Spider mites on tomato leaves

For future searchers, this is a confirmed case of spider mites on tomato leaves.  Fine, light yellow spots on the leaves, on top and underneath.  This is what wiped out almost my entire tomato crop last August.

It's actually pretty easy to confirm if you know what to look for.  If you see this kind of spot pattern, tap the leaves over some smooth, flat surface, watch the particles that come off to see if they start crawling.  Also, examining the underside of the leaf with a high powered magnifier will reveal the little [explitive]s.

Still researching the best remedies, but identifying the cause is 90% of the battle.

A friend of mine swears by rosemary tea for spider mites, but it didn't work for me.

After trying  the usual integrated pest management suggestions without success, I've had to use a pyrethrin spray for spider mites and aphids.

It's called Doktor Doom!

I think I saw that brand at a hydroponics store. A real pyrethrin is rare anymore. I found that Neem oil helped on my beans and squash last year.

Awesome post, Kate. Such practical knowledge to share! I'm sure many of us are going to be seeing this sort of pattern on our leaves and wondering what it is and what to do about it.

I never knew about the shaking and watching for crawling uglies before.

There were a couple of products at my local garden center they offered.  One had pyrethrin and neem oil in it.  Another was a soap insecticide.

The pyrethrin product had an environmental hazard warning on it that said the product is toxic to bees.  I did some research on that, and found that the product is only toxic if a bee comes into direct contact with it when it is still wet.  Once the product dries it is no longer a hazard to bees.  So it can be applied safely at night or whenever you're sure there are no bees present.

The soap product also claims to kill mites and aphids, also works by direct contact, and from what I've read, doesn't target bees at all, but it's still a good idea to avoid spraying them directly with the product.

I'm also concerned about the spiders, since they are beneficial as predators to the mosquitoes, and the frogs that live in my yard.  Problem is, I don't know how realistic it is to find something to keep them all happy, while saving my plants.  And really, after finding a brown recluse crawling on my neck earlier today, maybe I can live without the spiders.

Brown recluse. And here I thought I had it bad with black widows. At least BW are very distinctive.

CitizenKate wrote:Problem is, I don't know how realistic it is to find something to keep them all happy, while saving my plants.  And really, after finding a brown recluse crawling on my neck earlier today, maybe I can live without the spiders.

!!!!! On your neck?? Arrrggghh!!! That would keep me freaked out for a few years.

2 oz of seaweed per gallon will wipe out spider mites

Fortunately, the BRs have a pretty tame temperament, and are more interested in avoiding humans than attacking them.  Still, I would have freaked out if I knew it was a BR before I flicked it off. 

Spiders in general don't bother me much.  Most of the ones we see here are harmless to us, and really can be helpful and quite fascinating.

@has55, I noticed the soap product said on the label it contained seaweed.  Had no idea before it was used in insecticides.

I must have missed where Has mentioned the name of a soap, that has seaweed in it.

Me too. Where am I supposed to get seaweed from?

sanderson wrote:I must have missed where Has mentioned the name of a soap, that has seaweed in it.

Not a soap, but plain liquid seaweed from the garden store. Here's a link. I didn't do the garlic-pepper part, but just the seaweed as mentioned in last paragraph.
Spider Mites

Thanks

here's a better link about seaweed and spiders mites.

Seaweed

CitizenJate any success with getting rid of your spider mites?

Sadly, no.  I mainly tried products I could get locally.  I started with the insecticide soap that had the seaweed ingredients.  That seemed to stop them for a few days, but they would show up again.  I'd see more spots on leaves where I hadn't seen them earlier.  Then I switched to the neem oil.  I'm treating the plants with that every week, spraying on top and the bottoms of leaves.  That worked a little better, but now the little devils have launched a new front that seems unstoppable.  I went back to get the pyrethrin, but they apparently sold out of it.  I've lost one tomato plant so far, three more are about to go down, and one more is now infected.  No salsa for me this year, they're winning.

Ditto.   I'm surprised the Neem didn't work. I also periodically hose down my beans to up the humidity against them. Gads, best of luck against those nasty teeny things.

Sanderson, the neem oil did seem to work for a few weeks.  The plants started recovering a bit, only showing any slight signs of new spider mite activity towards the end of the 7-day period between sprayings.  Then last week I stepped out to check on them mid-week, and there was a huge flare-up.  It was just after a few rain showers, followed by several very hot, humid days.  I tried to follow up a rainfall with another treatment after the plants dry out, but these things are just relentless.

Here you can see the damage on 3 plants I don't expect to recover.  I've been cutting off branches as they die, and there's almost nothing left of them, and the few tomatoes that have set on them are ripening at a very small size for this hybrid.  If you look to the right end of the row, there's still one celebrity plant that is lush and green, and full of big tomatoes.  That's what they normally look like this time of year here.

Someone asked me to post more closeups of the infested leaves to see if anyone has any ideas about dealing with this.  I've pretty much given up on much of a harvest this season, but if I've seen this two years in a row, chances are they will be back next year, and I want to be prepared to give them the smack-down as soon as they show up - or before, if possible.

The top of a heavily damaged leaf...


Bottom side of the same leaf... not as much leaf damage visible here, but some of those tiny yellowish-white specks you see are crawling around.


Another leaf where you can see some of the mites... there are other particles there, too, but if they're crawling, they're mites.


I think one thing that makes this particularly difficult to combat, is that the spray of most miticide products must make contact with the critter to have any effect on it.  On a very leafy plant, it's very difficult to get the spray to reach to the underside of the inside foliage of the plant.  And that's why they die from the inside out.

I haven't seen mites on tomato leaves.

I put on my "optivisor" magnifier to see them, but with the light just right, my camera's macro lens can see them, too.