What could this be?!

[GreenisGrand]

Hello again folks,
It was difficult to get pictures to show what I'm seeing, so I had to take the picture with light from behind to help show the dots on the leaves.
It's been spreading to a few of my plants, and so whatever it is, I remove that leaf to help keep things under control.
I see little black circles on the underside of the leaf, they are quite small, but have green in the middle, some are just brown in the center in the advanced sections. On the top of the leaf the spots begin to show through as brown or deficient looking sections.

I'm pretty certain this is a biotic problem,
virus?
bacteria?
fungus?
What should I do to treat it?
Thanks for your help everybody!

 

[Rosebud]

Hi greenis.. Everything I see these days I think are thrip. I am not certain. The little black spots can be bug ****. Does it come off or is it in the leaf? I vote for bugs. Good luck and some more folks will be coming along with ideas.

 

[GreenisGrand]

hm, i was hoping for insects vs. fungus if it has to be something, as i'm 3 weeks into flower. the little black spots are on there good, i've tried rubbing it off and it's on there good, whatever it is it's in or directly on the leaf. where can i read more about thrip?
thanks RB, i'll check out any other ideas that come up here.

 

[Rosebud]

The Pest: Thrips

First Sign: Leaf surfaces finely speckled with yellow spots. Later, a silvery metallic looking sheen may cover leaf surfaces. Not all Thrips create this sheen. With or without the sheen, you'll also see black specks (Thrip fecal material). Only on close inspection is the pest itself found. About 1/16" long, thrips can move quite quickly for their size. Many gardeners report thrips as a small "worm with legs". Larvae and adults look similar, but adults have wings and can fly.

 

[Hushpuppy]

That looks like some kind of leaf muncher. You need to get a magnifying glass and look at the leaves while they are on the plant. I wouldn't remove the leaves unless they are pretty badly damaged(at least 50%). I would suspect some kind of leaf miner or aphid that is attacking the underside of the leaves. Gently lift the leaves and look at them so as to not scare the critters into jumping off that leaf. By picking them to look at, you are most likely knocking off the bugs or causing them to bail out.

I like to use Azamax to get rid of bugs as it is biodegradable within the plant(or so they say) and is broken down within a week so that there isn't residue to smoke. The Azamax gets absorbed into the plant and makes it taste bad to the munchers as well as causing them to quit reproducing.

Make sure you discover what it is before treating tho so that you don't waste money and chemicals on bugs that aren't there.

 

[GreenisGrand]

Thanks, and I'll be sure not to remove so many leaves next time. I'll take a close look for some insects.
Don't leaf miners live in between the top and bottom layers of the leaf, making them impossible to see?
so none of you guys think this is bacteria or fungus right?

 

[Hushpuppy]

It is really hard to tell from our angle, but it looks more like bugs of some sort. It looks like something is biting into the leaf and sucking out the juice. I could be wrong as I have never had to fight any pathogens so I don't know what they look like up close. I think fungi would be localized in a certain area rather than dispersed across the leaves, and bacteria would sicken the whole plant rather than cause necrotic patches.

There are so many leaf munching critters that the only way to be sure is to just look very carefully at the leaves in the damage area of the plant. I think the actuall leaf miners lay their eggs within the flesh of the stems or on the undersides of the leaves. Many of them have slug-like larvae that do the munching. I know that thrips, like Rose said, will create little holes in the plant that will turn necrotic. But I suspect any of the mites or aphids can do similar damage.

 

[GreenisGrand]

thanks HushPuppy. I can't find anything on this website about bacteria or fungus on leaves, so I guess it's not a common problem whatsoever.

I've been looking with a magnifying glass, but I maybe only saw one thing that could have been an insect on the underside of a leaf then it dropped off.
The reason I'm pretty positive that it's insects is because fungi according to my horticulture class will be kind of wet blotches and bacteria will look spotty on the leaf and like you said it WOULD make the whole plant sick, as it would transport itself through the vascular system of the plant.
It does look like something is sucking the juice out of the plant, because when I look at affected leaves the circles seem to move in a pattern down the leaf (like an insect sucking then moving down a little to get more etc etc)
but if I can't visibly see any insects or noticeably any eggs, can I be pretty sure it's still insects?

Does anybody know of some further reading I can do about insect pests but also bacteria/fungus just to be sure I'm treating things properly?

Thanks so much, you guys and gals have been a huge help in saving my plants before :clap: