I don't know which would be more effective for rose midge. I am not a rose grower so I had to read up a bit on what rose midge is. It appears this refers to the larval form of the pest. What I read indicates the adults lay eggs inside developing buds and the larvae then eat the blossom from the inside out.

If this is the case I don't think either would be particularly effective.

Both spinosad and azadirachtin work when the insect eats it. These aren't contact killers, but must be ingested to work. The question would be how would either product get inside the buds where the larvae feed?

In terms of toxicity neither is really toxic to much of anything that doesn't eat it. In the case of neem oil some humans actually consume it as a health food type product and there are make-up and oral hygiene products using it so that should tell you something about the very low toxicity of neem.

I am glad you are concerned about toxicity, I am a parent and pet care taker as well so I certainly understand where you are coming from. I just don't see how either would effectively target the larvae inside the buds.

Wanted to add that it seems there are only 2 kinds of pesticides that seem likely to offer reasonable control. The first would be a contact pesticide applied at the time the adults emerge. The idea would be to kill the adults on the plant before they can lay the eggs inside the plant.

Once the eggs are in the plant only a systemic pesticide (it's absorbed inside the plant) seems likely to work.

Given your concerns about toxicity there are some contact pesticides relatively low in toxicity (to humans and pets), but I don't know of any systemics fitting that criteria.

Wish I had more optimistic news for you, sounds like you have a real challenge.

Start by looking closely at the soil those affected roses are growing in and work at correcting any problems that exist there. Spraying anything is a short term correction to a problem and like any spray or dust due care is needed when using them. Both of these are most toxic in the wet state and can kill a wide variety of insects when wet. Once dry both exhibit negligable toxicity. The soil your plants are growintg in should be your first defense against any insect pest since plants growing in a good, healthy soil will better withstand attacks by insect pests, as well as plant diseases.

They don't eat the buds so much as feeding on new growth. With midge, you usually don't even get buds. Just crispy brown ends of the canes.

The soil your plants are growintg in should be your first defense against any insect pest since plants growing in a good, healthy soil will better withstand attacks by insect pests, as well as plant diseases.

How would the most healthy soil on the planet protect against an overwintering adult insect that emerges and lays eggs inside of developing buds such that those buds never develop?

Are you saying that a 'healthy soil' is a soil that insects we regard as pests won't be able to overwinter in, but insects we regard as good or neutral will be able to overwinter in? How does that work, exactly?

Sir Albert Howard, Lady Eve Balfour, Friend Sykes, J. I. Rofdale, and others all wrote about the benefits of good, healthy soil years ago. Todays garden writers such as Rebecca Coles, Ann Lovejoy, Lee Reich, P. Allen Smith and many more that I cannot even remember are also writing about the benefits of a good, healthy soil. But simply a good, healthy soil grows strong and healthy plants that are better able to withstand insect pest attacks, ward off plant diseases, plant that grow up not at all attractive to the insect pests and diseases. This is a basic premise of organic gardening that plants growing in a good, healthy soil will grow up strong and healthy and will be better able to withstand these problems.
If this concept is not true why bother with organic gardening?

The concept that plants grown in good condition will have fewer problems and be better able to withstand those problems isn't being questioned.

What I am asking is how *in this case* the health of the plant or quality of the soil would have any impact on the damage rose midge does to the developing buds of the plant?

Certainly a healthy soil and healthy plant offer no defense against hail. There are limits to the ability of a healthy plant to avoid/withstand pest and disease. Since you told Dawn to focus on the soil in response to her request for assistance with rose midge I thought you would have some justification for the response.

I cannot answer the 'how it works' question but I have seen it work. My eight-year long battle with aphids on my roses ended the day I started using corn meal under the plants. It has been six years since and no aphids.

When I mentioned that to a local organic researcher he took me to his green house to show me something. He was doing an experiment with soils. He had three plants growing in 4-inch pots. The plants themselves were about 8 inches tall and the canopies of all three were touching. One of the plants had aphids all over it while the other two had none. The canopies were touching but the aphids did not make the trip over to the other two plants. I asked him what the difference was and he said it was the soil. He could not tell me what the three different soils were because it was on ongoing blind experiment where he did not know which plant was which, but the point was made that soils made the difference. I can say that we spent a long time talking about his experiments. From those discussions I would guess that all three pots started life in a generic bag of potting soil from Wal-Mart. To that he added compost to two of them and probably a product he sells called Texas Greensand and one called Vulcanite.

I also judged the botany category at a regional science fair for about 20 years. During that time I saw numerous projects where the students were able to specify a plants' resistance to different pests or disease simply by exposing the plant to various vapors. One vapor they liked to use a lot was salicylic acid (methyl salicylate or oil of wintergreen). One of the particularly gifted students proved that these vapors worked at the genetic level by turning on or off certain genes that the plant uses to protect itself. He also proved that certain combination of vapors stimulated a dormant gene that nobody knew what it was there for. When you see a breakthrough in scientific understanding at the high school level, it can make the mundane science fair much more fun to do. That boy went on to win the international science fair. So if you want to know "exactly" how these things work, maybe I can connect you with that kid. I'm sure he's out of college now - or maybe working on his Ph.D.

The midge lifecycle sounds like the thrips lifecycle. We can control thrips in the soil over the winter with beneficial nematodes applied in January. Our climate is so much warmer than most places that January may be too early for many of y'all.