Grammatiphylum issues - Orchid Board

littleflower · #1 01-03-2021, 07:49 PM

I have 2 grammatophylums.... The big one (first 2 pics) has sticky substance on the underside of the sleeves, and reddish brown spots. The smaller one (second 2 pics) has a lot of spots on its leaves. I’ve had a problem with spider mites in the past, but they both been treated. Help would be greatly appreciated

Roberta · #2 01-03-2021, 08:58 PM

How recently were they treated for spider mites? And how many times? Generally, when using a pesticide one is not done... you need to apply it every 5 -7 days, at least 3 times to be sure that you have killed multiple generations.

littleflower · #3 01-03-2021, 09:20 PM

I failed, I only treated it once. I will start over, are the spider mites related to the sticky substance?

Roberta · #4 01-03-2021, 09:26 PM

Very likely.... they nibble on the cells on the underside of the leaves, causing them to "leak" and eventually die. Yeah, hit those bad boys again. Most pesticides don't kill eggs, so that's why the repeat applications are needed. You kill the adults, but then the eggs hatch and grow up to be new adults... you want to nail the successive generations so that they don't keep reproducing. And make sure that what you're treating with is a miticide... mites are arachnids not insects, so insecticides don't kill them, at least not efficiently. If you are using something mild, like Neem, there is no residual effect so even more important to be persistent.

littleflower · #5 01-03-2021, 09:59 PM

Thank you so much!! I have Ortho insect, mite and disease spray, so I will hit them up weekly for the next several weeks. Really hoping to get rid of this problem for good!!

Roberta · #6 01-03-2021, 10:02 PM

Well, not for good... for the time being. They're teensy, and in the environment. You'll get the ones that you have right now, but you'll still need to stay vigilant, the world is full of them and they are small enough to find their way into the house.

littleflower · #7 01-03-2021, 10:18 PM

Sigh, ok, I’m sure you’re right, it’s just disheartening to me. Thank you again

Roberta · #8 01-03-2021, 10:48 PM

The invertebrates were on the planet long before we were, and likely will be there when we're extinct. We can mitigate, but permanent victory not going to happen.

estación seca · #9 01-04-2021, 04:55 AM

Some thin-leaved orchids are more susceptible to spider mites. Grammatophyllums are in this category. You need to look at them frequently for mites.