does this sound like spider mites?

13 years ago

Last year my Meyer Lemon was losing leaves. They would turn partially yellow and fall off and it also would lose green leaves. I thought it was potted improperly and getting too much water. I think the water was an issue but only partially by causing the plant stress that allowed it to succumb to pests. After repotting it has one new branch with leaves and the rest had died back but I noticed an orange tree that was unaffected last year is suffering from the same leaf drop problem. I do notice little webs but we also have a lot of spiders here and I also have seen spiders on the plants so I wasn't sure it was mites. I have not seen any mites and am not sure exactly what to look for. I just discovered tonight that whatever it is has spread to my pomegranate. It is losing leaves, twig ends are dying back and also has tiny webs.

I sprayed them all down with some homemade insecticidal soap. Earlier in the spring, when I first suspected the mites, I sprayed with pyrethrins. That didn't seem to work so I released a bunch of ladybugs in the garden. Some ladybugs are still around but so is the problem.

My questions are 1) does this sound like spider mites? 2) If so and I treat with insecticidal soap, how often do I need to spray down the plants to prevent the mites from getting re-established?

Thanks in advance,

Depressed about my plants in CA

Comments (4)

slyrrp
13 years ago
Tiny webs sure sounds like them. And boy do they love Citrus. With a loupe or hand lens you should be able to see them moving along the little web strands, and on the undersides of leaves. Or try tapping a suspected leaf over a piece of white paper; you should see tiny specks not much bigger than dust slowly moving around.

AFA spraying there's plenty of info out there. One site suggests adding horticultural oil to the soapy mix. Just make sure you get the leaf undersides really well. I've tried spraying my indoor plants time & time again but they always seem to find their way back eventually. I heard ladybugs will eat mites, but I imagine their preference is for insects (mites are arachnids, maybe explains why the pyrethrin didn't work?). I've had some success with predator mites, although IIRC a second application is usually needed.
taz6122
13 years ago
I had a major infestation last summer and through part of the winter but have since got rid of them by alternating neem oil and joy dish soap. I don't know which or if it was the combination of both but I have no spidermites now. I think by alternating I've kept them from building a tolerance to either. I used 4-5 drops of dish soap per pint in a spay bottle and the equivalent to 2T per gallon of neem. Make sure and get the undersides of the leaves and apply every 5-7 days until they are gone. Here are a couple of pictures showing the mites and damage.

This is a tomato leaf with all stages of spidermites and damage.

Here's a Colocasia with spidermites and damage on top of the leaf.

Here's a crop of the picture above before reducing it showing an adult spidermite with freshly laid eggs.
laur07
Original Author
13 years ago
Thanks for the responses. Those pics are excellent. I've looked online for pictures to know what I am looking for and have never seen a photo of the actual mite let alone eggs. I'm off to find some Neem oil. Wish me luck. I love my little garden and I can't believe the damage these mites can cause. It's so frustrating.

FYI, I read that green lacewings are excellent for mite control but I went for the ladybugs because they were locally available. The green lacewing larvae are superior because they can't fly and so stay on the plant you put them on and eat the mites and aphids too.If anyone has tried them, I'd love to hear if they had success eliminating the mites with them.
dawn06
13 years ago
Wow taz6122, those pictures are excellent! I am having a problem on a rose and mites didn't even occur to me. I don't know why but your pics jogged the memory and I'm off to mix the neem oil now. Thanks you!