Hello Joan,

Unfortunately, neither of the photos you provided are good enough to offer a definitive answer.

The photo showing the top most leaves of the plant reveals damage by a sucking type insect. Since four line plant bugs love the shasta daisy family (Montauk Nippon Daisy) that would be a good starting point. https://extension.umn.edu/yard-and-garden-insects/four-lined-plant-bugs

If it is (was) four line plant bug, there is little to do now, since their feeding cycle is essentially over.

Sucking insects like to reside on the topmost canopy of the plant. That along with the lower leaves not appearing to exhibit the “stippling” may indicate you have multiple causes to the daisy’s decline. The lower leaves may show signs of a fungal disease. We have had a wetter spring/summer to date than usual, and fungal diseases abound right now.

You can take better pictures (more leaves in focus, and close-ups of individual leaves showing the stippling and general browning, also the back of the leaves – leaves should be isolated and placed on a white sheet of paper for the photo) and respond to this email, but in reality, it won’t help much because fungal infections are nearly impossible to determine positively from a photo. And to be sure what to do about the insect causing the stippling, you really need to capture evidence of the culprit (ie an actual insect) before we can offer good treatment options.

You may be better off to send a sample to the MSU Diagnostics lab so that they can determine what exactly is causing the browning of the lower leaves. Information about services and the fee structure for the diagnostics laboratory are contained here: https://www.canr.msu.edu/pestid/

This is an excellent reference for taking plant samples to submit: https://www.canr.msu.edu/pestid/submit-samples/

To limit the chance for fungal infections on your daisy, make sure not to water from above, wetting the leaves. You may also want to thin out the area the daisy is planted to increase airflow around the foliage.