What is turning my sunflower leaves brown and puffy?

[Green]

My sunflower plants are about a month old and now the a leaf on two of the plants turned dark brown and puffy. There may be bugs inside the leaf, I'm not sure.

Does anyone know what is causing this??

What should be done to help?

I've posted two photos and have since removed the leaves.

 

[roadrunner]

How much sun are they getting? I'm seeing a lot of shade there; sun flowers need tons of sun. As for the brown spot, I get that a lot, but the sun flowers are otherwise healthy for the most part.

 

[ReslerMomma]

I had the same problem. I thought it was some kind of bug. I sprayed neem oil and no more have turned dark.

 

[CrazyConure]

I have the same exact thing. It doesn't usually harm the plant.

 

[Green]

How much sun are they getting? I'm seeing a lot of shade there; sun flowers need tons of sun. As for the brown spot, I get that a lot, but the sun flowers are otherwise healthy for the most part.

Hello. They receive morning and afternoon sun. It may have been later in the day that I took the photo. And, yes, otherwise they are very vibrant. I started them from seeds and will be replanting them into the ground soon. I wanted them to become nice and sturdy first.

 

[Green]

I had the same problem. I thought it was some kind of bug. I sprayed neem oil and no more have turned dark.

I have neem and will certainly spray them. So far I've just removed the sections of the leaves.