Black swirls?

Asked August 4, 2020, 6:47 PM EDT

These clumps made from thin black lines swirled into circles or clumps on my plants. It's spreading everywhere. Looks like poop lines? Been spraying with neem oil for weeks already...there are less but they still appear everyday.

Miami-Dade County Florida

3 Responses

Can you please post an image of the issue and tell me what the plant is? From the sound of it, I think you may be dealing with leafminers. Neem oil only works by contacting the insects. Leafminers are inside the leaf, so you need to apply an insecticide the will penetrate into the plant (called "systemic" on the label) or use a more hands-on approach, which is literally to flatten each leaf between your fingers and squish the leafminer insect inside the leaf. Here is more information on leafminers: https://edis.ifas.ufl.edu/in507

Don't believe it's leaf miners which I thought were white squiggly lines.

Thanks for the image. You are correct it's not leafminer feeding. However, this is insect frass, possibly night-feeding beetles or larvae or another insect. Neem will only help if you are getting it on the insects, but if they are feeding at night, probably not. You can try rinsing it off with a hose, but you will need to find the beetles or insects for identification before we can figure out how to stop them. You might try viewing the plant at night with a flashlight to see if you can find the culprits.