Oh No!
 

In all my pepper growing years I've never seen this. Any ideas what it is? It started as a yellowish spotting/mottling on the leaves on the west end of the garden and is rapidly moving eastward through the rest of the plants. At this point it is affecting about 3/5 of the plot. The leaves eventually turn pale yellow and fall off, some develop "infected" looking lesions like in the picture below. I've had to pull two plants so far. :o

Yellow mottling on leaves, rear of leaf and close up of lesion. I think after opening the thumbnail you can zoom in further on these.

Have you checked for insects or mites?
The 4th photo looks like some leaf miner trails.
What's are those two white spots on the 3rd photo, is that webbing?

No insect problem that I'm aware of. I checked these leaves over with a hand lens and didn't see anything other than what you mentioned, the possible leaf miner trails. I think that is the remains of a spider web/nest in the 3rd pic, we have lots of them in the garden.

How strong is your hand lens. You need about 10X or better magnification to see spider mites.
It looks to me like insect damage from some sucking insect. The distorted bumpy areas on the leaves look like what spider mites or thrips cause.

sure looks like mite damage to me.
the proximity of initial visual sympthoms to the central leaf vein strongly suggests insects anyway.
what are the temps over there?

I'm using a 10x hand lens. It's been in the upper 80's to low 90's the past several weeks.

OK, after examining several leaves very carefully I've found some, but not many, tiny (smaller than a flea) opaque white oval critters. They are so small I can't tell if they have 6 or 8 legs.

One other note. I have a nearby grape vine that is showing the same symptoms but worse. Are peppers and grapes vulnerable to the same pests?

Thrips and aphids eat everything. (Maybe it just feels that way.) I've been battling both.

Sorry to hear about your peppers! Did you see any curled leaves, by any chance?

Here's a few pics of the plants themselves, and yes, there is some leaf curl on some of the affected plants.

I'm absolutely not an expert, but I am pretty sure that the damage on mine -- bumpy leaves, extremely curled new growth -- is from aphids. From what I can see, it looks like the damage can show up even after they've been dealt with.

I don't have brown spots, though. Terribly frustrating to try and diagnose leaf issues, I completely sympathize. Is whatever it is killing the plants or just defoliating them? Could it be a nutrient deficiency?

it looks like mite damage in the first pictures you posted to me, but in the second set of pictures I see a winged aphid in the first photo right on the edge of the leaf (which I sincerely think will cause the damage you are seeing. I would expect to see them all over the backs of the leaves and on the new growth to make a difference in the plants health, spray the plants with a strong spray of a healthy dose of soapy water) and in the third photo the bottom of the leaves look as if there is some fungal issue going on...like patches of grey mold like tomatoes get. I have never noticed my peppers affected by fungal problems, but that could just be that areas in which we both garden being so very different or just the appearance in the photo.

Well, this isn't good. I contacted the county cooperative extension and they think it's mosaic virus. :?:
They told me to cut back the surrounding vegetation next year (the darn grapes!) and grow resistant varieties.

It was a good year while it lasted and it's Fall anyway (I keep telling myself).

I don't know which mosaic virus the extension agent is seeing (there are several that can infect pepper plants or grapes for that matter) , but I don't see it. Did the agent inspect the grape leaves too? Any symptoms on fruit? Without any obvious mosaic patterns on the leaves there is no way of saying with any certainty that a plant has a mosaic virus by looking at it. A lab test can prove it one way or another if the density of the infection is high enough.
If you had plants with one of the mosaic virus's, the vector would be aphids or thrips. Some mosaic virus's can be seed born, but you would see the symptoms way before the plants were mature and bearing fruit.

No he didn't see the grape leaves. Fruits are OK. Never (strangely) had any issue at all with aphids this year. My first year in this area. Is it possible earwigs could have been the vector? They've been my only bug problem.

[QUOTE=Mojave;378536]Well, this isn't good. I contacted the county cooperative extension and they think it's mosaic virus. :?:
They told me to cut back the surrounding vegetation next year (the darn grapes!) and grow resistant varieties.

It was a good year while it lasted and it's Fall anyway (I keep telling myself).[/QUOTE]

mosaic virus:)

could you check the third leaf- floor ( the third set of branches counting from the top of the plant ) and see if there is any unusually shaped leafs there ( leafs which miss some parts, usually at leaf- top area, but not miss it as if some insect ate it but as if the leaf was genetically shaped that way )?

also, could you check the intenodia ( spacing between two consequent branch- levels ) at your plants, and would you estimate it very short, and visually shortening as you check higher levels ( in other words, longer internodia in lower parts of the plant, and obviously shortening at higher plan parts )?

and, finally, are the tops ( not just new growth but complete 20-25% top plant area ) of your plants extremely deformed, with shortened branches, distorted leafs which appear unusually long and extremely thin, and overaly 'bushy' appearance?

if yes to all the questions, it's a virus.
but don't worry, those are good old mites you got there, the pepper sympthoms of those are often miss-diagnosed with viruses:).