Return to the Garden Clinic Forum | Post a Follow-Up

 o
I need a safe killer for sawflies

Posted by ms_minnamouse 7a (My Page) on
Tue, Mar 31, 09 at 0:48

Every year my hardy hibiscus get covered with sawfly larvae and they end up looking horrible. One year I used Systemic stuff and it was great but it's highly toxic, from what I understand.

We get a lot of hummingbirds, especially around my hibiscus and I don't want to poison them. Is there anything safe that I can use to kill the sawflies? Are there any safe but effective systemic products? Or do systemic chemicals not leach into the plant's nectar?

I don't want to use beneficial insects because I don't want them getting into my butterfly garden and killing the caterpillars.


Follow-Up Postings:

 o
RE: I need a safe killer for sawflies

Although it has not been extensively studied there are some reports that systemic pesticides are part of the problem with Colony Collapse Disorder that is causing the loss of so many bees today. I find that squishing the larva on my Hibiscus, or spraying with an insecticidal soap, is as effective as any thing else.


 o
RE: I need a safe killer for sawflies

kimmsr, why do even mention the weak reports about the relationship of systemics and Bee Colony Collapse? These conclusions were based on isolated and observational evidence. Not very scientific.

I would add that insecticidal soap must be reapplied every couple of days as larva hatch since the soap is a contact insecticide and has no residual effect. It is important that responders to these questions provide correct and complete answers otherwise don't answer.


 o
RE: I need a safe killer for sawflies

ms minna, I think you'll find that commercial insecticidal soap will do a good job for you. Yes, it needs to come into contact with those darned insects for it to work, but a good spraying can wipe out an entire generation of sawflies all at once. I've found that once you get the population under control, sawfly larvae are easy to manage by hand removal.

Systemics are found in nectar and pollen, so you are right to avoid using them if you have those kinds of plants in your garden.


 o
RE: I need a safe killer for sawflies

  • Posted by jean001 z8aPortland, OR (My Page) on
    Tue, Mar 31, 09 at 14:17

Systemics are of minimal if any value for chewing pests.

The above mentioned direct hits of insecticidal soap will work on youngsters.

But so, too, will handpicking if the plant is of a reasonable size.


 o
RE: I need a safe killer for sawflies

There's thousands as I have a row of these plants. And they get very tall, they're 'Moy Grande'. So hand picking isn't practical.

It's going to take a heck of a lot of insecticidal soap and I've tried it before, various brands, and it didn't make a dent.

The systemic DID make a HUGE difference. What do you mean "Systemics are of minimal if any value for chewing pests."??


 o
RE: I need a safe killer for sawflies

I used insecticidal soap last year for the first time on pine sawfly larva and it worked like a champ. Used concentrate mixed in a sprayer (about a gallon). Had some left over and used it on mugo pines of two of my neighbors. We were all happy with the results.

tj


 o
RE: I need a safe killer for sawflies

"What do you mean "Systemics are of minimal if any value for chewing pests"
Jean001,

I would also be interested in what you mean by this.

Schmoo


 o
RE: I need a safe killer for sawflies

Well, I contacted Bonide about their systemic insect killers and they said yes, anything systemic would get into the nectar. So I looks like I'm stuck spraying the hibiscus down weekly with neem or something.

Insecticidal soap isn't very safe either, is it?


 o
RE: I need a safe killer for sawflies

Insecticidal soaps are considered a very safe (and organic) control for soft bodied insects. The commercial products (such as Safers Soap) are especially manufactured to break down the cuticle of the critter, causing dehydration and death in a very short time. These products are not effective against hard-bodied insects.

They are called 'Insecticidal Soaps' because that is the only purpose for which they are manufactured. They are much harsher on the insect's soft exoskeleton than home-made versions. These products also have a label, with precise directions for mixing and application. I consider that to be a huge benefit.

To get the most out of an IS application, apply in the early evening so that it doesn't evaporate quickly. Product must come into contact with the pests in order for it to work. Also, there will be less chance of foliar burn. Do NOT mix the product any stronger than the directions call for, and do not apply more frequently than directed to do so. Over applications can also cause burn.

If you have naturally hard water, use a bit of Calgon in the sprayer.


 o
RE: I need a safe killer for sawflies

  • Posted by jean001 z8aPortland, OR (My Page) on
    Thu, Apr 2, 09 at 15:06

It was asked: ""What do you mean "Systemics are of minimal if any value for chewing pests"
Jean001,
I would also be interested in what you mean by this."

The commonly believed notion is that systemics are distributed throughout a plant. But not necessarily so.

Another commonly held belief is that systemics are effective against all insects and mites. But not so, not ever.

Then, too, some pesticides are "systemic" only in that they travel from the upper leaf surface to the lower surface.

Systemics are used in managing sucking pests, but function at peak efficiency only if applied under the correct conditions and if the plant is growing vigorously. With stressed or poorly growing plants, the systemic isn't readily distributed through the appropriate plant parts.

When it comes to chewing pests such as sawflies and others, the keys to success with a pesticide are direct contact with the critter (as with insecticidal soap and more) or a residue on the plant part which the critter eats.

Of course, there's always hand-to-hand combat.

Sawflies are chewers. You need to deal with them directly. Further, your pesticide of choice must be applied while the beasts are young -- that is when they are small. If applied later on, they can "escape" the effects and ultimately become a mating & egg-laying adult.


 o
RE: I need a safe killer for sawflies

jean001,

Concerning the comments on systemics....to keep it simple, your comments are "mostly" true (in the chemical world, if it penetrates into the plant, its systemic...but there is a LOT of variation in what the chemicals do from there. Your example "they travel from the upper leaf surface to the lower surface" is termed locally systemic, there are others that do more than that).
But when you add "not ever", that may be close to "over simplifying" it in my opinion.

Schmoo


 o
RE: I need a safe killer for sawflies

Because the manufacturers of systemic poisons do not target bees they are not required to test their products to see if they are a cause of problems with the loss of bees, therefore most of the information that is available about how systemics affect bees is annecdotal.
Until the USEPA and USFDA are required to do the job they were meant to do this wil not change.
If you follow simple logic, a systemic poison spreads throughout a plants system, and that would then include the pollen, then systemic poisons must adversly affect the health of pollinators, bees.


 o
RE: I need a safe killer for sawflies

"If you follow simple logic"

kimmsr,

Please educate us on the facts and truths you use to support your "logic".

Schmoo


 o
RE: I need a safe killer for sawflies

There seems to be a lot of debate here on what systemic actually entails or accomplishes.

I'll be waiting anxiously for the day they create safe systemics. Safe to everything but the pest insects.


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Garden Clinic Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here