Just looks like a minor case of coneflower mites to me. Continue cutting bad flowers out and clean up the ech leaf litter a bit earlier in the fall and pitch it to try and get and eggs. From my experience, as long as you don't get the petals that are green or the mini green flowers growning from the cone itself.... Then it's not asters yellow.

A minor case or the beginning of coneflower rosette mites?

Seems that some gardeners are able to control it (live with it) and some not.

I haven't had it in long-lived old cultivars; namely, 'Magnus' and 'White Swan', but have had it in newer ones (including 'Hot Papaya').

Perhaps the older ones and the species are more resistant.

I have had them pop up in most of the collection here and there.... But if you do the bloom removal and early cleanup... They seem to go away. The only ones that have never had a problem are the paradoxa and pallida types. Both bloom much earlier then purpurea and hybrids so I don't know if they are resistant or they just aren't around the same times mites are.

I definitely keep an eye out for any infected blooms when buying any new echs at a nursery.... if a plant or two show signs then I just skip the lot. But this is never fool proof since they might not be blooming yet and I have brought them home I new plants. The few nurseryman I have talked to note that they are getting plants already infected from the growers... Why they aren't returning them beats me.
In the end it's no more of an issue that you have to deal with on other perennials or veggies in the garden... But I am quite bias to echs.

Fantastic pictures! Finches and such are all over my sunflowers, but never seem to bother with the coneflowers. I could use someone to pick out the worms.

I'm no expert, but would think if the plant is infected with aster yellows it's in the whole plant and picking blooms will not help.... It may help with mites though, and I would pick them anyway just because they bug me (no pun intended)

Wow. Nice shots and timing to catch them in the act!

Nice bird photos!
I'll keep an eye out and discard funny looking blooms.
Nevermore44 you commented that some nurserymen said plants are coming in from growers infested. That's too bad. I mail-ordered three Hot Papaya coneflowers. They have been in the ground about 6 to 7 weeks and have not grown much. (I have watered and we have had decent rains) Only one has a bloom forming, and it doesn't look right -- nothing like the Hot Papaya I had previously. I am hoping they turn out fine and are just putting all their energy into growing roots. Or maybe the nursery sent the wrong plants. On the other hand, the plain pink echs and Pow Wow wildberry echs I have grown from seed are going gangbusters.

I don't think there should still be confusion between the symptoms of coneflower rosette mite and those of aster yellow.

In the former case, only the flower is affected in an otherwise healthy plant. Also some of the original flower colour usually remains.

Re above: as has been said, by the time the flower damage is apparent, the mite is already established in the plant.

Coneflower rosette mites are microscopic, their population builds up to very large number in a single flower, they apparently spread by wafting from leaf surfaces, in the wind, and they overwinter as adult females in plant debris.

It's very informative to read NM's comments.

As said, my 'Magnus', "White Swan' and species have never been affected. It seems interesting that the only affected coneflowers I've had, have been newer cultivars that were purchased within the last ten years. Maybe it's when the plants were purchased as much as what cultivars they were.

NM, re the retailers (and other parts of the horticultural industry) it's all about the money. But I bet you knew that!

This post was edited by SunnyBorders on Tue, Jun 24, 14 at 11:31

Those pics are too cute!!