If the downed twigs have clean cuts around the break, it is the twig girdler. The best prevention is to remove every downed piece in your yard and any areas close buy. They target other trees also. The next generation will develop in these twigs if they are not destroyed.

The sticky mess is caused by aphids and probably the best thing you can do about it is nothing. Either that or buy a bunch of lady bugs. This was the worst year for them I have seen recently. At worst they cause the trees to lose their leaves earlier than usual which will make next years crop smaller.

The mature pecans falling in October and November with little holes in them are caused by the pecan weevil and you can get rid of a lot of them by either putting circle traps around all of your trees or using something like Tanglefoot. These things need to be put up in late July and left up until the pecans mature (shucksplit) about the beginning of November. I can give you more info if you want about these options. (You need to try to get the neighbors to put up the same things on their pecan trees to get the best results.) Just like pecans usually bear every two years, the next generation of weevils will not appear until two years from now. There is no easy solution to the weevil problem.

The chemicals you applied may have helped a little, but probably did not do much to get these specific pests. A little nitrogen before budbreak each year will likely help your crops over time.

What cultivars do you have?

Scottokla,
Thanks for the information. We have several cultivars grafted on our trees....Stuart, Commanche, Wichita and two totally native trees. An old farmer showed/taught my husband how to graft the trees over 30 years ago. We live out in the country surrounded by wheat fields with the nearest pecan trees on the south side of the section - about 1 mile away (where I grew up!) Will the bugs travel that far?
Several years ago I applied several different minerals all around the drip line of the trees. I had read about this in the Daily Oklahoman and went to Horn's Seed in OKC to get the bags of minerals. I remember driving a stake in the ground about a foot down, pulled it out and poured the minerals (all mixed together in a bucket)in the hole. That really seemed to help my trees. Zinc?? + ??
I appreciate any and all information. Are there any books, fact sheets regarding pecan trees that you would recommend? Thanks again.

Nitrogen and zinc (if soil pH is low) applied to the dripline before budbreak will often help pecans produce heavier if they have never been managed previously. Really the weather and insects play just as big a role as soil fertility in the productivity of the trees from year to year.

I'm guessing you are near I35 or further west based on the cultivars you listed. That and the fact there are no pecans in the immediate area will make things easier for you. Some of the insect can travel that far annually, but it still makes things a lot easier being that isolated.

The three best things you can do to make your trees more productive are to (1) get a leaf analysis done through the Noble Foundation, (2) check out the OSU fact sheets on pecans, and (3) get a copy of the latest pecan book by Wes Rice (Ponca City). I can find the links or get the e-mail addresses for these if you want them. Let me know.

Scott