose midges all over the country? I've never had them yet. (Knock Wood!)

Ditto what karenforroses said, treat for midge only, try to use granular products instead of sprays. I'm not sure how much midge has spread, it is a good question, I'll see if I can find out.

The hotspot for rose midge has always been PA, lower NY, NJ, and adjacent areas.

Recently there have been outbreaks in the Midwest and PNW. Midge were first reported in the PNW about 15 years ago. I don't know how much of a problem it currently is there.

From time to time--including right now-- I've seen symptoms that could be midge damage, but I've ignored it and it has gone away. I think there must be some natural controls that keep midge from being chronic except in certain areas.

I would like to add just one thing to the information about sawfly larvae. I find mine on top of the leaves. Apparently there are three kinds: one stays on top; one stays on the bottom; one is bi-sidal (yup, I made up that word).

Mine are definitely topsiders, which actually makes them pretty easy targets for my squashing missions. On the other hand, there are sooooooo many of them on soooooo many roses (more each year it seems) that it is truly impossible to squish them all, and I have resorted to spraying the most bothered roses with Pyganic usually once in the late spring.

Susan

Here is a link that might be useful: Pyganic

Thank you for that info. But where can you buy it outside of wholesalers? Is it stocked in stores? (I've never seen it......) I have so much leaf damage I'm not sure I could keep up with all the manual squashing......

Occasionally has turned into more frequently. I'll get rose slugs and then hit them in late spring. Then these Jap Beetles are terrible this time of year.

I have been using Sevin as it is effective on Japanese Beetles. I also pick them off between sprays or when they aren't as numerous.

In the last couple of years, I've been lucky that I might use a bioinsecticide once or twice a year. Mostly I let mother nature take care of the bad bugs. However, this year has been the worst and I have to believe its due to the strange weather earlier in the growing season. I can't remember when I had thrip this bad. The roses were barely blooming a day when they looked awful. I finally got the thrip under control when I got JB for the first time. Its amazing what four of these things can do to roses in a matter of a day or two. Then the cucumber beetles moved in but I never spray for them. Actually they haven't been that bad. Now the blasted heat is just stressing them out even my willows are begging for relief. I have noticed that I didn't see any lacewings, very few ladybugs and so far no praying mantis either this year. So I'll be reintroducing the lacewings next year and perhaps look into beneficial nematodes.

What do thrips look like and what do they do? I'm seeing some new damage and it isnt from the sawfly. Something is eating the leaves. Caterpillar?

Thrips are 1/20th of an inch, elongated, amber colored, and moving actively. They scrape the petals, causing a dirty-looking, bruised appearance and browning of the petal tips.

Thank God, I dont have that problem yet! Something ate just about all the leaves on a new minirose. :( Just left the stems!

Rebbits will eat off leaflets and leave the leaf stems.

GREAT. Hadnt thought of rabbits. So many foes to battle......

"Thank you for that info. But where can you buy it outside of wholesalers? Is it stocked in stores? (I've never seen it......) I have so much leaf damage I'm not sure I could keep up with all the manual squashing......"

One of my local nurseries carries it.

I'll have to look around. I've never seen it though. Expensive?

OK, I surrender :)

The insecticide pyrethrins, under discussion, is contained in many products with different brand names. For example, you could check labels of "house and garden" aerosols that are sold in supermarkets. Aerosol might be convenient for you. The ingredients are pyrethrins + pepironyl butoxide. Be sure it is labeled for use on plants. This insecticide kills most bugs (good or bad) on contact, but has no residual effect. This means you must reach each insect with the spray. It is considered relatively safe for mammals.

Another low-risk insecticide is spinosad. It is residual but has less effect on beneficial insects. Google the term for brand names. Fertilome, Monterrey, and Gardens Alive are some producers. You want the active ingredient spinosad. It will kill rose slugs. You need a tank sprayer to apply it.

Use insecticides only on plants where there is active damage going on.

Yes, it's expensive.

A quart bought locally has a label that says it cost $49.00. The dilution rate is 3 oz/gallon. (I have to assume I paid an enormous amount of tax in addition)

At Amazon it looks like the same container costs $60. (shipping is probably free)

Here is a link that might be useful: Pyganic at Amazon

Hey, I do NOT advocate spraying.
I do wish I could say I had a "no spray garden".

I try really hard not to cave in, but sometimes the devastation just gets to me and I feel like I need to give the roses a break from the onslaught.

When I do spray I do my best to make it sparing and targeted and I try to use the least damaging stuff I can, even if I have to pay through the nose for it.

All that is to counteract any impression that I think anyone should spray as their first response to insects or disease. Spraying (if I must) is a last and minimal response rather than a way of life....here.

Whew (do I sound defensive????)
Susan who is sorry she sometimes sprays (but has nothing at all on the skunk living under the cottage out back and he's completely natural.....:-))))))))

Yes, I've seen sprays with pyrethrins in stores at a far cheaper price or I may stick with my Bayer insect spray that I use on Japanese beetles (if I can find the slugs!) No slug is worth 60 bucks! (LOL)

Keep in mind that "sprays with pyrethrins" are not all the same. I chose the Pyganic because of the high % of pyrethrin in the concentrate. I can't tell you how many labels I read trying to find something that was just pyrethrins and not mixed with a lot of other stuff I didn't understand well enough to use.

And....it isn't for slugs which are not bugs or insects, they are mollusks for which Sluggo will do the job.

Yes, I understand. But I dont want to invest that kind of money.

Almost never, i don't worry too much about sharing. For Japanese Beetles (who don't like to share) Dawn Dish washing liquid works great

I spray rarely since birds and wasps do most of the work but if I have to spray I use Neem oil because it's effective on most rose problems and minimal impact on other wildlife (including most beneficial insects)