FoolishPleasure,

Not all bugs are bad. Some are good, and many are neutral. I get small fly like insects on my trees this time of year. I don't know what they are, but they do no damage.

Once I saw an winged insect with an orange band on one of my stone fruit trees. Although it didn't quite match the pictures of a peach tree borer, I was concerned it could be, so I killed it and sent pictures of it to an entomologist.

The entomologist identified it as a mydas fly, and indicated it was a predator.

I can't remember where you live, but you may well have to protect your fruit from plum curc. and oriental fruit moth, but don't become alarmed and treat just because you see bugs.

From what you describe, may have been aphids. If so, a harsh water spray would have dispatched them as would a tad of squishing. But Sevin won't do anything.

Without images, we can only guess what they are. Any chance of pictures?

If they were aphids Sevin does indeed list them as being controlled.

I think that Sevin isn't great, for some types of aphids, at least. Pests can be on a label without being reliably controlled by a product.

I tried controlling my greenhouse aphids with Triazide after failing to do so with soapy water, pyrethrin and almost killing the plants with Purespray oil (but not bothering the aphids too much). Triazide is labeled for aphids and oil should have worked also (but shouldn't have been applied to stressed plants as mine were). So far nothing has worked!

Malathion has always been my chemical of choice for controlling aphids, no matter what other products may say on their label. As I recall, Sevin didn't work well for this purpose in the past for me. I found some Malathion in my med cabinet and dosed the plants yesterday. This better work- never had such an aphid issue. I haven't ever had to use a synthetic chemical for vegetables before.

I was skeptical about Triazide but used it anyway because the label listed aphids. Figures a pyrethroid might fail if pyrethrin did.

Yes a picture would probably be helpful. If they are round bodied and about a millimeter in dia., they may be aphids.

The type of flies I was referring to are larger and look more like flies.

I've had good luck with Sevin on aphids. In fact most of the time if I can just kill the ants to stop the aphid farming, the aphids will go away.

This is on outside production. I know aphids can be much more difficult in a greenhouse.

Triazicide kills my apple and cherry aphids but they come right back (or the ants bring them back) before the next spray. Sevin has a shorter interval and that powdery coating which stays under the leaves. Malathion also has a short respray. The quick resprays seem key for me.
I've also used Safer insecticidal soap w/pyrethrum (but that was a very long time ago).

Usually all I have to do is knock aphids down once and use some ant stakes and the problem is solved. I only bother to do this for cherry aphids where they hide in rolled leaves- otherwise I let the lady bugs deal with it. If I spray the LB probably get killed- at any rate, I'd rather they do the work. That's my site, your results may vary.

some aphids have wings. Especially when the colony gets crowded.

Of course, they have to get there from somewhere. Doesn't infestation always start with fliers?- except maybe sometimes in a greenhouse when we bring them in from outdoors on plants like I did.

I am really very confused. This bug is little as very small fly and it has yellow stripes around their bodies. They hang on the tip of the branches even the branch has no leaves. Also they hang on the tip of the leaves. A lot of them are on the plum, Apple and some on the apricot. None on the peach or the Figs. They don't move or fly and I [put some on my Palm thay are dead. Only one of the whole ordeal was alive and flew. I don't know if they dead naturally or the sevin killed them. No damage to the leaves only I noticed few holes in very few leaves and I am not sure if they did the holes or some thing else I gathered few of them and I will take a picture and I hope I will be able to get it on the post here. Really I need help.

Could be seed corn maggots, they seek out high points on trees and then die from a fungus. I get them on my fruit trees. I ignore them as they are most all dead.

Some of my customers worry about every unexpected thing they see on their trees- which I like, because it means they're concerned, but I still have to bill them every time they insist I drive out to inspect the latest non-problem.

I'm not saying that you're behaving like a mother of an only child- the insects may be truly alarming, but generally no harm- no foul. If you see only insects and no symptoms you can probably relax.

I suggest you find a source of info on common fruit pests in your area that contains photos and start to learn the faces of our true roster of villains. This will make your thoughtful surveilance much more useful to your trees and the process much more satisfying.

Or you can post pictures here of every insect you find on your trees. The funny thing is that most of the insects that do real damage you seldom see if you don't trap them.

images would help. A lot!

Go here and ID it.

Here is a link that might be useful: http://bugguide.net/node/view/15740

hoseman
You are right they are seed Corn Maggots. On Internet site of UNC They have a picture of an adult which looks like the one I have. I had only one little fruit damaged with a hole. I was going to spray Fungicide but good I did not let the Fungus kill them. You are in Zone 7a so probably they famous in that zone.
Abe

Yes, since I last posted I sprayed my table grapes and they were full of the corn maggot flies, most with the fungus killing them. I was pretty sure that is what you had. Years ago I was concerned as you were when I first saw them on my fruit trees. I had them sent off to the state lab for confirmation, so I was pretty sure even without picture. They are no harm to your trees. I have my backyard orchard in an old farm field, probably was a corn field, just a guess!