skip to main content

Control of Rose Stem Sawflies

14 years ago

Hi,

I am looking for something that can control rose stem sawflies before they damage rose canes.

Most people recommend cutting and burning the canes after they are infected, but I am tired of losing all my new canes to these pests every year.

I try to be organic as much as possible, but a chemical is fine as long as it can be used on food crops (I want to avoid the kind of product where you can't plant edible crops in that area for several years if possible), since the season of these pests only lasts one month or so.

I have over 100 roses, so anything that could help this would be a great benefit. Would anyone happen to have any ideas?

Thanks very much in advance!

Sort by:Oldest

Comments (5)

michaelg
14 years ago
At the appropriate time (midsummer here), I start scouting for randomly wilted growth tips. Stems with worms in them feel hollow; also one of the kinds here girdles the growth tip two leaves from the top when laying eggs. I am usually able to save all but a foot or so of stem. As you know, they will destroy a six-foot cane if not found early.

If you want to try a chemical, try spinosad applied to the new growth a couple of times during the period that eggs are being laid (you'll have to look that up for your area). Spinosad has a good environmental profile and won't encourage spider mites, but don't spray it into open flowers. It is sold as Ferti-lome Borer, Bagworm etc., and as Monterey Insect Spray.

I think the western version of this insect is known as the Raspberry Horntail.
Hepatica
Original Author
14 years ago
Hi Michael,

Thanks so much for the tip! I went to my local nursery today and bought a bottle of spinosad.

I'm very glad that you told about spinosad, as I can feel safe using it around my vegetables and herbs.

I was about to give up and try a systemic product that can't be used on food crops, but I was uncomfortable because we have a dog and he likes play in our back yard.

Thanks so much!
Related Discussions
Organic ways for pest control on roses
Q
Comments (15)
I went no-spray many years ago. Encouraging birds, lizards, toads & frogs helped a lot. The rose area has a couple of bird feeders, three waters, including one big plant platter on the ground that the frogs love to soak in. Has some large rocks in it so tiny birds feel safe using it for baths & drinking. Please, NO OFFENSE intended, but I didn't have outdoor cats or dogs, which helps if you're trying to establish a wildlife-friendly yard. Yes, I LOVE pets!!! If you have outdoor pets, maybe you can place feeders & water in more raised or sheltered locations. Hang a few bird houses in sheltered places & I'm careful not to disturb bird nests in nearby shrubs & trees. My dad's fruit trees (also native species) attract birds, too. They sample a bit, but do little harm. A few overturned broken pots under shrubs make good toad hideouts. I have sprayed the veggies & some herbs that were getting gobbled. Used a solution of blender-shredded artemisia leaves--bitterest stuff I could think of--& it seemed to work. So now I clip stems & leaves to mulch them around the affected plants. Good luck.
...See More
Sawflies,sawflies and carpenter bees...
Q
Comments (3)
Thank, this is a very smart post. The term "borer" confuses a lit of people. Holes in cut cane ends signal the relatively benign ones, which are small carpenter bees and certain beneficial pygmy wasps. These are not eating the rose stem; they are just using a small bit of it for a nursery. The SCB, which looks like a large winged black ant, eats only pollen and is a major pollinator. The tiny wasps eat aphids and other small pest insects. I stopped worrying about these 25 years ago. I don't seal cane ends, and I don't prune out the bored cane ends except during spring pruning. Maybe one out of 500 hundred of these goes deep enough to ruin a cane. On the other hand, the rose stem sawfly larvae will ruin every infested cane unless you catch it early. Look for wilted growth tips on one or a few canes when the rest of the roses look perky. Squeeze canes a foot or two below the wilted tip, checking for hollowness. Look for girdling cuts in the bark near the tip. The villain is a white segmented worm with a black head. It does not enter cut cane ends, but comes from eggs laid near the growth tip. If not discovered and killed, it eats its way down the length of a cane.
...See More
Is there an organic control for sawfly larvae?
Q
Comments (18)
There are a couple of things that you can use to distinguish most sawfly larvae from caterpillars (with the exception of the slug sawflies and some of the stem borers). Look on the underside. There are three jointed legs on the segments following the head (on the thorax). After these, on the abdomen you'll see fleshy things that look like legs (called prolegs) and serve the same function. If there are 6 or more pairs or these things (including the one at the back end) then it's a sawfly larva. Sawfly larvae also do not have velcro-like grippers at the ends of these pro-legs. Caterpillars do but they're not always easy to spot, even with a good hand lens. A good link that shows a side view of a CATERPILLAR (identifying true legs, prolegs, etc.) is below. Hope this helps. Regards, Colin Here is a link that might be useful: Caterpillars
...See More
Is this the (adult) Rose Sawfly?
Q
Comments (2)
Those are baby katydids. They very much enjoy eating plants, flowers and leaves. I usually have cicada killers that also eat katydids and grasshoppers. Praying mantis and large spiders will also get rid of them. Sawfly are a very large group. here is a photo of the slugs that feed on roses and pear trees Rose and pear slugs (sawflies) - Missouri Botanical Garden
...See More
michaelg
14 years ago
Let us hear what happens.

Another possibility is azadirachtin, which is somewhat systemic but quite safe for non-insects.
barb_roselover_in
14 years ago
Don't mean to horn in on your post, but wonder just how much of this would be used in a gallon of water or even half gallon? Thanks for the help! - barb
michaelg
14 years ago
Follow the label exactly for mixing any pesticide.

Related Stories

GARDENING GUIDES Great Design Plant: Knock Out Roses

By J. Peterson Garden Design

As glorious as their high-maintenance kin for a fraction of the work, Knock Out roses make even beginners look like garden stars

GARDENING GUIDES What Kind of Roses Should You Grow?

By Noelle Johnson Landscape Consulting

Want to add the beauty of roses to your garden? Find out which ones, from old-fashioned to modern, are right for you

WINTER GARDENING Pruning Secrets for Exquisite Roses

By Annie Thornton

Encourage gorgeous blooms year after year with this time-tested advice on how to prune your rosebush in winter for health and shape

GARDENING GUIDES 5 Sweet to Spirited Pink Roses for an Enchanting Garden

By J. Peterson Garden Design

Whether you go demure or daring, there's a pink rose here to make you flush with garden pride

FLOWERS 10 Beautifully Blossoming Spring Centerpieces

By Samantha Schoech

Pick a single stem or gather a bouquet. Whatever your style, there's a fresh spring floral arrangement here for you

GARDENING GUIDES This Fly Is One of the Most Beneficial Insects Around

By Pollination Press LLC

Meet the syrphid fly, a colorful pollinator that also beats chemicals for controlling aphids and other garden pests

WINTER GARDENING California Gardener's January Checklist

Winter-defying blooms and pruning saws earn a cheer, while California-focused gardening design books get a well-deserved shout-out

GARDENING GUIDES Sweet Serendipity: Opening to Happy Garden Discoveries

By Jay Sifford Garden Design

Unplanned nature scenes can be unbelievably beautiful; you just need to know how to look

CONTAINER GARDENS 7 Deer-Resistant Flowers for Your Summer Containers

Grow these as protection for edibles or just for their colorful beauty — deer might not like them, but everyone else will

EARTH DAY 5 Ideas for a More Earth-Friendly Garden

By Benjamin Vogt / Monarch Gardens

Consider increasing the size of garden beds, filtering rainwater and using plants to reduce energy use

Sponsored

More Discussions

Etsy roses sellers we can trust.

252

Thierry Marx is not happy!

25

My Evelyn rose has very pale leaves

24

Rose Breeders in Central and South America?

3

Just posting healthy pics as a reference...

2