I wonder if this would work.

Here is a link that might be useful: Recent data have shown that silicon can increase the degree of resistance of host plants to insect pests.

The problem with Whiteflies is that they reproduce at a rate that makes bunnies look infertile -- so if you kill the current generation of them, you've accomplished little, because a new generation hatches out.

AND you have killed all of the beneficial insects that might have eaten them.

So, using pesticides for Whiteflies is a vicious and frustrating cycle. I've had plenty of opportunity to learn this because over the decades our area has suffered repeated infestations -- and -- guess what? The REASON this has happened over and over is the volume of non-specific pesticides which have been used in the vegetable fields all around here.

So -- if pesticides don't work -- WHAT DOES?
A combination of things.

One of the big changes here has been the fostering -- on a very big scale -- of insects that eat whiteflies. One is a minute predatory wasp -- but there are others. Pesticide use has been greatly reduced in the surrounding fields, and most fields now are surrounded by "insectaries," clumps of host plants and grasses that offer a home to beneficials. The other day, we passed some berry fields which were surrounded by thick hedges of bright annual flowers. It was lovely AND practical. We haven't seen whiteflies now for several years, thank Heaven.

In your own yard, you can do everything possible to attract hummingbirds, which LOOOOOOOOVE to eat whiteflies, right along with aphids. You could look into ordering some predatory insects, and you might contact your Dept. of Agriculture, to find out WHY they are invading at this time.

One thing to do is lose the insecticides. If you're dealing with a whitefly infestation, they do more harm than good.

OH, and you could go around your garden, and see if you can discover what plants are hosting them. You'll find, on the underside of rather broad-leafed plants, oval "racetracks" of powdery white stuff. That's their eggs. You can wipe 'em right off with your fingers, and kill hundreds, right there. It's fun! I've found them on things like begonias, brugmansias, plumerias, citrus ... Not on roses. They don't host them.

Jeri in Coastal Ventura Co., SoCal

Here it was a Confederate Rose (related to hibiscus) they had infested. I fought them for a couple of years and finally yanked it out because, as Jeri said, they were getting into other plants and it just wasn't worth it.

Thanks for the very detailed info Jerijen.

I have a couple more questions.

1. Would having a neighbor who does composts, but does not tend the bin properly have anything to do with this infestation, if, these are white flies? My next door neighbor is an avid gardener, however, I noticed last year that her compost bin constantly has flies buzzing around it. It's a big source of flies coming into my home in the summer as the bin is quite close to our property line (and, the yards are small to begin with).

I have no idea how to discuss this with them politely. They obviously are not turning the compost enough, or throwing things in it which don't belong there.

2. The organic insecticide I have is comprised of soybean oil, neem oil and some other things. The article that Henry linked to mentioned soybean oil. I'm wondering about this.

3. The roses where it's worst, happen to be right by 3 very large hydrangeas. Obviously, broad leaved. I'll have to take a look at them.

4. Does heavy doses of water wash them away similar to aphids? It was pouring today, and is supposed to rain for the next few days.

5. I actually had not used any insecticides at all yet, up until Sundays screw up, which pretty much doesn't even count considering that I washed it off right away. I really don't want to get obsessive about the whole bug thing this time around (it's my second home, 2nd time growing roses).

Last, when it stops raining, I'll try and get a photo if they are still there. They were SO small what I saw, I could barely make out what they were, but I really didn't recognize them as being aphids, or thrips, or any other tiny insect which I am familiar with.

Heavy washing with water should always be helpful.

DO check your hydrangeas! I do not grow them, for they are miserably unhappy here, but I'd suspect whitefly might love them. (And yes, hibiscus attract them like nobody's business.)

Your neighbor's compost pile, while doubtless annoying as all getout, probably is not a whitefly attractant.

Here is a GREAT site on Whiteflies:
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7401.html

That's from U.C. Davis, and it is RIGHT ON TARGET.

If you feel a desperate need to spray SOMETHING, I really recommend water, but you could use something like Neem Oil.

That said, remember:
If the spray does not get ON the individual bug, you won't kill it (but you may kill some beneficials).
Read the info on the site carefully, about spraying instructions. Personally, I wouldn't do it. It won't do you that much good -- other than psychological. :-)

You'll probably accomplish more by removing the egg masses from the underside of the leaves of host plants in your area.

I recommend again -- CHECK with your local Dept. of Agriculture.
Perhaps because I live in an agricultural County, these periodic invasions are treated seriously here.

They are not attacked with pesticides.
They are treated with predatory insects, with great success.

As I think I said, earlier -- I truly DETEST whitefly. Aside from everything else, the #%##$@@# things make me sneeze.

Jeri

You need to get on the web and see exactly what whiteflies look like--and their scale-like pale green larvae on the underside of the leaves. It is hard to mistake them for something else. You get clouds of white gnats flying up when you disturb the foliage.

I see them on other plants, but gardening for 35 years in a similar climate to yours, I have never had a problem with whiteflies on roses outdoors. Apparently it is more of a problem on the West Coast sometimes. Maybe a different species.

They make a new generation in about a week, so the trick to whitefly control is to spray the undersides thoroughly every three days (4x) to kill the larvae.

Been there, done that. My roses do not usually get whiteflies, but my Hibiscus sure do. There is a MAGIC!!! solution, however. Get some worm castings and spread a 1/4 inch layer on top of the soil out under the whole canopy of the plant you want to protect. I use Wormgold, but any brand would do. The whiteflies will go elsewhere. Works like a charm.

Kathy

Well, I did some reading up and it seems unlikely in NJ, for the most part. Also, I checked around the hydrangeas and see nothing, so that's good.

However, I have seen swarms of minute flying things A LOT in my yard. I even remember them from last year, before I had the roses in. Don't know if what's on the roses is related to these or not. I have no hibiscus (the one Rose of Sharon I had was ripped out last year, as it was old and scraggly and served little ornamental purpose when re-doing the landscaping).

The rain seems to have washed them away for now. One of my French Lace buds, which was on the verge of blooming has been completely ruined by whatever it is. Hoping that the rest of them make it!