I don't know what the worms are called put they are in all pecans to some degree some worse than others. They also burrow into hickory nuts if you shell any of them. Commercial pecan growers have to spray their trees to keep the worms out. Also some years they are worse than other years. Any pecan with a tiny hole in it can be tossed. Maybe next year will be better.

The little white worms probably are pecan shuck worms. I am not sure what is causing the black mushy nut meat. Maybe pecan scab? I have had stinkbug damage on pecans before that turned a portion of the but a dark color, but I haven't had black, mushy pecans.

Scott is our resident pecan expert and I expect that he'll be able to tell you what it is when he sees this thread.

We have a nice, big native pecan tree that sits on the western edge of our big veggie garden. Some years it produces incredible crops, some years it produces so-so crops, and some years there is not crop at all. This tree is tall and old and there's no way I can spray it, so I just try to keep the soil healthy around it. Pecan trees need regular spraying, particularly with fungicides, in order to stay healthy and produce well. Unfortunately, due to their size, it is hard for a homeowner to spray very large, mature trees. Commercial growers generally have the type of equipment needed to spray the trees as required or hire someone to spray their trees for them.

We also have other native pecan trees scattered around in our 10 acres of woodland. While I collect the pecans from the tree in the yard, I tend to leave the ones in the woodland for the wild things to eat.

I'm going to link one of my favorite pages on pecan tree diseases because it is very informative.

Here is a link that might be useful: What Happened To My Pecans?

Pecan Weevil

Here is a link that might be useful: pecan weevil

Yes, the little white "grubs" that eat out the inside and then make a small hole in the shell to get out are pecan weevil. Plus, the ones that are black mush on the inside might also be have had weevil attack them, just at a slightly different timing. They might also have been attacked by hickory shuckworm. The fall insects weevil, shuckworm, and 3rd generation casebearer have a bit of a complicated impact on the nuts they attack based on the exact timing related to the stage the little nut is in at the time of the attack. Pecan scab and occasionally powdery mildew can also cause pecans to be bad, and sometimes tree genetics and rainfall can also cause the pecans to be aborted late in the year.

The weevil that eat this years nuts will go into the soil and emerge in August or September of 2016 (two year life-cycle) and attack that year's crop. There are not a lot of ways to get rid of these guys, but it might be possible.

Can you give me more information about what part of the state you are in, how big your acreage is, and what other trees (if any) are around this pecan tree?

Sorry it's taken me so long to respond.
I live in central Oklahoma--it's a Norman address, but actually is IN OKC (I think), and Moore schools--they call it "no mans land".
Our property is 1.12 acres.
We do have other trees around. I'm not sure what kind, though. I really know very little about trees. And there is a weird vine thing that grows on the fence next to the pecan tree. I cut the vine way back and away from the tree when we first moved in back in April. It had grown up into the tree.
I can take some pics tomorrow. There is another pecan tree across the street--maybe two. They're not healthy either, I'm afraid.

Lots of weevils actually means the tree is probably healthy and productive, especially if there are few other pecan trees around. If the tree went three years in a row without nuts then all weevils would disappear except for the ones that fly in looking for nuts in any given year.

Once again, sorry it's taken so long to get back with the pictures, Scott. It's practically dark by the time I get home from work now!

What do you think? Can you tell anything from the pics?

Also, thanks everyone for the useful links!

another tree pic

Some of the best flavored pecans I have eaten were "wild" ones in Checotah. My sis had a friend she knew from their school days and he told her to pick up all she wanted. Not a worm in any of them. We used to pick them up on halves when I was little. Not a worm in any of the ones she gave me. The environment and weather could account for the worms.

You can see the weevil exit holes in two of those nuts.

You really cannot tell much from looking at the tree as it is going dormant, but I can tell that your tree is at least moderately resistant to pecan nut scab which is good news, and that it appears to have a little bit of zinc deficiency based on the wavy leaf edges. Maybe not too big a deal though.

It's interesting to look at the nuts. Any nuts that the shucks have not split on will not be any good at this point. They will all have had weevils in them since all good native nuts will have split the shuck by now here in Oklahoma.

It is possible that this is an improved variety, but I can't really tell without seeing the nuts or seeing the tree earlier in the year.

Two years from now the weevils will likely get all the pecans unless it is a huge crop or you get a couple of circle traps to put high on the trunk.

So...what do I do about pecan weevils? Circle traps work well?
I suppose I should reseach weevils and circle traps...
Thanks!

PBS Oklahoma Gardening had a show about Pecan Trees on Sat. 8th. Nov. It called the worms Hickory shuck weevils and showed the hulls with black mush in them from the weevils saying that they were worms that had died early in the season. They said the best way to get rid of the weevils is to keep the ground clean of old pecan hulls & branches that another weevil have cut off of the tips of the branches and lay their eggs under the bark. I know this isn't much help. But they talk like these pest over winter in the old trash lying on the ground under the trees and it is important to keep it as clean under the trees as possible.

Okay. Thanks! I can certainly clean up the area under the trees. It seems such a shame to have these beautiful large pecans and not be able to eat them.

Shuckworms and twig girdlers can be reduced by cleaning up girdled twigs and infested shucks, but this damage is most likely pecan weevil which go into the ground once they have consumed the nut.

Shuckworms and weevils can both cause the nut to be aborted back in August before the pecan kernel matures, but once the shell hardens inside the shuck the shuckworm will just reduce the quality of the nut a bit whereas the weevil will consume/destriy the kernel and then chew a hole to get out.

Circle traps (2 will be enough probably) can be found for less than $20 and will last for 5-7 years if left up only from early August till shucksplit in Oct. There are usually a couple of sources each year in Oklahoma. Sooner Pecan Company in Bristow (Bristow Pecan and Ag) can find some for you.

PBS Oklahoma Gardening show pecan weevil traps, probably like scottoka was describing and said you could get plans of how to build them yourself from your county extension office. Hope you have a better crop next year.

I watched the pecan show on PBS and it was a good show. Those were the traps I was talking about. On the show they said the vast majority of the weevils can be caught, even more than I was thinking, as long as there are not other trees around the pecan trees.